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.
