Exposure to West Nile Virus in Wild Lagomorphs in Spanish Mediterranean Ecosystems

Background

West Nile virus (WNV) is the most widely distributed mosquito-borne flavivirus. Over the past decade, its spread across Europe has raised significant concerns for both public and animal health. Although WNV exposure has been evidenced in various wild mammal species in Spain, no seroepidemiological studies have been conducted on this flavivirus in wild lagomorphs so far.

Aim

This study aimed to assess WNV exposure in European wild rabbit (Oryctolagus cuniculus) and Iberian hare (Lepus granatensis) populations inhabiting Spanish Mediterranean ecosystems.

Methods

Sera from 540 wild lagomorphs (399 European wild rabbit and 141 Iberian hares), from 106 hunting grounds distributed throughout Andalusia (southern Spain), were collected between the 2018/2019 and 2022/2023 hunting seasons.

Results

Antibodies against flavivirus were detected by blocking enzyme-linked immunosorbent assay (bELISA) in 5.0% (27/540; 95% CI: 3.2–6.8) of the wild lagomorphs. Exposure to WNV was confirmed in 4.8% (19/394; 95% CI: 2.7–6.9) of wild rabbits and 0.7% (1/141; 95% CI: 0.0–2.1) of Iberian hares by virus microneutralisation test. Anti-WNV antibodies were found in wild lagomorphs sampled from three (2.8%) hunting grounds located in western Andalusia during the seasons 2020–2021 and 2021–2022. Remarkably, this spatiotemporal distribution overlaps with the largest outbreak of WNV in Spain. Antibodies against Usutu virus and Bagaza virus were not detected in the wild lagomorph populations analysed.

Conclusions

This study constitutes the first report of WNV exposure in wild rabbit in Spain and in Iberian hare worldwide. While these species seem not play a primary role in the epidemiology of the virus, they could serve as sentinel for monitoring WNV in Iberian Mediterranean ecosystems.