In endemic zones, the activation of hepatic hypnozoites is responsible for over 80% of all Plasmodium vivax blood-stage acute attacks. Currently, there is no diagnostic tool to detect this dormant stage. As relapse usually occurs within 4 weeks to 9 months, a validated panel of serological exposure markers (SEMs) that signal within this period may identify most individuals who are likely to harbour hypnozoites. The use of these new antigens in a serological screen and treatment strategy is therefore predicted to prevent recurrence and thus potentially reduce P. vivax transmission.
One thousand two hundred ninety-eight schoolchildren aged 6-15 years have been screened as of August 2022. Microscopic examination was performed on 622 of these screened subjects, and 10 (2%) were found positive for malaria. Nine hundred thirty-four subjects were enrolled and actively followed every month to calculate the incidence rate over a 9-month period. Among these subjects, 76 (8%) were found seropositive during the enrolment.