Detection of equine herpesvirus-1 (EHV-1) in urine samples during outbreaks of equine herpesvirus myeloencephalopathy

• Published in: Equine veterinary journal 2024-05, Vol.56 (3), p.456-463
• Main Authors: Velloso Alvarez, Ana, Jose-Cunilleras, E, Dorrego-Rodriguez, Abel, Santiago-Llorente, Isabel, de la Cuesta-Torrado, Maria, Troya-Portillo, Lucas, Rivera, Belen, Vitale, Valentina, de Juan, Lucia, Cruz-Lopez, Fatima
• Format: Article
• Language: English
• Subjects: Animals; Disease Outbreaks - veterinary; DNA, Viral - genetics; Herpes viruses; Herpesviridae Infections - diagnosis; Herpesviridae Infections - epidemiology; Herpesviridae Infections - veterinary; Herpesvirus 1, Equid - genetics; Horse Diseases - diagnosis; Horses; Horses - genetics; Infections; Real-Time Polymerase Chain Reaction - veterinary; Urine
• ISSN: 0425-1644; 2042-3306
• DOI: 10.1111/evj.14007

Real-time PCR is the diagnostic technique of choice for the diagnosis and control of equine herpesvirus-1 (EHV-1) in an outbreak setting. The presence of EHV-1 in nasal swabs (NS), whole blood, brain and spinal cord samples has been extensively described; however, there are no reports on the excretion of EHV-1 in urine, its DNA detection patterns, and the role of urine in viral spread during an outbreak. To determine the presence of EHV-1 DNA in urine during natural infection and to compare the DNA detection patterns of EHV-1 in urine, buffy coat (BC) and NS. Descriptive study of natural infection. Urine and whole blood/NS samples were collected at different time points during the hospitalisation of 21 horses involved in two EHV-1 myeloencephalopathy outbreaks in 2021 and 2023 in Spain. Quantitative real-time PCR was performed to compare the viral DNA load between BC-urine samples in 2021 and NS-urine samples in 2023. Sex, age, breed, presence of neurological signs, EHV-1 vaccination status and treatment data were recorded for all horses. A total of 18 hospitalised horses during the 2021 and 2023 outbreaks were positive for EHV-1, and viral DNA was detected in urine samples from a total of 11 horses in both outbreaks. Compared with BC samples, DNA presence was detected in urine samples for longer duration and with slightly higher concentration; however, compared with NS, detection of EHV-1 in urine was similar in duration with lower DNA concentrations. Limited sample size, different sampling times and protocols (BC vs. NS) in two natural infection outbreak settings. EHV-1 was detected in the urine from naturally infected horses. Urine should be considered as complimentary to blood and NS in diagnosis of EHV-1 infection.