Vector-borne diseases (VBDs) are on the rise in horses globally which comprises bacterial, viral or parasitic diseases. Some of these VBDs are relevant to humans, making horses potential indicators of human infections. West Nile virus (WNV) has been increasingly detected by serological methods in horses and humans in European countries spreading further north from its endemic area in the Mediterranean basin. Slovak equine populations have been exposed to WNV as demonstrated in several studies prior 2018. Hungary, a neighbouring country of Slovakia, has experienced several outbreaks in recent years reaching the second most affected country in Europe after Italy. In line with the current WNV spreading in Europe, we performed a serological analysis of 69 horse sera obtained from five different locations in Slovakia. Serum samples were processed with the INGEZIM West Nile COMPAC ELISA kit according to the manufacturer’s procedure. The seroprevalence varied between 0–15.4 % with a mean average of 8.7 %. Our results indicate similar occurrence of WNV in horses as compared to other more endemic countries such as Spain or Italy. It is hence plausible that Slovakia is gradually becoming more exposed to WNV, and that the virus will spread even further North with increasing temperatures and bird migration. Horses are excellent hosts for WNV activity as they barely travel long distances, have a long lifespan, are cost-effective and are frequently exposed to mosquitoe bites. The findings could help authorities to reshape management policies to decrease WNV incidence and to reduce mosquito exposure to humans.
This work was financially supported by the VEGA Project No. 1/0368/21 granted by the Ministry of Education, Research, Development and Youth of the Slovak Republic.