Schistosomiasis Haematobia

S. haematobium discovered by Bilhartz 1851 Cairo; disease named Bilharziasis after him. Endemic Africa (thousands of years in mummies). Adult worms in bladder/pelvic venous plexus → urogenital disease: terminal hematuria, bladder irritation/obstruction.

Common Symptoms

Urinary frequency; retrograde bacterial infection; diarrhea; abdominal pain; urinary tract obstruction; fatigue; dysuria

Causes and Pathogenesis

Male 10-15 × 0.8-1.0 µm, microtuberculate, oral/ventral suckers, gynecophoral canal, 4-5 testes; female 20 × 0.25 mm, uterus 20-100 eggs, 500-3000 eggs/day. Mature eggs pale brown, transparent shell, terminal spine; miracidium. Intermediate snail: Bulinus (Africa), Ferrisia tenuis (Bombay), Planorbarius metidjensis (Portugal/Morocco). Cercariae: 5 pairs penetration glands, free-swimming up to 3 days (usually <24 h). Skin penetration → skin veins → right heart → lungs → liver → portal venous maturation (~20 days) → paired worms migrate against flow to inferior mesenteric/vesical/pelvic plexus; 10-12 weeks from penetration to oviposition. Pathology: egg granulomas (adults rarely cause disease); eggs deposit in bladder/distal ureter submucosa/muscle, especially trigone; bladder neck fibrosis/achalasia; diverticula; mucosal polyps; irreversible fibrosis/calcification; hydronephrosis; secondary bacterial infection; renal failure. Genital: prostate/glans penis; cervix/vagina/labia. Ectopic: appendix/cecum/colon/rectum (fecal eggs); liver (pseudotubercles/periportal fibrosis). Lung: eggs via bladder veins/IVC → pulmonary arterial embolization → necrotizing endarteritis → pulmonary hypertension; angiogenic dilatation; no hypoxia/cyanosis (obstruction pre-capillary).

Treatment

Drug therapy, supportive therapy

Preventive Measures

(1) Mollusciding: water projects + molluscicides; repeat. (2) Mass treatment: praziquantel 40 mg/kg single oral dose; prevents re-infection is issue. (3) Sanitation/fecal management/safe water—costly.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.