Advancing Mycobacterium leprae transmission research: Insights from the R2STOP fund

Leprosy remains a significant public health burden in many low- and middle-income countries, with the transmission pathways of Mycobacterium leprae remaining incompletely understood. The Research to Stop Transmission of Neglected Tropical Diseases (R2STOP) fund was established by two NGOs to address this gap by supporting research projects focused on M. leprae transmission. This article outlines R2STOP's selection process for funding projects and summarizes the impact and findings of the resulting research, illustrating the collective progress in understanding M. leprae transmission.

The funding priorities established by R2STOP in the call were: (i) human-to-human transmission, (ii) non-human reservoirs, (iii) host-pathogen interactions and (iv) transmission networks. R2STOP allocated a total budget of CAD one million to support research projects focused on M. leprae transmission. The selection process involved remote reviews of letters of intent and full proposals, followed by an in-person proposal review meeting where projects were evaluated based on criteria such as significance, innovation, approach, and environmental impact. Final selections were made by a Scientific Review Committee, resulting in the funding of six projects. The funded projects all yielded significant findings from exploring a variety of topics such as persistent transmission in the Comoros islands; the potential role of patients and soil in transmission; ticks' role in transmission to hosts; biomarkers for leprosy progression; ofloxacin resistance in India; and methods to grow M. leprae on axenic media. Twenty-four MSc and PhD students were involved in the six funded research projects, and 29 scientific articles were published.

The R2STOP funding scheme played an important role in advancing our understanding of M. leprae transmission pathways and showcased the relevance of having funds allocated to this neglected aspect of leprosy control. Relevant research continues to be supported through the Leprosy Research Initiative.