RADZEC - Reactive Case Detection in Zanzibar: Effectiveness and Cost

Over the past 15 years, Zanzibar (United Republic of Tanzania) has achieved a substantial reduction in the burden of malaria by distributing insecticide treated mosquito nets, indoor residual spraying and artemisinin based combination treatment. Since 2008, Zanzibar has implemented the Malaria Epidemic Early Detection System (MEEDS), a mobile phone-based electronic surveillance system developed jointly by the Zanzibar Malaria Elimination Programme (ZAMEP), USAID/CDC President’s Malaria Initiative (PMI) and RTI International. The reactive case detection system implemented to date in combination with the other suite of interventions in Zanzibar does not appear to have interrupted local malaria transmission and may have ceased to lead to further declines in malaria incidence.

This project aims at contributing to the elimination of malaria on Zanzibar by providing evidence to improve the currently implemented surveillance-response strategy. Specifically, the project will address the following overall objectives:

1) To determine the effective coverage of the surveillance-response system,

2) To evaluate the surveillance-response system and identify potential improvements, and

3) To estimate the cost and cost-effectiveness of the system.

The study will include several components, including a procedural audit of existing program data, a rolling cross-sectional household survey as follow-up of reactive case detection activities, a treatment adherence study, and a qualitative inquiry into obstacles to the implementation of the current surveillance-response procedures.

It also involves a strong capacity building component, where Swiss TPH supports the training of ZAMEP collaborators in the areas of epidemiology and molecular laboratory techniques.

Project partners:

• Zanzibar Malaria Elimination Programme (ZAMEP)
• Tulane University | School of Public Health and Tropical Medicine
• Ifakara Health Institute
• University of Notre Dame | Eck Institute of Global Health

Involved Regions: Africa
Involved Countries: Tanzania, United Republic of, United States of America (the)

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Grossenbacher B, Holzschuh A, Hofmann N.E, Omar K.A, Stuck L, Fakih B.S, Ali A, Yukich J, Hetzel M.W, Felger I. Molecular methods for tracking residual Plasmodium falciparum transmission in a close-to-elimination setting in Zanzibar. Malar J. 2020;19:50. DOI: 10.1186/s12936-020-3127-x

Van der Horst T, Al-mafazy A.W, Fakih B.S, Stuck L, Ali A, Yukich J, Hetzel M.W. Operational coverage and timeliness of reactive case detection for malaria elimination in Zanzibar, Tanzania. Am J Trop Med Hyg. 2020;102(2):298-306. DOI: 10.4269/ajtmh.19-0505

Das A.M, Hetzel M.W, Yukich J.O, Stuck L, Fakih B.S, Al-mafazy A.H, Ali A, Chitnis N. The impact of reactive case detection on malaria transmission in Zanzibar in the presence of human mobility. Epidemics. 2022;41:100639. DOI: 10.1016/j.epidem.2022.100639

Das A.M, Hetzel M.W, Yukich J.O, Stuck L, Fakih B.S, Al-mafazy A.H, Ali A, Chitnis N. Modelling the impact of interventions on imported, introduced and indigenous malaria infections in Zanzibar, Tanzania. Nat Commun. 2023;14:2750. DOI: 10.1038/s41467-023-38379-8

Holzschuh A, Lerch A, Gerlovina I, Fakih B.S, Al-mafazy A.H, Reaves E.J, Ali A, Abbas F, Ali M.H, Ali M.A, Hetzel M.W, Yukich J, Koepfli C. Multiplexed ddPCR-amplicon sequencing reveals isolated Plasmodium falciparum populations amenable to local elimination in Zanzibar, Tanzania. Nat Commun. 2023;14:3699. DOI: 10.1038/s41467-023-39417-1

Fakih B.S, Holzschuh A, Ross A, Stuck L, Abdul R, Al-mafazy A.H, Irema I, Mbena A, Thawer S.G, Shija S.J, Aliy S.M, Ali A, Fink G, Yukich J, Hetzel M.W. Risk of imported malaria infections in Zanzibar: a cross-sectional study. Infect Dis Poverty. 2023;12:80. DOI: 10.1186/s40249-023-01129-5

Holzschuh A, Lerch A, Fakih B.S, Aliy S.M, Ali M.H, Ali M.A, Bruzzese D.J, Yukich J, Hetzel M.W, Koepfli C. Using a mobile nanopore sequencing lab for end-to-end genomic surveillance of Plasmodium falciparum: a feasibility study. PLOS Glob Public Health. 2024;4(2):e0002743. DOI: 10.1371/journal.pgph.0002743

Vera-Arias C.A, Holzschuh A, Oduma C.O, Badu K, Abdul-Hakim M, Yukich J, Hetzel M.W, Fakih B.S, Ali A, Ferreira M.U, Ladeia-Andrade S, Sáenz F.E, Afrane Y, Zemene E, Yewhalaw D, Kazura J.W, Yan G, Koepfli C. High-throughput Plasmodium falciparum hrp2 and hrp3 gene deletion typing by digital PCR to monitor malaria rapid diagnostic test efficacy. eLife. 2022;11:e72083. DOI: 10.7554/eLife.72083

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