P. vivax is considered the most difficult human malaria to eliminate because of the inability of conventional diagnostics to detect individuals with latent liver forms. These individuals account for 80% of all infections and can readily infect mosquitoes. Currently countries can test knowing this has little impact or and the treat everyone which exposes individuals to drugs with potentially dangerous side effects. Parasite specific antibody responses have been shown to correlate with the likelihood of hypnozoite carriage and can be used to identify individuals who should be treated. Aim is to implement a Cluster-Randomised Trial in Ethiopia and Madagascar to demonstrate the effectiveness of a new anti-malaria intervention based on Plasmodium vivax serological testing and treatment (PvSTATEM) with primaquine to prevent the relapse infections responsible for maintaining P. vivax transmission. Simultaneously, we will assess social and health system acceptability of such an approach as well as refine new mobile technologies which interface with point-of-care diagnostic tests and guide treatment decisions. We aim to reduce malaria burden at both the individual and population level in two countries which experience the highest levels of P.vivax in Africa. We expect to have a significant effect in reducing morbidity and improving health. We will ensure community engagement and assess the adoption of new technologies that align with those existing in the health system. The proposal is built on equal partnership and shared capacity to address a substantial public health burden.