Molecular Detection of Equine Herpesviruses from Field Outbreaks in Donkeys in Northwest Amhara Region, Ethiopia

Abstract

Equine herpesviruses pose a threat to equine health and potentially cause substantial economic losses to the global equine industry. EHV outbreaks have been reported in various parts of Ethiopia and the Amhara region specifically. This study aimed to detect EHVs from suspected outbreak cases in selected districts of the Northwest Amhara region. A cross-sectional study was performed from January 2022 to July 2022 to detect EHVs from suspected outbreak cases. Clinical observation was conducted for the presumptive identification of equine herpesvirus infection, and nasopharyngeal swab samples were collected for molecular detection of the viruses for confirmation. Out of 463 donkeys observed, 23 donkeys showed clinical signs suggestive of equine herpesvirus infection. Samples from 10 suspected donkeys were further subjected to polymerase chain reaction (PCR) test, amplifying ORF30 for EHV-1 and gB for EHV-2 and EHV-5. Among the 10 donkeys tested, seven (<i>n</i> = 7) were positive for EHV-5. All ten (<i>n</i> = 10) tested donkeys were negative for EHV-1 and EHV-2. EHV-5 was detected in animals with nervous signs, respiratory signs, a combination of nervous and respiratory signs, and a combination of abortion, respiratory, and nervous signs. Generally, only EHV-5 was identified from the outbreak, and more detailed epidemiological/molecular studies should be performed to better understand its dynamics and inform preventive measures.