The Efficacy of Single-Dose versus Double-Dose Praziquantel Treatments on Schistosoma mansoni Infections: Its Implication on Undernutrition and Anaemia among Primary Schoolchildren in Two On-Shore Communities, Northwestern Tanzania

Abstract

Administering more than one treatment may increase Praziquantel cure and egg reduction rates, thereby hastening achievement of schistosomiasis transmission control. A total of 431 S. mansoni-infected schoolchildren were randomized to receive either a single or repeated 40 mg/kg Praziquantel dose. Heights, weights, and haemoglobin levels were determined using a stadiometer, weighing scale, and HemoCue, respectively. At 8 weeks, cure rate was higher on repeated dose (93.10%) compared to single dose (68.68%) (p < 0.001). The egg reduction rate was higher on repeated dose (97.54%) compared to single dose (87.27%) (p = 0.0062). Geometric mean egg intensity was lower among those on repeated dose (1.30 epg) compared to single dose (3.18 epg) (p = 0.036) but not at 5 (p > 0.05) and 8 (p > 0.05) months with no difference in reinfection rate. No difference in the prevalence of stunting was observed between the two treatment regimens (p > 0.05) at 8 months, but there was an increase in the prevalence of wasting among those on repeated dose (p < 0.001). There was an increase in the mean haemoglobin levels at 8 months with no difference between the two arms (p > 0.05). To achieve reduction of transmission intensity and disease control in highly endemic areas, repeated treatments alone may not be sufficient. This trial was registered with PACTR201601001416338.

Figure 1

Study profile and compliance among 431 S. mansoni-infected schoolchildren in an endemic area, northwestern Tanzania.

Figure 2

Infection intensity expressed as geometric mean of the log of fecal eggs count per gram of faeces at baseline, 8 weeks, 5 months, and 8 months following treatment of S. mansoni infections with a single dose of PZQ (40 mg/kg) versus 2 × 40 mg/kg in the study area.

Figure 3

Box-and-whisker plot showing the relationship between median and range of haemoglobin levels (g/dL) at baseline (n = 383) and at 5 months (n = 321) and 8 months (n = 332) after baseline treatment for the single-dose and double-dose Praziquantel treatments. The thick line within each box stands for the median haemoglobin value. The lower and upper edges of each box represent the 25th and 75th percentiles, respectively. The lower and upper whiskers represent the lower and upper values (range), respectively, excluding outliers.