A risk assessment of equine piroplasmosis entry, exposure and consequences in the UK

Background Equine piroplasmosis (EP) is currently not endemic in the UK, despite a lack of formal surveillance and the presence of carrier horses in the equine population. Pathogen establishment would have significant welfare and economic impacts on the national equine industry, but the disease is often overlooked by UK practitioners. Objectives To assess the risk of disease entry, exposure and consequences to the UK equine population. Study design Qualitative risk assessment. Methods A qualitative risk assessment was constructed utilising the current World Organisation for Animal Health (OIE) published framework for importation risk assessment, assessing the key areas of disease entry, exposure and consequences to the UK equine population. Results The overall risk of EP entry to the UK via importation of infected equidae with acute disease is very low but considered medium with subclinical carrier animals. Entry via importation of ticks or the importation of blood is considered very low. The risk of EP exposure to susceptible equidae in the UK is considered low by the infection routes of tick-bites, contaminated needles and contaminated blood, but very high via transplacental transfer. However, the consequences of EP endemic establishment are considered of high significance to the UK equine industry. Main limitations A lack of available numerical data for events and variables in disease import risk meant a qualitative assessment was the most practical method for this scenario. Conclusions This risk assessment highlights that EP positive animals are able to enter and are currently present in the UK, and that conditions do exist that could allow forward transmission of the disease. It has highlighted a gap in existing policy where the UK falls behind OIE guidelines and has suggested steps to correct this discrepancy and improve national biosecurity.

Automated summary

This study conducted a qualitative risk assessment of the risk of Equine Piroplasmosis (EP) entry, exposure, and consequences to the UK equine population. The results showed that the risk of EP entry via infected equidae with acute disease is very low but medium with subclinical carrier animals. Entry through ticks or importation of blood is very low. The risk of EP exposure to susceptible equidae in the UK is low through tick bites, contaminated needles, and blood, but very high through transplacental transfer. However, the consequences of EP endemic establishment are of high significance to the UK equine industry.