Detection of West Nile Virus and other common equine viruses in three locations from the Leeward Islands, West Indies.

This study investigated the prevalence of several major equine infectious diseases in horses and donkeys in the Leeward Islands, West Indies. The results revealed the presence of antibodies against West Nile Virus, Equine Herpes Virus, and Equine Influenza, underscoring the need for better surveillance plans.

Objective of the Study

• The main aim of this research was to examine the prevalence of antibodies for West Nile Virus (WNV), Equine Herpes Virus-1 and 4 (EHV-1 and EHV-4), Equine Influenza (EI), Equine Viral Arteritis (EVA), and Equine Infectious Anemia Virus (EIAV) in the Caribbean basin, specifically in the Leeward Islands, West Indies.

Methodology

• The researchers conducted a retrospective serological convenience study using 180 equine serum samples.
• These samples were collected from 140 horses and 40 donkeys in St. Kitts, Nevis, and Sint Eustatius between 2006 and 2015.
• Tests were performed using ELISA kits and virus neutralization tests (for WNV and EVA).

Findings

• Of the studied samples, 13.8% were found to be positive for West Nile Virus. A further 1.6% of the samples showed doubtful results.
• The study found antibodies to Equine Herpes Virus-1 in 23.7% of the equines and to Equine Herpes Virus-4 in a whopping 82.8% of the subjects. The mean ages of these animals were 6.7 and 6.3 years, respectively.
• Antibodies against Equine Influenza were found in 27.2% of the equines, with a mean age of 7.5 years. Some of these had been previously vaccinated horses.
• No antibodies against Equine Viral Arteritis (EVA) were detected. However, one animal tested positive for EVA on the ELISA test.
• All the samples were negative for Equine Infectious Anemia Virus.
• The seroprevalence for EHV-1 and EHV-4 is comparable to that in other parts of the world.

Study Significance

• These findings are important as this is the first time that serologic evidence of antibodies against WNV and EI has been reported in this location.
• The results indicate that both native and imported animals are exposed to these equine diseases, emphasizing the need for better surveillance plans to detect these viruses.
• The authors recommend further studies to help define the prevalence, rates of transmission, characterize local virus strains, and study the impact of these diseases on equine populations in the region.