Stream of revelation: detection of equine herpesvirus-1 (EHV-1) in urine during myeloencephalopathy outbreaks
Investigation published in Equine veterinary journal
September 25th, 2024
Background: The detection of EHV-1 by real-time PCR in nasal swabs (NS), whole blood, brain, and spinal cord samples has been extensively described. However, there remains a notable gap in understanding the excretion of the virus in urine, the patterns of DNA detection, and the potential role of urine in viral dissemination during an outbreak.
Objectives: To ascertain 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.
Study design: Prospective clinical study.
Methods: During the hospitalisation of twenty-one horses involved in two EHV-1 myeloencephalopathy outbreaks in Spain in 2021 and 2023, urine, whole blood, and NS samples were collected at various intervals. Viral DNA load was compared in BC-urine samples from 2021 and NS-urine samples from 2023 by quantitative, real-time PCR.
Results: EHV-1 was detected in a total of eighteen hospitalised horses during the 2021 and 2023 outbreaks, and EHV-1 positivity was confirmed in urine samples from 11 horses across both outbreaks. Comparative analysis revealed that, in contrast to BC samples, the presence of viral DNA persisted in urine for a longer duration (up to 22 days from first fever vs. 13 days) and exhibited significantly higher concentrations in urine samples. However, in comparison to NS, the detection of EHV-1 in urine showed a lower duration and significantly lower DNA concentrations.
Main limitations: These include a restricted sample size and variations in sampling times and protocols between BC and NS samples across the two distinct natural infection outbreak scenarios.
Conclusions: Detection of EHV-1 in urine from naturally infected horses suggests that non-invasively collected urine could serve as a valuable complement to blood and NS samples in the management of infected horses during an outbreak.
Ethical animal research: Not required: performed on archive
Velloso-Alvarez A., Cunilleras EJ., Dorrego-Rodriguez A., Santiago-Llorente I., Cuesta M., Troya-Portillo L., Rivera B., de Juan L. and Cruz F..
 | Servicio de Vigilancia Sanitaria Equina (SEVISEQ). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
| Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
| Hospital Clínico Veterinario Complutense (HCVC). Universidad Complutense (UCM). |
 | Universidad CEU Cardenal Herrera (CEU-UCH). |
 | Unitat Equina. Fundació Hospital Clínic Veterinari. Universitat Autònoma de Barcelona (UAB). |
| Department Medicina i Cirurgia Animals. Facultat de Veterinària. Universitat Autònoma de Barcelona (UAB). |
