This PhD opportunity is being offered as part of the LSTM and Lancaster University Doctoral Training Partnership. Find out more about the studentships and how to apply.
| Abstract | Malaria prevention still relies greatly on vector control (VC) interventions. However, increasing levels of resistance to pyrethroids across Africa have significantly reduced the efficacy of pyrethroid-based interventions contributing to a stagnation and/or an increase of malaria burden. Consequently, it is imperative to expand the toolbox for VC to turn the tide and accelerate malaria control and elimination efforts. Recent clinical trials have demonstrated that spatial repellents (SR) can provide protective efficacy against malaria (PMID 35382856; PMID 39709979), which led the World Health Organization (WHO) to issue a conditional recommendation for the use of SRs in malaria prevention in 2025. The tested intervention lasted, according to manufacturing instruction, for 28 days but a new device has been developed that affords annual protection. This brings advantages logistically and ecologically, both reducing delivery costs and waste management. A full recommendation by WHO remains critical to accelerate SR adoption and deployment by control programmes on top of the understanding of their effectiveness in different field epidemiological settings or against different vectors species. Catalyzing SR adoption will also require their proven ability to overcome current insecticide resistance challenges, to control invasive species, particularly in urban environments, their cost effectiveness, and the best strategies of deployment alongside existing tools. The CANVeCT project, led by Prof Charles Wondji, CRID, Cameroon (https://unitaid.org/news-blog/unitaid-funded-research-drives-who-recommendation-of-spatial-repellents-the-first-new-malaria-vector-control-tool-in-decades/), will conduct a randomized controlled trial (RCT) to generate evidence for a full recommendation. This new trial must include robust social studies and ecological impact assessment as key components along with establishing clear oversight and shared governance mechanisms. The RCT will be implemented in Cameroon to demonstrate the protective efficacy of SRs either in combination with long-lasting insecticide treated nets (ITNs) or as a standalone intervention, learning from previous trials to maximise trial quality, and to ultimately enable robust evaluation of SRs for malaria prevention by the WHO. CANVeCT will implement this RCT in a region of poor coverage and low use ITNs, with high transmission, and elevated pyrethroid resistance from a diverse range of malaria vectors allowing the project to establish their comparative efficacy both when combined and when used alone, which is a key factor for the market shaping plans. All insecticidal interventions are tested for their safety against non-target organisms prior to use by humans (Vector Control Product List | WHO - Prequalification of Medical Products (IVDs, Medicines, Vaccines and Immunization Devices, Vector Control)). A series of tests confirm or not that the product dose is safe, or an acceptable risk, if experienced by mammals, birds, fish, other aquatic organisms, invertebrates and flora through inhalation, ingestion or dermal contact. However, these laboratory based assessments lack the ecological detail of real environments. The transfluthrin spatial repellent product continually releases volatile transfluthrin into the peridomestic space. This chemistry could settle on surfaces depending on microclimatic conditions, and if food is left exposed, this is a feasible exposure route for household members. The scaled use of the product throughout communities also means that the potential dose and residue from the volatile chemistry might cause ecological harm that is not highlighted by the preliminary safety testing process. Ecological impact assessments are not regularly performed at the RCT stage, nor for scaled interventions once they have achieved recommendations, probably due to a lack of funding. We have an opportunity here to both rigorously test the ecological and public safety of a product that is likely to be the next major intervention against malaria vectors, and to establish standard protocols for testing the ecological safety of the products to follow. The explicit questions in this space that CANVeCT sets out to answer include:
Thus, the PhD Candidate would be ideally based in Cameroon and co-supervised by Prof Charles Wondji, Dr Magellan Tchouakui and Dr Ellie Sherrard-Smith. This is a fantastic opportunity to work within a consortium of international partners and contribute to delivering public health and creating environmentally responsible practice for scaled interventions. Results of this project will be regularly disseminated to stakeholders including: i) through a large focus on community, civil society and NMCP engagement to support optimal deployment decisions; ii) dissemination to Cameroon and observer countries with a focus on operational decision making; iii) through transmission models, by generalising results to explore efficacy and cost-effectiveness given different ecological scenarios and to inform decision-making on implementation options in various settings; iv) by providing the results to the WHO with the aim of informing evolution of the recommendation on SRs; v) and other dissemination routes notably through engagement with global implementers. Altogether, through a comprehensive set of studies, method development, operational research studies, and market shaping activities for SRs - that the PhD candidate can contribute to and learn from - CANVeCT will generate high-quality outputs including an evaluation framework and resources that include a database of methods and transmission modelling that will be readily applicable to other future vector control tools. A successful implementation of this project will facilitate the adoption and effective deployment of novel tools across malaria-endemic regions to help reduce malaria burden. |
| Where does this project lie in the translational pathway? | T1 - Basic Research,T2 - Human /Clinical Research,T3 - Evidence into Practice ,T4 - Practice to Policy/Population |
| Methodological Aspects | Environmental Impact Assessments will be designed that focus on generating quantifiable data to assess outcomes on species diversity, abundance of health signals. Survey efforts will be longitudinal, ideally performed monthly throughout a baseline year and for at least 1 year follow up. Analysis will involve development of methods that consider time series data before and after an action; consideration of potential interannual variability in seasonal abundance, and a collection of potential covariates that could be informative to the analysis (differences in use of interventions between clusters, habitat specifics and conditions [temperature, humidity - that could impact evaporation rates of active ingredients within spatial repellent devices]) The development of Standard Operating Procedures for assessment of impacts from scaled interventions will follow The candidate will also be able to learn about Life Cycle Assessments and CO2e emission estimates - with outcomes feeding into wider work assessing vector control with a One Health Perspective. Here, the aim is to develop algorithms allowing decision makers to evaluate products across an array of dimensions faciliating strategies to be developed that align with specific ethics of the implementer (e.g. weighting decisions toward ecological outcomes, or emissions targets, or price restrictions, or regularity of replacement etc). |
| Expected Outputs | Key outcomes will be: evidence of any perturbation to the ecosystem that can be attributed to the use of spatial repellents in the Cameroon context (Publication 1); quantification and comparison of the emissions from the delivery of a scaled spatial repellent and insecticide treated net (ITN) campaign in the Cameroon context (Publication 2); development of Standard Operating Protocols to assess Environmental Impact from scaled vector control - feasibility, costs, benefits and limitations (Publication 3) CANVeCT is funded by Unitaid to deliver the cost-effectiveness estimates for the Guardian product that offers year-long protection to users. The PhD candidate will be exposed to a comprehensive set of studies, method development, operational research studies, and market shaping activities for SRs - contributing wherever feasible. This opportunity will offer huge additional benefit to generate detailed information on environmental impacts that are rarely considered for scaled interventions for malaria control. |
| Training Opportunities | The student will be able to train with the field team for all survey work. Analytical training opportunity will be identified to upskill the student in ecological analyses and statistical analysis. The student can attend the workshops and ultimately help deliver workshops to different stakeholders - building their skills in communication of research. The complementary skills sets of the 3 supervisors will ensure the student has access to each training element required. |
| Skills Required | Quantitative skills in approaching research R skills are advantageous Ecological perspective of interactions in ecosystems Experience in fieldwork is advantageous |
| Subject Areas | Malaria & Other Vector Borne Diseases |
| Key Publications associated with this project |
Evaluation of the protective efficacy of a spatial repellent to reduce malaria incidence in children in Mali compared to placebo: study protocol for a cluster-randomized double-blinded control trial (the AEGIS program): https://pubmed.ncbi.nlm.nih.gov/35382856/ Effect of a spatial repellent on malaria incidence in an area of western Kenya characterised by high malaria transmission, insecticide resistance, and universal coverage of insecticide treated nets (part of the AEGIS Consortium): a cluster-randomised, controlled trial: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)02253-0/fulltext Sherrard-Smith et al 2025 Heterogeneous impacts for malaria control from larviciding across villages and considerations for monitoring and evaluation: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1013287 Recommendations for environmental risk assessment of gene drive applications for malaria vector control: https://malariajournal.biomedcentral.com/articles/10.1186/s12936-022-04183-w |