Preventive chemotherapy for schistosomiasis is rapidly scali
Preventive chemotherapy for schistosomiasis is rapidly scaling up worldwide. The global coverage that was less than 10% in 2010 is now higher than 30%, however, the main limitation for the scaling up is the availability of donated drug. In school age children, the age group for which praziquantel is donated, the coverage is almost 45%, while the coverage in adults is less than 15% because of the absence of donation for this age group. The present donation of praziquantel is expected to reach 250 million tablets in 2017 (corresponding to 100 million doses) but this quantity would be sufficient only to treat the school age children in need, assuming their appropriate allocation and distribution.
To reach the 2020 WHO target for schistosomiasis and to eliminate the disease, the treatment of all age groups is required. It will be essential to obtain a donation of praziquantel for adults in need and if preschool children will be included in the preventive chemotherapy targeted group, the new formulation for their treatment must be available free of charge.
In conclusion, the distribution of praziquantel for preventive chemotherapy is simple to implement and very low cost, however, the availability of the drug is essential to treat all the people in need. WHO is looking forward to the development of a paediatric formulation of the drug provided it glutathione peroxidase will be available as a donation. In the absence of treatment alternatives, a single dose of praziquantel of 40 mg/kg, recommended by the WHO for infections in school-aged children can be endorsed for preschool-aged children in preventive chemotherapy programmes.
Despite encouraging evidence about the health benefits of individual water, sanitation, and hygiene (WASH) interventions, much less is known about the benefits of combined or packaged interventions delivered through public-health campaigns and programmes. Rigorous assessment of such combined intervention programmes has many challenges. For example, such assessments usually require a deep understanding of a complicated study design, typically entailing a cluster-randomised trial. These study designs frequently demand large sample sizes and geographically dispersed study units to avoid possible spillover effects that distort the noted estimates of effect. As a result, the sample sizes demanded by these studies usually need substantial budgetary resources that can be alarming for funders without previous experience of this type of work. These challenges are compounded by the importance of maintaining high retention of participants and good adherence to the intervention, goals that further strain study resources and need (often humbling) insight into human behaviour. Finally, these studies might need to include an untreated control; such a design feature might be off-putting to communities and leaders, whose assent and participation is essential for the work. In , Sheela Sinharoy and colleagues show that, despite these challenges, rigorous assessment of combined WASH intervention programmes is possible and aligns appropriately with broader goals in science toward reproducibility and transparency in research. They did a cluster-randomised trial to compare two models of community health clubs, which are multi-session village-level gatherings designed to promote healthy behaviours mainly related to WASH, with a control (no intervention). Among children younger than 5 years, the prevalence of caregiver-reported diarrhoea in the previous 7 days (primary outcome) was 14% in control villages, 14% in villages allocated a shortened (eight sessions) intervention (prevalence ratio compared with control 0·97, 95% CI 0·81–1·16; p=0·74), and 14% in villages assigned a longer (20 sessions) intervention (0·99, 0·85–1·15; p=0·87). Moreover, no effects of the interventions were noted on secondary outcomes of height-for-age and weight-for-height scores and water quality.