(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 Filarioidea are a superfamily of threadlike, parasitic worms, with numerous families, genus, and species. Their definitive hosts are vertebrates, but only a few filarial species infect humans... 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.