Zoonotic Onchocerca lupi Infection in Dogs, Greece and Portugal, 2011–2012

Domenico Otranto

, Filipe Dantas-Torres, Alessio Giannelli, Maria Stefania Latrofa, Elias Papadopoulos, Luís Cardoso, and Helder Cortes

Author affiliations: Università degli Studi di Bari, Valenzano, Italy (D. Otranto, F. Dantas-Torres, A. Giannelli, M.S. Latrofa); Aggeu Magalhães Research Institute, Recife, Brazil (F. Dantas-Torres); Faculty of Veterinary Medicine, Thessaloniki, Greece (E. Papadopoulos); University of Trás-os-Montes e Alto Douro, Vila Real, Portugal (L. Cardoso); Institute for Molecular and Cell Biology, Oporto, Portugal (L. Cardoso); University of Évora, Evora, Portugal (H. Cortes)

Abstract

Onchocerca lupi infection is reported primarily in symptomatic dogs. We aimed to determine the infection in dogs from areas of Greece and Portugal with reported cases. Of 107 dogs, 9 (8%) were skin snip–positive for the parasite. DNA sequences of parasites in specimens from distinct dog populations differed genetically from thoses in GenBank.

Zoonotic onchocercosis has been attributed to species that primarily infest cattle (Onchocerca gutturosa), horses (O. cervicalis), the European deer (O. jakutensis), and wild boars (O. dewittei japonica) (1). In their definitive hosts, all these species localize in subcutaneous tissues, muscular fasciae, or cervical ligaments, whereas in humans, O. gutturosa and O. cervicalis also have an ocular localization (reviewed in 2).
O. lupi is a recently recognized parasite causing nodular lesions associated with ocular disease (i.e., conjunctivitis, ocular swelling, photophobia, lacrimation, discharge, exophthalmia) in dogs (3). The zoonotic potential of this filarioid has been suspected (4) but has only recently been demonstrated in a patient from Turkey (5). Ocular cases in humans are increasingly being reported worldwide, including in Iran (6), Turkey, and Tunisia (7). In addition, O. lupi infection was recently diagnosed near the spinal canal in a 22-month-old child from Arizona, USA (2).