Pulmonary Schistosomiasis in the Philippines

¹ Manila, Philippines

This report documents the authors' experience with pulmonary schistosomiasis due to Schistosoma japonicum. Ten cases are the subjects of this report consisting of five children and five adult Filipinos. In order to reach the lungs, the ova bypass the liver taking a direct course to the heart through porto-caval anastomoses created as a result of chronic portal hypertension. It appears that the initial pulmonary lesions are vascular, the ova embolized within the pulmonary arterioles. A later stage is the parenchymal, the ova migrating through the vessel wall as a consequence of toxic substances secreted by the ova which produce the characteristic necrosis. The healing of the vasculitis finalizes the completion of the luminal obliteration. The terminal stage, therefore, is one of pulmonary hypertension, a cardiovascular stage that eventually leads to cor pulmonale. Death is inescapable and is often due to congestive heart failure. Pulmonary schistosomiasis, or for that matter, the stage of embolization, is incurable.