Towards malaria elimination: Innovative tools and interventions to accelerate interruption of transmission in The Gambia

Project summary

Between 2000 and 2015, the scale-up of insecticide-treated bed nets (ITNs), indoor residual spraying (IRS), and artemisinin-based combination therapy (ACT) resulted in a substantial reduction of malaria morbidity and mortality worldwide, including in sub-Saharan Africa.  These remarkable achievement have renewed interest for malaria elimination and eradication. However, despite such substantial reduction in malaria burden, malaria elimination may be more difficult to achieve as in recent  years progress has stalled. It is widely acknowledged that with the current tools, malaria elimination would not be attainable. Therefore, innovative tools, strategies and interventions are required to achieve elimination.

In The Gambia, the malaria burden substantially decreased over the past two decades and the country is now targeting elimination for 2025. Nevertheless,  despite the high coverage of standard control interventions, malaria transmission has not been interrupted, especially in eastern Gambia. In a low transmission setting such as The Gambia, the challenge to achieve elimination is to target the hidden parasite reservoir in the human host. Sub- patent infections, which are detectable by only molecular diagnostic methods represent most of the reservoir of human infections. Current routine diagnostic tools, i.e., microscopy and malaria rapid diagnostic tests (RDTs) are unable to detect such infections, missing up to 80% of them. Therefore, the human reservoir of infection should be targeted with innovative tools and interventions. These include mass drug administration (MDA) of at-risk populations with an effective antimalarial (ACTs) or complemented with existing drugs (ivermectin, primaquine);   field deployment of an improved diagnostic test  for  surveillance and mass screening and treatment. Additionally, innovative tools such as controlled human malaria infection (CHMI) model would accelerate development of efficacious malaria vaccines and drugs.

The aim of this doctoral research is to evaluate innovative tools and interventions to support malaria elimination efforts in The Gambia and beyond.  Specific objectives are as follows:

  1. Determine the diagnostic accuracy of a highly sensitive Rapid Diagnostic Test:  Alere™ Malaria Ag P.f;
  2. Determine the impact of mass drug administration of ivermectin and dihydroartemisinin-piperaquine on malaria transmission in Gambian communities with high coverage of vector control interventions;
  3. Determine the efficacy and safety of three different treatment regimens of pyronaridine – artesunate in malaria-infected asymptomatic individuals and
  4. Assess the perception and acceptability of controlled human malaria infection (CHMI) studies in Gambian communities