Declining malaria incidence offers the opportunity to accelerate toward its elimination, which requires accurate information to target control where it is most needed and will deliver the greatest impact. The impact of environmental adaptation on vector populations, their vectorial capacity and susceptibility to control remain poorly understood. Anopheles arabiensis is common in arid areas, increasing in relative prevalence throughout sub-Saharan Africa, and is the dominant malaria-vector in Senegal. We aim to investigate how natural and anthropogenically-influenced landscape variation influences its genetic diversity, population structure and gene-flow, and how this may impact disease incidence, and aid targeting of vector control. We aim to test the hypothesis that its population structure in Senegal is impacted by both its prevailing environment and recent range expansions toward the more humid parts of the country. Furthermore, local adaptation, especially during this expansion, may have reduced genetic population sizes and genetic diversity, and gene flow between locally-adapted populations. Expected outcomes are: 1. Characterisation of An. arabiensis population structure and connectivity to provide predictions for targeted control 2. Understanding how genetic diversity, and potential adaptability/vulnerability of its populations depends on environment and range expansion 3. Investigation of how the above impact parasite diversity and vector blood feeding, and vectorial capacity. The sub-Saharan Africa region has been and still the area that carries the heaviest malaria burden. However, the incidence of malaria has been reduced significantly by the successful scaling-up of insecticide-based vector control interventions (indoor residual spraying (IRS) and long-lasting insecticide-treated nets (LLIN). The decline of malaria makes elimination a possible, especially in areas where vector populations may be particularly vulnerable such as arid regions of sub-Saharan Africa. Elimination, however, requires increasingly detailed information about the characteristics of both the vector and the parasite populations to target control optimally and to design new interventions. How the environment affects the interconnection of vector populations and their vulnerability to control is poorly understood. In this project, we propose to address this question using a combination of country-wide sampling of the major malaria vector Anopheles arabiensis in Senegal, whole genome sequencing to identify markers of local adaptation, and investigation of how environment acts as a template for population size and connectivity. The results will provide general information on vector-environment inter-relationships, and specific information on how to predict vulnerability and optimally target populations for control.

Malaria eradication efforts are severely hampered by the rapid emergence and spread of resistance in mosquitoes due to widespread use of insecticide-based vector-control tools. Recently, we have published a study proposing a novel malaria intervention strategy based on the use of a bacterial strain, Delftia tsuruhatensis TC1 (TC1 for short) and its secreted active component, Harmane (HA). The TC1-intervention interrupts malaria parasite development in mosquitoes without affecting mosquito survival and fitness thereby circumventing selection of resistant mosquitoes. Extensive studies to evaluate efficacy, safety and manufacturability have been successfully completed in both, laboratory and contained semi-field settings and further validate use of the TC1-intervention for malaria control. Although, WHO has established product evaluation pathways and regulatory pipelines for insecticide-based vector control tools these are not suited for TC1 and other ‘TC1-like’ control strategies which do not fall within the ‘main-stream’ conventional category of malaria vector-control tools. To date all vector control tools have been evaluated in cluster randomized control trials (RCTs) to demonstrate epidemiological benefit but RCTs are becoming increasingly difficult and extremely expensive to conduct as standard-of-care increases the heterogeneity between clusters, diminishes the effect size of novel interventions thereby requiring higher numbers of clusters to reliably power studies. An urgent need exists for rigorous and validated entomological metrics which infer epidemiological benefit. This project aims to develop a novel trial for generating the evidence base of the TC1-intervention in open-field settings at the scale of the individual mosquito, to help support the regulatory process and expedite the time between product development and widespread deployment. Additionally, this novel trial could be extrapolated to similar interventions for controlling vector-borne diseases.

Access to "essential goods and services" (g&s-ess) has become a core component of the new international agenda, enshrined in the Sustainable Development Goals (SDGs). This framework of universal access marks a turning point in development policy, characterized by the growing significance of financialization and climate challenge. It encourages the institutionalisation of g&s-ess markets, aiming to broaden access by attracting investment, fostering innovation in green technologies, and promoting a variety of market configurations on the supply side. The g&s-ess market now encompasses a wide array of actors—including financiers, multinationals, start-ups, and impact businesses—along with public-private partnerships, socio-technical systems (networks, decentralized mini-grids, autonomous systems), variety of regulation and governance regimes (public, private, cooperative, hybrid) and modes of supply and payment. Drawing on a multidisciplinary approach, the MARSE project investigates the social, political, and economic dimensions of markets for g&s-ess. By integrating international, national, and local perspectives, it critically examines the concept of universal access, especially with respect to supply inequalities at the heart of sustainability issues. The analysis zeroes in on the water and electricity sectors as representative of "essential goods", aiming to examine the particular market dynamics and the intrinsic tensions they confront (market and solvency, globalisation from above and below, responsibility and profitability, universality and inequality, centralisation and decentralisation). Based on the case of Senegal, which presents interesting characteristics regarding such changes, the research addresses four critical levels of inquiry: the evolution of international policies for universal access to g&s-ess and the escalating participation of the private sector in development initiatives; the role of public action in enacting new market regulations at the national level; the emergence of market configurations that lead to a diversity of offerings with disparities in price and service; and, finally, the public debates and local conflicts that surface due to issues of service inequality. The methodology is founded on an interdisciplinary approach that combines the sociology of markets, institutional economics, and planning sciences. It employs a multi-scalar perspective, tracking the social construction of g&s-ess markets from international levels to local implementations, alongside a multi-sectoral analysis to discern patterns of convergence within the institutional mechanisms of market organisation. The knowledge produced by the MARSE project will contribute to significant scientific debates surrounding the financialisation of public policies, sovereignty of African states, the dynamics of contemporary capitalism in the interplay between the global North and South, and global energy/water justice. The collaboration between PACTE, CLERSE, and LEREPS, coupled with the association with two Senegalese universities, reinforces the synergies between areas of expertise such as development policy, the marketization of public services, and the governance of water and energy in Africa.