Through its RAP program, SCORE is conducting systematic evaluations and meta-analysis of existing research evidence concerning several key operational issues relevant to schistosomiasis control and elimination.
RAP 1 – What is the impact of double treatment (two doses close together) for S. mansoni and for S. haematobium?
In a paper published in PLoS NTD, King et al. showed that, although schedules for repeated treatment with praziquantel require greater inputs in terms of direct costs and community participation, cure rates and egg-reduction rates with double treatment were higher, particularly for S. mansoni infection. Based on decision-tree simulations, there are expected to be cost-effective incremental health benefits to this approach, with an estimated cost of $153 for S. mansoni and $211 for S. haematobium per additional lifetime QALY gained by using double treatment in school-based programs. RAP 1 is now available as a 2-page brochure for download.
RAP 2 – How well do urine dipsticks perform for assessing prevalence of S. haematobium in low-prevalence areas?
King and Bertsch showed that heterogeneity between studies, even in stratified subgroups, has been very high. Nevertheless, dipsticks appear to be 58 – 75% sensitive relative to egg detection, with rates varying depending on underlying intensity of infection. Interestingly, post-treatment performance is not much different from pre-treatment values, perhaps because studies presenting such data have focused on high risk areas, where there were often many infected children still included in the post-control follow-up surveys. RAP 2 is now available as a 2-page brochure for download.
RAP 3 – Do adults in areas with S. haematobium get reinfected after treatment, and, if so, at what rates?
Evaluation of adult reinfection with S. haematobium showed that adults do get reinfected and can contribute to transmission cycles. The quality and quantity of data on this topic did not support a formal review. However, we developed a “summary of the evidence” (see RAP3).
RAP 4 – How effective is niclosamide-based mollusciciding in reducing snail numbers and in reducing local Schistosoma infection risk?
RAP 4 is examining the literature to determine and compare the efficacy of niclosamide application for intermediate host snail control in Schistosoma-endemic areas. We have completed and published a scoping historical review of the perceived pros and cons of this approach, including a list of the technical inputs required to deliver snail control (see King and Bertsch). A second article, published December 2015 in PLOS Neglected Tropical Diseases, provides a quantitative meta-analysis of the reported impact of molluscicide-based snail control programs on Schistosoma incidence and prevalence among local human populations (see King, Sutherland, and Bertsch). RAP 4 is now available as a 2-page brochure for download.
RAP 5 – How best can treatment programs focused on school age children reach those who are not in school?
This scoping review will summarize the different approaches that MDA programs have taken to increase treatment participation by 5 – 18 year old children who are not in school. This group of children often have the greatest risk for infection and disease, yet often get missed by standard school-based treatment programs.
RAP 6 – On a quantitative basis, how does treatment-related reduction in Schistosoma infection intensity translate into reduction in infection-related morbidities?
This systematic review and meta-analysis examined the quantitative link between reported reductions in post-treatment Schistosoma infection intensity (egg reduction rate, ERR) and the changes seen in population prevalence of anemia, hepatosplenomegaly, growth retardation, and other clinical complications of schistosomiasis. The project’s objective was to document the impact of varied ERRs on prevalence of specific morbidities, in order to provide quantitative measures of the impact of anti-schistosomal treatments. This project was performed in collaboration with Universidade Federal de Minas Gerais, Brazil and has been published (see Andrade et al.)