Periodic global One Health threats update

Reperant, Leslie A.; MacKenzie, John; Osterhaus, Albert D.M.E.

Poultry Wild birds H5N1 H5N6 H5N1 H5N2 H5N3 H5N6 H5N8 H5N1 H5N2 H5N6 H5N8 Africa 185 1162 7 Americas 1 1 239 4 2 40 23 Asia 72 3 1395 558 26 54 534 38 2 2 34 Europe 3 13 8 6 Total 258 3 2561 804 26 54 551 48 42 2 in April 2013 soon after the first identification of the virus as a cause of a zoonotic case of infection. Epidemics subsequently re-occurred in winter 2014 and 2015, with the highest reported numbers of animal outbreaks and zoonotic cases of infection during the months of January-February of each year. LPAIV H7N9, in contrast to most other avian influenza viruses, can bind to the cellular receptors used by seasonal influenza viruses [9, 10] . This ability is associated with one or two specific amino-acids in the hemagglutinin glycoprotein. Because seasonal influenza viruses and LPAIV H7N9 peak coincidentally during the winter months, they may co-infect an individual and subsequently reassort [11] . This may give rise to a transmissible variant, against which the human population has little pre-existing immunity, and may be at the origin of a new influenza pandemic. Strict monitoring and isolation measures are therefore essential to limit the risk of seasonal influenza and reassortment in individuals with zoonotic H7N9 virus infection.