Zoonotic Thelazia callipaeda eyeworm in brown bears (Ursus arctos): a new host record in Europe.

Thelazia callipaeda (Spirurida, Thelaziidae) eyeworm, a zoonotic parasite transmitted by lachryphagus drosophilids, causes subclinical to clinical ocular disease in a wide range of animal species, including humans. In the past 20 years, the infection spread where the vector thrives, being endemic in many European countries. Recently, the infestation has been reported also in the United States. Here, we describe the first records of the brown bear (Ursus arctos) as a host of T. callipaeda. Eight (26.7%) out of 30 bears were found to be infested with T. callipaeda adult worms. In addition, the parasite was detected in 13 wolves (Canis lupus) sharing the same environment with the brown bears. At the molecular characterization all nematodes belonged to the haplotype 1, which is the only one recorded in Europe, as yet. This finding demonstrates that brown bears may act as hosts for this parasite suggesting its potential role in the maintenance of the cycle not only in the wild, but also in captivity. Under the above circumstances, brown bears may represent potential zoonotic risks for humans both in rural and in urban areas where other reservoirs may be infected. This article is protected by copyright. All rights reserved.