Abstract:
Avian infectious bronchitis virus is a highly contagious disease occurring in respiratory, urogenital, and reproductive tissues of
chicken causing considerable losses due to death, egg drop, and reduced production. *is preliminary study was conducted to
investigate the prevalence of antibodies against infectious bronchitis virus (IBV) and to assess the potential risk factors in chickens
of northwest Ethiopia. A cross-sectional study was conducted from November 2020 to June 2021. A total of 768 serum samples
from three zones were collected. To investigate the presence of antibodies against IBV, the indirect ELISA serological test was
applied. Positivity for anti-IBV antibodies was observed in 23.96% (95% CI: 20.98–27.14) of the samples. *e mixed-effect logistic
regression analysis of potential risk factors showed that IBV prevalence was significantly higher in young chickens than adults
(p < 0.001) and higher in intensive farm type than in extensive type (p < 0.001). Based on the production purposes of the chickens,
the odds of seropositivity for IB was significantly higher in layers than in broilers (p < 0.001) and dual purposes (p < 0.001). *is
study revealed higher seroprevalence in farms which had the “all-in-all-out” rearing method than in farms with different batches
in one house with a significant difference (p < 0.001), higher seroprevalence in the poor ventilated type than in good ones
(p < 0.001), and higher seroprevalence in the houses that did not remove used litter at all than houses of completely disposed and
partially disposed litter (p � 0.002). Moreover, disinfection of houses had significant effect on the occurrence of IB. Having
personal protective equipment was significantly affecting the occurrence of IB, being higher in the farms that have no wearing
clothes and shoe than in those having wearing clothes and shoe (p � 0.002). In conclusion, the seroprevalence finding in the
present study indicated that the organism is circulating among the population of chickens and high enough to cause significant
economic losses *erefore, poultry houses should be cleaned, disinfected, and well ventilated and farm attendants should have
separate farm shoe and clothes. Further studies on the virus isolation and molecular characterization of the target gene are needed