Infectious bursitis of chickens
The infectious bursal disease of chickens ( IBu , Gumboro disease , infectious bursal disease , Avian nephrosis ) is a disease occurring by way of viral disease of young chickens , with a hemorrhagic inflammation of the bursa of Fabricius associated. It was first observed in Gumboro , Delaware (USA) in 1957 and is now occurring worldwide. It is one of the notifiable animal diseases .
Pathogen and occurrence
The causative agent of infectious bursitis is the avibirnavirus (Syn. Infectious bursal disease virus, IBDV) from the family Birnaviridae . There are two different serotypes and 17 different virus strains.
The virus mainly affects chickens, but also turkeys , and ducks may also be susceptible. The virus can be cultivated in incubated hen's eggs , chicken fibroblast cultures or embryonic bursa cells.
The disease occurs worldwide. The virus is excreted through the faeces. The virus is extremely resistant to environmental influences. It can remain infectious in chicken coops for up to 122 days and in feed for up to 52 days. The infection occurs mainly through indirect contact with virus-contaminated objects.
Clinical picture
The disease is characterized by a characteristic course of the disease. Only young animals up to an age of 11 weeks become ill. After an incubation period of 2 to 3 days, almost all animals ( morbidity up to 100%) experience restlessness, reduced food consumption, ruffled plumage, green-white diarrhea, dehydration and tremors. Up to the 3rd day after the outbreak, there is a sharp increase in deaths. Day again significantly decrease. The mortality is up to 30%. Chronically infected animals show decreased weight gain and anemia .
If there are new outbreaks in the same herd, the disease is very mild, possibly even unnoticed.
Diagnostics and control
Pathologically and anatomically, enlargement, edematization and yellowing of the bursa fabricii, severe intestinal inflammation and muscle bleeding are evident. This, together with the clinical course, is already characteristic. The virus can be cultivated in the cell cultures described above.
A causal treatment is not possible. Even disinfection measures can not usually stop the spread due to the high tenacity of the virus. The most effective control measure is vaccination of dams. It is carried out three to seven weeks before the start of laying and then refreshed annually. The vaccination protects the newly hatched chicks with antibodies transmitted through the egg . In Switzerland, genetic engineering vaccines have also been temporarily approved for organic farming .
In Germany, infectious bursitis in chickens is one of the notifiable animal diseases . It is also subject to mandatory registration in Austria.
literature
- Rolle / Mayr (Ed.): Medical microbiology, infection and epidemic theory . Enke Verlag Stuttgart, 8th edition 2007, p. 226. ISBN 3-8304-1060-3
Individual evidence
- ↑ Georg Humbel: Genetic injection for Swiss organic chicken. In: srf.ch. November 7, 2018, accessed November 7, 2018 .
- ↑ The Bud remains GMO-free. Retrieved November 21, 2019 .
- ↑ Annex to Section 1 of the Ordinance on Notifiable Animal Diseases (TKrMeldpflV) in the version published on February 11, 2011 ( Federal Law Gazette I p. 252 ), last amended by Article 381 of the Ordinance of August 31, 2015 ( Federal Law Gazette I p. 1474 )
- ↑ § 13 of the Poultry Hygiene Ordinance of 2007
