Evidence of Antibodies to H5 Subtype Avian Influenza Virus in Commercial Layer Farms in Jos, Nigeria

摘要

Highly pathogenic avian influenza (HPAI) devastated the poultry industry in Jos north and south local government area (LGAs) of Plateau State, Nigeria during the 2006 epidemic. A combination of modified stamping out and improved biosecurity was used to eradicate the disease. This study was conducted in 2011 with the aim of determining the presence of antibodies to H5 subtype avian influenza (AI) virus in layers in previously affected and non-affected farms in two local government areas (LGA) of Plateau State. Records of the number of farms that were depopulated, and laboratory confirmation of HPAI in farms that had birds’ positive for AI H5N1 virus during the 2006 outbreaks was use for this study. Twenty farms that had birds that suffered from the 2006 epidemic of HPAI were randomly selected from the list of confirmed HPAI positive farms and referred to as affected farms. Another 20 farms that were located close to the affected farms and had bird during the 2006 AI epidemic but did not suffer from the disease were selected and referred to as non-affected farms. Blood samples were collected from 10 layers in each of the previously HPAI affected and non-affected farms and serological assay was done using haemagglutination inhibition (HI) test and enzyme linked immunosorbent assay (ELISA). An overall sero prevalence of 31.6% (ELISA) and 69% (HI) and an overall mean HI titre of 9.86±0.035 log? was recorded for the affected and non-affected farms. The non-affected farms had a higher prevalence (38.3%) than the affected farms (24.9%), while Jos South LGA had a higher prevalence (34%) than Jos North LGA (30%) using ELISA. Antibodies to H5 using both ELISA and HI test were present and in high concentration in layers in both affected and non-affected farms