What is the recommended treatment for schistosomiasis?

Treatment of Schistosomiasis

Praziquantel is the drug of choice for all forms of schistosomiasis, with dosing of 40 mg/kg orally as a single dose for S. mansoni, S. haematobium, S. intercalatum, and S. guineensis, or 60 mg/kg orally divided into two doses for S. japonicum and S. mekongi. 1

Standard Treatment Regimens by Species

For Most Schistosoma Species

• Administer praziquantel 40 mg/kg orally as a single dose for S. mansoni, S. haematobium, S. intercalatum, and S. guineensis infections 1, 2
• This regimen provides approximately 76% protection rate across these species, with no significant differences in efficacy between S. haematobium, S. japonicum, or S. mansoni 3

For Asian Schistosoma Species

• Use praziquantel 60 mg/kg orally divided into two doses for S. japonicum and S. mekongi infections 1
• This higher dosing is specifically required for infections from the Asia-Pacific region 1, 2

Acute Schistosomiasis (Katayama Syndrome)

For acute schistosomiasis presenting 2-8 weeks after freshwater exposure, initiate corticosteroids first, followed by praziquantel after the acute inflammatory phase subsides. 1

Treatment Protocol

• Give prednisolone 20-30 mg daily for 5 days to reduce symptom duration and severity 1
• Administer praziquantel 40 mg/kg as a single dose after completing corticosteroids 1
• Repeat praziquantel treatment at 6-8 weeks because eggs and immature schistosomulae are relatively resistant to initial treatment 4, 1

Critical Pitfall to Avoid

• Never give praziquantel during the acute inflammatory phase without corticosteroids, as this may worsen symptoms 1
• Always exclude strongyloidiasis co-infection before starting corticosteroids to prevent hyperinfection syndrome 1
• Avoid dexamethasone if possible, as it increases praziquantel metabolism and reduces drug levels 1

Neuroschistosomiasis

For CNS involvement, use prolonged high-dose praziquantel combined with corticosteroids. 1

• Administer praziquantel 40 mg/kg twice daily for 5 days 1
• Combine with dexamethasone 4 mg four times daily, tapering after 7 days, for a total duration of 2-6 weeks 1
• In acute neuroschistosomiasis, give corticosteroids first before starting anthelmintic therapy 1

Treatment Failure or Recurrence

If parasitological failure occurs, repeat praziquantel 40 mg/kg at 6-8 weeks after initial treatment. 2

Management Approach

• The 6-8 week interval allows maturation of any surviving immature parasites, making them susceptible to treatment 2
• Confirm active infection through microscopy of stool or terminal urine samples before retreatment 2
• Higher protection rates (up to 91%) can be achieved by elevating doses to 60-80 mg/kg divided into multiple doses 3

Evidence for Combination Therapy

• Praziquantel combined with artemisinin derivatives (artemether or artesunate) achieves higher protection rates of 84% for treatment compared to praziquantel monotherapy 3
• This combination approach is particularly suitable for patients with repeated exposure to infected water 3

Monitoring and Follow-up

Do not use serology to assess treatment success, as antibodies persist for years after cure. 1, 5, 2

• Confirm cure through microscopy demonstrating absence of eggs in stool or urine 2
• Monitor patients with hepatic fibrosis for development of kidney disease 5
• Evaluate patients with persistent hematuria or elevated creatinine for bladder cancer or urinary obstruction, which are common complications of S. haematobium 5

Special Populations

Pregnancy and Lactation

• Refer to specialized guidelines for dosing adjustments 4

Immunocompromised Patients

• Seek specialist advice for management 4
• No immunosuppressive agents are indicated in schistosomal nephropathy 5

Key Clinical Pearls

• The 40 mg/kg single-dose regimen remains the WHO-recommended standard despite reports of alternative regimens used in non-endemic settings 1, 6
• Praziquantel has high efficacy, excellent tolerability, few transient side effects, and competitive cost, making it virtually the only drug of choice 3, 7
• Multiple doses and elevated dosing improve efficacy but should be reserved for treatment failures or specific species 3
• Always adjust dosage based on Schistosoma species to prevent treatment failure 1