ZEST - Zanzibar Elimination of Schistosomiasis Transmission

Background Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. Importantly, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3-5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the outcomes and impact measured in a randomized intervention trial.  Methods/Design In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9-12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be recordedand monitored longitudinally.
Discussion Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere.

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Selected projects at this location:

Knopp S, Ame S.M, Person B, Hattendorf J, Rabone M, Juma S, Muhsin J, Khamis I.S, Hollenberg E, Mohammed K.A, Kabole F, Ali S.M, Rollinson D. A 5-year intervention study on elimination of urogenital schistosomiasis in Zanzibar: parasitological results of annual cross-sectional surveys. PLoS Negl Trop Dis. 2019;13(5):e0007268. DOI: 10.1371/journal.pntd.0007268

Knopp S, Mohammed K.A, Ali S.M, Khamis I.S, Ame S.M, Albonico M, Gouvras A, Fenwick A, Savioli L, Colley D.G, Utzinger J, Person B, Rollinson D. Study and implementation of urogenital schistosomiasis elimination in Zanzibar (Unguja and Pemba islands) using an integrated multidisciplinary approach. BMC Public Health. 2012;12:930. DOI: 10.1186/1471-2458-12-930

Knopp S, Person B, Ame S.M, Mohammed K.A, Ali S.M, Khamis I.S, Rabone M, Allan F, Gouvras A, Blair L, Fenwick A, Utzinger J, Rollinson D. Elimination of schistosomiasis transmission in Zanzibar: baseline findings before the onset of a randomized intervention trial. PLoS Negl Trop Dis. 2013;7(10):e2474. DOI: 10.1371/journal.pntd.0002474

Knopp S, Corstjens P.L, Koukounari A, Cercamondi C.I, Ame S.M, Ali S.M, de Dood C.J, Mohammed K.A, Utzinger J, Rollinson D, van Dam G.J. Sensitivity and specificity of a urine circulating anodic antigen test for the diagnosis of Schistosoma haematobium in low endemic settings. PLoS Negl Trop Dis. 2015;9(5):e0003752. DOI: 10.1371/journal.pntd.0003752

Knopp S, Person B, Ame S.M, Ali S.M, Muhsin J, Juma S, Khamis I.S, Rabone M, Blair L, Fenwick A, Mohammed K.A, Rollinson D. Praziquantel coverage in schools and communities targeted for the elimination of urogenital schistosomiasis in Zanzibar: a cross-sectional survey. Parasit Vectors. 2016;9:5. DOI: 10.1186/s13071-015-1244-0

Webster B.L, Rabone M, Pennance T, Emery A.M, Allan F, Gouvras A, Knopp S, Garba A, Hamidou A.A, Mohammed K.A, Ame S.M, Rollinson D, Webster J.P. Erratum to: Development of novel multiplex microsatellite polymerase chain reactions to enable high-throughput population genetic studies of Schistosoma haematobium. Parasit Vectors. 2015;8:519. DOI: 10.1186/s13071-015-1134-5

Webster B.L, Rabone M, Pennance T, Emery A.M, Allan F, Gouvras A, Knopp S, Garba A, Hamidou A.A, Mohammed K.A, Ame S.M, Rollinson D, Webster J.P. Development of novel multiplex microsatellite polymerase chain reactions to enable high-throughput population genetic studies of Schistosoma haematobium. Parasit Vectors. 2015;8:432. DOI: 10.1186/s13071-015-1044-6

Rollinson D, Knopp S, Levitz S, Stothard J.R, Tschuem Tchuenté L.A, Garba A, Mohammed K.A, Schur N, Person B, Colley D.G, Utzinger J. Time to set the agenda for schistosomiasis elimination. Acta Trop. 2013;128(2):423-440. DOI: 10.1016/j.actatropica.2012.04.013

Knopp S, Becker S.L, Ingram K.J, Keiser J, Utzinger J. Diagnosis and treatment of schistosomiasis in children in the era of intensified control. Expert Rev Anti Infect Ther. 2013;11(11):1237-1258. DOI: 10.1586/14787210.2013.844066

Person B, Ali S.M, A'Kadir F.M, Ali J.N, Mohammed U.A, Mohammed K.A, Rollinson D, Knopp S. Community knowledge, perceptions, and practices associated with urogenital schistosomiasis among school-aged children in Zanzibar, United Republic of Tanzania. PLoS Negl Trop Dis. 2016;10(7):e0004814. DOI: 10.1371/journal.pntd.0004814

Celone M, Person B, Ali S.M, Lyimo J.H, Mohammed U.A, Khamis A.N, Mohammed Y.S, Mohammed K.A, Rollinson D, Knopp S. Increasing the reach: involving local muslim religious teachers in a behavioral intervention to eliminate urogenital schistosomiasis in Zanzibar. Acta Trop. 2016;163:142-148. DOI: 10.1016/j.actatropica.2016.08.004

Person B, Knopp S, Ali S.M, A'Kadir F M, Khamis A.N, Ali J.N, Lymo J.H, Mohammed K.A, Rollinson D. Community co-designed schistosomiasis control interventions for school-aged children in Zanzibar. J Biosoc Sci. 2016;48(Suppl 1):S56-S73. DOI: 10.1017/S0021932016000067

Pennance T, Person B, Muhsin M.A, Khamis A.N, Muhsin J, Khamis I.S, Mohammed K.A, Kabole F, Rollinson D, Knopp S. Urogenital schistosomiasis transmission on Unguja Island, Zanzibar: characterisation of persistent hot-spots. Parasit Vectors. 2016;9:646. DOI: 10.1186/s13071-016-1847-0

Knopp S, Ame S.M, Hattendorf J, Ali S.M, Bakar F, Khamis M.A, Person B, Kabole F, Rollinson D. Urogenital schistosomiasis elimination in Zanzibar: accuracy of urine filtration and haematuria reagent strips for diagnosing light intensity Schistosoma haematobium infections. Parasit Vectors. 2018;11:552. DOI: 10.1186/s13071-018-3136-6

Knopp S, Person B, Ame S.M, Ali S.M, Hattendorf J, Juma S, Muhsin J, Khamis I.S, Mohammed K.A, Utzinger J, Hollenberg E, Kabole F, Rollinson D. Evaluation of integrated interventions layered on mass drug administration for urogenital schistosomiasis elimination: a cluster-randomised trial. Lancet Glob Health. 2019;7(8):e1118-e1129. DOI: 10.1016/S2214-109X(19)30189-5

Keller D, Rothen J, Dangy J.P, Saner C, Daubenberger C, Allan F, Ame S.M, Ali S.M, Kabole F, Hattendorf J, Rollinson D, Seyfarth R, Knopp S. Performance of a real-time PCR approach for diagnosing Schistosoma haematobium infections of different intensity in urine samples from Zanzibar. Infect Dis Poverty. 2020;9:128. DOI: 10.1186/s40249-020-00726-y

Contact

Stefanie Knopp

Stefanie Knopp, PhD
Scientific Project Leader, Wissenschaftliche Mitarbeitende/Post-Doc (SHIS 530)

+41612848727
s.knoppswisstph.ch

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