The Jeremiah Metzger Lecture: avian influenza.

Avian influenza has been identified as the major potential risk to the US. There have been three influenza pandemics in the past century, but the 1918–19 epidemic of “Spanish flu” dwarfs all others in terms of morbidity and mortality (Table 1). In the past two years there has been the rapid dissemination of Avian influenza (influenza A H5N1) among birds and a modest number of cases in people. Despite the relatively low attack rate, there are highly disturbing features: the mortality rate is reported at about 50%, there are clinical, pathologic and sequence analyses that show several features in common with the influenza strain of the 1918–19 pandemic, and this strain now appears to be widely distributed by uncontrollable flight patterns of migratory birds. The purpose of this report is to review the current knowledge of Avian influenza and the plans to control it. TABLE 1 Influenza pandemics