Avian mite dermatitis: an Italian case indicating the establishment and spread of Ornithonyssus bursa (Acari: Gamasida: Macronyssidae) (Berlese, 1888) in Europe

Background: Avian mite dermatitis is a skin disease caused in mammals by the incidental bites of blood-sucking mites which customarily parasitize wild and domestic birds. It manifests in the form of pruritic, erythematous, or urticarial papules, with a central sting mark, in skin regions normally covered by clothing. The species mainly implicated in human bite cases are Dermanyssus gallinae, Ornithonyssus sylviarum and, less frequently, Ornithonyssus bursa. The latter is mainly a tropical and subtropical mite and its – presumably transitory – presence has been recorded only once in Europe, in migratory birds. Case report: We report a case of avian mite dermatitis in a 70-year-old man, an owner of chickens, who lived in Sicily, an island in southern Italy. He presented with an itching, erythematous, papular eruption. Numerous mites were seen racing across his skin. The precise identification of O. bursa was based on the morphology of its plates and chelicerae and on the arrangement of its setae. Conclusions: Not only does this paper report the first European case of human infestation with O. bursa, it provides evidence that this alien species has settled and spread in the Old Continent. It may have been flown in from a small focus reported in Danish migratory birds in the 1980s or may have been accidentally introduced into Italy through the importation of infested poultry from South America. Such occurrences may have unpredictable epidemiological and ecological consequences. More comprehensive veterinary inspection of imported birds is desirable