Cardiopulmonary manifestations of schistosomiasis

Three major schistosome species infect hundreds of millions of people worldwide. The majority of these infections are asymptomatic, but significant morbidity and mortality can occur as a consequence of ongoing egg deposition in host tissues. Acutely, transient chest radiographic abnormalities and nonspecific influenza-like symptoms can occur, including cough. The most common chronic pathological sequelae of schistosomiasis are those of portal hypertension with Schistosoma mansoni or S. japonicum, and genitourinary tract obstruction with S. haematobium. In less than 5% of infections, schistosomal egg obstruction of the lung vasculature results in pulmonary hypertension and cor pulmonale. Limited data suggests that cardiopulmonary schistosomiasis is seen most often in S. mansoni infections. Hepatic fibrosis and portal hypertension appear to be a prerequisite to the development of schistosomal cor pulmonale caused by this species. The premortem diagnosis of cardiopulmonary schistosomiasis depends on the detection of viable schistosomal ova in stool or urine along with evidence of characteristic hepatic fibrosis and pulmonary hypertension. Although treatment with praziquantel can effectively eradicate all schistosomal infections with minimal toxicity, cardiopulmonary manifestations are not likely to be reversible given the chronic fibrotic tissue changes that are present.