Symptomatic human dirofilariasis is very rare, but larvae may become encapsulated in infarcted lung tissue and produce well-defined pulmonary nodules; rarely, larvae form nodules in the eyes, brain, and/or testes.
Patients may have chest pain, cough, and occasionally hemoptysis. Many patients remain asymptomatic, and a pulmonary nodule, which may suggest a tumor, is discovered during routine chest x-ray.
Dirofilariasis is diagnosed by histologic examination of a surgical specimen.
No anthelmintic treatment is indicated in humans; infection is self-limited.