To determine levels of antibodies to influenza virus A/H5N1 in serum samples of people living in different regions of Russia in order to assess the risk of infection with avian influenza H5N1.
Two thousand one hundred sixty-eight serum samples were tested by hemagglutination inhibition assay for the presence of antibodies to influenza virus A/H5N1.
Twenty-six serum samples obtained from residents of Khanty-Mansiysk Autonomous Area and 2 samples from residents of Novosibirsk region were positive for antibodies to serotype A/H5. There were no clinical cases of avain influenza A/H5N1 infection in medical history of studied persons.
Since cases of asymptomatic carriage of A/H5N1 influenza virus in water birds are described and ability of the virus to survive in water environment for a long time is shown, it seems logical to detect antibodies to influenza virus A/H5 in sera of subjects living in Russian Federation taking into account that influenza virus A/H5N1 is isolated from wild fowl and poultry since 2005.