Rintis Noviyanti, PhD
Prof J Kevin Baird, PhD, FASTMH
Sponsor: Eijkman Institute for Molecular Biology
Funder: Bill and Melinda Gates Foundation. Contract with the Walter and Eliza Hall Institute of Medical Research.
All current malaria diagnostic tests are based on directly detecting parasites or parasite antigens in the blood of a patient suffering an acute febrile illness. There is no test or tool known to be practical in making a diagnosis of hypnozoites in the liver. Clinical studies have shown that relapses contribute up to 80% of all P. vivax blood-stage infections, clinical episodes and gametocyte carriage. Therefore, it is very important to be able to identify and treat hypnozoite carriers. Walter and Eliza Hall Institute (WEHI) have developed a panel of immunogenic P. vivax antigens to identify if a person has been exposed to P. vivax in the previous 9-12 months (US preliminary patent 62438963). Such a test could then be used to identify and target the dormant reservoir of P. vivax infections in any endemic population. While WEHI have demonstrated the ability of the pilot serological markers to be able to identify people with both concurrent and recent past P. vivax infections with good precision, their ability to also identify the people with the highest risk of relapse is yet to be demonstrated. Such proof-of-concept of a serological biomarker of hypnozoite carriage can be done in longitudinal cohort studies where subjects have been exposed to infection but then removed from that risk for follow-up. Under these circumstances, an occurrence of patent parasitemia may be firmly attributed to relapse rather than reinfection. At the end of follow-up, we can know with certainty who carried hypnozoites at baseline and who did not. Our study aims to identify individuals with hypnozoites positive versus hypnozoite negative using a combination of serological antigens.
Coordinator: Rintis Noviyanti