Abdominal Ultrasound: Schistosomiasis

Ultrasound is the principal imaging tool for chronic schistosomiasis, grading hepatic periportal fibrosis in S. mansoni/japonicum infection and detecting urinary-tract disease in S. haematobium. Standardised assessment follows the WHO Niamey protocol, which allows reproducible grading and community-level monitoring in endemic regions. It is safe, portable and repeatable, guiding praziquantel treatment and surveillance of portal-hypertensive and urological complications.

Indications

Screening in endemic communities and known or treated schistosomiasis
Hepatosplenomegaly or signs of portal hypertension (variceal bleeding, ascites)
Terminal haematuria, dysuria or suspected urinary S. haematobium disease
Evaluation of hydronephrosis and bladder pathology in urinary schistosomiasis
Assessment before and after praziquantel therapy to monitor regression or progression
Investigation of unexplained portal hypertension in a patient from an endemic area

Contraindications & Cautions

No contraindications; ultrasound is safe, non-ionising and repeatable
Safe in pregnancy and children
Bowel gas, obesity and operator dependence may limit periportal and retroperitoneal assessment
Grading requires standardised technique and trained operators for reproducibility

Patient Preparation

Fasting 4-6 hours reduces bowel gas and improves liver and portal visualisation
A moderately full bladder is needed to assess bladder wall thickness and masses for urinary disease
Supine and decubitus positioning; deep inspiration to display the liver and spleen
Explain the examination and obtain verbal consent
Record geographic exposure, species where known, and prior treatment history

Technique & Parameters

Curvilinear transducer 3-5 MHz; use the WHO Niamey protocol for standardised liver assessment
Grade periportal fibrosis by peripheral portal branch wall thickness/echogenic cuffing (image patterns A-F, network/pipe-stem)
Measure liver (including left lobe/caudate) and spleen dimensions and describe surface and parenchyma
Portal vein diameter and Doppler flow direction/velocity; assess for collaterals and ascites in portal hypertension
For urinary disease: measure bladder wall thickness (abnormal >5 mm at adequate filling), look for masses, calcification and pseudopolyps
Assess both kidneys and ureters for hydronephrosis and hydroureter

Systematic Review

Liver: size, echogenicity, periportal cuffing pattern and Niamey grade
Portal system: portal vein diameter, flow direction, collaterals and thrombosis
Spleen: size and any secondary changes of portal hypertension
Peritoneum: free fluid/ascites and gallbladder wall changes
Bladder: wall thickness, calcification, masses, pseudopolyps and residual volume
Upper tracts: hydronephrosis, hydroureter, ureteric wall thickening and calcification
Overall correlation of hepatic and urinary findings with species and exposure

Key Findings & Significance

Periportal (pipe-stem) fibrosis: echogenic bands/cuffs along portal tracts, graded 0-3 (WHO Niamey) - hallmark of hepatic S. mansoni
Portal hypertension: portal vein dilatation, splenomegaly, collaterals and ascites with a normal-sized or shrunken right lobe and left-lobe/caudate hypertrophy
Splenomegaly out of proportion to hepatocellular dysfunction (presinusoidal hypertension)
Bladder wall thickening >5 mm, focal masses, pseudopolyps and mural calcification in S. haematobium
Hydronephrosis and hydroureter from ureteric involvement and obstruction
Regression of early fibrosis and bladder changes after praziquantel; established fibrosis may persist

Differential Considerations

Periportal echogenicity: schistosomal fibrosis versus congenital hepatic fibrosis, cholangitis, portal tract oedema
Presinusoidal portal hypertension: schistosomiasis versus portal vein thrombosis, congenital hepatic fibrosis, non-cirrhotic portal fibrosis
Massive splenomegaly: schistosomiasis, chronic malaria, visceral leishmaniasis, haematological disease
Thick-walled bladder: schistosomiasis, chronic cystitis, neurogenic bladder, outlet obstruction, tumour
Bladder calcification: S. haematobium versus tuberculosis or prior therapy
Hydronephrosis: schistosomal ureteric disease, calculus, tuberculosis, malignancy

Pearls & Pitfalls

Preserved hepatocellular function with marked portal hypertension is characteristic - it is presinusoidal, not cirrhotic
Use the WHO Niamey image patterns for reproducible grading and follow-up
S. haematobium bladder disease is a recognised risk factor for squamous cell carcinoma - flag suspicious focal masses
Assess the bladder only when adequately filled; an empty bladder overestimates wall thickness
Coexisting infections (malaria, viral hepatitis, HIV, TB) can confound the hepatic and splenic picture
Established pipe-stem fibrosis may not regress after treatment, whereas early disease and bladder lesions often do

Structured Report

State species/exposure context and whether the WHO Niamey protocol was applied
Report liver size, periportal fibrosis pattern and grade
Describe portal vein calibre, flow, collaterals, spleen size and ascites
For urinary disease, report bladder wall thickness, calcification, masses and upper-tract dilatation
Flag any suspicious bladder mass warranting cystoscopy/biopsy
Impression: summarise disease grade and complications, correlate with clinical and lab data, and recommend praziquantel and follow-up ultrasound

References

WHO/TDR Niamey-Belgium Protocol: Ultrasound in Schistosomiasis (Richter J et al.)
WHO Guideline on control and elimination of human schistosomiasis
WHO Manual of Diagnostic Ultrasound
RadioGraphics: Imaging of Schistosomiasis

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

Abdominal Ultrasound: Schistosomiasis

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References