Human pulmonary dirofilariasis: a case report and review of the recent Japanese literature.

Human pulmonary dirofilariasis is a rare zoonotic infection caused by the dog heartworm Dirofilaria immitis, which is transmitted via a vector/intermediate host, generally the mosquito. The authors present a case of histologically diagnosed human pulmonary dirofilariasis, in which the lesion was resected using video-assisted thoracic surgery (VATS). The authors also review 24 cases of such zoonosis reported in Japan from 1998 to 2004. Of these 24 patients with human pulmonary dirofilariasis, 12 (50%) were men (mean age 54 years, range 29-80 years) and 67% were asymptomatic. Most patients (83%) had a solitary lung nodule, 95% of the lesions were <30 mm and 13% had a pleural effusion. VATS was performed to obtain a histopathological diagnosis in the majority (61%) of patients whom the authors reviewed. VATS would appear to be the best method for diagnosing pulmonary dirofilariasis.