The Clinical case of human subcutaneous dirofilaria repens infection in Lithuania

Abstract

Background: D. repens is filarial nematode commonly found in the subcutaneous tissue of dogs and other canids where they survive for the long period of time. Infection is transmitted by Culex, Aedes, and Anopheles mosquitoes. Zoonotic D. repens infection is prevalent in several regions of the world and is considered emerging zoonosis in Africa, Asia and Europe. Observation: We report on a 55 years old female patient who was referred to oncologist due to firm painful nodule on her right temple and two nodules on the left side of her trunk. The primary clinical diagnosis of Neurinoma and Lipofibroma was made and surgical excision of nodules was performed. Based on histologic examination an infection with Dirofilaria repens was confirmed. The patient was referred to Clinic of Infectious Diseases where a new firm nodule in the pelvic wall was diagnosed. From epidemiological history we found that patient visited Turkey 3 months ago where she had mosquito bites. Laboratory findings showed elevated levels of anti-toxocara IgG - 2,29 IU/m and IgE - 1930 IU/m. As no registered ivermectin is available for humans in Lithuania, the anthelmintic treatment with Albendazole 400 mg twice daily for five consecutive days was initiated. Subsequently antifilarial treatment with the single dose of Ivermectin 15 mg was prescribed. After ivermectin treatment new subcutaneous nodules has appeared and therefore surgical node removal was performed. After the treatment anti-toxocara IgG became negative and no new nodules were found. Key message: Dirofilariasis is a rare disease in Lithuania which could be mistakenly diagnosed as the subcutaneous tumor. Histological and molecular tests confirm the diagnosis. Surgical node removal is the main treatment option.