(See also Approach to Parasitic Infections Approach to Parasitic Infections Human parasites are organisms that live on or in a person and derive nutrients from that person (its host). There are 3 types of parasites: Single-cell organisms (protozoa, microsporidia) Multicellular... read more and Overview of Filarial Nematode Infections Overview of Filarial Nematode Infections Threadlike adult filarial worms reside in lymphatic or subcutaneous tissues. Gravid females produce live offspring (microfilariae) that circulate in blood or migrate through tissues. When ingested... read more .)
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.