Influenza aviar y riesgo de pandemia

Abstract

Influenza is a common season pathology that occasionally presents pandemia, caused by a new Influenza A virus subtype that results from the genomic recombination of human virus with virus from other species. During the last years, there is a worldwide alert situation in terms of a new pandemia, due to the existence of Influenza A virus subtype H5N1 in birds from Southeast Asia, Europe and Africa. There are some sporadic cases in humans produced by close exposure with infected birds. The present article reviews the virologic characteristics of Influenza A H5N1 virus in humans and the chilean guidelines for a potential pandemia. Influenza is a respiratory disease produced by Influenza virus A,B,C, being the A type the most important due to its capacity to change structure and cause epidemia or pandemia. The last pandemias were classified as Spanish flu in 1918-1919 (H1N1), Asian flu in 1957 (H2N2) and the Hong-Kong flu in 1967 (H3N2), with the biggest death population in 1918. In template countries, Influenza presents in epidemia affecting the winter months; in tropical countries, the virus circulation occurs during the whole year.