SERO-PREVALENCE AND MOLECULAR DETECTION OF INFEC TIOUS BRONCHITIS VIRUS AND ITS ASSOCIATED RISK FACTORS FOR NON-VACCINATED CHICKEN IN HADIYA AND SILTE ZONES OF CENTRAL ETHIOPIA REGION

Abstract

Infectious bronchitis is one of the poultry diseases, which causes production loss due to egg dropping in layer chicken and low meat production in broilers. Thus, a cross-sectional study was conducted in the Hadiya and Silte Zones of the Central Ethiopia Region from November 2023 to April 2024 with the objectives of detecting the sero-prevalence of infectious bronchitis virus, the associated risk factors, and the circulating gene. The blood and swab samples were tested by using the indirect enzyme linked immuno sorbent assay and reverse transcriptase polymerization chain reaction respectively. Closed type of questionnaire was used to interview stock holders for the assessment of associated risk factors on pre-prepared variables. The data was analyzed using the descriptive statistics, and uni-variable and multivariable logistic re gression. From 384 serum samples, 57.8% (222/384) samples were positive for anti-IBV anti bodies and 16% (2/12) of tracheal swab samples were positive for molecular detection. Based on multivariable logistic regression analysis, IBV prevalence was significantly higher in chickens of Werabe Administrative Town of Silte Zone than Shashogo District of Hadiya Zone (p=0.01) and higher in the poorly ventilated farm than in good ventilated one (p<0.001). Based on the production purposes of the chickens, the odds of sero-positivity for IB was signif icantly higher in layers than in broilers (p=0.009). This study revealed higher sero-prevalence in farms which had no litter removed than in farms with litter completely disposed house with a significant difference (p=0.001). In conclusion, the sero-prevalence and molecular findings in the present study indicated that the clue for the presence of infectious bronchitis virus among the population of chickens, which is high enough to affect the poultry production. Therefore, strict biosecurity measures for the poultry houses should be applied. Further stud ies on the virus isolation and molecular characterization of the target gene of the virus in the study area are needed to specify circulating genotype.