Antibodies against H5 and H9 Avian Influenza among Poultry Workers in China

Abstract
Human infection with the H5N1 or H9N2 avian influenza virus has been reported in the city of Guangzhou in southern China.1,2 To assess the risk of avian influenza virus infection among humans, we conducted a serologic surveillance study in Guangzhou. A total of 2191 healthy persons were recruited from 230 workplaces and seven types of occupations from March 2007 through July 2008. This study was approved by the ethics committee of the Guangzhou Center for Disease Control and Prevention, and written informed consent was obtained from the subjects.