Molecular Identification of Equine Herpesvirus 1, 2, and 5 in Equids with Signs of Respiratory Disease in Central Ethiopia.

Background: Equine herpesvirus (EHV) infections have major economic, health, and welfare impacts on equids. This study was performed in three selected zones of central Ethiopia with the objectives of detecting EHV-1, -2, and -5 in horses and donkeys with suggestive signs of respiratory tract disease and to assess epidemiological risk factors associated with infections.

Methods: A total of 58 nasopharyngeal swab samples were collected from donkeys and horses showing clinical signs of respiratory disease. Polymerase chain reaction (PCR) was used to detect EHV-1, -2, and -5. Evaluation of the associated risk factors was conducted using a multivariable logistic regression model.

Results: Among the 58 equids tested, 36 (62%), 31 (53%), and 15 (25%) equids were positive for EHV-1, -2, and -5, respectively. Concurrent infections with EHV-1 and EHV-2 (31%), EHV-1 and EHV-5 (17%), EHV-2 and EHV-5 (15.5%), and EHV-1, -2, and -5 (13%) were recorded. EHV-1 was detected significantly in higher proportion in donkeys (76%; 95% CI: 1.066-2.251; P = 0.047) compared with horses (51.5%). In contrast, horses had fourteen times more likely to be positive for EHV-2 (OR: 13.66; 95% CI: 3.119-59.816; P = 0.001) compared to donkeys. Detection of EHV-1, -2, and -5 was no significant association with age, sex, and body condition score.

Conclusion: The present study revealed the molecular evidence of EHV-1, -2, and -5 infection in donkeys and horses with signs of respiratory disease. It also documented that donkeys and horses have varying levels of susceptibility to EHVs. This species-specific in susceptibility difference to EHVs infections should be further elucidated.