Seroprevalence of Avian Influenza virus subtype H5N1 in chickens of the two main poultry market in Surakarta area, Central Java

Avian influenza (AI) subtype H5N1 virus is very contagious among domestic poultry such as chicken (Gallus gallus) and potentially infecting humans through direct or indirect contact with the infected animal. In the Surakarta area, Central Java, there are two major poultry markets, Silir poultry market and Jumantono farm. Here, we determined the seroprevalence of the AI virus in chickens sold in both poultry markets. The method was conducted using an explorative experiment by collecting 140 samples of chicken blood serum. The presence of antibodies to the AI virus subtype H5N1 was measured through a standard serological test via hemagglutination-inhibition (HI) assay. The HI assay detected a large antibody difference against AI from samples of both locations; 4.28% from Silir poultry market and 48.57% from Jumantono farm. Because the chickens from the Silir poultry market were not vaccinated, the level of antibody detected indicatesd that some chickens were exposed to the virus through infection. Meanwhile, the high positivity rate in Jumantono farm might reflect the presence of neutralizing antibody, since the chickens from this farm received periodic vaccinations. Continuous quality surveillance in the environment of the poultry market is essential to reduce the impact of AI outbreaks against chickens and humans.