Radical cure for Plasmodium vivax malaria after G6PD qualitative testing in four provinces in Cambodia, results from Phase I implementation

• Published in: Malaria Journal
• Main Authors: Dysoley Lek, Yu-Cheng Tsai, Jillian Hirano, Siv Sovannaroth, Voeurng Bunreth, Prak Vonn, Or Vannthen, Tol Bunkea, Top Samphornarann, Nguon Sokomar, Mak Sarath, Soy Ty Kheang, Evelyn Wong, Michelle K. Burbach, Jayme Hughes, Huy Rekol
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2024
• Subjects: Malaria; Radical cure; Cambodia; Plasmodium vivax; Glucose-6-phosphate dehydrogenase; 8-aminoquinoline; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-024-04884-4; https://doaj.org/article/2c7c141c70024d6f81d5a5f299896045

Abstract Background Cambodia aims to eliminate all forms of malaria by 2025. In 2020, 90% of all malaria cases were Plasmodium vivax. Thus, preventing P. vivax and relapse malaria is a top priority for elimination. 14-day primaquine, a World Health Organization-recommended radical cure treatment regimen, specifically targets dormant hypnozoites in the liver to prevent relapse. Cambodia introduced P. vivax radical cure with primaquine after glucose-6-phosphate dehydrogenase (G6PD) qualitative testing in 2019. This paper presents Cambodia’s radical cure Phase I implementation results and assesses the safety, effectiveness, and feasibility of the programme prior to nationwide scale up. Methods Phase I implementation was carried out in 88 select health facilities (HFs) across four provinces. Males over 20kgs with confirmed P. vivax or mixed (P. vivax and Plasmodium falciparum) infections were enrolled. A descriptive analysis evaluated the following: successful referral to health facilities, G6PD testing results, and self-reported 14-day treatment adherence. P. vivax incidence was compared before and after radical cure rollout and a controlled interrupted time series analysis compared the estimated relapse rate between implementation and non-implementation provinces before and after radical cure. Results In the 4 provinces from November 2019 to December 2020, 3,239 P. vivax/mixed infections were reported, 1,282 patients underwent G6PD deficiency testing, and 959 patients received radical cure, achieving 29.6% radical cure coverage among all P. vivax/mixed cases and 98.8% coverage among G6PD normal patients. Among those who initiated radical cure, 747 patients (78%) completed treatment. Six patients reported side effects. In implementation provinces, an average 31.8 relapse cases per month were estimated signaling a 90% (286 cases) reduction in relapse compared to what would be expected if radical cure was not implemented. Conclusions Plasmodium vivax radical cure is a crucial tool for malaria elimination in Cambodia. ...