Plasmodium falciparum Asymptomatic infections: treating Carriers to explain and impact Transmission – FACE-IT

Plasmodium falciparum malaria persists in Sahelian Africa, where incidence follows a highly seasonal pattern. In the near-absence of mosquito vectors, parasites depend on human hosts to survive the dry season. This carriage is generally asymptomatic and remains untreated allowing parasites hosted by chronically infected individuals to reignite transmission when favourable conditions return. An intervention depleting this reservoir could fill a gap in existing malaria control strategy.

To exploit the dry season transmission bottleneck efficiently, we need to understand:
- how transmission restarts at the onset of the rainy season
- how to intervene most efficiently against this carriage
- how to integrate such intervention in ongoing control strategies.

We will address these challenges in a population study conducted in Kedougou region, Senegal. We will conduct a pilot trial comparing 4 intervention villages receiving mass drug administration (MDA) to deplete the reservoir to 4 control villages, followed over 18 months (2 transmission seasons).
We will evaluate feasibility, safety, acceptability, effectiveness of the intervention, and its process.
We will compare transmission dynamics between depleted (intervention) vs full parasite reservoir (control). We will assess the contribution of parasite importation (newcomers and mobile inhabitants) and of infection persistence throughout the dry season) with highly sensitive molecular detection tools and genomics.
We will integrate these results into relevant evidence for Malaria Control Programs and Health Systems of Sahel countries, by analysing the cost-effectiveness of the proposed strategy, and conducting a regional geoepidemiological analysis of onset dynamics to propose target intervention areas.

Our results will shed light on the community-level dynamics of transmission restoration, and provide evidence to design high impact interventions towards malaria elimination.