Development and validation of serological markers for detecting recent exposure to Plasmodium vivax infection

In order to accelerate towards malaria elimination, improved targeting of limited resources is essential. A major gap in our elimination toolkit forPlasmodium vivaxmalaria is the identification of individuals carrying arrested liver stages, called hypnozoites. These clinically silent but frequently relapsing hypnozoites are key toP. vivaxpersistence. Whilst hypnozoites cannot be directly detected, individuals who have had recent exposure toP. vivaxand have not been treated are likely to harbor these parasites. By measuring IgG antibody responses to over 300P. vivaxproteins, a panel of serological markers capable of detecting exposure toP. vivaxinfections in the prior 9-month period was identified and validated. Using antibody responses to 8P. vivaxproteins, 80% sensitivity and specificity for detecting recent infections were achieved in three independent studies conducted in Thailand, Brazil and the Solomon Islands. As these individuals have a high likelihood of harboring hypnozoites, the suite of these 8 antibody responses can serve as biomarkers for the identification of individuals who should be targeted for treatment with liver-stage drugs such as primaquine and tafenoquine in mass drug administration programs aimed at controlling and eliminatingP. vivaxmalaria.One Sentence SummaryThe manuscript describes identification and validation of a novel panel of P. vivax proteins that can be used to detect recent exposure to P. vivax infections within the prior 9 months.