The Protean Manifestations of Schistosomiasis Mansoni

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Abstract
A new clinicopathologic classification for schistosomiasis mansoni is presented by correlating the predominant symptoms of the disease with the pathologic alterations in the tissues and with the life cycle of the parasite in the human host. The disease is classified as asymptomatic and symptomatic (acute and chronic). The chronic forms are gastrointestinal, obstructive vascular (intra-hepatic venous (portal hypertension) pulmonary arterial (cor pulmonale)) and granulomatous. The asymptomatic infections are detected only by finding the eggs in a routine stool examination, by positive skin test, complement fixation, or circumoval tests or by accidental findings at autopsy. Acute schistosomiasis is a hyper-immune condition with explosive onset 21-42 days after exposure. It is characterized by fever, chills, malaise, myalgias, dry cough, headache, weight loss and diarrhea. Generalized lymphadenopathy, enanthematous rectal mucosa, hepatosplenomegaly, eosinophilia and hypergammaglobulinemia are present. Liver biopsy shows eosino-philic infiltration and pseudotubercles with normal parenchyma. Gastrointestinal schistosomiasis is characterized by non specific gastrointestinal symptoms. Pathological material will reveal pseudotubercles and areas of fibrosis around the gall bladder, duodenum and intestines. The intrahepatic venous obstructive schistosomiasis is characterized by portal hypertension manifested by hepatosplenomegaly and bleeding varices. Eosinophilia, abnormal Hanger''s test, elevated BSP and hypergammaglobulinemia are frequent. Evidence of severe liver damage such as icterus, liver palms, gynecomastia, atrophic testicles, edema and ascites are not frequent. Pathologic material will reveal obstructive pseudotubercles in the portal tributaries and portal fibrosis. The pulmonary arterial obstructive picture occurs in patients with portal hypertension as the collateral circulation permits the eggs to reach the lungs. It is characterized by dyspnea, palpitation and dry cough. Accentuated or split P2, para-sternal heaving; systolic and diastolic murmurs are frequent. There is pulmonary hypertension with a dilated pulmonary artery and right ventricular hypertrophy. Pathological material reveals arteriolitis with changes in the elastica, angiomatoids, obstructive phenomena and hyalin thrombi. The granulomatous phase of the disease is localized at the site of the lesion and varies with the extent of damage. The clinical manifestations of schistosomiasis mansoni occur after ovi-position and its clinical syndromes depend upon the tissues affected, the severity of the infection and the resulting degree of damage to the tissues, and the condition of the host.