# Seroprevalence and Molecular Detection of Bovine Viral Diarrhea Virus in Selected Dairy Farms in Southwest Ethiopia

## TL;DR

This study found that a notable portion of dairy cattle in Southwest Ethiopia have been exposed to BVD virus, but no persistent infections were detected.

## Contribution

The study identifies risk factors for BVD seroprevalence and confirms the absence of persistent infection in dairy cattle in Southwest Ethiopia.

## Key findings

- 18.8% of tested animals and 41.7% of farms showed BVDV antibodies, but no antigen or viral genome was detected.
- Age, respiratory issues, breeding system, and housing system were associated with seroprevalence.
- No evidence of persistent BVDV infection was found among the farms.

## Abstract

Bovine viral diarrhea (BVD) is a significant economic concern due to the risk of persistent infection and complex epidemiology in cattle‐producing countries, including Ethiopia. This study aimed to identify the circulating BVD virus type in dairy cattle, investigate seroprevalence, and assess associated risk factors in Jimma town, Oromia regional state, Southwestern Ethiopia. A cross‐sectional study was conducted from November 2023 to April 2024, involving 48 randomly selected dairy farms out of 130 registered ones. In total, 383 serum samples from BVD virus (BVDV) nonvaccinated animals were tested for BVD virus antibodies and antigens using a competitive enzyme‐linked immunosorbent assay (ELISA) kit (ID Screen BVD p80 antibody). Additionally, a one‐step reverse transcription polymerase chain reaction (RT‐PCR) was used to detect the viral genome in pooled swab samples. Analytical statistics, including chi‐square and multivariable logistic regression, were employed for data analysis using SPSS, Version 26. The study revealed that 72 animals (18.8%) and 20 farms (41.7%) tested positive for BVDV antibodies. All the tested samples were negative for BVDV antigen and viral genome. Age, history of respiratory problems, breeding system, and housing system were statistically associated with seroprevalence (p < 0.05). At the farm level, only the production system showed a significant association (p < 0.05). Adult animals had 2.2 times the odds of being seropositive (OR = 2.2; p = 0.02). Animals with respiratory issues and those housed in head‐to‐tail arrangements had 2.7 (p = 0.205) and 4.8 (p = 0.021) times the odds of being seropositive, respectively. In conclusion, a substantial proportion of dairy cattle in the study area are exposed to BVD virus. However, no evidence of persistent infection was found among the dairy farms. Effective management strategies are crucial, including vaccination, biosecurity measures, and housing management.