Long-term efficacy of single-dose oral treatment in schistosomiasis haematobium

Abstract

A two-year follow-up was conducted in children who had been the subjects of a six-month double-blind trial in the single-dose treatment of Schistosoma haematobium infection. The trial had assessed therapeutic efficacy of three oral preparations-praziquantel 40 mg/kg, metrifonate 10 mg/kg, and the 'combination' (concurrent niridazole 25 mg/kg and metrifonate 10 mg/kg administration). Reduction in urinary egg excretion remained high up to follow-up at two years, based on a comparison of pre- and post-treatment geometric mean counts-praziquantel 96.9% (n = 96 at six months, 51 at two years); the 'combination' 93.9% (n = 97 at six months, 48 at two years); and metrifonate 90.3% (n = 92 at six months, 49 at two years). The differences in percentage reduction were not significant (p greater than 0.1). However, a significantly greater reduction in egg output was produced by praziquantel (81.7%) and the 'combination' (82.5%) than by metrifonate (54.2%), on comparing pre- and post-treatment arithmetic mean counts (p less than 0.01). A significantly smaller percentage of subjects were excreting greater than or equal to 125 ova/10 ml urine two years after treatment with praziquantel (10.3%), compared to treatment with the 'combination' (25.7%) and metrifonate (35.8%) (p less than 0.01). The cure rate was significantly higher in the praziquantel group (47.4%) compared to the 'combination' (24.7%) and metrifonate (17.4%) groups, for the six to 24-month follow-up period (p less than 0.001). The pattern and level of transmission had contributed to the long-term efficacy recorded in this study.

Drugs for treating urinary schistosomiasis

“…Stephenson 1989 KEN reported treatment failure at eight months, its only time point. A single dose of praziquantel reduced treatment failure by 86% compared to placebo (RR 0.14, 95% CI 0.08 to 0.22; 209 participants, one trial, Analysis 1.1).…”

“…Percent egg reduction was variable in the placebo group, ranging from 26% increase to 54% reduction at three months and from 5% to 64% reduction at six months (see Table 4). One additional trial, Stephenson 1989 KEN, reported percent egg reduction at eight months as its only time point (209 participants, see Table 4). Percent egg reduction after praziquantel was 99% compared to 5% with placebo.…”

“…Three trials measured a variety of growth parameters (Befidi Mengue 1992 CMR; Olds 1999 KEN; Stephenson 1989 KEN). Two trials reported little or no effect on the outcomes measured (Befidi Mengue 1992 CMR; Olds 1999 KEN).…”

Therapeutic failure of praziquantel in the treatment of Schistosoma haematobium infection in Brazilians returning from Africa

“…Although praziquantel is the drug of choice for the treatment of S. haematobium infections (Gentilini et al 1982, McMahon 1983, Pugh & Teesdale 1984, Stephenson et al 1989, McNeeley et al 1990, King et al 1992, King & Mahmoud 1999, King et al 2002, cases of treatment failure have been frequently reported, probably due to a progressive increase in the resistance of the parasite to the drug, as observed by some authors (Groning et al 1985, Herwaldt et al 1995, Hatz et al 1998, Ernould et al 1999, Liang et al 2000. Despite the controversies regarding the rapid emergence of praziquantel resistance, constant surveillance of this progression is important.…”

Praziquantel, Oxamniquine, and Metrifonate in the Treatment of Schistosomiasis in Riyadh

“…10 We observed a 90% cure rate in patients with S. haematobium infection who were treated with metrifonate, and this is comparable to the rates reported in other studies. [12][13] Oxamniquine in different dosages has been used in different parts of the world to treat schistosomiasis. 14,15 The cure rate in our study was 91%.…”