title: 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.
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. russell.stothard@lstmed.ac.uk.
authors.forename: J Russell
authors.identifier: http://orcid.org/0000-0002-9370-3420
authors.initials: JR
authors.lastname: Stothard
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
authors.forename: Suzy J
authors.initials: SJ
authors.lastname: Campbell
authors.affiliation: Department of Environmental Biology and Health, Council for Scientific and Industrial Research-Water Research Insitute, P.O. Box M 32, Accra, Ghana.
authors.forename: Mike Y
authors.initials: MY
authors.lastname: Osei-Atweneboana
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
authors.forename: Timothy
authors.initials: T
authors.lastname: Durant
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Stanton
authors.affiliation: Neglected Tropical Diseases Programme, Ghana Health Services, Accra, Ghana.
authors.forename: Nana-Kwadwo
authors.initials: NK
authors.lastname: Biritwum
authors.affiliation: Department of Life Sciences; Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
authors.forename: David
authors.initials: D
authors.lastname: Rollinson
authors.affiliation: Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon.|Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon.
authors.forename: Dieudonné R Eloundou
authors.initials: DR
authors.lastname: Ombede
authors.affiliation: Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon.|Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon.|National Programme for the Control of Schistosomiasis and Intestinal Helminthiasis, Ministry of Public Health, Yaoundé, Cameroon.
authors.forename: Louis-Albert
authors.initials: LA
authors.lastname: Tchuem-Tchuenté
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D000818:Animals; D062665:Epidemiological Monitoring; D005618:Fresh Water / Q000469:parasitology; D006801:Humans; D011159:Population Surveillance / Q000379:methods*; D012547:Schistosoma / Q000302:isolation & purification*; D012552:Schistosomiasis / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control* / Q000635:transmission; D012908:Snails / Q000469:parasitology
keywords: Environmental monitoring; Freshwater snails; WASH; Zoonosis; eDNA