Y1 Progress report | Grite Mwaijengo

An Integrated Framework for Sustainable Schistosomiasis Control in a Changing Climate: A One Health Approach for Northeastern Tanzania

During the initial phase of the fellowship, I undertook several foundational activities to ensure the smooth, effective implementation of the project. I conducted stakeholder consultations through both virtual and in-person meetings across the project catchments, engaging key stakeholders from the water, environment and health sectors. These consultations fostered a shared understanding of the project’s objectives, strengthened stakeholder engagement, and generated valuable input that informed project implementation and established a clear roadmap toward achieving the expected outputs.

Study design, protocol development, site selection, research approvals, and evidence synthesis

Between July and September 2025, I developed field sampling protocols in collaboration with scientists from the National Institute for Medical Research (NIMR) to ensure alignment with national research standards and best practices. During the same period, I conducted a desktop mapping exercise to identify potential sampling sites, including lakes, ponds, reservoirs, slow-moving sections of rivers and streams, irrigation canals, rice paddies, drainage channels, swamps, and seasonal wetlands. These sites were prioritised based on their suitability as habitats for intermediate host snails and their high levels of human–water interaction, making them high-risk environments for schistosomiasis transmission. In addition, I have continued conducting a comprehensive literature review to strengthen the study's scientific foundation and compiled available secondary data on schistosomiasis prevalence in the study area.

These activities have informed the development of a draft position paper titled “Beyond the Pill: Integrating One Health, Eco-Hydrology, and Climate Science for Sustainable Schistosomiasis Control in Tanzania”, which is planned for submission. I also prepared and applied for a research permit to support field activities, which was subsequently granted on 15 December 2025 by the Tanzania Commission for Science and Technology (COSTECH).

Stakeholder engagement and transdisciplinary collaboration

On 18 September 2025, a stakeholder engagement workshop was organised at the Lake Jipe catchment in collaboration with the Mwanga District Council. The workshop brought together stakeholders, including the Pangani Basin Water Board, the National Environmental Management Council Northern Tanzania Zone, Mwanga District Council, health and environmental practitioners, NGOs, and local communities. It provided a platform for discussing environmental and public health challenges in the catchment and enhanced stakeholder awareness of socio-ecological conditions and waterborne disease risks under climate and environmental change. The discussions underscored the importance of collaborative, transdisciplinary approaches to addressing water-related diseases. The workshop also laid a strong foundation for subsequent fieldwork, household surveys, and interviews, and strengthened a collaborative network essential for long-term project sustainability.

Field data collection and ecohydrological surveys

Three comprehensive fieldwork sessions were conducted in the Lake Jipe, Babati, and Manyara catchments, generating essential ecohydrological, habitat condition, and land-use data. A total of 126 sites were visited and sampled across multiple habitat types, including slow-moving rivers and streams, irrigation canals, ponds, swamps/wetlands, lakes, and rice paddies. Site selection prioritised areas with high human-water and animal-water interaction, particularly livestock and wildlife access points. Multiple data domains were collected, including snail populations and species, macroinvertebrates, ecological and epidemiological parameters, water quality, human-water interaction and exposure patterns, and land-use characteristics. In addition, more than 200 environmental and biological samples were collected and transported to NM-AIST for analysis.

Snail distribution, seasonality, and transmission ecology

Field observations revealed considerable spatial variation in the distribution of intermediate host snails across sampled sites. At several locations, no intermediate host snails were detected. In some communities, molluscicide use was reported, and only empty shells were observed, suggesting possible local snail control interventions.

The field surveys also provided ecological insights into seasonality. The dry season appeared more favourable for detecting snails due to lower water levels and stable environmental conditions. In rice paddy ecosystems, agricultural practices strongly influenced snail occurrence, with reduced abundance observed during early land preparation and following pesticide application. The most frequently encountered intermediate host snails belonged to the genus Bulinus, the principal intermediate host of Schistosoma haematobium. Biomphalaria spp., the intermediate host of Schistosoma mansoni, were recorded at only twelve sites. Additionally, Bulinus spp. potentially associated with Schistosoma bovis were identified, highlighting the importance of the human-livestock-environment interface and reinforcing a One Health approach.

Field innovation: Mobile laboratory and sample processing

One of the most innovative aspects of the project was the establishment of a mobile field laboratory during sampling campaigns. Live Bulinus and Biomphalaria snails were required for cercarial shedding experiments, and selected water samples required processing within 48 hours. Given that laboratory facilities were more than 150 km away, a temporary mobile laboratory was established in collaboration with local communities. This ensured the timely processing of samples while strengthening community participation in research. Laboratory work is ongoing. Parasite samples have been preserved on FTA cards for molecular analysis, while snail specimens have been stored in 99% ethanol for molecular characterisation and 70% ethanol for taxonomic identification. Data analysis is underway in preparation for a second manuscript that examines relationships among environmental conditions, snail distribution, and parasite occurrence.

Operational challenges and adaptive strategies

Several logistical challenges were encountered during fieldwork. These included damage to field equipment (scooping net) and restricted access to sites due to poor road conditions following heavy rainfall. Adaptive strategies such as community-supported repairs and flexible sampling schedules ensured continuity of field activities. Lessons learned include the importance of backup equipment, flexible field planning, and strong community collaboration to manage logistical constraints effectively.

Key informant interviews and epidemiological insights

Key informant interviews were conducted with 30 key informants across the three catchments, including diverse stakeholders such as health officers, water officers, environmental officers, teachers, fishermen, extension officers, and community leadership representatives. Most informants demonstrated a good understanding of schistosomiasis transmission and environmental drivers. They indicated that climate change is one of the emerging threats to most waterborne diseases. Health officers reported low perceived prevalence but emphasised the need for clinical and parasitological confirmation. These findings highlight the need for systematic stool and urine-based surveys to assess Schistosoma mansoni and Schistosoma haematobium infection levels, particularly among high-risk groups such as children, women, and fishing communities.

Emerging outputs, impact, and knowledge translation

The combined field and laboratory datasets provide a robust empirical foundation for achieving project outputs, particularly the development of spatial risk maps of schistosomiasis transmission hotspots and snail habitats. These outputs support the co-production of policy-relevant evidence and contribute to the long-term co-production of an integrated framework for sustainable schistosomiasis control. Beyond scientific outputs, the project has strengthened local awareness of schistosomiasis and established a collaborative stakeholder network. This platform supports dialogue, prioritisation, and integrated disease management approaches, facilitating translation of research into policy and practice.

Annual report submitted by Dr Grite Mwaijengo

(summarised for publication by Heidi Sonnekus for the FAR-LeaF Programme)