02.12.2011

Toffan et al., Veterinary Record 2011 169: 589

A study, published as a letter reported a QX-like IB infection in Africa.
In August 2011, a set of 10 cloacal swabs, 10 tracheal swabs and 25 serum samples from Zimbabwe was submitted for investigation. Samples were collected from two villages in the Beitbridge district, namely Mapai and Majini, which had reported high mortality in domestic birds.
Only chickens appeared to be affected while other species, such as guinea fowl and pigeons, were apparently healthy.
Clinical signs observed included dropping of wings and leg paralysis, greenish, watery diarrhoea, dyspnoea and The birds belonged to indigenous breeds and were not vaccinated against infectious bronchitis, Newcastle disease and infectious bursal disease (IBD).
The sequence analysis of the S1 gene fragment showed the highest nucleotide similarity (98.6 per cent) with the IBV strain QX L-1148.
Isolation in specific pathogen-free embryonated chicken eggs was successful and sequence analysis of the allantoic fluid harvested confirmed the identity of the virus.
Haemagglutination inhibition performed on serum samples collected from sick birds confirmed the presence of specific antibodies to QX infectious bronchitis variant.