Evaluation on risk of human AIV infection after a H5N1 subtype avian influenza epidemic in a food market

Objective To evaluate the risk of human H5N1 avian influenza virus(AIV) infection after a H5N1 subtype AIV epidemic in a food market of Guangzhou.Methods The H5N1 RT-RCR test of throat swab sample and a 7 days medical observation were conducted among contacts of poultry died of H5N1 AIV.The influenza-like case was monitored in epidemic area and N5N1 test of the throat samples was done for persons with AIV exposure history.The blood samples of poultry butchers,normal food retailers,and food buyers in the food market were collected for tests of hemagglutination inhinbition and neutralization tests for H5-Ab and H9-Ab.Results Thirteen close contacts were H5N1 nucleic acid negative.Among 3971 influenza-like cases,53 had AIV exposure history,but all of them were H5N1 nucleic acid negative.All of the 176 serum samples were H5-Ab negative,but the H9-Ab positive rate in the poultry butchers(21.05%)was higher than that of in the normal food retailers(1.59%)and food buyers(1.00%).Conclusion H5N1 subtype AIV didn't transmit to human in this epidemic,and the poultry-human transm ission ability of H5N1 subtype AIV is very limited.But the poultry butchers in food market have a higher risk of AIV infection.