Thursday, April 30, 2009

Swine Flu spreads worldwide -- at least 32 nations have suspected cases, 11 nations have 257 (+ at least 13 not yet reported) confirmed cases with 8 confirmed deaths

Swine Flu World Map

Thursday, April 30th regular AM Update

WHO Update 6 added the Netherlands to the list of countries, with one confirmed case.  The cases from Costa Rica and Peru have not yet been reported to WHO.  The additional New Zealand cases have not yet been reported to WHO.  WHO's Canadian count has jumped from 13 to 19.  WHO's UK count has increased from 5 to 8.  The total count of confirmed cases reported to WHO is now 257.


Thursday, April 30th early AM Update

There's so much to take in that the PM update has become an early AM update.

WHO has not published another update on international reported, confirmed cases. Based on news reports, confirmed cases include  Austria (1), Canada (13), Germany (3), Israel (2), New Zealand (14), Spain (10), the United Kingdom (5), Costa Rica (2) and Peru(1).  In both New Zealand and Spain, there are large numbers of suspected cases that have not yet been confirmed. 

Wednesday, April 29th AM Update

WHO has announced reported confirmed cases in 9 nations; a total of 148 reported confirmed cases; in addition to US and Mexico, confirmed cases include  Austria (1), Canada (13), Germany (3), Israel (2), New Zealand (3), Spain (4) and the United Kingdom (5). The US has reported 91 confirmed cases and 1 death, currently providing a case/fatality ratio of just over 1%.  Mexico has reported 26 confirmed cases and seven deaths.   That would be a case/fatality ratio over 25%, however, the vast bulk of Mexican cases and deaths have not yet been reported and confirmed.  Assuming the number of suspected cases (2517 with 159 suspected deaths) turn out to be accurately identified, this provides a case/fatality ratio of 6+%.  That is about 3 times as deadly as the 1918 Spanish flu pandemic, which killed 20- 40 million people.  Fortunately, we have large quantities of anti-viral drugs and have been planning for this event for several years now, so deaths should be extremely limited.


Tuesday April 28th update (PM):

According to AP, the confirmed Canadian cases now number 13, rather than six. AP report Both Spain and Israel now have 2 confirmed cases according to WHO, with WHO reporting 2 confirmed New Zealand cases and 2 confirmed UK cases, rather than the 3 NZ cases previously reported..

Denmark, Columbia, Czech Republic, Australia, and Russia have joined the list of countries with suspected cases.


Tuesday April 28th update (AM):

Israel and New Zealand have confirmed cases.  Switzerland added to suspected case list .Washington Post link  The Washington Post has a nice map, but it only tracks North American cases. WP map  The New York Times has a global map showing both confirmed and suspected cases.  NYT graphic  However, both of the maps are lagging behind -- the NYT didn't pick up the 3 confirmed New Zealand cases or the suspected cases in the EU.


Monday April 27th Update

New Zealand news link

There have been six lab-confirmed cases of mild swine flu in Canada and one in Spain, which became the first country in Europe to confirm a case after a man who returned from a trip to Mexico last week was found to have the virus. Spain has 26 suspected cases under observation and a New Zealand teacher and a dozen students who recently travelled to Mexico are being treated as likely mild cases  Countries including Australia, France, Germany, Norway, Sweden, Israel, Guatemala, Costa Rica and South Korea are all testing suspected cases of the flu. In the first confirmed cases in Britain, Scotland's health minister says two people tested positive for swine flu.

The Scottish cases bring the number of nations with confirmed cases to five and the number of nations with suspected cases to 14.

April 30, 2009 in Australia, EU, Governance/Management, International, North America, Physical Science, Science, Travel, US | Permalink | TrackBack (0)

Wednesday, April 29, 2009

How this virus developed and why it may be a killer

The Mexican swine flu virus is a swine influenza A/H1N1 virus hybridized (mixed) with human and bird viruses.  We have some immunity to human flu and to some strains of swine influenza A/H1N1;  We don't have immunity to bird flu, which is why that virus is so virulent - with a kill ratio of almost 50% -- and why so much pandemic planning and preparedness focused on bird flu.

New Scientist reports:

This type of virus emerged in the US in 1998 and has since become endemic on hog farms across North America. Equipped with a suite of pig, bird and human genes, it was also evolving rapidly.  Flu infects many animals, including waterfowl, pigs and humans. Birds and people rarely catch flu viruses adapted to another host, but they can pass flu to pigs, which also have their own strains.If a pig catches two kinds of flu at once it can act as a mixing vessel, and hybrids can emerge with genes from both viruses. This is what happened in the US in 1998. Until then, American pigs had regular winter flu, much like people, caused by a mutated virus from the great human pandemic of 1918, which killed pigs as well as at least 50 million people worldwide. This virus was a member of the H1N1 family - with H and N being the virus's surface proteins haemagglutinin and neuraminidase.  Over decades, H1N1 evolved in pigs into a mild, purely swine flu, and became genetically fairly stable. In 1976, there was an outbreak of swine H1N1 in people at a military camp [Fort Dix] in New Jersey, with one death. The virus did not spread efficiently, though, and soon fizzled out.

But in 1998, says Richard Webby of St Jude's Children's Research Hospital in Memphis, Tennessee, swine H1N1 hybridised with human and bird viruses, resulting in "triple reassortants" that surfaced in Minnesota, Iowa and Texas. The viruses initially had human surface proteins and swine internal proteins, with the exception of three genes that make RNA polymerase, the crucial enzyme the virus uses to replicate in its host. Two were from bird flu and one from human flu. Researchers believe that the bird polymerase allows the virus to replicate faster than those with the human or swine versions, making it more virulent.

By 1999, these viruses comprised the dominant flu strain in North American pigs and, unlike the swine virus they replaced, they were actively evolving. There are many versions with different pig or human surface proteins, including one, like the Mexican flu spreading now, with H1 and N1 from the original swine virus. All these viruses still contained the same "cassette" of internal genes, including the avian and human polymerase genes, reports Amy Vincent of the US Department of Agriculture (USDA) in Ames, Iowa (Advances in Virus Research, vol 72, p 127). "They are why the swine versions of this virus easily outcompete those that don't have them," says Webby.

But the viruses have been actively switching surface proteins to evade the pigs' immunity. There are now so many kinds of pig flu that it is no longer seasonal. One in five US pig producers actually makes their own vaccines, says Vincent, as the vaccine industry cannot keep up with the changes. This rapid evolution posed the "potential for pandemic influenza emergence in North America", Vincent said last year. Webby, too, warned in 2004 that pigs in the US are "an increasingly important reservoir of viruses with human pandemic potential". One in five US pig workers has been found to have antibodies to swine flu, showing they have been infected, but most people have no immunity to these viruses.

The virus's rapid evolution created the potential for a pandemic to emerge in North America.  Our immune response to flu, which makes the difference between mild and potentially lethal disease, is mainly to the H surface protein. The Mexican virus carries the swine version, so the antibodies we carry to human H1N1 viruses will not recognise it. That's why the CDC warned last year that swine H1N1 would "represent a pandemic threat" if it started circulating in humans. The avian polymerase genes are especially worrying, as similar genes are what make H5N1 bird flu lethal in mammals and what made the 1918 human pandemic virus so lethal in people. "We can't yet tell what impact they will have on pathogenicity in humans," says Webby. It appears the threat has now resulted in the Mexican flu. "The triple reassortant in pigs seems to be the precursor," Robert Webster, also at St Jude's, told New Scientist.

While researchers focused on livestock problems could see the threat developing, it is not one that medical researchers focused on human flu viruses seemed to have been aware of. "It was confusing when we looked up the gene sequences in the database," says Wendy Barclay of Imperial College London, who has been studying swine flu from the recent US cases. "The polymerase gene sequences are bird and human, yet they were reported in viruses from pigs."

So where did the Mexican virus originate? The Veratect Corporation based in Kirkland, Washington, monitors world press and government reports to provide early disease warnings for clients, including the CDC. Their first inkling of the disease was a 2 April report of a surge in respiratory disease in a town called La Gloria, east of Mexico City, which resulted in the deaths of three young children. Only on 16 April - after Easter week, when millions of Mexicans travel to visit relatives - reports surfaced elsewhere in the country.

Local reports in La Gloria blamed pig farms in nearby Perote owned by Granjas Carroll, a subsidiary of US hog giant Smithfield Foods. The farms produce nearly a million pigs a year. Smithfield Foods, in a statement, insists there are "no clinical signs or symptoms" of swine flu in its pigs or workers in Mexico. That is unsurprising, as the company says it "routinely administers influenza virus vaccination to swine herds and conducts monthly tests for the presence of swine influenza." The company would not tell New Scientist any more about recent tests. USDA researchers say that while vaccination keeps pigs from getting sick, it does not block infection or shedding of the virus.

All the evidence suggests that swine flu was a disaster waiting to happen. But it got little research attention, perhaps because it caused mild infections in people which didn't spread. Now one swine flu virus has stopped being so well-behaved.

This leads us to the policy question: why should humans keep pigs?  Like other meat, pigs consume an extraordinary amount of resources to provide nutrition.  Maybe the ancient Israelites had an insight that we have lacked -- there may be more wisdom in the Torah and its laws than we knew.  Perhaps it is time, or past time, for our eating habits to evolve lest an even more virulent strain of swine flu develop.  Assuming that this pandemic passes without too many deaths, we may need to rethink whether it is good to keep large quantities of pigs.  For now, the virulent bird flu does not seem easily communicable.  Let's keep it that way. 

April 29, 2009 in Agriculture, Asia, Australia, Biodiversity, Current Affairs, Economics, EU, Food and Drink, Governance/Management, International, North America, Religion, Sustainability, US | Permalink | TrackBack (0)

Tuesday, April 28, 2009

Check out Peter Gleick's blog on water issues

Gleick Joins the Blogosphere

 

Read and discuss everything water with internationally renowned expert Peter Gleick, president of the Pacific Institute, on his new blog.

GleickFeatured on City Brights, San Francisco Chronicle's luminary blogger site, Gleick explores the water challenges facing California, the West, and our world. Follow along as he discusses the threats to our freshwater resources and viable solutions to those threats, drawing from not only his experiences and viewpoint, but also by way of numbers: each post will include an important, unusual, or newsworthy "water number" that will highlight some piece of the water issue.

Click to check it out or join the conversation:
http://www.sfgate.com/cgi-bin/blogs/gleick/index

April 28, 2009 in International, Physical Science, US, Water Quality, Water Resources, Weblogs | Permalink | TrackBack (0)

Saturday, April 25, 2009

CDC Health Advisory

This is an official CDC Health Advisory CDC Link Distributed via Health Alert Network April 25, 2009, 3:00 EST (03:00 PM EDT) CDCHAN-000281-2009-04-25-ALT-N Investigation and Interim Recommendations: Swine Influenza (H1N1) CDC, in collaboration with public health officials in California and Texas, is investigating cases of febrile respiratory illness caused by swine influenza (H1N1) viruses. As of 11 AM (EDT) April 25, 2009, 8 laboratory confirmed cases of Swine Influenza infection have been confirmed in the United States. Four cases have been reported in San Diego County, California. Two cases have been reported in Imperial County California. Two cases have been reported in Guadalupe County, Texas. Of the 8 persons with available data, illness onsets occurred March 28-April 14, 2009. Age range was 7-54 y.o. Cases are 63% male. The viruses contain a unique combination of gene segments that have not been reported previously among swine or human influenza viruses in the U.S. or elsewhere. At this time, CDC recommends the use of oseltamivir or zanamivir for the treatment of infection with swine influenza viruses. The H1N1 viruses are resistant to amantadine and rimantadine but not to oseltamivir or zanamivir. It is not anticipated that the seasonal influenza vaccine will provide protection against the swine flu H1N1 viruses. CDC has also been working closely with public health officials in Mexico, Canada and the World Health Organization (WHO). Mexican public health authorities have reported increased levels of respiratory disease, including reports of severe pneumonia cases and deaths, in recent weeks. CDC is assisting public health authorities in Mexico by testing specimens and providing epidemiological support. As of 11:00 AM (EDT) April 25, 2009, 7 specimens from Mexico at CDC have tested positive for the same strain of swine influenza A (H1N1) as identified in U.S. cases. However, no clear data are available to assess the link between the increased disease reports in Mexico and the confirmation of swine influenza in a small number of specimens. WHO is monitoring international cases. Further information on international cases may be found at: http://www.who.int/csr/don/2009_04_24/en/index.html Clinicians should consider swine influenza infection in the differential diagnosis of patients with febrile respiratory illness and who 1) live in San Diego or Imperial counties, California, or Guadalupe County, Texas, or traveled to these counties or 2) who traveled recently to Mexico or were in contact with persons who had febrile respiratory illness and were in one of the three U.S. counties or Mexico during the 7 days preceding their illness onset. Patients who meet these criteria should be tested for influenza, and specimens positive for influenza should be sent to public health laboratories for further characterization. Clinicians who suspect swine influenza virus infections in humans should obtain a nasopharyngeal swab from the patient, place the swab in a viral transport medium, refrigerate the specimen, and then contact their state or local health department to facilitate transport and timely diagnosis at a state public health laboratory. CDC requests that state public health laboratories promptly send all influenza A specimens that cannot be subtyped to the CDC, Influenza Division, Virus Surveillance and Diagnostics Branch Laboratory. Persons with febrile respiratory illness should stay home from work or school to avoid spreading infections (including influenza and other respiratory illnesses) to others in their communities. In addition, frequent hand washing can lessen the spread of respiratory illness. CDC has not recommended that people avoid travel to affected areas at this time. Recommendations found at http://wwwn.cdc.gov/travel/contentSwineFluUS.aspx will help travelers reduce risk of infection and stay healthy. Clinical guidance on laboratory safety, case definitions, infection control and information for the public are available at:http://www.cdc.gov/swineflu/investigation.htm. • Swine Influenza A (H1N1) Virus Biosafety Guidelines for Laboratory Workers: http://www.cdc.gov/swineflu/guidelines_labworkers.htm • Interim Guidance for Infection Control for Care of Patients with Confirmed or Suspected Swine Influenza A (H1N1) Virus Infection in a Healthcare Setting: http://www.cdc.gov/swineflu/guidelines_infection_control.htm • Interim Guidance on Case Definitions for Swine Influenza A (H1N1) Human Case Investigations: http://www.cdc.gov/swineflu/casedef_swineflu.htm Morbidity and Mortality Weekly Reports Dispatch (April 24) provide detailed information about the initial cases at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0424a1.htm For more information about swine flu: http://www.cdc.gov/swineflu
Additional information is also available by calling 1-800-CDC-INFO (1-800-232-4636) ____________________________________________________________________________________ Categories of Health Alert messages: Health Alert conveys the highest level of importance; warrants immediate action or attention. Health Advisory provides important information for a specific incident or situation; may not require immediate action. Health Update provides updated information regarding an incident or situation; unlikely to require immediate action. ##This Message was distributed to State and Local Health Officers, Public Information Officers, Epidemiologists and HAN Coordinators as well as Clinician organizations##

April 25, 2009 in Current Affairs, Governance/Management, International, North America, Physical Science, Sustainability, US | Permalink | Comments (0) | TrackBack (0)

Local flu preparedness planning

As of 4:30 pm PDT, 11 cases of H1N1 swine flu have been confirmed in the US -- now including Kansas.

U.S. Human Cases of Swine Flu Infection
State # of laboratory
confirmed cases
California 7 cases
Texas 2 cases
Kansas 2 cases
TOTAL COUNT 11 cases
International Human Cases of Swine Flu Infection
See: World Health OrganizationExternal Web Site Policy.
As of April 25th, 2009 7:30 p.m. EDT


Oregon Flu Plan 

Marion County Pandemic Flu Resource Page

Marion County Family Preparedness Brochure

April 25, 2009 in Current Affairs, Governance/Management, International, North America, Physical Science, US | Permalink | Comments (0) | TrackBack (0)

Swine Flu with Pandemic Potential Hits US and Mexico: Previous Study indicated that the only way to delay spread of an epidemic is to contain the local epidemics and to prevent international travel

WHO warned today that it may be too late to prevent the spread of the swine flu that has been reported in three places in Mexico as well as California and Texas.  WHO Swine Flu Home page WHO Swine flu fact sheet  Mexico is currently conducting health screening of international air travelers.  However, that precaution, according to the Caley study published on this blog two years ago with respect to the pandemic flu threat, will be ineffective at even delaying the spread of the flu. 

The most recent news from WHO on the Stage 3 pandemic alert is WHO link.

Experts at WHO and elsewhere believe that the world is now closer to another influenza pandemic than at any time since 1968, when the last of the previous century's three pandemics occurred. WHO uses a series of six phases of pandemic alert as a system for informing the world of the seriousness of the threat and of the need to launch progressively more intense preparedness activities.  The designation of phases, including decisions on when to move from one phase to another, is made by the Director-General of WHO.  Each phase of alert coincides with a series of recommended activities to be undertaken by WHO, the international community, governments, and industry. Changes from one phase to another are triggered by several factors, which include the epidemiological behaviour of the disease and the characteristics of circulating viruses.  The world is presently in phase 3: a new influenza virus subtype is causing disease in humans, but is not yet spreading efficiently and sustainably among humans.

WHO reported this after today's Emergency Committee meeting:  

In response to cases of swine influenza A(H1N1), reported in Mexico and the United States of America, the Director-General convened a meeting of the Emergency Committee to assess the situation and advise her on appropriate responses. The establishment of the Committee, which is composed of international experts in a variety of disciplines, is in compliance with the International Health Regulations (2005). The first meeting of the Emergency Committee was held on Saturday 25 April 2009.  After reviewing available data on the current situation, Committee members identified a number of gaps in knowledge about the clinical features, epidemiology, and virology of reported cases and the appropriate responses. The Committee advised that answers to several specific questions were needed to facilitate its work. The Committee nevertheless agreed that the current situation constitutes a public health emergency of international concern.  Based on this advice, the Director-General has determined that the current events constitute a public health emergency of international concern, under the Regulations.

Concerning public health measures, in line with the Regulations the Director-General is recommending, on the advice of the Committee, that all countries intensify surveillance for unusual outbreaks of influenza-like illness and severe pneumonia.  The Committee further agreed that more information is needed before a decision could be made concerning the appropriateness of the current phase 3.

WHO currently considers this phase 3 of a pandemic. You might want to read the Global Influenza Preparedness Plan to see what happens in phase 3 and look at phase 4 and 5, which is probably where we are heading.  WHO Global Influenza Plan

From my research, the only effective measure is to contain the local epidemic and prevent international travel, especally air travel.  The occurrence of the same flu in California and Texas suggests that the Mexico flu has already escaped to the US.  Now, internal travel restrictions  within the western US and Mexico as well as international travel probably need to be implemented.  To quote the conclusion of the Caley study:

The delay until an epidemic of pandemic strain influenza is imported into an at-risk country is largely determined by the course of the epidemic in the source region and the number of travelers attempting to enter the at-risk country, and is little affected by non-pharmaceutical interventions targeting these travelers. Short of preventing international travel altogether, eradicating a nascent pandemic in the source region appears to be the only reliable method of preventing country-to-country spread of a pandemic strain of influenza.

The US and Mexico have not even advised people not to travel to Mexico, California, and Texas, much less prevented travel:

CDC has NOT recommended that people avoid travel to Mexico at this time. If you are planning travel to Mexico, follow these recommendations to reduce your risk of infection and help you stay healthy. CDC travel recommendations

In my judgment, it is irresponsible to travel into or out of these areas at this time.  I also believe the governments need to respond more strongly to what is obviously a virulent strain of communicable flu.  But, if they're doing what they are supposed to in phase 3, I admit they are probably busy.

WHO press release yesterday:

24 April 2009 -- The United States Government has reported seven confirmed human cases of Swine Influenza A/H1N1 in the USA (five in California and two in Texas) and nine suspect cases. All seven confirmed cases had mild Influenza-Like Illness (ILI), with only one requiring brief hospitalization. No deaths have been reported. The Government of Mexico has reported three separate events. In the Federal District of Mexico, surveillance began picking up cases of ILI starting 18 March. The number of cases has risen steadily through April and as of 23 April there are now more than 854 cases of pneumonia from the capital. Of those, 59 have died. In San Luis Potosi, in central Mexico, 24 cases of ILI, with three deaths, have been reported. And from Mexicali, near the border with the United States, four cases of ILI, with no deaths, have been reported.Of the Mexican cases, 18 have been laboratory confirmed in Canada as Swine Influenza A/H1N1, while 12 of those are genetically identical to the Swine Influenza A/H1N1 viruses from California.The majority of these cases have occurred in otherwise healthy young adults. Influenza normally affects the very young and the very old, but these age groups have not been heavily affected in Mexico. Because there are human cases associated with an animal influenza virus, and because of the geographical spread of multiple community outbreaks, plus the somewhat unusual age groups affected, these events are of high concern. The Swine Influenza A/H1N1 viruses characterized in this outbreak have not been previously detected in pigs or humans. The viruses so far characterized have been sensitive to oseltamivir, but resistant to both amantadine and rimantadine.

The World Health Organization has been in constant contact with the health authorities in the United States, Mexico and Canada in order to better understand the risk which these ILI events pose. WHO (and PAHO) is sending missions of experts to Mexico to work with health authorities there. It is helping its Member States to increase field epidemiology activities, laboratory diagnosis and clinical management. Moreover, WHO's partners in the Global Alert and Response Network have been alerted and are ready to assist as requested by the Member States.  WHO acknowledges the United States and Mexico for their proactive reporting and their collaboration with WHO and will continue to work with Member States to further characterize the outbreak.

CDC Information: CDC link - Human Swine Influenza Investigation

April 25, 2009 1:00 p.m. ET

Human cases of swine influenza A (H1N1) virus infection have been identified in the U.S. in San Diego County and Imperial County, California as well as in San Antonio, Texas. Internationally, human cases of swine influenza A (H1N1) virus infection have been identified in Mexico.

U.S. Human Cases of Swine Flu Infection
State # of laboratory
confirmed cases
California 6 cases
Texas 2 cases
International Human Cases of Swine Flu Infection
See: World Health OrganizationExternal Web Site Policy.
As of April 25th, 2009 11:00 a.m. ET

Investigations are ongoing to determine the source of the infection and whether additional people have been infected with similar swine influenza viruses.

CDC is working very closely with state and local officials in California, Texas, as well as with health officials in Mexico, Canada and the World Health Organization. On April 24th, CDC deployed 7 epidemiologists to San Diego County, California and Imperial County, California and 1 senior medical officer to Texas to provide guidance and technical support for the ongoing epidemiologic field investigations. CDC has also deployed to Mexico 1 medical officer and 1 senior expert who are part of a global team that is responding to the outbreak of respiratory illnesses in Mexico.

Influenza is thought to spread mainly person-to-person through coughing or sneezing of infected people. There are many things you can to do preventing getting and spreading influenza:

There are everyday actions people can take to stay healthy.

  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hands cleaners are also effective.
  • Avoid touching your eyes, nose or mouth. Germs spread that way.

Try to avoid close contact with sick people.

  • Influenza is thought to spread mainly person-to-person through coughing or sneezing of infected people.
  • If you get sick, CDC recommends that you stay home from work or school and limit contact with others to keep from infecting them.

Topics on this page:

General Information

Swine Flu and You
What is swine flu? Are there human infections with swine flu in the U.S.? …

Swine Flu Video Podcast
Dr. Joe Bresee, with the CDC Influenza Division, describes swine flu - its signs and symptoms, how it's transmitted, medicines to treat it, steps people can take to protect themselves from it, and what people should do if they become ill.

Key Facts about Swine Influenza (Swine Flu)
How does swine flu spread? Can people catch swine flu from eating pork? …

Swine Influenza in Pigs and People
Brochure

Information in Spanish
Datos importantes sobre la influenza porcina…

Summary Guidance

CDC has provided the following interim guidance for this investigation.

Residents of California and Texas

CDC has identified human cases of swine influenza A (H1N1) virus infection in people in these areas. CDC is working with local and state health agencies to investigate these cases. We have determined that this virus is contagious and is spreading from human to human. However, at this time, we have not determined how easily the virus spreads between people. As with any infectious disease, we are recommending precautionary measures for people residing in these areas.

  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hands cleaners are also effective.
  • Try to avoid close contact with sick people.
  • If you get sick, CDC recommends that you stay home from work or school and limit contact with others to keep from infecting them.
  • Avoid touching your eyes, nose or mouth. Germs spread that way.

There is no vaccine available at this time, so it is important for people living in these areas to take steps to prevent spreading the virus to others. If people are ill, they should attempt to stay at home and limit contact with others. Healthy residents living in these areas should take everyday preventive actions.

People who live in these areas who develop an illness with fever and respiratory symptoms, such as cough and runny nose, and possibly other symptoms, such as body aches, nausea, or vomiting or diarrhea, should contact their health care provider. Their health care provider will determine whether influenza testing is needed.

Clinicians

Clinicians should consider the possibility of swine influenza virus infections in patients presenting with febrile respiratory illness who:

  1. Live in San Diego County or Imperial County, California or San Antonio, Texas or
  2. Have traveled to San Diego and/or Imperial County, California or San Antonio, Texas or
  3. Have been in contact with ill persons from these areas in the 7 days prior to their illness onset.

If swine flu is suspected, clinicians should obtain a respiratory swab for swine influenza testing and place it in a refrigerator (not a freezer). Once collected, the clinician should contact their state or local health department to facilitate transport and timely diagnosis at a state public health laboratory.

State Public Health Laboratories

Laboratories should send all unsubtypable influenza A specimens as soon as possible to the Viral Surveillance and Diagnostic Branch of the CDC’s Influenza Division for further diagnostic testing.

Public Health /Animal Health Officials

Officials should conduct thorough case and contact investigations to determine the source of the swine influenza virus, extent of community illness and the need for timely control measures.

Guidance Documents

Swine Influenza A (H1N1) Virus Biosafety Guidelines for Laboratory Workers Apr 24, 2009
This guidance is for laboratory workers who may be processing or performing diagnostic testing on clinical specimens from patients with suspected swine influenza A (H1N1) virus infection, or performing viral isolation.

Interim Guidance for Infection Control for Care of Patients with Confirmed or Suspected Swine Influenza A (H1N1) Virus Infection in a Healthcare Setting Apr 24, 2009

Interim Guidance on Case Definitions for Swine Influenza A (H1N1) Human Case Investigations Apr 24, 2009
This document provides interim guidance for state and local health departments conducting investigations of human cases of swine influenza A (H1N1) virus.  The following case definitions are for the purpose of investigations of suspected, probable, and confirmed cases of swine influenza A (H1N1) virus infection.

Travel Notices

Outbreak Notice: Swine Influenza in the United States
April 25, 2009 12 p.m. ET

Travel Health Precaution: Swine Influenza and Severe Cases of Respiratory Illness in Mexico
April 25, 2009 12 p.m. ET

Transcripts

Unedited Transcript of CDC Briefing on Public Health Investigation of Human Cases of Swine Influenza
April 24, 2009 2:30 p.m. ET

CDC Briefing on Public Health Investigation of Human Cases of Swine Influenza
April 23, 2009 press briefing…

Reports & Publications

Update: Swine Influenza A (H1N1) Infections --- California and Texas, April 2009
Morbidity and Mortality Weekly Report (MMWR) April 24, 2009 / Vol. 58 / Dispatch;1-3

Swine Influenza A (H1N1) Infection in Two Children – Southern California, March—April 2009
Morbidity and Mortality Weekly Report (MMWR) April 21, 2009 / Vol. 58 / Dispatch

Related Links

WHO - Influenza-Like Illness in the United States and MexicoExternal Web Site Policy.

Past Updates

Caley study:

Bird Flu Blues: Source Country Suppression is the Only Viable Means to Prevent the International Transmission of Pandemic Strains

Peter Caley , Niels Becker, and David Philp of the National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia have modelled the impacts of various pandemic preparedness efforts on the timing of international spread of pandemic strains.  The bottom line is that "[s]hort of preventing international travel altogether, eradicating a nascent pandemic in the source region appears to be the only reliable method of preventing country-to-country spread of a pandemic strain of influenza."PLoSOne link The entire article is available courtesy of a Creative Commons license:

Background

The time delay between the start of an influenza pandemic and its subsequent initiation in other countries is highly relevant to preparedness planning. We quantify the distribution of this random time in terms of the separate components of this delay, and assess how the delay may be extended by non-pharmaceutical interventions.

Methods and Findings

The model constructed for this time delay accounts for: (i) epidemic growth in the source region, (ii) the delay until an infected individual from the source region seeks to travel to an at-risk country, (iii) the chance that infected travelers are detected by screening at exit and entry borders, (iv) the possibility of in-flight transmission, (v) the chance that an infected arrival might not initiate an epidemic, and (vi) the delay until infection in the at-risk country gathers momentum. Efforts that reduce the disease reproduction number in the source region below two and severe travel restrictions are most effective for delaying a local epidemic, and under favourable circumstances, could add several months to the delay. On the other hand, the model predicts that border screening for symptomatic infection, wearing a protective mask during travel, promoting early presentation of cases arising among arriving passengers and moderate reduction in travel volumes increase the delay only by a matter of days or weeks. Elevated in-flight transmission reduces the delay only minimally.

Conclusions

The delay until an epidemic of pandemic strain influenza is imported into an at-risk country is largely determined by the course of the epidemic in the source region and the number of travelers attempting to enter the at-risk country, and is little affected by non-pharmaceutical interventions targeting these travelers. Short of preventing international travel altogether, eradicating a nascent pandemic in the source region appears to be the only reliable method of preventing country-to-country spread of a pandemic strain of influenza.

Introduction

The emergence of a pandemic strain of influenza is considered inevitable [1]. Provided the emerged strain is not too virulent, it may be possible to eliminate a nascent influenza pandemic in the source region via various combinations of targeted antiviral prophylaxis, pre-vaccination, social distancing and quarantine [2], [3]. If early elimination in the source region is not achieved, then any delay in a local epidemic that a country can effect will be highly valued. To this end, countries may consider introducing non-pharmaceutical interventions such as border screening, promoting early presentation of cases among arriving passengers, requiring the use of personal protective equipment during travels (e.g. the wearing of masks), and reducing traveler numbers. While the case for believing that measures such as these can not stop the importation of an epidemic from overseas has been argued strongly, whether it be SARS or influenza [4][6], the extent to which such interventions delay a local epidemic is currently not well quantified, and hence of considerable interest.

In this paper we demonstrate how the delay to importation of an epidemic of pandemic strain influenza may be quantified in terms of the growing infection incidence in the source region, traveler volumes, border screening measures, travel duration, in-flight transmission and the delay until an infected arrival initiates a chain of transmission that gathers momentum. We also investigate how the delay is affected by the reproduction number of the emerged strain, early presentation of cases among arriving passengers, and reducing traveler numbers. As noted in previous simulation modeling [7], many aspects of this delay have a significant chance component, making the delay a random variable. Therefore, the way to quantify the delay is to specify its probability distribution, which we call the delay-distribution.

Some issues of the delay distribution, such as the natural delay arising in the absence of intervention and the effect that reducing traveler numbers has on this delay has been studied previously [6][8]. Specifically, if the originating source is not specified, and homogeneous mixing of the worlds population is assumed, then the most likely time to the initial cases arising in the United States is about 50 days assuming R             0 = 2.0 [7]. The additional delay arising from travel restrictions appears minimal until a>99% reduction in traveler numbers [6][8].

This paper adds to previous work [5][8] by simultaneously including a wider range of epidemiological factors and possible interventions, such as elevated in-flight transmission, flight duration, the effect of wearing of mask during flight, early presentation of cases among travelers, and quarantining all passengers from a flight with a detected case at arrival.

Methods

General

Consider a region in which a new pandemic strain of influenza has emerged, and a region currently free from the infection. We refer to these as the source region and the at-risk country, respectively. Travel between these countries is predominantly via commercial air travel and/or rapid transport which could potentially be subject to border screening and other interventions. We restrict our discussion to air travel. The aim is to assess the effects that a variety of non-pharmaceutical border control measures have, individually and in combination, on the time it takes before the epidemic takes off in the at-risk country. An epidemic is said to have “taken off” when it reaches 20 current infectious cases, after which its growth is highly predictable (i.e. nearly deterministic) and the probability of fade-out by chance is very low, if intervention is not enhanced. The source country of origin will undoubtedly have a large impact on the natural delay until importation of an epidemic, although this is difficult to quantify [7]. An alternative is to fix the originating city, for example a highly connected city such as Hong Kong [6], with the obvious effect that results are highly dependent on the choice. We adopt no specific source region, but assume that the number of international travelers originating from it is reasonably small (see Methods), suggestive of a rural or semi-rural source region [2]. It is further assumed that the current heightened surveillance for pandemic influenza is continued and that a nascent pandemic with human-to-human transmission is identified and the pandemic is declared when there are 10 concurrent cases in the source region.

For an epidemic to take off in an at-risk country, a series of events need to occur. First, the epidemic needs to get underway in the source region. Second, an intending traveler needs to be infected shortly before departure. Third, the infected traveler must actually travel and successfully disembark in the at-risk country. Fourth, the infected traveler, or fellow travelers infected during the flight, must initiate an epidemic in the at-risk country with the infectiousness that remains upon arrival. Finally, the epidemic needs to reach a sufficient number of cases to begin predictable exponential growth.

Infected travelers

International spread of the emerged pandemic strain of influenza may occur when a recently infected person travels. By ‘recently infected’ we mean that their travel is scheduled to occur within ten days of being infected. We assume that the number of individuals traveling from the source region to the at-risk country each day is known. The probability that a randomly selected traveler is a recently-infected person is taken to be equal to the prevalence of recently-infected people in the source region on that day. The incidence of infection in the source region is assumed to grow exponentially initially, with the rate of exponential growth determined by the disease reproduction number (the mean number of cases a single infective generates by direct contact) and the serial interval (the average interval from infection of one individual to when their contacts are infected) (Figure 1A).

thumbnail
Figure 1.  

The process through which a pandemic is imported. (A) The prevalence in the source region, which determines the probability that a randomly selected traveler is infected at scheduled departure. (B)–(D) Density functions of the time since infection during the early stages of the epidemic in the source region for infected travelers (B) before and (C) after departure screening, and (D) after arrival screening for clinical symptoms. In (B), the step illustrates the probabilistic removal of travelers who have completed their incubation period. In (D), the distribution of time since infection in (C) will have shifted to the right by an amount equal to the flight duration, and cases incubated in-flight may be detected by symptomatic screening, as will those symptomatic cases that were not detected previously. Screening sensitivity for this illustration is 60% on both departure and arrival. (E) Upon entering the community undetected, an infected traveler may initiate a minor (inconsequential) or major epidemic, depending on the characteristics of the disease and public health policy.

doi:10.1371/journal.pone.0000143.g001

The time since infection of a recently-infected traveler is a key component of the calculations, because it affects the chance of positive border screening, the chance of in-flight transmission and the infectivity remaining upon arrival in the at-risk country. The time since infection at the time of scheduled departure is random and the dependence of its probability distribution on the exponential growth rate of infection is illustrated by Figure 1B (see also Supporting Information). The higher the epidemic growth rate in the source region, the greater the probability than an infected traveler will have been infected more recently.

Traveler screening at departure

It is assumed that individuals detected by departure screening are prevented from traveling. To be detected by screening an infected traveler must be symptomatic and positively screened. An individual is assumed to become symptomatic 48 hours after being infected (cf. [3] who use 1.9 days). The probability of being symptomatic when presenting for departure screening is computed from the curve in Figure 1B. The distribution of the time since infection immediately after departure screening, given that the infected traveler was not detected, is given by the curve in Figure 1C. It contains an adjustment for the probability of being detected at departure.

In-flight transmission

The instantaneous rate at which susceptible contacts are infected depends on the time since infection, and is described by an infectiousness function ([9], page 45). We use a peaked infectiousness function, motivated by viral shedding and household transmission data [2], which has a serial interval of 2.6 days. The basic reproduction number (R                0), namely the reproduction number when there is no intervention in place and every contacted individual is susceptible, is given by the area under the infectiousness function. However, our concern is with the effective reproduction number R that holds when various interventions are in place. We obtain any R by simply multiplying the infectiousness function by the appropriate constant (to make the area under the curve equal to R). This keeps the serial interval the same. In the absence of suitable data we assume for most scenarios that the aircrafts ventilation and filtration systems are functioning properly, and that infected travelers transmit the infection at the same rate during a flight as they would while mixing in the community. We examine the sensitivity of this assumption by increasing the in-flight transmission by as much as 10-fold (as could potentially happen if air-circulation and filtration systems malfunction, e.g. see [10]). The in-flight transmission rate is set to zero under the optimistic scenario that all travelers wear 100% effective masks during transit. In terms of a sensitivity analysis this illustrates what would be achievable in a best-case scenario. The number of offspring that an infected traveler infects during a flight is a random variable, taken to have a Poisson distribution with a mean equal to the area under the infectiousness function over to the flight duration.

Traveler screening at arrival

Travelers infected during flights of less than 12 hours duration are asymptomatic at arrival and will not be detected by screening. The probability that an arriving traveler who was infected in the source region is detected on arrival is computed from the distribution of the time since infection on arrival. This distribution is obtained from the curve in Figure 1C by shifting it to the right by an amount equal to the duration of the flight. The distribution of the time since infection for an individual infected in the source region, who passes through arrival screening undetected has a further adjustment for the chance of being detected at arrival (Figure 1D). This curve shows that an infected traveler who escapes detection at departure and arrival is highly likely to enter the at-risk country with most, or all, of their infectious period remaining.

Authorities are assumed to implement one of two control options when detecting an infected traveler by arrival screening. Under option one (individual-based removal), all passengers who test negative are released immediately and only passengers who test positive are isolated. Under the second option (flight-based quarantining), authorities prevent all passengers from dispersing into the community until the last person has been screened from that flight. Should any one passenger be detected as infected then all passengers will be quarantined, as previously recommended [5].

Transmission chains initiated by infected arrivals

Transmission chains can be initiated in the at-risk country by infected travelers who mix within the community upon arrival. Suppose now that a flight arrives with one, or more, infected passengers who mix within the community. We classify these infected arrivals into those who are ‘pre-symptomatic’ and those who are ‘symptomatic’ at entry. It is assumed that the ‘symptomatic’ infected arrivals do not recognize their symptoms as pandemic influenza and will not present to medical authorities. In other words, they spend the remainder of their infectious period mixing in the community. On the other hand, the ‘pre-symptomatic’ infected arrivals, including all individuals infected during flight, are assumed to mix freely in the community only from entry until they present to medical authorities after some delay following the onset of symptoms.

Probability that an undetected infected traveler initiates a major epidemic

Not all infected travelers entering the community initiate a ‘major’ epidemic, even when the reproduction number (R) exceeds one. Quite generally, the distribution of the size of an epidemic initiated by an infected arrival is bimodal, with distinct peaks corresponding to a major epidemic and a minor outbreak (Figure 1E). In the latter event the outbreak simply fades out by chance despite there being ample susceptibles in the population for ongoing transmission [11]. The number of cases in an outbreak that fades out is typically very small compared to an epidemic.

The probability that a typical infective generates a local epidemic is computed by using a branching process approximation [12] for the initial stages of the epidemic, and equating ‘epidemic’ with the event that the branching process does not become extinct. This calculation is well known (e.g. [13], page 473), but is modified here to allow for the fact that the process is initiated by a random number of infected arrivals and some of them have spent a random part of their infectious period before arriving in the at-risk country. The distribution for the random number of individuals infected by an infected individual when all their contacts are with susceptible individuals is needed for the calculation. The lack of data prevents a definitive conclusion for the most appropriate offspring distribution for influenza transmission [14], and we use a Poisson distribution with a mean equal to R, discounted for individuals who spent only some of their infectious period mixing in the at-risk country. A Poisson offspring distribution is appropriate when the area under the infectiousness function is non-random (i.e. all individuals have the same infection ‘potential’). We assume that R is the same in the source region and the at-risk country. For an undetected infected traveler and all their in-flight offspring to fail to initiate an epidemic on arrival, all of the chains of transmission they initiate must fail to become large epidemics (see Supporting Information).

The delay until an epidemic gathers momentum in the at-risk country

We calculate the probability distribution of D, the total delay until an epidemic gathers momentum by noting that it is given by D = D                1+D                2, where D                1 is the time until an epidemic is first initiated and D                2 is the time from initiation until the local epidemic gathers momentum. For an epidemic to be first initiated in the at-risk country on day d, it must have not been initiated on all previous days. Hence the probability distribution of the time delay (D                1) until the epidemic is first initiated in the at-risk country following identification in the source region is described by:

                                  
where pd                 denotes the probability that the epidemic is initiated on day d , and                                    denotes the probability that the epidemic is not initiated on day d (see Supporting Information for calculation of pd                ).

Once successfully initiated, an epidemic may initially hover around a handful of cases before reaching a sufficient number of cases for its growth to become essentially predictable. As mentioned, 20 concurrent cases is our criterion for an epidemic to have gathered momentum. We determine the distribution of D                2, the time to this occurrence, from 10,000 stochastic simulations and approximate this empirical distribution by a shifted gamma distribution. Our criterion of 20 concurrent cases is conservatively high, as results from the theory of branching processes shows that the probability of a minor epidemic (and hence no take-off) starting from 20 concurrent cases is about 3×10−8 when R = 1.5, and even smaller for higher values of R. Finally, the distribution of the total delay (D = D                1+D                2) from the pandemic being identified in the source region until 20 cases in the at-risk country was calculated by the convolution of the distributions of D                1 and D                2.

Parameter values

For the illustrative purposes, we chose values of 1.5, 2.5 and 3.5 for R, which encompass estimates proposed for previous pandemics [2], [3], [15]. The number of people within the infected source region was assumed reasonably small (5 million), and there was one flight per day traveling from the source region to the at-risk country carrying 400, 100 or 10 passengers. A higher number of travelers affects the delay only marginally, assuming the epidemic takes off in the source region (see Results). We assume a typical travel duration between attempted departure and possible arrival of 12 hours, but also examine the effect of varying this from 0–48 hours. The time to presentation following symptom onset is varied from ‘immediately’ to ‘never presenting’, with a time of 6 hours considered likely in the presence of an education campaign. The sensitivity of symptomatic screening is varied from 0–100%, with results presented for 0, 50 and 100% sensitivity.

Results

Evading traveler screening

The probability that a recently infected traveler evades screening is substantial even if screening reliably detects symptomatic travelers (Figure 2A), because the typical travel duration is shorter than the 2-day incubation period. In addition, during the early stages of the epidemic a high R in the source region acts to increase the probability that an infected traveler has been infected quite recently and hence will escape detection due to being asymptomatic during their travels (Figure 2A). For example, assuming 100% sensitivity for detecting symptomatic infection, we calculate that during the early stages of the epidemic the proportion of infected travelers that evade both departure and arrival screening after 12 hours of travel is 0.26, 0.45 and 0.59 for disease reproduction numbers 1.5, 2.5 and 3.5, respectively.

thumbnail
Figure 2.  

Effects of border screening and early presentation. (A) The effects of screening sensitivity andon the probability of escaping detection on both departure and arrival during a 12 hour transit. (B) The effects of screening sensitivity and travel duration on the probability than an infected traveler escapes detection during transit and initiates an epidemic after arrival (assuming no other symptomatic individuals on the same flight are identified). R = 3.5 with no early presentation. (C) The effects of R and the time from symptom onset to presentation on the probability that an infected traveler, having entered the wider community following arrival, will initiate an epidemic. There is no screening.

doi:10.1371/journal.pone.0000143.g002

As the duration of travel approaches the disease incubation period, effective symptomatic screening substantially reduces the likelihood that a traveler evades screening and initiates an epidemic (Figure 2B). Reducing the time from the onset of symptoms to presentation (and subsequent isolation) for each infected arrival also reduces the probability that a major epidemic is initiated, however the best case scenario of infected travelers and all their in-flight offspring presenting immediately following the onset of symptoms still poses a substantial risk of epidemic initiation arising from pre-symptomatic transmission (Figure 1C).

The time until an epidemic gathers momentum in the at-risk country

The delay contains a fairly substantial natural component, primarily due to the time it takes to increase the number of infectives in the source region sufficiently to make the chance of a recently infected traveler appreciable (Figure 3A), and the time (D                2) it takes for a local epidemic in the at-risk country to gather momentum following successful seeding (Figure 4A). In the absence of any interventions, the number of infected individuals who successfully enter the community of the at-risk country initially increases exponentially (Figure 3A). With individual-based removal of infected travelers, the number of individuals entering the at-risk country undetected by screening is proportionately reduced over the course of the epidemic (Figure 3A). With flight-based quarantining, the number of infected individuals entering the at-risk country undetected is dramatically reduced over the course of the epidemic, even for relatively insensitive screening (Figure 3A). With flight-based quarantining, the number of infected passengers slipping through undetected is bimodal, with the first peak occurring when the number of infected travelers attempting to travel is still in single figures.

thumbnail
Figure 3.  

Components of delay until initiation and effects of border screening. (A) The number of infected people successfully arriving and entering the community of an at-risk country (KA                      ) on each day following the identification of an outbreak of pandemic type strain influenza, assuming a source region population of 5 million, 400 intending travelers per day, R = 1.5, and three levels of symptomatic screening (solid line = nil, dashed line = 50% sensitivity with individual-based removal, dotted line = 50% sensitivity with flight-based quarantining). (B) Corresponding daily probability of initiation (pd                      ) as a function of time since pandemic identified. (C) Distribution of the delay time until the initiation (D                      1) of an epidemic in an at-risk country by an infected traveler from a source region.

doi:10.1371/journal.pone.0000143.g003
thumbnail
Figure 4.  

Components of the delay in at-risk country following initiation. (A) Results of 10,000 simulations (bars) and fitted shifted-Gamma distribution of delay time (D                      2) until 20 concurrent cases occur in the at-risk country, given that an epidemic has been initiated, andequals 1.5 with a serial interval of 2.6 days. (B) The total delay distribution until there are 20 concurrent cases in the at-risk country from when a pandemic type strain of influenza outbreak is identified in a source region with a population of 5 million, 400 intending travelers day−1, an R of 1.5, and three levels of symptomatic screening (solid line = nil, dashed line = 50% sensitivity with individual removal, dotted line = 50% sensitivity with flight-based quarantining).

doi:10.1371/journal.pone.0000143.g004

Without screening, the daily probability that an epidemic is initiated (pd                ) increases, and becomes near certain once the number of infected travelers arriving undetected exceeds about 10 (Figure 3B, solid line). With screening and individual-based removal of infected individuals, pd                 follows a similar pattern only reduced somewhat. With screening in combination with flight-based quarantining, this probability is changed dramatically. After an initial rise it dips, to become essentially zero during the height of the epidemic in the source region (Figure 3B, dotted line). This arises because once a flight has several infected travelers, the probability that at least one is detected approaches one (even if screening is imperfect), and all passengers on such a flight are quarantined. Once the epidemic starts to wane in the source region (assuming the unlikely event of the pandemic strain is restricted to the source region), the probability of initiation rises once again. The corresponding distribution of D                1, the delay until the epidemic is first initiated in the at-risk country, is bi-modal in the presence of screening (Figure 3C).

Although flight-based quarantining is effective in preventing the entry of infected travelers during the height of the epidemic, a substantial cumulative risk of initiation has already occurred before this from the handful of infectives that have slipped through undetected (Figure 3B). Hence, whilst the effect of border screening, particularly in conjunction with flight-based quarantining, on the daily probability of initiation is dramatic, its effect on the delay to initiation is much less pronounced (Figure 3C). Border screening, even with perfect sensitivity for detecting symptomatic cases, tends to increase D                1, the time to an epidemic being initiated, by a matter of days to weeks. The time (D                2) from initiation (the arrival of the index case) to an epidemic reaching 20 concurrent cases within the at-risk country is adequately modeled using a shifted Gamma distribution (Figure 4A). The convolution of this right-skewed Gamma distribution with the left-skewed delay-distribution of D                1 (Figure 3C) yields the distribution for D, the total delay until the epidemic reaches 20 cases in the at-risk country (Figure 4B). The distribution of D is approximately symmetrical. The effect of border screening on the total delay D is quite modest, though sensitive to how screening is implemented. For example, with R = 1.5 and 400 travelers per day, 100% sensitive screening with individual-based removal increases the median delay from 57 to 60 days (Figure 4B). Flight-based quarantining would extend the median delay to 70 days. In general, the added delay arising from flight-based quarantining is about four-fold that arising from individual-based removal.

The natural component of the delay is highly sensitive to the disease reproduction number (Figure 5A). For example, with 400 passengers per day departing the source country and in the absence of any interventions, the median delay ranges from a low of 17 days for R = 3.5 to 57 days for R = 1.5 (Table 1). The delay is less sensitive to the number of intending travelers, with little appreciable increase in the median delay occurring until traveler numbers become very low (Figure 5B). For example, if R = 1.5, with no other border control measures, decreasing the number of intending travelers departing the source region from 400 to 100 per day increases the median total delay D from 57 to 66 days. A further decrease in the number of intending travelers to 10 per day increases the median delay to 83 days (Table 1).

thumbnail
Figure 5.  

Effects of interventions on the total delay D. (A) The effects of R on delay-distribution. (B) The effects of daily traveler number on the median delay for different values of R. (C) The effects of the time from symptom incubation until presentation and isolation (tSP                      ) on the delay-distribution. (D) Additive effects of implementing 100% sensitive border screening (individual removal), the wearing of masks during transit, immediate presentation following symptom onset, and flight-based quarantining on the median delay, assuming 400 travelers per day attempting to depart the source region.

doi:10.1371/journal.pone.0000143.g005
thumbnail
Table 1. Summary measures of the expected time until an epidemic of pandemic strain influenza in an at-risk country reaches 20 cases, for three values of R and three values for the number of intending travelers when the source region contains 5 million people.
doi:10.1371/journal.pone.0000143.t001

The delay is quite insensitive to the rate of transmission in-flight. For example, with R = 1.5, a 12-hour flight, 400 travelers per day and no other interventions, preventing in-flight transmission altogether increases the median delay from 57 to 58 days. Conversely, doubling the rate of in-flight transmission reduces the median delay from 57 to 56 days. A 10-fold increase in the rate of transmission in-flight only decreases the median delay from 57 to 53 days. Encouraging the early presentation of cases among travelers following the onset of symptoms has a limited effect on the delay distribution (Figure 5C). For example, for R = 1.5, 400 intending travelers per day and no other interventions, reducing the time to presentation from ‘never presenting’ to 6 hours increases the median delay from 57 to 61 days. Immediate presentation at symptom onset only increases the median delay a further day in this scenario.

In general, the additional delay achieved by introducing non-pharmaceutical border control measures is generally small in comparison with the natural delay (Figure 5D). For the scenario with R = 1.5 and 400 intending travelers per day, a combination of 100% flight-based quarantining, 100% compliance with mask wearing during travel and immediate presentation at symptom onset extends the estimated median delay from 57 to 79 days (Figure 5D). This added delay diminishes in absolute terms as R increases. For example, if the same interventions are applied with R = 3.5, the median delay is extended from 17 to just 20 days (Figure 5D). The one exception to this generalisation is when travel numbers are reduced dramatically. The added delay achieved when a drastic reduction in travel numbers is combined with other border control measures appears to be greater than adding the delays each achieves on its own. For example, if R = 1.5, and we reduce the number of intending travelers from 400 to 10 per day, implement 100% flight-based quarantining, implement compulsory mask wearing during travel and presentation at 6 hours following symptom onset then there is a substantial probability (0.74) that the pandemic strain will never be imported (assuming the epidemic is confined to the source country). The estimated quartile delay (the median in this case is undefined) to the start of a major epidemic in an at-risk country is extended from 50 to 125 days. Again, the added delay decreases rapidly as R increases, and if the above interventions were applied with R = 3.5, the estimated median delay is extended from 17 to 26 days, and the importation of the epidemic is certain (Figure 5D).

Discussion

We have formulated a model of the importation of an infectious disease from a source region to an at-risk country that permits a comprehensive analysis of the effect of border control measures. Our results are most relevant to the early stage of a pandemic when most cases are contained within a single source region. Once the pandemic has spread to several countries, models with greater complexity and ability to more realistically model global mixing patterns [6][8] are required. Our model is developed with a pandemic-strain of influenza in mind, but could apply to any emerging infectious disease that is transmitted from person to person. We have assumed a Poisson distribution for the number of secondary infections, which a natural choice when each infected individual has the same infectivity profile. A distribution with a larger variance is appropriate when individuals vary substantially in their infectiousness. Our results are conservative in the sense that they give an upper bound for the probability that an infected traveler manages to initiate an epidemic, compared to an offspring distribution with a greater variance but the same reproduction number [14].

The nature of the next pandemic influenza virus, and particularly its reproduction number, is uncertain. If its reproduction number is low (R<2.0), our results indicate that at-risk countries receiving a reasonably small number of travelers (say 400 per day) from the infected source region can expect a natural delay until importing an epidemic of the order of 2 months. This is quite variable and under favourable conditions it could be 4 months. However, the natural delay decreases rapidly as R increases.

The additional delay from isolating individuals detected by border screening is merely a few days under most plausible scenarios, even if both departure and arrival screening is introduced and screening detects every symptomatic traveler. While the extra delay is more than quadrupled if flights with a detected case(s) are quarantined, the effect remains modest (weeks at most) and it is questionable whether the extra delay achieved warrants the disruption created by such a large number of quarantined passengers.

In-flight transmission is a commonly raised concern in discussions about the importation of an infection, so inclusion of in-flight transmission is an attractive feature of our model. Events of substantial in-flight transmission of influenza have been documented [10], [16] and modeling of indoor airborne infection risks in the absence of air filtration predicts that in-flight transmission risks are elevated [17]. However, it difficult to estimate the infectiousness of influenza in a confined cabin space, as there is undoubtedly substantial under-reporting of influenza cases who travel and fail to generate any offspring during flight. Provided the aircraft ventilation system (including filtration) is operational, it is considered that the actual risk of in-flight transmission is much lower than the perceived risk [18]. Our results indicate that the delay is relatively insensitive to the rate of in-flight transmission, making in-flight transmission less of an issue than commonly believed. A highly elevated transmission rate in-flight will hasten the importation of an epidemic only marginally. Consistent with this, eliminating in-flight transmission by wearing protective masks increases the delay only marginally.

Early presentation by infected arrivals not detected at the borders was found to add only a few days to the delay. To some extent this arises due to our assumption that pre-symptomatic transmission can occur, for which there is some evidence. In contrast, Ferguson et al. [2] assume that the incubation and latent periods are equal, with a mean of 1.5 days. In their model pre-symptomatic transmission is excluded and infectiousness is estimated to spike dramatically immediately following symptom onset and declining rapidly soon afterwards. Under their model assumptions, immediate presentation at onset of symptoms would reduce transmission effectively. However, as presentation occurs some time after onset of symptoms and the bulk of infectivity occurs immediately after onset of symptoms the results on the effect of early presentation of cases are likely, in practical terms, to be similar to those found here. Given the variable nature of influenza symptoms, there is likely to be a difference between the onset of the first symptoms as measured in a clinical trial (e.g. [19]) and the time that a person in the field first suspects that they may be infected with influenza virus. To fully resolve the issue of how effective very early presentation of infected travelers is in delaying a local epidemic we need better knowledge about the infectiousness of individuals before and just after the onset of symptoms.

Of the border control measures available, reducing traveler numbers has the biggest effect on the delay and even then it is necessary to get the number of travelers down to a very low number. An equivalent control measure is to quarantine all arriving passengers with near perfect compliance.

Our results indicate that short of virtually eliminating international travel, border control measures add little to avoiding, or delaying, a local epidemic if an influenza pandemic takes off in a source region. All forms of border control are eventually overwhelmed by the cumulative number of infected travelers that attempt to enter the country. The only way to prevent a local epidemic is to rapidly implement local control measures that bring the effective reproduction number in the local area down below 1, or to achieve rapid elimination in the source region, in agreement with other recent studies [6][8]. Preventing the exponential growth phase of an epidemic in the source region appears to be the only method able to prevent a nascent influenza pandemic reaching at-risk countries.

Supporting Information

Text S1.

Estimating the daily probability of epidemic initiation

(0.08 MB PDF)

Acknowledgments

We thank James Wood, Katie Glass and Belinda Barnes and an anonymous reviewer for helpful comments.

Author Contributions

Conceived and designed the experiments: NB PC. Performed the experiments: PC DP. Analyzed the data: NB PC DP. Contributed reagents/materials/analysis tools: PC DP. Wrote the paper: NB PC.

References

  1. Germann TC, Kadau K, Longini IM, Macken CA. (2006) Mitigation strategies for pandemic influenza in the United States. Proceedings of the National Academy of Science 103: 5935–5940. Find this article online
  2. Ferguson NM, Cummings DAT, Cauchemez S, Fraser C, Riley S, et al. (2005) Strategies for containing an emerging influenza pandemic in Southeast Asia. Nature  437: 209214. Find this article online
  3. Longini IM, Nizam A, Xu S, Ungchusak K, Hanshoaworakul W, et al. (2005) Containing pandemic influenza at the source. Science  309: 1083–1087. Find this article online
  4. John RK St, King A, de Jong D, Bodie-Collins M, Squires SG, et al. (2005) Border screening for SARS. Emerging Infectious Diseases  11: 6–10. Find this article online
  5. Pitman RJ, Cooper BS, Trotter CL, Gay NJ, Edmunds WJ. (2005) Entry screening for severe acute respiratory syndrome (SARS) or influenza: policy evaluation. British Medical Journal 331: 1242–1243. Find this article online
  6. Cooper BS, Pitman RJ, Edmunds WJ, Gay NJ. (2006) Delaying the international spread of pandemic influenza. PloS Medicine  3: e212. Find this article online
  7. Ferguson NM, Cummings DAT, Fraser C, Cajka JC, Cooley PC, et al. (2006) Strategies for mitigating an influenza pandemic. Nature  442: 448–452. Find this article online
  8. Hollingsworth TD, Ferguson NM, Anderson RM. (2006) Will travel restrictions control the international spread of pandemic influenza? Nature Medicine  12: 497–499. Find this article online
  9. Becker NG (1989) Analysis of Infectious Disease Data. London: Chapman and Hall. 
  10. Moser MR, Bender TR, Margolis HS, Noble GR, Kendal AP, et al. (1979) An outbreak of influenza aboard a commercial airline. American Journal of Epidemiology  110: 1–6. Find this article online
  11. Lloyd-Smith JO, Cross PC, Briggs CJ, Daugherty M, Getz WM, et al. (2005) Should be expect population thresholds for wildlife disease? Trends in Ecology and Evolution  20: 511–519. Find this article online
  12. Harris TE (1963) The Theory of Branching Processes. Berlin: Springer. 230 p p. 
  13. Caswell H (2000) Matrix Population Models: Construction, Analysis, and Interpretation. Sunderland, , Massachusetts: Sinauer Associates, Inc. 727 p p.
  14. Lloyd-Smith JO, Schreiber SJ, Kopp PE, Getz WM. (2005) Superspreading and the effect of individual variation on disease emergence. Nature  438: 355–359. Find this article online
  15. Mills CE, Robins JM, Lipsitch M. (2004) Transmissibility of 1918 pandemic influenza. Nature  432: 904–906. Find this article online
  16. Marsden AG. (2003) Influenza outbreak related to air travel. The Medical Journal of Australia  179: 172–173. Find this article online
  17. Liao C, Chang C, Liang H. (2005) A probabilistic transmission dynamic model to assess indoor airborne infection risks. Risk Analysis  25: 1097–1107. Find this article online
  18. Mangili A, Gendreau MA. (2005) Transmission of infectious diseases during commercial air travel. The Lancet  365: 989–996. Find this article online
  19. Hayden FG, Treanor JJ, Fritz RS, Lobo M, Betts RF, et al. (1999) Use of the oral neuraminidase inhibitor oseltamivir in experimental human influenza. Journal of the American Medical Association 282: 1240–1246. Find this article online

January 18, 2007 in Governance/Management, International, Physical Science | Permalink

TrackBack

TrackBack URL for this entry:
http://www.typepad.com/services/trackback/6a00d8341bfae553ef00d83571f01969e2

Listed below are links to weblogs that reference Bird Flu Blues: Source Country Suppression is the Only Viable Means to Prevent the International Transmission of Pandemic Strains:

April 25, 2009 in Current Affairs, Governance/Management, International, North America, Physical Science, Science, Travel, US | Permalink | Comments (1) | TrackBack (0)

Tuesday, April 21, 2009

Ocean acidification

According to the Science blog:

The U.S. Environmental Protection Agency has asked scientists how to revise the Clean Water Act to protect seas against ocean acidification from atmospheric carbon dioxide. Under the current rules, waters are designated as impaired if their pH deviates from naturally occurring levels by 0.2 units. But biologists say that some organisms are affected by smaller changes. A more complex approach would also take into account how organisms or ecosystems are affected differently by changing pH levels.

April 21, 2009 in Climate Change, International, Sustainability, Water Quality | Permalink | TrackBack (0)

Friday, April 17, 2009

Call for Entries - 4th International Water Film Festival

If you're traveling this summer, you might want to film something about water and submit your masterpiece to the 4th International Water Film Festival.  Entries are due July 31st.  For more info, visit  Drink Water for Life blog - water film festival.


April 17, 2009 in Agriculture, Biodiversity, Current Affairs, Film, Governance/Management, International, Land Use, Sustainability, Water Quality, Water Resources | Permalink | Comments (0) | TrackBack (0)

Saturday, April 11, 2009

65% see current economic crisis as opportunity for sustainability

I was browsing at Worldwatch Institute and saw these results from their poll.  By the way, I voted for reengineering the energy system:

What opportunities for sustainability may emerge in 2009
because of the current economic crisis?

The world could get a respite from surging carbon emissions.
8% (312 votes)
Significant steps will be made to reengineer the energy system in order to create jobs.
32% (1288 votes)
People will buy less stuff, and generally produce less waste.
25% (987 votes)
Opportunities will actually be hindered because bad economic times put the environment low on policymakers’ agendas.
35% (1387 votes)
Total votes: 3974

April 11, 2009 in Climate Change, Economics, Energy, Governance/Management, International, Sustainability | Permalink | TrackBack (0)

Friday, April 3, 2009

Arctic Sea Ice Melting Fast

According to a new report by Wang and Overland in Geophysical Research Letters, the arctic sea ice is melting fast enough that it will be largely gone within 30 years.  The ice is melting so fast because arctic temperatures in the last four years have risen to a level (a 9 degree Fahrenheit increase) which was not expected to occur for another 60 years.  The sea ice reflects sunlight so the planet will heat even faster as the ice melts.  So....perhaps all of those changes that we were expecting in 2010 may be here by 2040, or earlier.

Common Dreams reports:

[Wang and Overland] expect the area covered by summer sea ice to decline from about 2.8 million      square miles normally to 620,000 square miles within 30 years.Last year's summer minimum was 1.8 million square miles in September, second lowest only to 2007 which had a minimum of 1.65 million square miles...Arctic sea ice reached its winter maximum for this year at 5.8 million square miles on Feb. 28. That was 278,000 square miles below the 1979-2000 average making it the fifth lowest on record. The six lowest maximums since 1979 have all occurred in the last six years.  Common Dreams Arctic Sea Ice

April 3, 2009 in Asia, Climate Change, Governance/Management, International, North America, Physical Science, Sustainability | Permalink | Comments (0) | TrackBack (0)

Thursday, April 2, 2009

Water News from Water Advocates

New Congressional Legislation: Strong support for drinking water and
sanitation continues on Capitol Hill, where legislation introduced in
the Senate would put the U.S. in the lead among governments in
responding to the Millennium Development Goals for water and sanitation.
Companion legislation is expected soon in the House. Titled "The Senator
Paul Simon Water for the World Act of 2009" (S624), the bipartisan bill
introduced by Senators Durbin, Corker and Murray on March 17 seeks to
reach 100 million people with safe water and sanitation by 2015 and to
strengthen the capacity of USAID and the State Department to carry out
the landmark Senator Paul Simon Water for the Poor Act of 2005.

USAID: Dozens of USAID missions, notably in Sub-Saharan Africa and
Southeast Asia, are gearing up to utilize increased appropriations to
implement the Senator Paul Simon Water for the Poor Act, after years of
lacking the tools to help extend safe, sustainable water, sanitation and
hygiene. USAID this past month announced a number of initiatives
including: new strategic partnerships to extend water and sanitation
access to the urban poor in Africa and the Middle East (with
International Water Association), new multilateral revolving funds (in
the Philippines), new collaborations (with Rotary International) and a
new USAID Water Site http://tinyurl.com/newUSAIDwater.

Appropriations: Through the recently passed Omnibus legislation,
Congress appropriated $300 million for Fiscal Year 2009, for "water and
sanitation supply projects pursuant to the Senator Paul Simon Water for
the Poor Act of 2005." As with last year's appropriations, forty percent
of the funds are targeted for Sub-Saharan Africa. Priority will remain
on drinking water and sanitation in the countries of greatest need.
Report language suggests increased hiring of Mission staff with
expertise in water and sanitation. It also recommends that $20 million
of the appropriation be available to USAID's Global Development Alliance
to increase its partnerships for water and sanitation, particularly with
NGOs.

In Fiscal Year 2010, a broad spectrum of U.S. nonprofit organizations,
corporations and religious organizations are urging $500 million to
implement the Senator Paul Simon Water for the Poor Act, as part of an
overall increase of foreign development assistance, a level also called
for by InterAction and the "Transition to Green" Report.

For more water news, visit Drink Water for Life.


April 2, 2009 in Africa, Asia, Economics, EU, Governance/Management, International, Law, Legislation, North America, Physical Science, Science, South America, Sustainability, US, Water Quality, Water Resources | Permalink | Comments (0) | TrackBack (0)

Monday, March 2, 2009

The New Subsistence Society

Sometimes its a good idea to stand back and contemplate the universe.  Today's early news that the Dow Jones Industrial Index took another header because of AIG's $60+ billion loss prompts me to do that. 
Dow_3209
What is the vector of our society?  What will it look like after all the dust has settled?  It is not just the financial crisis that prompts me to contemplate this.  Although the phrase is over-used, we are in the midst of a perfect storm -- a global economy that creates and distributes goods and services through the internet, computerized machines and cheap labor virtual collapse of the financial system, the advent of peak oil, and the climate crisis.  How will all of these things cumulatively affect our future?

We've lived with the first problem for decades now -- what do people do as they  become less and less important to production of goods and services.  The science fiction of our times: what happens when people and their primary asset, labor, becomes virtually superfluous.  Certainly countries with high labor costs relative to Asia and South America already are beginning to experience the problem.  Computerized machines can plant, water, and harvest the fields; robots can make the cars and prefabricated housing; department stores, bank branches, car dealers, even retail grocery stores can be replaced by internet marketing; 100 law professors lecturing to law students and 1000 college professors lecturing to college students is more than enough -- creating the prospect of a British or continental education system, with those professors raised to unseemly heights and the remainder left to do the grunge work of tutors; even more radically, 100 K-12 teachers can teach a nation of students with computer graded exams, if we believe that convergent answers are the goal of education; priests and ministers can be replaced by TV showmen and megachurch performers. 

So what do the other 6.95 billion of us do?  Now, we consume.  Voraciously.  If we don't, then the basics can be provided by a very few and the rest of us become unwanted baggage.  A non-consumer is a drag on the system.  We depend on the velocity of money, excess consumption, and inefficiency to provide each of us with a job and to maintain the current economy.

And what happens when money moves at a crawl, when people stop consuming, when production becomes life-threatening to the planet, and when a key resource for production, oil, reaches the point of no return???  The answer is a new subsistence economy.  A new world where a few are need to produce, a few more can consume, and the remainder have no economic role and are left to subsist as best they can.

Admittedly, it will be subsistence at a higher level -- through the internet, computerization, and technology, each of us will have the capacity to do things for ourselves that are beyond the imagination of today's impoverished subsistence farmers.  But, relative to those who own all of the means of production, a few entertainers (be they basketball players, lecturers, moviestars, or mega-church leaders), and a few laborers (building the machines, computers, the information infrastructure and doing basic and applied research), we will all be poor.  Perhaps only relatively and perhaps only in material terms.  But poor, living at a subsistence level, consuming food from our own gardens, building our own houses, wearing clothes for function not fashion, educating our own children through the internet, capturing essential power through distributed energy, and buying very little of goods that are bound to be too expensive for most -- probably just computers.  It won't necessarily be bad.  Perhaps we can refocus on relationships, family, community, art, music, literature, and life, rather than define ourselves in terms of our job and our things.  Perhaps we can refocus on spirituality instead of materialism. Who knows?  Maybe the new society won't be such a bad thing after all -- at least if we insist that the few who have the privilege of production have a responsibility to share the wealth with the many.

March 2, 2009 in Africa, Agriculture, Air Quality, Asia, Australia, Biodiversity, Cases, Climate Change, Constitutional Law, Economics, Energy, Environmental Assessment, EU, Forests/Timber, Governance/Management, International, Land Use, Law, Legislation, Mining, North America, Physical Science, Social Science, South America, Sustainability, Toxic and Hazardous Substances, US, Water Quality, Water Resources | Permalink | TrackBack (0)

Wednesday, February 25, 2009

Obama gains nothing on tar sands in Canada

President Obama appears to have made no progress with Canadian Prime Minister Stephen Harper about the Canadian tar sands issue.  Harper has requested that tar sands production be excluded from any global climate treaty -- which would be disasterous in terms of the greenhouse gas emissions associated with tar sands development.  Obama appears to have been overly diplomatic in his discussions with Harper -- perhaps in hopes of softening Harper up over time.  I trust that he isn't really prepared to concede on the tar sands issue.

Muckracker posted this analysis on Grist (Grist link) about Obama's visit north with respect to tar sands and clean energy:

President Obama ventured north to Canada on Thursday to meet with Prime Minister Stephen Harper, but environmentalists looking for any indication that the two leaders would issue unequivocal calls for action on global warming or a curtailing of America's dependence on Canada's vast oil deposits were left disappointed. The two leaders, instead, promised a "clean energy dialog" that commits senior officials from both countries to collaborate on technologies that will reduce greenhouse gases and combat climate change, said Harper. That will include a monetary partnership on the development of carbon capture and storage technologies -- the holy grail for many oil and coal boosters who insist that renewable energies can't replace fossil fuels. The United States already committed to using the $3.4 billion in the newly enacted economic stimulus package for carbon capture and storage demonstrations, while Canada has committed $1 billion to a Clean Energy Fund in the government's Economic Action Plan. The two leaders also agreed to partner on the development of smart grid technologies.

"How we produce and use energy is fundamental to our economic recovery, but also our security and our planet, and we know we can't afford to tackle these issues in isolation," said Obama during a joint news conference.

Beyond dialog and promised investments in technology, there weren't a whole lot of answers from either leader on how their governments will deal with energy and climate in the short term. A major issue between the two nations has been oil from Canada's tar sands. The United States imports a lot of Canadian oil - 1.9 million barrels a day in 2008, to be exact. That's more than the U.S. imported from Saudi Arabia, Venezuela, and all those other nations that are so often targeted in complaints about U.S. energy "dependence."

Harper's government wants any climate pact to exempt the vast tar sands of Alberta from regulation. The tar sands contain up to 173 billion barrels of oil, but their extraction is an environmental nightmare (not to mention the problem of burning it). Thousands of acres of forests have to be destroyed to get to the oil. Separating the oil from the sand and clay is extremely energy intensive, and the waste material drenches waterways in toxic sludge. 

Asked about the issue today, Obama compared the tar sands problem with the coal problem in the United States (a comparison many Canadians have also made). While he was clear that carbon capture technologies are not cost effective at this point, he implicitly endorsed efforts to spend billions more on researching them. "In the United States, we have issues around coal, for example, which is extraordinarily plentiful and runs a lot of our power plants and if we can figure out how to capture the carbon, that would make an enormous difference in how we operate," said Obama. "Right now, the technologies are at least not cost effective. So my expectation is is that this clean energy dialog will move us in the right direction."

In an interview with the CBC on Tuesday, Obama acknowledged that tar-sands oil "creates a big carbon footprint," but was optimistic that the both the tar sands and coal problems "can be solved by technology."

              

Continue reading

February 25, 2009 in Air Quality, Climate Change, Energy, Governance/Management, International, North America, Sustainability, US, Water Quality, Water Resources | Permalink | TrackBack (0)

President Obama's "State of the Union" Speech

The White House has published the "Remarks of President Barack Obama -- Address to Joint Session of Congress" as prepared for delivery on Tuesday, February 24th, 2009. White House link   The President called for Congress to send him a cap and trade bill to address climate change and stressed investments in clean energy as the path to America's future.  What a difference from last year!

As the President says about the long term investments that are absolutely critical to our economic future:

It begins with energy.

We know the country that harnesses the power of clean, renewable energy will lead the 21st century.  And yet, it is China that has launched the largest effort in history to make their economy energy efficient.  We invented solar technology, but we’ve fallen behind countries like Germany and Japan in producing it.  New plug-in hybrids roll off our assembly lines, but they will run on batteries made in Korea.

Well I do not accept a future where the jobs and industries of tomorrow take root beyond our borders – and I know you don’t either. It is time for America to lead again.

Thanks to our recovery plan, we will double this nation’s supply of renewable energy in the next three years.  We have also made the largest investment in basic research funding in American history – an investment that will spur not only new discoveries in energy, but breakthroughs in medicine, science, and technology.

We will soon lay down thousands of miles of power lines that can carry new energy to cities and towns across this country.  And we will put Americans to work making our homes and buildings more efficient so that we can save billions of dollars on our energy bills.

But to truly transform our economy, protect our security, and save our planet from the ravages of climate change, we need to ultimately make clean, renewable energy the profitable kind of energy.  So I ask this Congress to send me legislation that places a market-based cap on carbon pollution and drives the production of more renewable energy in America.  And to support that innovation, we will invest fifteen billion dollars a year to develop technologies like wind power and solar power; advanced biofuels, clean coal, and more fuel-efficient cars and trucks built right here in America.

As for our auto industry, everyone recognizes that years of bad decision-making and a global recession have pushed our automakers to the brink.  We should not, and will not, protect them from their own bad practices.  But we are committed to the goal of a re-tooled, re-imagined auto industry that can compete and win.  Millions of jobs depend on it.  Scores of communities depend on it.  And I believe the nation that invented the automobile cannot walk away from it.

None of this will come without cost, nor will it be easy.  But this is America.  We don’t do what’s easy.  We do what is necessary to move this country forward.

Continue reading

February 25, 2009 in Africa, Agriculture, Air Quality, Asia, Australia, Biodiversity, Cases, Climate Change, Constitutional Law, Economics, Energy, Environmental Assessment, EU, Forests/Timber, Governance/Management, International, Land Use, Law, Legislation, Mining, North America, Physical Science, Social Science, South America, Sustainability, Toxic and Hazardous Substances, US, Water Quality, Water Resources | Permalink | TrackBack (0)

Creating a Sustainable Society - the Role of Social Entrepreneurs and Volunteers

Today, the House Committee on Education and Labor had a Congressional hearing on volunteerism. Both Van Jones and Cheryl Dorsey testified to the value of volunteerism for the future of the green movement and social entrepreneurship.  Cheryl Dorsey’s video testimony can be found here Dorsey video link  and her written testimony is here. Dorsey written link  Van Jones’ video testimony is here Jones video link  and his written testimony is here.Jones' written link   Although we frequently focus on using regulation to control traditional profit-oriented business endeavors, it's good to remind ourselves that social entrepreneurs and volunteers can make a real difference in the quality of life in our communities as well as the quality of the environment.

February 25, 2009 in Africa, Asia, Australia, Biodiversity, Forests/Timber, Governance/Management, International, Legislation, North America, South America, Sustainability, US, Water Quality, Water Resources | Permalink | TrackBack (0)

National Environmental Law Moot Court Competition

Congratulations to all of the participants in the National Environmental Law Moot Court Competition held at Pace University during the last few days.  Roughly 70 law schools participated in the competition, which featured a difficult and oft-times confusing problem about salvage of a Spanish shipwreck.  The law covered by the problem included admiralty law, administrative law, international law such as the UNESCO treaty and the Law of the Sea, the National Marine Sanctuaries Act, the Endangered Species Act, the Clean Water Act, the Rivers and Harbors Act, the Outer Continental Shelf Lands Act, and for good measure, the Submerged Military Craft Act.  Just typing that list makes me tired!

The learning is in participating, but the honors for Best Briefs go to University of Houston, Georgetown, and University of California at Davis, with Houston winning overall Best Brief.  The Best Oralist Honor goes to Louisiana State University.  The final round of the competition featured Lewis & Clark law school, University of Utah, and Louisiana State. Lewis & Clark prevailed, winning the overall competition for the 2d time in a row.  If I recall correctly, that may be the first back to back win.  Congratulations to everyone!

The students of Pace University deserve special mention for sacrificing their ability to compete and for running a flawless competition.  More details can be found at the NELMCC site.

February 25, 2009 in Africa, Agriculture, Air Quality, Asia, Australia, Biodiversity, Cases, Climate Change, Constitutional Law, Economics, Energy, Environmental Assessment, EU, Forests/Timber, Governance/Management, International, Land Use, Law, Legislation, Mining, North America, Physical Science, Social Science, South America, Sustainability, Toxic and Hazardous Substances, US, Water Quality, Water Resources | Permalink | TrackBack (0)

Sunday, February 15, 2009

Christopher Field and Anny Cazenave AAAS reports on rapidly worsening climate change

On Saturday, I noted the AAAS meeting report on climate change by Christopher Brown.Climate change worsens more rapidly than IPCC anticipated   Here's a bit more on Christopher Field's report from MSNBC:

Carbon emissions have been growing at 3.5 percent per year since 2000, up sharply from the 0.9 percent per year in the 1990s..."It is now outside the entire envelope of possibilities" considered in the 2007 report of the International Panel on Climate Change...The largest factor is the widespread adoption of coal as an energy source... "and without aggressive attention societies will continue to focus on the energy sources that are cheapest, and that means coal."  Past projections for declines in the emissions of greenhouse gases were too optimistic, he added. No part of the world had a decline in emissions from 2000 to 2008.

Anny Cazenave of France's National Center for Space Studies [reported] that improved satellite measurements show that sea levels are rising faster than had been expected... Rising oceans can pose a threat to low level areas such as South Florida, New York and other coastal areas as the ocean warms and expands and as water is added from melting ice sheets...And the rise is uneven, with the fastest rising areas at about 1 centimeter — 0.39 inch — per year in parts of the North Atlantic, western Pacific and the Southern Ocean surrounding Antarctica...

MSNBC link
 

February 15, 2009 in Asia, Australia, Climate Change, Energy, International, Law, Legislation, North America, Physical Science, Sustainability, US, Water Resources | Permalink | TrackBack (0)

Sunday, February 1, 2009

Chartering Sustainable Transnational Corporations

This link connects to a paper I just posted on SSRN.  I presented the paper at the 6th Colloquium of the IUCN International Academy of Environmental Law in Mexico City in November 2008.  I am submitting a short version of the paper for possible publication in a book incorporating papers presented at the conference on the theme of Alleviating Poverty and Environmental Protection.  And I am preparing a more complete and elaborate version for possible law review publication.  I would deeply appreciate your comments on the subject of how we ensure that transnational corporations act in a sustainable manner and the obstacles or concerns with the approach I suggest.  SSRN link

Abstract:    
Using a recent innovative Oregon sustainable corporation law as a springboard, this article argues for requiring all transnational corporations to be chartered as sustainable corporations. Given the far-reaching effects of their operations and their uniquely powerful role, the global wealth that has been accumulated in these organizations must be fundamentally redirected toward creating a sustainable world. As a privilege of doing transnational business, transnational corporations should be required to incorporate environmental and social responsibility into their corporate charters-the document that sets forth the prime mission of the corporation and its directors, essentially baking sustainability into the corporate DNA of transnational corporations.

To be both effective and to harness the entrepreneurial creativity of these organizations, the sustainable corporation charter must be implemented per provisions that require transnational corporations to develop corporate sustainability strategies in accordance with the guidance provided by the implementing provisions. The implementing provisions should also require that the transnational corporations monitor and report in a standardized manner compliance with the corporate sustainability strategy, with sustainability-related laws, and with nonbinding environmental, labor, human rights, corruption, and other sustainability-related standards.

The sustainable corporation charter requirement should be imposed as a matter of international law, through an international convention and administered by an international commission. The requirements should be directly applicable to transnational corporations as a condition of doing transnational business. The commission should be authorized to take enforcement action directly against the corporation. In addition, both home and host nations to transnational corporations should agree to compel the corporations - either incorporated in that nation or doing business in that nation-to comply with the sustainable corporation charter requirement as a condition of doing any business. Nations that fail to join the international convention, or that fail to enforce the international convention, should be subject to mandatory trade and other economic sanctions by all signatories to the international agreement.

We can no longer allow transnational corporations to aggregate the bulk of societal wealth and then operate in an environmentally and socially irresponsible manner. The proposals in this article are one step toward turning transnational corporations into sustainable corporations.

Keywords: transnational corporations, corporate charters, multi-national corporations, sustainability, environmental, international convention, environmental assessment, voluntary compliance, environmental standards, alien tort, corporate social responsibility, human rights, international law, enforcement

February 1, 2009 in Africa, Agriculture, Air Quality, Asia, Australia, Biodiversity, Climate Change, Economics, Energy, Environmental Assessment, EU, Forests/Timber, Governance/Management, International, Land Use, Law, Legislation, Mining, North America, South America, Sustainability, Toxic and Hazardous Substances, US, Water Quality, Water Resources | Permalink | Comments (2) | TrackBack (0)

Friday, January 23, 2009

The Obama Administration's Energy and Environment Agenda

ENERGY AND THE ENVIRONMENT  White House link

The energy challenges our country faces are severe and have gone unaddressed for far too long. Our addiction to foreign oil doesn't just undermine our national security and wreak havoc on our environment -- it cripples our economy and strains the budgets of working families all across America. President Obama and Vice President Biden have a comprehensive plan to invest in alternative and renewable energy, end our addiction to foreign oil, address the global climate crisis and create millions of new jobs.

The Obama-Biden comprehensive New Energy for America plan will:

  • Help create five million new jobs by strategically investing $150 billion over the next ten years to catalyze private efforts to build a clean energy future.
  • Within 10 years save more oil than we currently import from the Middle East and Venezuela combined.
  • Put 1 million Plug-In Hybrid cars -- cars that can get up to 150 miles per gallon -- on the road by 2015, cars that we will work to make sure are built here in America.
  • Ensure 10 percent of our electricity comes from renewable sources by 2012, and 25 percent by 2025.
  • Implement an economy-wide cap-and-trade program to reduce greenhouse gas emissions 80 percent by 2050.

Energy Plan Overview

Provide Short-term Relief to American Families

  • Crack Down on Excessive Energy Speculation.
  • Swap Oil from the Strategic Petroleum Reserve to Cut Prices.

Eliminate Our Current Imports from the Middle East and Venezuela within 10 Years

  • Increase Fuel Economy Standards.
  • Get 1 Million Plug-In Hybrid Cars on the Road by 2015.
  • Create a New $7,000 Tax Credit for Purchasing Advanced Vehicles.
  • Establish a National Low Carbon Fuel Standard.
  • A “Use it or Lose It” Approach to Existing Oil and Gas Leases.
  • Promote the Responsible Domestic Production of Oil and Natural Gas.

Create Millions of New Green Jobs

  • Ensure 10 percent of Our Electricity Comes from Renewable Sources by 2012, and 25 percent by 2025.
  • Deploy the Cheapest, Cleanest, Fastest Energy Source – Energy Efficiency.
  • Weatherize One Million Homes Annually.
  • Develop and Deploy Clean Coal Technology.
  • Prioritize the Construction of the Alaska Natural Gas Pipeline.

Reduce our Greenhouse Gas Emissions 80 Percent by 2050

  • Implement an economy-wide cap-and-trade program to reduce greenhouse gas emissions 80 percent by 2050.
  • Make the U.S. a Leader on Climate Change.

January 23, 2009 in Agriculture, Air Quality, Biodiversity, Climate Change, Economics, Energy, Governance/Management, International, Land Use, Law, Legislation, Mining, Sustainability, US | Permalink | TrackBack (0)

Let Clean Water Flow

Here's my church's video to launch our 2009 Drink Water for Life lenten challenge.  If you benefit from the work I do on this blog, please, please, please......take the challenge or find another way to contribute to organizations that do community-based water projects.  Church World Service or Global Ministries are great faith-based organizations.  Water for Life and Water for People are great secular groups. Every 15 seconds, a child dies from a water borne disease like cholera or dysentery from lack of clean water and sanitation.  Together, we can change this.  Village by village. 

Let Clean Water Flow 

January 23, 2009 in Africa, Agriculture, Air Quality, Asia, Australia, Biodiversity, Cases, Climate Change, Constitutional Law, Economics, Energy, Environmental Assessment, EU, Forests/Timber, Governance/Management, International, Land Use, Law, Legislation, Mining, North America, Physical Science, Social Science, South America, Sustainability, Toxic and Hazardous Substances, US, Water Quality, Water Resources | Permalink | Comments (0) | TrackBack (0)