Schistosomiasis (شستوسوما – البلهارسيا)

• Cause: Blood flukes (Schistosoma mansoni, S. haematobium, S. japonicum).

• Transmission: Contact with freshwater containing cercariae that penetrate skin.

• Respiratory involvement:

  • Acute phase (Katayama syndrome): Immune reaction → fever, cough, wheezing.

  • Chronic phase: Eggs embolize to lungs → granulomas, pulmonary hypertension, cor pulmonale.

• Pathophysiology:

  1. Eggs lodge in pulmonary arterioles.

  2. Granulomatous inflammation → fibrosis.

  3. Pulmonary vascular resistance ↑ → pulmonary hypertension.

• Clinical features: Dyspnea, hemoptysis, signs of right heart strain.

• Diagnosis: Serology, stool/urine for eggs, imaging for pulmonary hypertension.

• Treatment: Praziquantel; manage pulmonary hypertension.