questions 0

Schistosomiasis

Author:
Topic updated on 08/13/17 12:52pm

Snapshot
  • A 28-year-old female presents to the hospital with a three-week history of pain in the left lumbar region and an episode of hematuria the day prior. She is a recent immgrant from a refugee camp in Somalia. Gynecological history was unremarkable. No tenderness or organomegaly could be detected on physical exam. Complete blood count was remarkable for eosinophilia of 750 cells/mm^3. Sonogram of abdomen reveals a thickened bladder wall. CT scan of the abdomen and pelvis revealed widespread calcifications of bladder and ureters. Sediment examination of a random urine specimen showed 15 RBCs/hpf and Schistosoma haematobium ova.
Introduction
  • Parasitic infection caused by trematodes (blood flukes)
    • genus Schistosoma
    • causitive organisms
      • S. mansoni (intestinal schistosomiasis)
      • S. haematobium (urinary schistosomiasis)
      • S. japonicum (Asian intestinal schistosomiasis)
    • most common cause of pulmonary HTN worldwide
    • snails are the intermediary agent between mammalian hosts
  • Epidemiology
    • incidence
      • 85% of those living in Africa
      • approximately 200,000 deaths annually
      • globally a major cause of morbidity and mortality
    • location
      • Asia
      • Africa
      • South America
      • waters containing freshwater snails
    • risk factors
      • washing clothes in contaminated water with infected snails
      • tourism to endemic areas
    • transmission  
      • penetration of human skin 
        • usually in contaminated fresh waters
      • migration to lungs
      • migration to portal vein
      • migration to venules of mesentery, bladder, or ureters 
  • Pathophysiology
    • immunologic reaction to the Schistosoma eggs trapped in tissue
    • granulomatous reaction ensues
    • collagen deposition and fibrosis (latter stages of disease)
  • Associated conditions
    • bladder cancer 
Presentation
  • Presentation
    • fever
    • diarrhea
    • abdominal pain
    • cough
    • liver fibrosis
    • urinary tract granulomas
    • dysuria
  • Physical exam
    • palpation
      • hepatosplenomegaly
    • vascular
      • portal HTN
Evaluation
  • Labs
    • eosinophilia
  • Diagnosis
    • demonstration of eggs in urine or feces 
    • parasitic antigens via ELISA
Differential
  • Broad and symptom based
    • acute febrile illness
    • eosinophilia
    • hematuria
    • abdominal symptoms
Treatment
  • Supportive care
    • stabilize patients that have acute complications
  • Pharmacologic
    • praziquantel
      • indications
        • any diagnosed schistosomiasis infection
      • outcomes
        • 65-90% cure rates
      • side effects
        • dizziness
        • headache
        • nausea/vomiting/diarrhea
        • abdominal discomfort
        • bloody stool
        • fever
  • Operative
    • tumor removals
    • ligation of esophageal varices
    • porta-caval shunt surgeries
Prognosis, Prevention, and Complications
  • Prognosis
    • good if treated early
  • Prevention
    • effective water sanitation programs
    • mass treatment of affected populace
    • no vaccines available
  • Complications
    • due to chronic disease
      • pulmonary hypertension
      • bladder cancer
      • portal HTN


  RATE CONTENT
4.0
AVERAGE 4.0 of 2 RATINGS

Qbank (0 Questions)



Evidence & References Show References




Topic Comments

Subscribe status: