Towards interruption of schistosomiasis transmission in sub-Saharan Africa: developing an appropriate environmental surveillance framework to guide and to support ‘end game’ interventions

Abstract

Schistosomiasis is a waterborne parasitic disease in sub-Saharan Africa, particularly common in rural populations living in impoverished conditions. With the scale-up of preventive chemotherapy, national campaigns will transition from morbidity- to transmission-focused interventions thus formal investigation of actual or expected declines in environmental transmission is needed as ‘end game’ scenarios arise. Surprisingly, there are no international or national guidelines to do so in sub-Saharan Africa. Our article therefore provides an introduction to key practicalities and pitfalls in the development of an appropriate environmental surveillance framework. In this context, we discuss how strategies need to be adapted and tailored to the local level to better guide and support future interventions through this transition. As detection of egg-patent infection in people becomes rare, careful sampling of schistosome larvae in freshwater and in aquatic snails with robust species-specific DNA assays will be required. Appropriate metrics, derived from observed prevalence(s) as compared with predetermined thresholds, could each provide a clearer insight into contamination- and exposure-related dynamics. Application could be twofold, first to certify areas currently free from schistosomiasis transmission or second to red-flag recalcitrant locations where extra effort or alternative interventions are needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0215-9) contains supplementary material, which is available to authorized users.

Parasites and allergy: Observations from Africa

“…Helminth infections are strongly linked to poverty, poor hygiene and inadequate sanitation and are more common in rural locations . Reduced exposure to helminths is thought to be one of the factors driving the rise in the incidence of allergic disease worldwide .…”

“…3 Helminth infections are strongly linked to poverty, poor hygiene and inadequate sanitation and are more common in rural locations. 4,5 Reduced exposure to helminths is thought to be one of the factors driving the rise in the incidence of allergic disease worldwide. 6 Increases in the prevalence of allergy-related diseases over time have also been seen on the African continent especially among children, 7,8 particularly in urban compared to rural areas.…”

Impact evaluation of schistosomiasis control into elimination interventions models in P. R. China and Africa

“…Also, novel integrated surveillance-response systems implementation for early and rapid detection assessment of threat or outbreak can enhance cost-effectiveness management and national schistosomiasis priorities. Contemporary genomic data mining in forecasting and modeling provide new opportunities in unraveling new point of care and reliable diagnostics, safe and efficacious drug and vaccine in schistosomiasis elimination [99,101,102,103]. Moreover understanding climatic and environmental interactions and impact is needed.…”

“…Sustainability of local strategies towards interrupting schistosomiasis transmission elimination also requires improving sanitation by supplying clean drinking water and improving WASH approach in remote rural communities/ dwellings including intensive health education a continuous awareness and resilience [2,15,29,[93][94][95]. Moreover, to nurture schistosomiasis ownership and reinforcement of public-private partnership and collaboration including the local community in sustained funding support from government and international organizations and development of disease resilience culture are proactive and efficient ways in revamping the persistent morbidity and mortality of this diseases China and mainly in sub-Saharan Africa [3,5,19,96,[99][100][101][102].…”

Prawn aquaculture as a method for schistosomiasis control and poverty alleviation: a win-win approach to address a critical infectious disease of poverty

“…While safe and effective treatments, such as the anthelmintic drug Praziquantel, are available to reduce parasite burden and associated symptoms from infected individuals, rapid reinfection in highly endemic areas leads to persistent hotspots of infection 3,4 . Successful long-term elimination efforts may require strategies that go beyond conventional mass drug administration (MDA) campaigns to explicitly target the environmental reservoir of the disease 5 .…”