Eye to eye with Thelazia-infected canids in Central European forests

TL;DR

The study found the eyeworm Thelazia callipaeda in red foxes and golden jackals in Hungary, suggesting a link between beech forests and infection spread.

Contribution

The study provides the first comprehensive surveillance of Thelazia callipaeda in wild carnivores in the Carpathian Basin.

Findings

Thelazia callipaeda was found in red foxes and golden jackals in southwestern Hungary.

Mustelids tested negative for the parasite.

Beech forests were associated with increased infection risk.

Abstract

The oriental eyeworm Thelazia callipaeda has been present in Europe since the late 1980s. Its occurrence in the Carpathian Basin has been known since 2014. Despite the central position of Hungary in the radial expansion of T. callipaeda in Central and Eastern Europe, no comprehensive surveillance has been conducted to date to determine the reservoir role of wild carnivores within the Carpathian Basin. The study involved the analysis of samples from 180 red foxes (Vulpes vulpes), 119 European badgers (Meles meles), 62 golden jackals (Canis aureus), and 10 stone martens (Martes foina) harvested in the framework of an authorised wildlife management programme. Among the mustelids (family Mustelidae), no infected individuals were found. In the red fox, prevalence and mean intensity were 12.2% (95% CI: 8.0–18.0%) and 2.6 (95% CI: 1.7–4.9), respectively; while in the golden jackal, these values were 9.7% (95% CI: 4.3–20.0%) and 3.0 (95% CI: 1.5–6.5), respectively. The difference in prevalence and mean intensity of infection between the two hosts proved non-significant. The generalised linear models suggested that the presence of hygrophilous beech (Fagus sylvatica) forests positively influenced the occurrence of infection in wild carnivores. Although the receiver operating characteristic (ROC) curve analysis showed only a modest discriminatory power for the models, these findings highlighted the potential of humidity in the spread of T. callipaeda in the Carpathian Basin.

Image 1

•Thelazia callipaeda was recorded in wild carnivores in southwestern Hungary.•Infection was confirmed in red foxes (Vulpes vulpes) and golden jackals (Canis aureus).•All examined mustelids (family Mustelidae) tested negative for the parasite.•Prevalence values were comparable to those reported in neighbouring Croatia.•A possible association was observed between beech forests and infection risk.

Thelazia callipaeda was recorded in wild carnivores in southwestern Hungary.

Infection was confirmed in red foxes (Vulpes vulpes) and golden jackals (Canis aureus).

All examined mustelids (family Mustelidae) tested negative for the parasite.

Prevalence values were comparable to those reported in neighbouring Croatia.

A possible association was observed between beech forests and infection risk.

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