Sero-Surveillance of Avian Influenza in Sudan, 2009-2010

Abstract

This study reports the evidence of circulation of avian influenza viruses (AIV) in domestic poultry in Sudan. A total of 3525 sera samples collected from 14 States from 2009-2010 and were assayed for avian influenza (AI) antibodies using ELISA. Sera were collected from commercial (2267), backyard (550) and live birds markets (581) poultry flocks as well as 127 other bird species. Positive sera were further confirmed for the presence of H5, H7 and H9 subtype-specific antibodies, using haemagglutination inhibition (HI) assay. The overall prevalence of Influenza A-specific antibodies was 8.3% the highest value was detected in western region (13.6%) and the lowest in eastern region (4.4%). Amongst the whole tested birds, the backyard flocks showed significant (P<0.05) highest values (10.5%) than the commercial (8.6%) or live bird markets (5.5%). Subtyping of all type A positive sera, showed that 1.7% contain antibodies to H5 antibodies with average mean titre of 5.1 log2 and 0.3% of the sera was found to be positive to H7 antibodies with average mean titre of 4.9 log2 while 2.5% were positive for H9 antibodies with average mean titre of 5.2 log2. The other birds species included in this study displayed 7.1% antibodies to AI type A and found negative for either of H5, H7 & H9 subtypes. These results proved the circulation of low pathogenic AIV in the country.

Keywords: Avian influenza, antibodies, birds, Sudan