In response to cases of swine influenza A (H1N1), The World Health Organization (WHO) is coordinating the global response to human cases of swine influenza A (H1N1) and monitoring the corresponding threat of an influenza pandemic. WHO Expressed concern about cases of swine flu currently being reported in some areas of Mexico and in the United States, emphasizing, however, that it is too early to talk about a beginning of a pandemic.

“We cannot say if it will cause a pandemic on the basis of currently available laboratory, epidemiological, and clinical evidence” said Experts in WHO.

In the United States, CDC announced a total of 11 laboratory confirmed human cases of swine flu infection. Of these 7 are from California, 2 from Texas and 2 from Kansas)..

In Mexico, there are 18 laboratory confirmed cases of H1N1, 16 of which are similar to the cases found in the US.

In Mexico, from 17-23 April, there have been 1149 persons (71 deaths, with fatality rate of 6.2%) under investigation for severe respiratory disease, of whom 856 (55 deaths, with fatality rate of 6.4%) fulfill the case definition of an acute febrile illness associated with prostration, chest pain and tachypnoea.

Dr Margaret Chan, the WHO Director-General convened a meeting Saturday25/4, 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 Director-General has determined that the current events constitute a public health emergency of international concern, under the Regulations and.

Dr Chan declared the situation as a public health emergency of international concern (PHEIC) following a recommendation from the Emergency Committee convened under the IHR (2005). WHO issued temporary advise to all countries of enhanced surveillance for unusual outbreaks of influenza-like illness and severe pneumonia and to immediately report any unusual influenza like illness cases to WHO.

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 and Tamiflu, but resistant to both amantadine and rimantadine.

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.

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.