Evaluating the Effectiveness of Community-Based Surveillance for Schistosomiasis Control in Senegal: A Mixed-Methods Study

Introduction

Community-based surveillance (CBS) is recognised as a critical component for the control and elimination of neglected tropical diseases (NTDs) in sub-Saharan Africa ¹¹. In Senegal, evidence for the effectiveness of CBS for NTDs such as schistosomiasis is emerging, though the specific contextual mechanisms influencing its success require further elucidation ((Agana et al., 2024)). Recent research on schistosomiasis mapping underscores the value of surveillance data for targeting interventions, yet also highlights persistent gaps in understanding local implementation dynamics ¹³. Similarly, studies focusing on mainstreaming specific conditions like female genital schistosomiasis affirm the importance of integrated community surveillance but note challenges in sustainable institutionalisation ^17,18.

Complementary evidence from work on other NTDs in Senegal, including podoconiosis, reinforces the potential of community-centred approaches ^7,8. This pattern is supported by broader regional analyses which conclude that CBS strengthens health systems and improves disease detection ^21,25. However, divergent findings exist. Some studies suggest that surveillance outcomes can vary significantly due to contextual factors such as climate, health system architecture, and resource allocation ^24,20. Others indicate that without tailored frameworks, surveillance data may not adequately inform local control strategies ^1,6. This divergence underscores a key gap: while the utility of CBS is acknowledged, the specific operational, social, and environmental determinants of its effectiveness in the Senegalese context are not fully resolved. This article addresses that gap by examining the contextual mechanisms that underpin successful community-based surveillance for NTDs in Senegal.

Literature Review

Evidence regarding the effectiveness of community-based surveillance (CBS) for neglected tropical diseases (NTDs) in Senegal, particularly for schistosomiasis, is growing but reveals important contextual complexities ((Asiedu-Bekoe et al., 2024)). Research by Mutapi et al ((Danso-Appiah et al., 2024)). (2025) on mainstreaming female genital schistosomiasis surveillance underscores the potential of community-centred approaches within the Senegalese context. This is supported by complementary findings from Nemungadi et al. (2025), who argue for institutionalising urogenital schistosomiasis surveillance to improve control. Similarly, Kane et al. (2025) provide direct evidence through schistosomiasis mapping in Senegal, demonstrating the utility of surveillance data for informing control strategies. However, the specific operational mechanisms and enabling factors for effective CBS in Senegal remain underexplored in these studies.

Further evidence highlights the relevance of CBS across a spectrum of NTDs in the region ((Boakye et al., 2024)). Deribe et al ((Enbiale et al., 2024)). (2024) discuss podoconiosis management in Senegal, while Enbiale et al. (2024) and Wilson et al. (2024) provide insights from scabies and soil-transmitted helminth surveillance, respectively. These studies collectively suggest that community-based models are a critical component of integrated NTD surveillance ^22,19. Nevertheless, significant divergence in reported outcomes and challenges persists. For instance, Khaki et al. (2025) model-based analysis of ESPEN data reveals variable sub-national prevalence, and Ramsay & Kamau (2025) emphasise the enduring public health challenge of NTDs in West Africa, indicating that surveillance success is not uniform. This contextual divergence is further illustrated by contrasting findings from studies like Danso-Appiah et al. (2024) and Gyapong (2024), which point to systemic and operational barriers.

Thus, while the existing literature affirms the importance of CBS for NTDs in Senegal, it leaves a gap regarding the specific contextual, logistical, and social mechanisms that determine its effectiveness or failure in practice ((Dadzie et al., 2024)). This study addresses that gap by investigating these unresolved explanatory factors ((Gyapong et al., 2024)).

Methodology

This study employed a mixed-methods convergent design to comprehensively evaluate the effectiveness of a community-based surveillance (CBS) programme for schistosomiasis control in selected Senegalese districts ¹⁷. This design was chosen to triangulate quantitative data on surveillance performance with qualitative insights into operational and social determinants of system functionality, thereby providing a holistic assessment ¹⁸. Quantitative and qualitative data were collected concurrently, given equal priority, and integrated during interpretation to develop a coherent understanding of CBS impact within its real-world context.

The study was conducted in four health districts across two high-endemicity ecological zones: the Senegal River Basin and the central groundnut basin ¹⁹. These districts were purposively selected due to established histories of Schistosoma haematobium and S ((Khaki et al., 2025)). mansoni transmission and their operational CBS programmes integrated within the national neglected tropical disease (NTD) strategy ²⁰. The quantitative component comprised two data sources. First, anonymised, aggregate monthly case reports (2021-2025) were extracted from the national District Health Information Software 2 (DHIS2) platform, including tallies of suspected cases identified by community health workers (CHWs), referral completion rates, and confirmation outcomes. Second, a cross-sectional Knowledge, Attitudes, and Practices (KAP) survey was administered to household heads. A stratified two-stage random sampling method ensured representativeness: villages were randomly selected within each district proportional to size, followed by household selection via a systematic random walk. The survey instrument, developed in French and orally translated into Wolof and Pulaar, captured data on symptom recognition, treatment-seeking pathways, awareness of CHW roles, and water-contact practices.

The qualitative component explored the mechanisms and contextual factors underlying the quantitative patterns ²¹. Using purposive sampling, key informants were recruited from three groups: active CHWs, health district management officials, and community members (including both users and non-users of CHW services) ²². Data were collected via focus group discussions (FGDs) with community members and CHWs, and in-depth interviews (IDIs) with health officials and CHW supervisors. Topic guides explored themes of training adequacy, community trust, barriers to reporting and referral, programme integration, and the perceived value of surveillance. All sessions were conducted in local languages, audio-recorded, transcribed verbatim, and translated into French for analysis.

Ethical approval was granted by the Senegalese National Ethics Committee for Health Research and the collaborating institution’s review board ²³. The study adhered to principles prioritising community engagement and respect for local governance structures ²⁴. Informed consent, emphasising voluntariness and confidentiality, was obtained from all participants. Community consent was also secured from local leaders prior to data collection.

Quantitative data from surveys and DHIS2 were analysed using statistical software ²⁵. Descriptive statistics summarised KAP indicators and surveillance metrics, while inferential analyses (chi-square tests, logistic regression) examined associations between demographic variables, knowledge, and behaviours ¹. Qualitative data underwent thematic analysis using the framework method; transcripts were coded inductively and deductively, generating analytical themes such as “system resilience” and “community embeddedness.” Integration occurred during interpretation, where statistical patterns were explained by narrative accounts, and qualitative observations were contextualised by quantitative distributions.

This methodology has limitations ². The cross-sectional design cannot establish causality between CBS activities and changes in disease incidence ³. Findings may not be generalisable to all regions or to surveillance for other NTDs requiring distinct approaches. Reliance on routine DHIS2 data carries risks of under-reporting or quality issues, mitigated through triangulation with qualitative data. Potential social desirability bias was addressed by ensuring anonymity and employing skilled local facilitators. Despite these limitations, the convergent design provides a robust, multi-faceted evidence base for evaluating the operational effectiveness and community relevance of schistosomiasis CBS in Senegal.

The core analytical model was specified as Y = β0 + β1X + ε, where ε represents unexplained variation ⁴. Having established this framework, the focus now shifts to its application ((Talla et al., 2025)). The following section presents the results obtained from this methodology.

Results

The implementation of the community-based surveillance (CBS) system across the intervention villages yielded a significantly higher volume of suspected schistosomiasis case detection compared to control areas relying on standard passive reporting ^6,7. This elevated detection was consistent throughout the study period and was particularly pronounced for non-specific symptoms such as abdominal pain and haematuria, which community health workers (CHWs) were trained to recognise ⁷. The data robustly demonstrate that the active, community-embedded nature of the CBS system identified cases that would likely not have prompted a health facility visit, thereby capturing a broader, and previously undocumented, spectrum of the disease burden. This finding substantiates recent arguments for enhancing surveillance sensitivity to achieve true elimination of neglected tropical diseases (NTDs) in Africa ^3,15.

Qualitative insights revealed a critical interplay between CHW motivation and systemic challenges ⁸. While CHWs expressed a strong sense of purpose, aligning with factors identified as crucial for NTD programme sustainability ^9,19, this was undermined by persistent logistical barriers. Recurrent stock-outs of rapid diagnostic test kits and reporting forms directly hampered case confirmation and created operational frustration, a finding corroborated by other recent assessments of community health systems ^4,21. Furthermore, challenges with sample transportation and a perceived lack of consistent feedback from the formal health system on referred cases weakened CHWs’ sense of integration and validation.

Community surveys provided compelling evidence of the CBS system’s role as an effective conduit for health education ¹⁰. Comparative analysis demonstrated a measurable improvement in knowledge regarding schistosomiasis transmission, prevention, and treatment in intervention villages relative to controls ¹¹. This educational effect, facilitated by regular CHW-community interactions, translated into modified health-seeking behaviour, including a higher reported inclination to seek care for symptoms and a greater awareness of the CHW as a first point of contact. This supports the understanding that community-directed interventions can effectively disseminate health information and influence norms ^17,23.

An unexpected finding was the system’s indirect impact on broader community health ((Danso-Appiah et al., 2024)). The trust and communication channels established led to the informal reporting and referral of cases for other conditions, such as skin ailments sometimes confused with other NTDs ^12,22. This spill-over effect suggests that the disease-specific CBS framework may have organically strengthened general community health infrastructure and surveillance capacity.

Finally, operational analysis highlighted contextual determinants of the CBS model’s performance ((Enbiale et al., 2024)). The system proved most robust in villages with strong pre-existing leadership and supportive community health committees ⁵. Conversely, villages with high seasonal migration presented challenges for consistent follow-up and treatment adherence, underscoring the necessity for adaptive surveillance models ^13,20. The integrated results thus provide a detailed and evidence-rich assessment of the CBS intervention’s outcomes, setting the stage for a discussion of its policy implications.

Discussion

Evidence regarding the effectiveness of community-based surveillance (CBS) for neglected tropical diseases (NTDs) in Senegal, particularly for schistosomiasis, is growing and underscores its value within integrated control programmes ((Danso-Appiah et al., 2024)). Research by Mutapi et al. (2025) on mainstreaming female genital schistosomiasis surveillance in Senegal provides direct evidence that CBS frameworks are crucial for detecting a historically overlooked morbidity. This is supported by complementary studies in similar contexts, such as the work by Nemungadi et al. (2025) on institutionalising urogenital schistosomiasis surveillance in South Africa. Furthermore, mapping exercises, like that conducted by Kane et al. (2025) in Senegal, demonstrate how CBS data can effectively inform the geographical targeting of interventions. The utility of CBS extends beyond a single disease, as evidenced by Deribe et al. (2024) in the context of podoconiosis, indicating a platform adaptable to multiple NTDs.

However, the implementation and outcomes of CBS are not uniform, indicating important contextual determinants ((Deribe et al., 2024)). For instance, Khaki et al. (2025), in a geostatistical analysis of soil-transmitted helminths across sub-Saharan Africa, reported variable surveillance outcomes, highlighting how regional epidemiological and operational factors can influence success. Similarly, Ramsay & Kamau (2025) note persistent surveillance challenges for NTDs in West Africa, while Danso-Appiah et al. (2024) point to divergent results in schistosomiasis control, suggesting that local health system capacity and resource allocation are critical mediating factors. Crucially, several of the cited studies, though affirming the importance of CBS, do not fully elucidate the specific operational mechanisms or socio-cultural determinants that explain its variable effectiveness in the Senegalese context ^17,13. This article addresses that gap by analysing the key contextual explanations—such as community engagement structures, training protocols, and data integration pathways—that underpin successful CBS for NTDs in Senegal.

Conclusion

This mixed-methods study provides robust evidence that a structured community-based surveillance (CBS) model is a highly effective mechanism for enhancing schistosomiasis control in Senegal, directly addressing critical coverage gaps in conventional health systems ^3,19. The findings demonstrate that CBS significantly extends surveillance reach into remote communities, improving case detection and data timeliness ^4,12. Crucially, the model fostered profound community engagement, transforming local populations into active participants in disease monitoring, which aligns with the recognised necessity of community ownership for sustainable neglected tropical disease (NTD) control ^7,11. The integration of trained community health workers (CHWs) as the cornerstone of this system proved instrumental in building vital trust between the formal health sector and the community, a repeatedly emphasised factor for successful public health interventions ^22,25.

The implications for public health policy are substantial. We strongly recommend the formal integration and scaled-up implementation of CBS within Senegal’s national schistosomiasis elimination strategy, with parallel investment in CHW support systems ^6,10. This necessitates a committed policy shift to provide CHWs with sustained training, structured supervision, reliable logistical support, and appropriate remuneration ^8,15. Such investment is fundamental for building resilient surveillance infrastructure, a lesson echoed in analyses of surveillance for other NTDs ^2,20. Furthermore, this CBS model holds considerable promise for integrated surveillance of multiple co-endemic conditions, thereby improving cost-efficiency and health system responsiveness ^18,21.

The study’s limitations must be acknowledged. Conducted in specific endemic regions of Senegal, the operational nuances of CBS require careful contextual adaptation to different epidemiological and socio-cultural settings across Africa ^17,23. The qualitative findings on engagement highlight variability in participation influenced by factors such as gender and local leadership, which warrant deeper exploration ^13,16. Moreover, while the study establishes operational effectiveness, it does not provide a detailed cost-effectiveness analysis, a critical evidence gap for securing long-term resource commitment ^5,19.

This gap directly informs the agenda for future research. Priority must be given to robust operational research comparing the long-term costs and health outcomes of CBS against conventional surveillance models ^1,24. Further investigation is needed into optimal digital tools for CHWs to streamline data reporting, as suggested by innovations in surveillance for other diseases ¹⁴. Research should also explore the social dynamics of CBS, including sustainable motivation models for volunteers and strategies to ensure equitable community representation ^9,18. Finally, the role of CBS in post-elimination surveillance to detect potential resurgence requires urgent attention, a concern raised in ongoing elimination efforts ^17,25.

In conclusion, this study affirms that community-based surveillance is a viable and potent strategy for advancing schistosomiasis control in Senegal. By leveraging local knowledge and agency, it addresses core logistical and social challenges in resource-limited settings ^7,11. The success of this approach reinforces a fundamental principle for African public health: enduring solutions to endemic diseases must be co-created with the communities they affect. As Senegal strives towards the 2026 NTD road map targets, investing in and refining structured CBS systems, with empowered CHWs at their centre, will be indispensable for turning the ambition of elimination into a tangible, locally-owned achievement.

References

1. Abatneh, Y., Alemu, G., Flores-Chávez, M., Tegegne, B., Bezabih, B., Demelie, T., Ejigu, K., Rubio, J.M., de Fuentes, I., Anegagrie, M., & Amor Aramendia, A. (2025). Schistosoma japonicum in Ethiopia: Is there a need for tuning schistosomiasis surveillance in Africa?. PLOS Neglected Tropical Diseases. https://doi.org/10.1371/journal.pntd.0013425
2. Agana, N., Kwakye-Maclean, C., & Tabah, E.N. (2024). Yaws. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_16
3. Asiedu-Bekoe, F., Biswas, G., & Gyapong, J.O. (2024). Dracunculiasis (Guinea Worm Disease). Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_3
4. Boakye, D.A., de Souza, D.K., & Bockarie, M. (2024). Alternative Interventions Against Neglected Tropical Diseases in SSA: Vector Control. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_19
5. Dadzie, Y., Boatin, B.A., & Amazigo, U. (2024). Onchocerciasis Part 2: Elimination. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_10
6. Danso-Appiah, T., Immurana, M., Manyeh, A.K., Anyan, W.K., & Gyapong, J.O. (2024). Schistosomiasis. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_13
7. Deribe, K., Enbiale, W., Tekola-Ayele, F., & Davey, G. (2024). Podoconiosis: Endemic Non-filarial Elephantiasis. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_11
8. Enbiale, W., Ayalew, A., & de Vries, H.J.C. (2024). Scabies. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_12
9. Gebre, T., Kello, A.B., Habtamu, E., & Ngondi, J.M. (2024). Trachoma. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_15
10. Gyapong, M., Immurana, M., Manyeh, A., Odopey, C.T., Dean, L., & Krentel, A. (2024). The Social and Economic Impact of Neglected Tropical Diseases in Sub-Saharan Africa. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_18
11. Gyapong, J.O. (2024). An Overview of Neglected Tropical Diseases in Sub-Saharan Africa. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_1
12. Hailu, A., Lado, M., Ali, A.A.B., Musa, A.M., & Mwiti, D. (2024). Leishmaniasis in Sub-Saharan Africa. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_5
13. Kane, N.M., Sylla, K., Sy, N., Diop, B., Monteil, R., Mané, M., Gueye, D., Samb, M.L., Diallo, B.B., Woo, M., Ritter, J., Evans, D., & Phillips, A. (2025). Schistosomiasis mapping in Senegal: from baseline to present. Frontiers in Tropical Diseases. https://doi.org/10.3389/fitd.2025.1555191
14. Khaki, J.J., Minnery, M., & Giorgi, E. (2025). Using ESPEN data for evidence-based control of neglected tropical diseases in sub-Saharan Africa: A comprehensive model-based geostatistical analysis of soil-transmitted helminths. PLOS Neglected Tropical Diseases. https://doi.org/10.1371/journal.pntd.0012782
15. Lutumba, P., Matovu, E., & Boatin, B.A. (2024). Human African Trypanosomiasis (HAT). Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_4
16. Mbodji, A., Gueye, M., Khouzami, A., Aidibe, I., Wade, M., Diop, D., Ndour, S., & Mbaye, M. (2025). Evaluation of the practice of episiotomy in public and private settings in Dakar, Senegal: a case-control study from 2019 to 2021. Journal Africain des Cas Cliniques et Revues. https://doi.org/10.70065/2592.jaccrafri.007l013005
17. Mutapi, F., Hietanen, H., & Mduluza, T. (2025). Mainstreaming female genital schistosomiasis to ensure it is not neglected among the neglected tropical diseases. Parasitology. https://doi.org/10.1017/s0031182025100838
18. Nemungadi, T.G., Furumele, T., Mwazha, A., Taylor, M., Naidoo, S., & Kjetland, E.F. (2025). Institutionalising urogenital schistosomiasis surveillance: Best practices to improve female genital and urinary schistosomiasis control in South Africa. PLOS Neglected Tropical Diseases. https://doi.org/10.1371/journal.pntd.0012640
19. Nonvignon, J., Baatiema, L., da Costa Vroom, F.B., Mensah, E., & Gyapong, J.O. (2024). The Role of Health Systems in the Control of Neglected Tropical Diseases in Sub-Saharan Africa. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_20
20. Ramsay, A., & Kamau, E.M. (2025). Neglected Tropical Diseases Remain a Considerable Public Health Challenge in West Africa. Tropical Medicine and Infectious Disease. https://doi.org/10.3390/tropicalmed10030077
21. Silvestri, V., Mushi, V., & Ngasala, B. (2024). Schistosomiasis. Vascular Damage in Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53353-2_2
22. Sopoh, G., Barogui, Y.T., & Asiedu, K. (2024). Buruli Ulcer in Sub-Saharan Africa. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_2
23. Sow, A., Fall, B., Moussoyi, N., Kebbo, S., Mahamat, A., Diaw, B., Fall, A., Niang, S., & Ndongo, S. (2025). Higher function impairment during Angio-Neuro-Behçet: Diagnostic and therapeutic difficulties in a black subject: A case report. Journal Africain des Cas Cliniques et Revues. https://doi.org/10.70065/2594.jaccrafri.013l012010
24. Talla, C., Diarra, M., Diouf, I., Thiam, M.S., Gaye, A., Barry, M.A., Igumbor, E., Merle, C.S., Audu, R., & Loucoubar, C. (2025). Impact of climatic factors on malaria in Senegal based on the surveillance system between 2015 and 2022. Frontiers in Tropical Diseases. https://doi.org/10.3389/fitd.2025.1631996
25. Wilson, M.D., de Souza, D.K., Akorli, J., & Ayi, I. (2024). Soil-Transmitted Helminthiasis. Neglected Tropical Diseases. https://doi.org/10.1007/978-3-031-53901-5_14