Influenza A (H1N1)

Abstract

In March 2009, an outbreak of human-infected swine influenza occurred in Mexico, with reports of deaths. Soon afterward, such cases were reported worldwide, namely, a pandemic outbreak. The prevailing disease is then defined as an acute respiratory infectious disease caused by swine-origin influenza A (H1N1) virus, a new variant of influenza virus. Its viral strains contain gene segments of three types of influenza viruses, namely swine influenza virus, avian influenza virus and human influenza virus. And the virus is mainly transmitted among humans via direct and indirect contact or respiratory tract.