Investigation on Infectious Bursal Disease Outbreak in Debre Zeit, Ethiopia

Abstract

An outbreak of infectious bursal disease affecting 20-45 days old broiler and layer chickens was investigated for the first time in Ethiopia in the months of March and April 2002. Death of chickens started at the 30th day of age and continues to the 55th day. The mortality rate of the disease in different poultry houses ranges from 45-50 %. The over all mortality rate was 49.89%. Broiler mortality was 56.09% while 25.08% for layer chickens. The major clinical symptoms were sudden drop in feed and water consumption, sever depression, white watery droppings and mass death. Grossly, hemorrhages in leg muscles, degeneration of the pectoral muscle, white mass (Urate deposit) in kidneys and in Cloaca were frequently observed during post mortem examination. In addition, haemorrhagic & swollen bursas filled with straw colored fluid were identified in few cases. Histopathology revealed hyperplasia of the reticulo-endothelia cells and interfollicular tissue of affected bursa of fabricius. The Agar Gel Immuno Diffusion (AGID) Test detected precipitating antibodies against Infectious Bursal disease virus in sera collected from convalescent chicken. Virus cytopathic effect was observed in chicken fibroblast cells (CFC) inoculated with bursa and spleen tissue suspension of sick chicken. Vaccination failures were encountered to Newcastle disease vaccine (Clone 30). This paper probably is the first to report the occurrence of infectious bursal disease in Ethiopia as the country has been known to be free from Infectious Bursal Disease(IBD).