infectious diseases
Schistosomiasis
Treatment of Schistosomiasis
Praziquantel Single-day oral treatment withpraziquantel(20 mg/kg twice a day forS. haematobium,S. mansoni, andS. intercalatum; 20 mg/kg 3 times a day forS. japonicumandS. mekongi) is recommended.Praziquantelis effective against adult schistosomes, but not developing schistosomula, which are present early in infection. Thus, for asymptomatic travelers who have had exposure in potentially contaminated fresh water, treatment is delayed for 6 to 8 weeks after the last exposure. Adverse effects ofpraziquantelare generally mild and include abdominal pain, diarrhea, headache, and dizziness. Therapeutic failures have been reported, but it is difficult to determine whether they are due to reinfection, the relative resistance of immature schistosomes, orpraziquantel-resistant adult schistosomes. If eggs are present at the time of diagnosis, follow-up examination 1 to 2 months after treatment is suggested to help confirm cure. Treatment is repeated if eggs are still present. Treatment of acute schistosomiasis (Katayama fever)is based on limited data. Corticosteroids can ameliorate severe symptoms; treatment withprednisone20 to 40 mg daily for 5 days in adults is usually effective. Once symptoms have subsided, treatment withpraziquantelis given as detailed above and repeated 4 to 6 weeks later after parasites have reached adulthood. Patients with eggs in stool or urine at the time acute or chronic schistosomiasis is diagnosed should be examined for living eggs 1 to 2 months after treatment. An experienced microscopist can distinguish viable eggs from empty shells based on the presence of living miracidium. Retreatment is indicated if viable eggs are present. 