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The increased reports of A(H5N1) outbreaks in poultry and wild bird populations, and the emergence of a further evolved lineage of the virus in poultry in some countries, do not change the current assessment of the risk to human health.

Highly pathogenic avian influenza A(H5N1) infections are continuing to occur in poultry and humans in Egypt. However there is no evidence of a significant change in the pattern of human illness and deaths related to A(H5N1) virus infections in the country. Certainly there are no epidemiological data or analyses consistent with adaptation of these viruses to humans.

Following reports of a human fatality due to highly pathogenic avian influenza A(H5N1) virus infection in China’s Guangdong province, the European Commission requested an update to the assessment of risk of human-to-human transmission occurring. ECDC does not consider that there is any change to the previous assessments that the risk for EU/EEA countries is very low.

The results of two, as yet unpublished, investigations of laboratory-induced genetic changes in avian influenza A(H5N1) viruses have been reported to have found that a surprisingly few number of changes make the viruses transmissible between ferrets, the most commonly used model for the way influenza behaves in humans. The possibility that this could have resulted in the development in laboratories of A(H5N1) influenza viruses transmissible between humans has caused concern for public safety and generated unusually high levels of debate in the scientific community. This report summarises and explains the complex public health and scientific issues around these developments including the positive and negative aspects of some of the responses that have been proposed internationally.