Seroprevalence of Newcastle disease and other infectious diseases in backyard chickens at markets in Eastern Shewa zone, Ethiopia

Abstract

This study was conducted to estimate the seroprevalence of Newcastle disease (ND), Pasteurella multocida (PM) infection, Mycoplasma gallisepticum (MG) infection and infectious bursal disease (IBD), and to assess the level of concurrent seropositivity during the dry and wet seasons of the year 2010. A total of 234 and 216 sera were collected during the dry and wet seasons respectively from unvaccinated backyard chickens at four live poultry markets in two Woredas (Districts) of Eastern Shewa Zone, Ethiopia, and were tested using commercial enzyme-linked immunosorbent assay (ELISA) kits. The overall seroprevalence of ND, PM, MG, and IBD was 5.9%, 66.2%, 57.7% and 91.9% respectively during the dry season, and 6.0%, 63.4%, 78.7% and 96.3% respectively during the wet season. The seroprevalence of MG was higher (P < 0.001) during the wet season than during the dry season and higher (P = 0.002) in Adami-Tulu-Jido-Kombolcha (ATJK) Woreda (74%) than in Ada’a Woreda (60%). Area and season had no significant effect on the seroprevalence of ND, IBD and PM, indicating the widespread presence of those pathogens throughout the year in the study area. Of all the chickens tested, 85.6% had antibodies concurrently to more than one of the pathogens investigated. Birds were concurrently seropositive to more diseases during the wet season (median = 3) than during the dry season (median = 2) (P = 0.002). As serology is not able to distinguish between strains, further studies are warranted to better understand the circulating strains, their interactions and their economic effect on backyard poultry production in Ethiopia.