Infectious bursal disease, Biology

Infectious bursal disease

Infectious bursal disease (popularly known as Gumboro disease) is an acute contagious disease of young chicks caused by an RNA virus, a member of family Birnaviridae. The virus mainly affects chickens of 3 to 6 weeks of age. Very young chicks up to 10-12 days of age and laying birds do not show signs. Older birds and turkeys may also get the infection. There are two serotypes of the virus, serotype-1 vary in virulence from mild to highly pathogenic (very virulent) causing mortality upto 80% in chickens whereas turkeys and ducks (but not chickens) show infection with serotype-2. In addition to the direct effect of the clinical disease, the damage caused to the immune system results in increased susceptibility to other opportunists and pathogens to cause significant losses. The virus is comparatively resistant and persists for a long period in the contaminated pens/materials. The disease is highly contagious. Mealworms and litter mites may harbour the virus for 8 weeks, and affected birds excrete large amounts of virus for about 2 weeks post-infection. There is no vertical transmission.

Symptoms and lesions: Incubation period is 2 to 3 days. In the acute form of the disease, clinical signs start with anorexia, ruffled feathers, watery diarrhea, and depression. The birds may die of dehydration in 1 to 3 days of the illness. The morbidity may be as high as 100% and mortality varies between 20-80%. The gross lesions observed are edematous, enlarged, hemorrhagic bursa of Fabricius and hemorrhages in the skeletal muscles particularly thigh muscles. The bursa may contain necrotic cheesy materials. Enlargement of the spleen and uretic deposits in the renal tubules/ureters are also observed in some birds. Hemorrhages are also seen at the junction of the gizzard and proventriculus. The bursa may return to normal size but continue to atrophy rapidly. The histopathology of the bursa reveals severe bursitis characterized by edema, cellular exudates and necrosis.

Diagnosis: Clinical symptoms, gross lesions, virus isolation, detection of viral antigens in bursa/spleen/kidney/liver by agar gel diffusion/ immunoperoxidase/ fluorescent antibody tests, and detection of specific antibodies by agar gel diffusion/ ELISA tests are used for diagnosis of the disease.

Prevention and control: Strict biosecurity, proper hygiene and good management practices are necessary for prevention of IBD. Live vaccines are given in drinking water during the third week to provide protection as maternal immunity wanes. Breeding hens are vaccinated with attenuated live virus vaccine between 4 and 10 weeks of age and then given an inactivated adjuvanted vaccine 6 to 8 weeks later.

Posted Date: 9/18/2012 8:53:34 AM | Location : United States







Related Discussions:- Infectious bursal disease, Assignment Help, Ask Question on Infectious bursal disease, Get Answer, Expert's Help, Infectious bursal disease Discussions

Write discussion on Infectious bursal disease
Your posts are moderated
Related Questions
Lung Biopsy: As with pleural biopsy,  lung biopsy may  be  done by  surgical exposure of the lung (open lung biopsy) with or without endoscopy using a needle designed to remove a

Explain Nevirapine and its adverse effects Nevirapine (NVP,Viramune) - Nevirapine is most effective at raising CD4 cell counts and lowering viral load when combined with 2 NRTI

A double-stranded piece of DNA, 100 base pairs in size, is exposed to a high pH environment. This causes all non-valent interactions to be disrupted. What will result from this tre

Q. In chemical terms how is the neuronal repolarization achieved? Repolarization is the return of the membrane probable from the action potential (+35 mV) to the resting potent

Patterns of Ageing and Death Plants and their parts develop continuously from germination until death. The latter part of the developmental process, which leads from maturity

Demographic Transition As we saw earlier, death rates and birth rates have been nearly equal throughout much of human history. However, in Western Europe, death rates began to

Explain the Techniques of Culturing? In the last practical we learnt how to prepare culture media. This practical has been introduced to make you aware of the technique of sub-

If the titration is done by adding NaOH to a solution containing 2.661 moles of lysine, how many milliliters (mL) of a 5 M solution of NaOH would you have to add to reach point "E"

What is risk factor interaction ? Coronary artery disease, as has been explained, is a multifactorial disease with diverse risk factors coming together and interacting to produ

Q. Areas affected in peptic ulcer? The areas affected in peptic ulcer (due to erosion) can be: 1. Lower part of the oesophagus. 2, stomach (lesser curvature - an urn, whe