An analysis of the application of community-based approached in prevention and control of neglected tropical diseases – a case study of schistosomiasis control in Malawi

Abstract

Introduction
Schistosomiasis is one of prevalent parasitic neglected tropical diseases (NTDs) in sub-Saharan Africa (SSA), causing considerable morbidity and numerous deaths. Preventive chemotherapy (PC) using mass drug administration (MDA) is one of the interventions recommended by the World Health Organization (WHO) for prevention and control of schistosomiasis. In Malawi, MDA is one of the community-based interventions, widely carried out by health workers annually since 2009. Over the years of MDA implementation, community coverage has been high at 87.0% (range: 51.5% – 95.0%) for praziquantel (PZQ) due to donor support. Maintaining these high coverage rates pose a sustainability challenge once the donor support comes to an end. This thesis, intended to compare the use of community-directed intervention (CDI) approach with the standard practice in delivery of MDA and other interventions against schistosomiasis, inclusive of One Health studies that explore zoonosis.

Methods
Using control of schistosomiasis in Malawi as an exemplar case, I carried out five mixed methods studies as follows:
Study 1 (chapter two): a comparative controlled intervention study carried out in Mangochi District over a period of 12 months involving four health centres and 16 villages assigned to use 1) a standard health worker-based approach and 2) a CDI based approach to deliver selected essential primary health care (PHC) services at community level.
Study 2 (chapter three): a cross-sectional and multi-methods evaluation research carried out in three sampled districts where in each district, four health centres and 16 villages were randomly selected to participate.
Study 3 (chapter four): a controlled study carried out in three districts, where four health centres and respective 16 villages in each district were selected and randomly assigned to intervention and control arms which implemented MDA campaigns using the CDI approach and the standard practice, respectively.
Study 4 (chapter five): a novel quasi-experimental pilot Global Positioning System (GPS) datalogging within specific cattle herds, a molecular epidemiological investigation using faecal miracidia hatching test (MHT) alongside a PZQ (40 mg/kg) treatment efficacy spot check and carcass inspections in three districts.
Study 5 (chapter six): a novel quasi-experimental pilot GPS-datalogging within specific goat herds, a molecular epidemiological investigation using faecal MHT alongside a PZQ (40 mg/kg) treatment efficacy spot check and carcass inspections in three districts.
Cross-sectional and mixed methods approach to data collection were used focusing on quantitative and qualitative data at baseline and follow-up. Data were analysed using IBM SPSS software version 26 and NVivo 12 for Windows.

Results
Study 1 (chapter two): Implementation of the CDI approach at community level as an add-on to essential health package (EHP)/PHC services is feasible and acceptable to health professionals, implementers and beneficiaries. Statistically significant increases were observed in intervention components coverage for long lasting insecticide treated net (LLIN) among children under 5 years of age and pregnant women. Increases were also observed for home management of malaria (HMM), vitamin A among children under 5 years of age and treatment against schistosomiasis but these increases were not statistically significant. Implementation was more costly in CDI area than in control areas.
Study 2 (chapter three): An assessment of the standard practice found that in 2018 and 2019 the districts registered high coverage rates for PZQ and albendazole (ALB) using community-based MDA (73.0% – 100.0%) and using school-based MDA (75.0% – 91.0%). Knowledge levels about schistosomiasis and soil-transmitted helminths (STH) in the districts varied according to disease aspects asked about. Both the health authorities and community members perceived the MDA approach as good because it brings treatment closer to people.
Study 3 (chapter four): High coverage rates for PZQ were registered in intervention (83% - 89%) and control (86.0% - 89.0%) communities, intervention (59.0% - 79.0%) and control (53.0% - 86.0% schools. At follow-up, knowledge levels increased, majority of respondents were more knowledgeable about what schistosomiasis was (41.0% - 44.0%), its causes (41.0% - 44.0%) and what STH were (48.0% - 64.0%). Costs for implementation of the study indicated that the intervention arm used more resources than the control arm. Health workers and community members perceived the use of the CDI approach as a good initiative and more favourable over the standard practice.
Study 4 (chapter five): Using MHT and carcass inspection at slaughter, mean prevalence of bovine schistosomiasis was 49.1% (95% CI: 43.7% – 54.6%) and 10.3% (95% CI: 6.0% – 16.2%) respectively, and Schistosoma mattheei, S. haematobium and hybrids were found. All GPS-tagged animals had
proven daily water contact with the lake and each animal was patently infected upon MHT. At a three-month review, whilst parasitological cure after PZQ treatment was 100.0%, all animals were patently (re)infected.
Study 5 (chapter six): Molecular genotyping of miracidia revealed the prevalence of S. mattheei in goats to be 0.0% in Nsanje (n = 30), 16.7% in Chikwawa (n = 30) and 25.3% in Mangochi (n = 170). Inspection of goat carcasses found only a single herd in Mangochi was infected with prevalence at 87.7% (n = 49). All GPS-tagged animals had daily water contact with the lake, and each animal was patently infected upon MHT. One week after PZQ treatment was administered at 40 mg/kg, cure rate was 92.3% while at three months approximately a third of the treated animals were shedding schistosome miracidia.

Conclusions
With the high MDA coverage obtained in communities and schools in the target districts, the effectiveness of MDA delivery using standard approach is satisfactory. The use of a community based CDI approach in delivery of MDA campaigns against schistosomiasis and STH is feasible, retains high coverages and is acceptable in intervention communities thereby strengthening delivery of essential PHC services. Our findings reveal occurrence of zoonotic schistosomiasis transmission calling for an integrated One Health intervention in future education across public health and veterinary sectors. Despite the initial high costs incurred, embedding other control interventions into community delivery platforms could be considered as a possible way forward addressing the sustainability concern when current donor support wanes.

Keywords
Primary health care, Community participation, Community-directed intervention, Community
based health services, Mass drug administration, Schistosomiasis, Zoonosis, One Health.

Date of Award	28 Apr 2026
Original language	English
Awarding Institution	Liverpool School of Tropical Medicine
Sponsors	Wellcome & National Institute for Health Research
Supervisor	Russell Stothard (Supervisor), Janelisa Musaya (Supervisor), James LaCourse (Supervisor) & Sekeleghe Kayuni (Supervisor)