A review of equid herpesvirus 1 for the veterinary practitioner. Part B: pathogenesis and epidemiology.

Equid herpesvirus (EHV) type 1 is a significant infectious disease affecting horses globally, leading to various serious health issues such as abortion, neonatal death or neurological disease. This review provides an update on recent research into its pathogenesis and its distribution, particularly within Australasia.

Pathogenesis and Epidemiology

• The review primarily focuses on the ‘pathogenesis’ and ‘epidemiology’ of Equid herpesvirus 1. Pathogenesis of an infection refers to the development of a disease, understanding its origins, its progression and the factors that influence its manifestation.
• For EHV-1, pathogenesis also covers how the virus infects the horse and how it leads to various health outcomes, some of which are severe like abortion, neonatal death, or neurological disease. The study aims to help the readers understand how the disease develops and operates in affected equines.
• Epidemiology, on the other hand, studies how diseases are distributed among populations and the factors that determine their occurrence. It is heavily focused on the spread and containment of diseases. The review provides crucial updates on EHV-1’s spread and its implications on equine health, particularly emphasizing data from Australasia.

Key findings and facts

• The study’s authors highlight a concerning trend; the number of reported cases of EHV-1 neurological disease has seen an increase in the United States and Europe over the past decade. While the analysis primarily focuses on Australasian data, these increases are of global concern and signal the need for worldwide attention and further research in the area.
• Despite the gained insight into EHV-1 pathogenesis and epidemiology, research has not fully explained all aspects of this virus. In particular, the review points out that there is still much to learn about the pathogenesis and epidemiology of the Equine Herpesvirus Myeloencephalopathy, a severe form of EHV-1 that affects the neurological system of horses.
• As such, understanding EHV-1 and its associated diseases remains an active and crucial area of research worldwide. The identification and refining of preventative measures and possible treatment options for this virus would provide significant benefits for animal health, especially in regions where horses play an integral role in the economy or society.