Maria Wesolowska | Department of Biology and Medical Parasitology, Wroclaw Medical University
Among vector-borne pathogens with a zoonotic potential, Dirofilaria and Onchocerca play significant roles in non-endemic areas because both of them affect domestic and wild animals and occasionally infect humans. First case of human zoonotic filarial infection was reported more than 100 years ago. Zoonotic filariasis infections are transmitted by blood-sucking vectors such as among others mosquitoes, horse-flies, black flies and biting midges that carry the filariform larvae from animal hosts to people. The life cycle, animal reservoir and transmission routes in most species are poorly known. The symptoms of the disease depend on species of nematodes and site of infection, but most often the worms affect subcutaneous tissues and may induce lesions, subcutaneous nodules, and inflammation of musculature, sometimes they penetrate deeper tissues or may infect the eye in human body. Amongst mosquito-transmitted nematodes Dirofilaria repens, parasite of domestic and wild canis, plays significant roles from epidemiological point of view. Yet, five species of zoonotic Onchocerca, have been described in human: O. lupi a common parasite of dogs and cats, O. gutturosa – cattle’s parasites, O. cervicalis parasitizing in horses, O. jakutensis found in red deer and O. dewittei japonica the wild boars parasites. The number of zoonotic filariasis cases has been increasing in recent years worldwide. Up till today, there have been only 39 known reports of zoonotic onchocerciasis in human worldwide but the majority of cases (30) were reported after 2000. Most cases of onchocerciasis in recent years have been described in Europe, USA and Japan. In Poland, the occurrence of autochthonous cases of both dirofilariasis and onchocercosis has been reported recently. Such factors as globalization, including immigration and travel and climate change which effect vector spread into new regions and environmental modification can lead to increased distribution of zoonotic filariasis.
Host: Olga Matos
