In the Greater Mekong Subregion (GMS), mobile migrant populations (MMPs) are often considered the key at-risk group and one of the final “obstacles” to malaria elimination given how hard they can be to reach. With this in mind, in 2013 Population Services International (PSI) began working on rubber plantations in Cambodia to provide on-site malaria test-and-treat services by trained volunteers selected from among the plantation workforce. Jumping forward five years, PSI now offers malaria services on 161 plantations in Cambodia and 168 in Myanmar.
During this time, much has been learned about how to select, engage and support volunteers in order to provide testing and treatment in accordance with national guidelines, and report data on a timely basis in order to contribute to national surveillance. In 2017, PSI-supported worksites conducted 25,827 rapid diagnostic tests and correctly treated 1,351 confirmed cases. This is not insignificant in areas of rapidly declining cases, but is it enough? New innovations have been rolled out to boost testing rates, but worksite positivity rates remain much lower than PSI’s other private sector networks. We began questioning our approach to the extent that it was decided not to replicate the program in Lao or Vietnam, where screening events revealed that worksites were not transmission hotspots.
So if not worksites, then where are the cases? Are MMPs a red herring? Recent evidence suggests that not all MMPs are at-risk of malaria, and not all people at-risk of malaria are MMPs. Routine data from PSI’s 20,000-strong private sector networks across four GMS countries are increasingly pointing to forest-goers, which can represent ethnic minorities and other marginalized groups. PSI is now testing approaches through non-health outlets frequented by these groups, and conducting participatory community research to co-create new interventions to reach those most in need.