Exposure of Horses in Israel to West Nile Virus and Usutu Virus.

Gili Schvartz,Sharon Tirosh-Levy,Oran Erster,Barbara Bazanow,Hadas Levy,Amir Steinman,Boris Gelman,Roni Shenhar

doi:10.3390/v12101099

Gili Schvartz, Sharon Tirosh-Levy + Show 6 more

Open Access

https://doi.org/10.3390/v12101099

Copy DOI

Abstract

West Nile virus (WNV) and Usutu virus (USUV) are arboviruses transmitted by mosquito vectors. Whereas WNV is endemic in Israel, the Middle East, Europe, and in the Americas, data regarding the prevalence of USUV in the Middle East is limited. While both viruses share similar reservoirs and vectors, exposure of horses in the area to USUV have never been assessed. The aim of this study was to estimate the seroprevalence and co-exposure of WNV and USUV in horses in Israel. A total of 327 serum samples from healthy unvaccinated horses in Israel collected in 2018 were tested for neutralizing antibodies against WNV and USUV. Seroprevalence for neutralizing antibodies against WNV and USUV was 84.1% and 10.8%, respectively. Management and age were significantly associated with WNV and USUV seropositivity. This is the first report describing exposure of horses in Israel to USUV, which indicates that this zoonotic pathogen should be included in the differential diagnosis list of neuroinvasive disease in this country.

Highlights

West Nile virus (WNV) is an ssRNA virus of the Flaviviridae family, Flavivirus genus and is the causative agent of West Nile fever (WNF)
Sampling of horses in 2018 followed summer outbreak of WNV in that year that was accompanied by increased morbidity and mortality in wild avian species in Israel [23]
Similar to 2015 [21], horses kept in pasture had lower seroprevalence of WNV than horses kept in stalls or paddocks, indicating relatively lower exposure in pasture horses, possibly due to relatively lower density of the vector in dry and well ventilated locations

Summary

Introduction

West Nile virus (WNV) is an ssRNA virus of the Flaviviridae family, Flavivirus genus and is the causative agent of West Nile fever (WNF). The virus is a mosquito-transmitted pathogen affecting various species of birds, as well as horses and humans [1,2,3]. While migratory and domestic avian species serve as natural virus reservoir, humans and horses are considered dead-end hosts [1,3,4]. WNV infection in mammals is mostly subclinical and, in some cases, may either cause flu-like symptoms, such as fever, headache (in humans) and malaise, or neuroinvasive disease that may manifest in meningoencephalitis or flaccid paralysis. Severe neuroinvasive disease in both horses and humans may lead to death and, in humans, affect mostly elderly peoples and immunocompromised individuals [1,6]. WNV is currently recognized as one of the most widespread arboviruses [7,9]

Objectives

Methods

Results

Conclusion