Report of Mixed Infection of Infectious Bursal Disease and Chicken Infectious Anaemia Viruses

Abstract

Infectious bursa disease (IBD) was tentatively diagnosed from an experimental cockerel flock. Clinical signs observed included dullness, diarrhoea characterized by greenish yellow colour and spiking mortality lasting four days. Post-mortem examination results showed pale and slightly enlarged liver and kidney, enlarged and haemorrhagic bursa, petechia haemorrhages on the spleen, keel and thigh muscles and thymus atrophy. Pale liver, thymus atrophy and haemorrhages in the bursa could also be presented in Chicken Infectious Anaemia (CIA) infection. The organs (Bursa, kidney, thymus and liver) from where the infected birds were further screened for IBD and CIA viruses using the polymerase chain reaction technique and were positive for both. This confirms IBD and CIA are responsible for the losses in the flock. This implies that many CIA infections or its mixed infection may be mistaken for IBD alone if no confirmatory diagnosis is carried out, since most post-mortem lesions presenting extensive syndrome are considered to be caused by IBD.