Gumboro Disease is a highly contagious and acute viral infection also known as Infectious Bursal Disease (IBD). It is an important poultry disease worldwide, which was first reported in the USA in 1962 and in 1987 in Europe. In 2012 IBD had worldwide distribution.
Generally it is seen only in domestic chickens between 3 and 8 weeks of age depending on maternal antibody levels. It can present as a clinical or subclinical disease, causes mortality of 40%+ and immune suppression resulting in secondary infections. It is shed in the faeces and spreads easily from bird to bird by way of droppings. Infected equipment and clothing are means of transmission between farms.
Chickens and turkeys appear to be natural hosts.
Clinical symptoms are manifested by initial inflammation and enlargement and subsequent atrophy of the bursa. Infected birds are depressed, have ruffled feathers, droopy appearance, unsteady gait, lack of appetite, produce watery white diarrhoea and may be seen pecking at the vent. The feathers around the vent are usually stained with faeces. Morbidity and mortality begins 3 days post infection and the birds that die usually do so as a result of dehydration which causes kidney lesions.
Unfortunately there is no treatment for this disease. Rigorous disinfection is always advised but IBD virus has an ability to resist many disinfectants and environmental factors and therefore disinfection achieves only limited success in contaminated farms after depopulation.
Vaccination of broilers against Gumboro Disease is essential. The vaccine is given via the drinking water at 16 days or at 16 and 22 days, depending on which vaccine used. Early infection and subsequent immunosuppression can be minimised if there are high levels of maternal antibodies during early brooding of chicks in broiler flocks (and in some commercial layer operations). During the growing period breeder flocks should be vaccinated one or more times, first with a live vaccine and again with an inactivated vaccine just before egg production.
The goal of any vaccination program should be to use vaccines that most closely match the antigenic profile of the field viruses. Diagnostic testing can be used to select the most appropriate vaccination program that is suitable for individual farms.