ORF virus infection in a hunter in Western Austria, presumably transmitted by game

Abstract

A variety of animals host parapoxviruses. Orf virus is prevalent in sheep and goats in the Tyrol region of Austria and Northern Italy. Zoonotic infections in humans mostly occur after occupational exposure. We report here a case of a hunter with a typical Orf lesion (contagious ecthyma) on the finger, with no history of direct contact with domestic animals. Three weeks previously he had been hunting chamois (Rupicapra rupicapra) and cut his finger while handling a carcass. Parapoxvirus infection was confirmed by electron microscopy and PCR, and the species was identified by DNA sequencing. The sequence was highly homologous with prevalent sheep Orf virus and rather distant from parapoxviruses found in red deer in Northern Italy. As this case indicated that the infection was acquired via game, we performed spot testing in the suspected area and detected several seropositive animals. This is a strong indication that Orf virus has been introduced into chamois in Western Austria. This probably occurred via roaming domestic sheep sharing the high alpine areas during the summer months.