Efficacy of oxamniquine and praziquantel in school children from two Schistosoma mansoni endemic areas
Thiong'o, F.W.; Mbugua, G.G.; Ouma, J.H.; Sturrock, R.K.
East African Medical Journal 79(1): 29-33
2002
ISSN/ISBN: 0012-835X PMID: 12380867 Document Number: 542022
Objective: To determine the relative susceptibility of S. mansoni infections to treatment with oxamniquine (OXA) and praziquantel (PZQ). Design and setting: Between 1990 and 1991, three separate cross sectional studies were performed in six primary schools located in two S. mansoni endemic areas in Eastern Kenya: Kangundo (low morbidity) and Kibwezi (high morbidity). Subjects: 1214 infected children aged 6-20 years were involved. Intervention: Each child received either 15 mg OXA/kg body weight twice within an interval of six hours or a single dose of 40 or 60 mg PZQ/kg body weight. Three duplicate Kato faecal examinations were done before and four or five weeks after treatment to assess treatment efficacy. Results: The cure rates in different schools with OXA were 71.7%-79.7% in Kangundo and 56.7%-61.9% in Kibwezi. In children treated with PZQ, the 40 mg/kg dose regimen achieved cure rates of 77.6%-87.2% in Kangundo and 67.1%-81.1% in Kibwezi, whereas the 60 mg/kg dose regimen attained cure rates of 93.2% in Kangundo and 76.3% in Kibwezi. Both OXA and PZQ efficacy declined significantly with age in Kangundo, whereas the age effect was not seen in Kibwezi. Conclusion: The poorer cure rates in Kibwezi than in the Kangundo children were not due to known previous drug exposure to either OXA or PZQ. The varying efficacy may be attributed to innate low drug susceptibility, possibly related to schistosome strain differences between the two areas.