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A sero-epidemiological survey of EDS '76 antibodies was carried out in chickens, guinea fowls, ducks and pigeons in various locations in Nigeria with the haemagglutination-inhibition test. Infection rates of 67.43, 79.68, 73.91 and 86.66% were obtained for chickens, guinea fowls, ducks and pigeons respectively. The high prevalence rates observed in these non-chicken species suggest that they should be considered as important in the epidemiology of EDS '76 in poultry in Nigeria. An extensive survey is recommended together with vaccination.

The occurrence of infectious bursal disease (IBD) in industrial poultry flocks in Cameroon was investigated by serological and virological techniques. Antibody to IBD virus was detected in 118 (33.9%) out of 348 serum samples collected in seven randomly selected areas. On the other hand, virological examination was performed on bursa of Fabricius samples obtained post-mortem from flocks in which there was a high mortality among young birds. This virological examination revealed the presence of IBD virus antigen. These observations confirm the occurrence of infectious bursal disease in Cameronian industrial poultry flocks.

A serological survey for IBD in market guinea fowls gave a total prevalence rate of 44.3% from five different locations in Nigeria. Guinea fowl keets were susceptible to experimental IBD infection and transmitted it to in-contact sentinel chickens. The infected guinea fowl keets showed the typical clinical-pathology and seroconversion for IBD. These results suggest that guinea fowls could play an active part in the epidemiology of IBD.

Five days old progeny chicks from breeders which have received primary and booster doses of live infectious bursal disease vaccine, demonstrated precipitating antibodies unlike progenies from single dose vaccinated breeders. All chicks from the two different groups of breeders were however seronegative at 22 days of age, despite vaccination at 7 or 14 days of age. Post vaccination seroconversion was first noticeable at 32 days in the group of chicks vaccinated at 7 days. Post challenge mortalities was significantly lower (P less than 0.05) and organ lesions very significantly minimized (P less than 0.01) in 7 day old vaccinated group than in 14 or 28 days old vaccinated chicks. These results showed that early (7 days) IBD Vaccination was superior to vaccination at 14 or 28 days, in terms of antibody response and protectivity against mortalities and bursal lesions.

Infectious bursal disease virus antigen was detected in the bursa of Fabricius of infected birds by the use of the counter immunoelectroosmophoresis technique. Eight suspected outbreaks were confirmed in this way and 82 out of 89 bursal samples submitted for laboratory confirmation were positive. The test was also suitable for the detection of antibody to infectious bursal disease virus in sera of infected birds. Precipitin lines were visible within 30 min as compared with 18 to 24 h with the Ouchterlony agar gel precipitation test. Counter immunoelectroosmophoresis is recommended for rapid confirmation of infectious bursal disease of poultry.