Lung disease induced by parasites

Parasitic pulmonary diseases are mainly present in developing countries. However, their importance is growing worldwide because of their association with AIDS and other states of immunosuppression, human migration, and worldwide travel. This review discusses the parasites that most commonly appear in clinical practice in both normal and immunosuppressed hosts. Toxoplasmosis and strongyloidiasis can induce respiratory failure especially in immunosuppressed patients. Lung involvement because of Plasmodium falciparum develops in 3% to 18% of infected patients and can lead to death if untreated. The presence of severe pulmonary hypertension in patients of endemic regions indicates the possibility of the diagnosis of pulmonary schistosomiasis. Patients with pulmonary amebiasis should undergo further investigation to exclude the presence of amebic pericarditis, which is associated with a 30% mortality rate. The differential diagnosis of pulmonary nodules must include dirofilariasis. Small and lobulated cysts seen on a chest roentgenogram may suggest the diagnosis of pulmonary echinococcosis. The pulmonary cycle of helminthic infestation can induce patchy migratory infiltrates and eosinophilia, defined as Loffler's syndrome. Basic hygiene procedures, the avoidance of undercooked food in endemic regions of paragonimiasis, and specific antimalarial prophylaxis must always be encouraged. In conclusion, a high level of clinical suspicion leading to an early treatment of the parasitic pulmonary diseases can be associated with successful treatment and good prognosis.