Eastern equine encephalitis virus: high seroprevalence in horses from Southern Quebec, Canada, 2012.

The research article focuses on understanding the prevalence of Eastern equine encephalitis virus (EEEV) in horses in southern Quebec, Canada. The study finds a remarkably high prevalence of the virus, despite a widespread perception of its high lethality.

Objective of the Study

• The research is aimed at conducting a cross-sectional study to evaluate the viral activity of the Eastern equine encephalitis virus (EEEV) in horses in southern Quebec by estimating its seroprevalence.

Study Design and Methodology

• The study analysed the blood samples from 196 horses that were 18 months and older. These horses had never been vaccinated against EEEV and have never traveled outside Canada.
• The horses were from 92 barns distributed throughout three administrative regions of southern Quebec.
• The prevalence of EEEV antibodies in these horses was identified using a plaque reduction neutralization test (PRNT).
• In addition, the study conducted surveys among horse owners and equine practitioners to estimate the coverage of the equine population vaccination.

Findings of the Study

• The study found an up to 8.7% EEEV seroprevalence, with 95% confidence limits ranging from 4.4% to 13.0%.
• The vaccination coverage in the horse population was estimated to be at least 79%.

Implications of the Findings

• This study provides the first-time measure of EEEV seroprevalence in horses in Canada.
• The high prevalence of the virus in unvaccinated animals challenges the common perception that EEEV is a highly lethal pathogen in horses.
• The findings highlight the importance of monitoring high-risk vector-borne infections such as EEEV in animal populations, as this can be an integral part of a public health surveillance strategy, population risk assessment, and early detection of epidemics.