Serosurvey for H5, H7 and H9 avian influenza viruses in local chickens in live bird markets within Kaduna metropolis, Nigeria.

Since the first 2006 Avian Influenza (AI) outbreak in Nigeria, it has continued to circulate and ravage the poultry industry with huge economic losses above 130 billion naira. Local poultry are important sources of AI transmission and maintenance of the highly pathogenic avian influenza H5N1. Live bird markets (LBMs) are "breeding grounds" and major risk factors for human infection of AI. The seroprevalence of AI in local chickens in LBMs in Kaduna Metropolis, Nigeria was determined. Sera were obtained from the local chickens (n=300) in 5 daily LBMs and subjected to competitive enzyme-linked immunosorbent assay (c-ELISA) to detect the nucleoprotein antibodies. The c-ELISA positive samples were further screened by haemagglutination inhibition (HI) test for AI using H5, H7 and H9 antigens. The overall AI seroprevalence was 1.7 % with the highest individual seroprevalence of 3.3% in Kawo and Railway LBMs. There was no statistically significant association between the location of LBMs and AI presence, and between the sex and presence of AI antibodies (p = 0.427). One sample was HI positive for antibodies against H5, H7 and H9 with mean titers of 4, 2.5 and 3.5 log2, respectively. This implies the potential danger of the spread of AI among humans and animals. There should be sustained surveillance and biosecurity in the live bird market. [ABSTRACT FROM AUTHOR]