Sero-prevalence of antibodies against avian influenza virus among people in poultry occupations in Guangdong province

Abstract

Objective To detect the positive rates of antibodies against avian influenza virus (AIV) subtypes H5, H6, H7 and H9 among people in poultry occupations in Guangdong province and to analyze the transmission of various subtypes of AIV from poultry to human contacts for the prevention and control of novel AIV infection in human beings. Methods Serum specimens were collected from 1066 people in poultry occupations (occupational group) and 205 people not in poultry occupations (non-occupational group) in 10 cities of Guangdong province. The inactivated AIV strains, isolated from poultry or environment of Guangdong province, were used as antigens to detect antibodies against AIV subtypes H5, H6, H7 and H9 by using the hemagglutination inhibition (HI) assay. Results The positive rates of antibodies against AIV subtypes H5, H6, H7 and H9 carried by people from the occupational group were respectively 0.44%, 0%, 0.30% and 0.30% in 2013 and 1.08%, 0.0%, 0.0% and 0.27% in 2014. Only the anti-H9 antibodies were detected in serum samples collected form people in the non-occupational group in 2013 with a positive rate of 0.95%. No significant differences with the positive rates of anti-AIV antibodies were found between the occupational group and the non-occupational group. However, the geometric mean titer (GMT) of anti-AVI antibodies in people from the occupational group was higher than that of the non-occupational group. Conclusion Although a grand spread of AIV from avian to human is not likely to happen yet, contacting with poultry is the risk factor for AIV infection in Guangdong population. A long-term surveillance of anti-AIV antibodies in serum should be strengthened among people in poultry occupations for the timely prevention and control of novel AIV outbreak. Key words: Avian influenza virus; Occupational group; Antibody detection