Thursday, April 30, 2009
To date, the United States has confirmed a total of 109 human cases of swine influenza A H1N1: 1 in Arizona, 14 in California, 1 in Indiana, 2 in Kansas, 2 in Massachusetts, 1 in Michigan, 1 in Nevada, 50 in New York City, 1 in Ohio, 10 in South Carolina and 26 in Texas. Other suspected cases are being investigated. 5 hospitalizations and a death have been registered. The dead case is a child of 22 months old, from Mexico who died in a hospital of Houston, Texas area.
The most recent cases detected as well as the registered death suggest that more serious cases could appear in the United States.
From 17 to 29 April, Mexico has reported 1,918 suspected cases of influenza with severe pneumonia including 84 deaths. The suspected cases were recorded in all Mexican states. Most of them in the Federal District, Guanajuato, State of Mexico, Aguascalientes, Queretaro and San Luis Potosí. The majority of these have occurred in previously healthy young adult people. There have been few cases in individuals under 3 or over 59 years old. 933 of the suspected cases are currently hospitalized.
The number of probable cases of swine influenza A H1N1 remains at 286, and a total of 97 cases has been confirmed. The considerable variation in the number of confirmed cases as of today is due to the recent laboratory confirmation of samples collected in previous weeks. The number of confirmed dead cases remains at 7. This figure is also subject to variations depending on the new laboratory information.
In Canada, to date 19 human cases of swine influenza A H1N1 have been confirmed (2 in Alberta, 4 in the province of New Scotland, 6 in British Columbia and 7 in Ontario) some of them with recent trip history to Cancun, Mexico. All the cases developed a mild form of influenza like illness. 2 of the cases presented, in addition, gastrointestinal symptoms. All of them are currently recovered and none required hospitalization. Laboratory tests were conducted in Winnipeg, Canada. `Indigenous` transmission is not discarded since not all the confirmed cases have trip history to Mexico.
The press has reported information on suspected cases in several countries of the Region; however this information has not been confirmed.
International Health Regulations (IHR)
At the request of the Director-General (DG) of WHO, the IHR Emergence Committee has been summoned and is advising the DG on the event. On its first day of deliberation, 25 April, it concluded that the present event constitutes a Public Health Emergency of International Concern.
On 29 April 2009, the DG decided to elevate the pandemic alert to Phase 5. In order to come to this urgent decision, the DG considered epidemiological information from the most affected countries, as well as the result of the scientific meeting held that same day. The latter indicated existence of sustained outbreaks of swine influenza A H1N1 at the community level in more countries within the Region.
The decision to increase the pandemic level of the alert should permit Member States to provide the required leadership and coordination as well as to consider the possibility of executing their contingency plans.
The DG recommends not closing borders or restricting travel. However, it is prudent for people who are sick to delay travel. Moreover, returning travelers who have become sick should seek medical attention in line with guidance from national authorities.
Production of seasonal vaccine should continue, but at the same
time, WHO is making all the efforts to facilitate the process of
development of a vaccine against swine influenza A H1N1.
The Committee will continue to advise the DG on the basis of the available information.
At this time, enhanced surveillance is recommended. On its Web page, PAHO has published orientations for the enhancement of surveillance activities, which are directed to the investigation of:
- Clusters of cases of ILI/SARI of unknown cause
- Severe respiratory disease occurring in one or more health workers
- Changes in the epidemiology of mortality associated with ILI/SARI; increase of observed deaths by respiratory diseases; or increase of the emergence of severe respiratory disease in previously healthy adults/adolescents.
- Persistent changes observed in the response to the treatment or evolution of a SARI.
The following risk factors should also cause suspicion of swine influenza A H1N1 virus:
- Close contact with a confirmed case of swine influenza A H1N1 while the case was sick.
- Recent travel to an area where there are confirmed cases of swine influenza A H1N1 have been confirmed
Virological surveillance of swine influenza A H1NI
It is recommended that National Influenza Centers (NIC) immediately submit to the WHO Collaborating Center for influenza (CDC of the United States) all positive but unsubtypable specimens of influenza A. Shipment procedures are the same as those used by NICs for seasonal influenza specimens.
The test protocols for the detection of seasonal influenza by Polymerase Chain Reaction (PCR) cannot confirm swine influenza A H1N1 cases. The Centers for Disease Control and Prevention of the United Sates are preparing testing kits that will include the primers and probes as well as the required positive control samples. The kits will be sent in the first week of May to those NICs that currently use the CDC protocol.
Infection prevention and control in health care facilities
Since the main form of transmission of this disease is by droplets it is recommended strengthening the basic precautions to prevent their dissemination, for example the hygiene of hands, adequate triage in the health facilities, environmental controls, and the rational use of the personal protective equipment in accordance with the local regulations.
The complete guides “Epidemic-prone & pandemic-prone acute
respiratory diseases Infection prevention & control in health-care
facilities” are available at:
Click on the Map to enlarge
Prevention and Control of Respiratory Diseases in Health Facilities
(Available in English)
- General Recommendatios for the organisation of Health Facilities in Countries where cases of Influenza A(H1N1) Virus have not yet been reported
(Only available in spanish)
- Control de infección: Precauciones estándares en la atención de la salud
- Enfermedades respiratorias agudas con tendencia epidémica y pandémica. Prevención y control de infección en la atención de la salud
- Reconocimiento temprano, notificación y manejo del control de infección de enfermedades respiratorias agudas de potencial preocupación internacional
- Recomendaciones para el control de infección de la influenza aviar en centros de atención de la salud
Updates on Swine influenza
- Aide Memoire - WHO Pandemic Phase Descriptions and Main Actions by Phase
- Infection prevention and control in health care in providing care for confirmed or suspected A(H1N1) swine influenza patients
- Sequencing primers and protocol
- Protocol for antiviral susceptibility testing by pyrosequencing
- Viral gene sequences to assist update diagnostics for swine influenza A(H1N1)
- Instructions for shipments of swine influenza A(H1N1) specimens and virus isolates to WHO Collaborating Centres for influenza
- Pandemic Influenza Preparedness and Response. A WHO Guidance Document
- Interim WHO guidance for the surveillance of human infection with swine influenza A(H1N1) virus
- Advise on the use of Oseltamivir
- Epidemic-prone & pandemic-prone acute respiratory diseases Infection prevention & control in health-care facilities Summary guidance
- Infection Control Strategies for Specific Procedures in Health-Care Facilities. Epidemic-prone and pandemic-prone acute respiratory diseases.A Quick Reference Guide
- Guidance to Influenza Laboratories diagnosing swine influenza A/H1N1
- Health Establishments Preparation for Unusual or Unexpected Cases or Clusters of Severe Acute Respiratory Infection (SARI)