Isolation and Molecular Detection of Infectious Bronchitis and Infectious Laryngotracheitis Viruses in Chickens in Maya City, and Seroprevalence in Selected Areas of Oromia, Ethiopia
No Thumbnail Available
Date
2026
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Abeba University
Abstract
The poultry industry in Ethiopia is highly vulnerable to significant economic risks posed by highly pathogenic respiratory viruses such as Infectious Bronchitis (IBV) and Infectious Laryngotracheitis (ILTV) due to their high morbidity and mortality. This cross-sectional study, conducted from November 2025 to May 2026, aimed to isolate and molecularly detect the IBV and ILTV in poultry farms in Maya City and to determine the seroprevalence of these viruses in selected towns of Oromia, Ethiopia. A total of 384 serum samples were randomly collected from selected chickens and analyzed using indirect ELISA to determine seroprevalence. Additionally, 12 pooled clinical oropharyngeal swab samples, representing 60 chickens from Maya City, were tested using one-step RT-PCR targeting the 3’ untranslated region for IBV and conventional PCR targeting the ICP4 gene of ILTV. Sam,,,,,mples positive by molecular methods were further subjected to virus isolation using specific pathogen-free embryonated chicken eggs for IBV and primary chicken embryo fibroblasts (CEF) cell culture for ILTV.
The overall seroprevalence of IBV was extremely high (99.7%), while ILTV seroprevalence was 17.2%, with the highest proportion observed in Maya City (53.8%). Backyard production systems showed higher ILTV prevalence (34.4%) compared to commercial systems (13.8%).Biosecurity measure were significantly associated with reduced odds of viral positivity. Specifically, the use of farm specific clothing (OR = 0.191; p < 0.001) and dedicated footwear (OR = 0.089; p < 0.001) acted as strong protective factors against infection.Molecular detection revealed IBV and ILTV rates of 41.7% and 33.3% , respectively. Characteristic embryonic lesions (stunting, curling, and feather dystrophy) were observed following IBV inoculation in embryonated eggs; however, subsequent RT-PCR failed to confirm viral RNA in later passages. ILTV isolation in CEF cell culture produced normal cytopathic effect (CPE) with the main characteristic being cell rounding and syncytium formation.In conclusion, this study demonstrates widespread exposure to IBV and the presence of both IBV and ILT in the
study area. The findings emphasize the need for improved surveillance, strengthened biosecurity practices, and further molecular characterization of circulating strains to support effective disease control strategies in Ethiopia’s poultry sector.
Description
Keywords
chickens, IBV, ILTV, isolation, molecular detection, seroprevalence