Cutaneous and pulmonal habronemosis transmitted by Musca domestica in a stable in the United Arab Emirates

Nematode larvae found in histological cuts of lung tissue of a horse from a farm in Al Dhaid (UAE) were determined to belong to the Habronematidae family. The clinical examination of the other 18 horses present in the farm revealed summer sores (cutaneous habronemosis) in two stallions. Nematode larvae were found in 147 (=26.2%) out of 561 male but only in 64 (=8.7%) out of 739 female Musca domestica caught at the farm in November and December 2008. Conversely, all 15 Stomoxys calcitrans specimens caught in the farm resulted negative for nematode larvae. The housefly population caught in the barn showed a prevalence of 20.9% with nematode larvae, while flies trapped outside the building on the territory of the farm had a much lower prevalence of 1.1%. The intensity of infection varied between one and 29 larvae per head. Larvae retrieved at the fly dissection were subjected to a ribosomal DNA-targeting semi-nested PCR protocol able to discriminate among the three nematode species Habronema muscae, Habronema microstoma, and Draschia megastoma. The larvae were identified to be H. muscae.