Epidemiological Survey of Two City-Cases Infected with Highly Pathogenic Avian Influenza Virus(H5N1)in Guangdong

Objective To analyze the possible source of infection under the condition of no exposure to sick or dead poultry and provide scientific evidence for further prevention and control of avian influenza.Methods Epidemiological and serological assays,emergency surveillance,ELISA,Real-time PCR,RT-PCR were used for the analysis and diagnosis of human cases infected with H5N1 avian influenza virus.Results The two human cases who had been usually visited farm product market infected with H5N1 were found.History of exposure to infected poultry,pneumonia of unknown etiology from close contacts of cases and evidence of human to human were not found.Conclusion The two cases were not human to human infection but are infected in city without any history of exposure to infected poultry.The source of infection might be from farmers market.