Trippler, L. and Ame, S. M. and Hattendorf, J. and Juma, S. and Abubakar, S. and Ali, S. M. and Kabole, F. and Rollinson, D. and Knopp, S.. (2021) Impact of seven years of mass drug administration and recrudescence of Schistosoma haematobium infections after one year of treatment gap in Zanzibar: repeated cross-sectional studies. PLoS Negl Trop Dis, 15 (2). e0009127.
![]() |
PDF
- Published Version
Available under License CC BY (Attribution). 3002Kb |
Official URL: https://edoc.unibas.ch/89524/
Downloads: Statistics Overview
Abstract
BACKGROUND: Considerable progress towards the elimination of urogenital schistosomiasis was made by the Zanzibar Elimination of Schistosomiasis Transmission project from 2012 till 2016, when biannual praziquantel mass drug administration (MDA) alone or with additional snail control or behaviour change interventions were implemented. Annual MDA was continued in 2017 and 2018, but not in 2019, imposing a 16-month treatment gap. We monitored the Schistosoma haematobium prevalence from 2012 till 2020 and assessed recrudescence patterns with focus on 2020. METHODOLOGY: Repeated cross-sectional surveys were conducted from 2011/12 till 2020 in 90 communities and 90 schools in Zanzibar. Annually, around 4,500 adults and up to 20,000 schoolchildren were surveyed. The S. haematobium prevalence was detected by urine filtration and reagent strips. In 2020, risk factors for infection were investigated using generalized estimated equation models. PRINCIPAL FINDINGS: In adults, the apparent S. haematobium prevalence was 3.9% in 2011 and 0.4% in 2020. In schoolchildren, the prevalence decreased from 6.6% in 2012 to 1.2% in 2019 with vicissitudes over the years. Prominent recrudescence of infection from 2.8% in 2019 to 9.1% (+225%) in 2020 was observed in 29 schools with historically moderate prevalences (>/=10%). Compared with 2019, reinfection in 2020 was particularly striking in boys aged 9-16 years. Being male was a risk factor for infection in 2020 (adults: odds ratio (OR): 6.24, 95% confidence interval (95% CI): 1.96-19.60; schoolchildren: OR: 2.06, 95% CI: 1.52-2.78). Living near to a natural freshwater body significantly increased the odds of infection in adults (OR: 2.90, CI: 1.12-7.54). CONCLUSIONS/SIGNIFICANCE: After 11 rounds of MDA over 7 years and a 16-month treatment gap, the urogenital schistosomiasis prevalence considerably rebounded in hotspot areas. Future elimination efforts in Zanzibar should focus on re-intensifying MDA plus additional interventions in hotspot areas. In low-prevalence areas, the strategy might be adapted from MDA to targeted surveillance-response.
Faculties and Departments: | 09 Associated Institutions > Swiss Tropical and Public Health Institute (Swiss TPH) 09 Associated Institutions > Swiss Tropical and Public Health Institute (Swiss TPH) > Department of Epidemiology and Public Health (EPH) > Eco System Health Sciences > Ecosystem Services, Climate & Health (Cissé) 09 Associated Institutions > Swiss Tropical and Public Health Institute (Swiss TPH) > Department of Epidemiology and Public Health (EPH) > Human and Animal Health > One Health (Zinsstag) |
---|---|
UniBasel Contributors: | Hattendorf, Jan and Knopp, Stefanie |
Item Type: | Article, refereed |
Article Subtype: | Research Article |
ISSN: | 1935-2735 (Electronic)1935-2727 (Linking) |
Note: | Publication type according to Uni Basel Research Database: Journal article |
Language: | English |
Related URLs: | |
Identification Number: |
|
edoc DOI: | |
Last Modified: | 21 Dec 2022 12:30 |
Deposited On: | 21 Dec 2022 12:30 |
Repository Staff Only: item control page