Dirofilariasis, Man

Synonyms

Zoonotic filariasis.

Pathology

Dirofilariasis is an infection of dogs, raccoons, bears, etc., caused by Dirofilaria immitis . It is occasionally transmitted by mosquitoes to humans. The young adult worms wander to the right heart and are usually propelled into a pulmonary artery branch, which they thrombus (Pathology, Fig. 28B) giving rise to a localized pulmonary infarct. The worm is usually dead in the thrombus. The release of worm antigens provokes an intense hypersensitive reaction, with central necrosis accompanied by eosinophils and a granulomatous or fibrotic reaction peripherally. Some of the older lesions calcify and become visible on radiological examination of the chest.

Main Clinical Symptoms

Undifferentiated heart pain, hypertrophy of heart, ascites.

Incubation Period

3–9 months.

Prepatent Period

7–9 months.

Patent Period

6–7 years (at least in dogs).

Diagnosis

Difficult, since no microfilariae are formed in humans; serological tests.

Prophylaxis

Avoid bites of...