‘COUNTDOWN – Integrated complementary strategies for surveillance of Neglected Tropical Diseases in Ghana’
Schistosomiasis (SCH) and Soil-transmitted Helminthiasis (STH) are endemic in Ghana, with STH being prevalent in most regions and SCH around water bodies containing Bulinus or Biomphalaria snail hosts. People contract schistosomiasis from contact with water containing Schistosoma cercariae, and STH from environmental contact resulting from poor hygiene, sanitation or access to clean water.
Mass Drug Administration (MDA) against SCH and STH focus on annual treatment of school-aged children in a school-based distribution programme. Inequity of access to deworming drugs by non-school cohorts is a recognised problem especially in the pre-school age population, high-risk adult groups and children who do not attend school.
This research will investigate expanded access to whole communities of the drugs praziquantel (PZQ) and albendazole (ALB) drugs against SCH and STH in high-transmission settings in Ghana.
The following groups will be targeted for treatment, and those who are currently outside of the National Control Programme run by the Ghana Health Service such as:
- Preschool-aged children
- Out-of-school school-aged children
- Adults including pregnant women
Baseline (pre-intervention) focus group discussions and in-depth interviews will be held with community members and key informants to determine understanding of the current MDA strategy, and to identify the feasibility and acceptability of expanding treatment in communities. Baseline surveying will be conducted in schistosomiasis-endemic areas of Ghana to determine schistosomiasis and STH prevalence in community settings. A multi-site longitudinal study will then be conducted to investigate the potential of expanded treatment strategies for PZQ and ALB.
An initial community cross-sectional study will be conducted to assess the baseline infection and morbidity status of both SCH and STH, including provision of PZQ & ALB. This will be followed by a longitudinal survey at 6, 12 and 18 months in these communities, in which disease reductions associated with the treatments will be assessed.
Nested within this study will be qualitative and health economic research that will explore accessibility, feasibility and economic impact of expanded treatment.
The specific objectives are:
1. To conduct targeted baseline parasitological and epidemiological surveys to describe infection levels of schistosomiasis and STH, and associated WASH and morbidity indicators
2. To assess expanded annual community treatment in reducing prevalence of schistosomiasis and STH
3. To assess community understanding of the current MDA programme and its strengths and weaknesses and economic aspects of whole community treatment.
4. To assess the acceptability and feasibility of introducing an alternative treatment strategy to the current treatment regimen from different perspectives
5. To investigate different levels of access and factors influencing scale-up to PZQ and ALB treatment in areas with limited treatment coverage
Study Area
Cross-sectional surveys will be conducted in SCH and STH co-endemic communities located in the Greater Accra region. Communities within these regions have been selected based on prevalence of at least 10% of schistosomiasis infection (being S. mansoni or S. haematobium, or both), and proximity to water bodies containing the intermediate snail host. For Ghana, up to three communities in the Ga South and Shai Osudoku Districts, Greater Accra which are organised at the district level.
DIAGNOSTICS
COUNTDOWN understands that a more effective strategy would be to use pre-existing faecal collections from local communities as a means of cutting down sample collection costs. One such example of faecal collections are those routinely collected by the global polio laboratory network (GPLN). These laboratories are spread across 19 countries in sub-Sharan Africa and regularly collect 100,000 samples per year, with Ghana receiving just under a thousand per year.
This study aims to evaluate the suitability of using the recently collected faecal samples from the Ghanaian polio laboratory to screen for the following parasitic worms, Ascaris lumbricoides, Trichuris trichuria, Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis and human schistosomiasis.
We will carry out a DNA extraction on the faecal samples and perform a highly sensitive DNA analysis assessment called Taqman qPCR. Briefly this method involves the amplification of DNA from the different helminth species of interest and the labelling of this DNA with a marker. Using this method, it will be possible to screen for multiple worms within the same reaction using a highly sensitive and specific test.
If we can prove that the faecal collections of the global polio laboratory network are suitable candidates for the detection of the previously mentioned parasitic worms we could use this to develop a cost-effective and sustainable means of monitoring intestinal worm and schistosomiasis prevalence’s in resource poor countries.
Our collaboration with the Ghanaian Polio Laboratory is published in this paper:
Expanding molecular diagnostics of helminthiasis: Piloting use of the GPLN platform for surveillance of soil transmitted helminthiasis and schistosomiasis in Ghana
Lucas J. Cunningham , John Odoom , Deborah Pratt, Linda Boatemaa, Nana Asante-Ntim, Keren Attiku, Bismarck Banahene, Mike Osei-Atweneboana, Jaco J. Verweij , David Molyneux, Russell J. Stothard , Emily R. Adams
PLOS NTD Published: January 25, 2018 https://doi.org/10.1371/journal.pntd.0006129