Vivax malaria elimination efforts have been hampered in the past because of lack of easy to use point-of-care tests to diagnose G6PD deficiency. SMRU has carried out a malaria elimination program in Karen state (Eastern Myanmar) since 2014 and has recently started providing radical cure for P. vivax at the village level using G6PD RDTs in malaria positive patients. As an alternative strategy to provide a G6PD diagnosis to be used in future malaria cases, G6PD surveys in malaria endemic villages have been conducted to identify villagers with deficient and intermediate G6PD phenotypes using the STANDARD G6PD test (SD Biosensor). Test users were trained during a 1-day training session with demonstration and hands-on practice. Appropriate counselling materials about G6PD deficiency were developed in the local languages, including a “G6PD card” with diagnosis.
From November 2020 to July 2021, 5510 subjects (2912 females and 2598 males) aged 6 months to 99 years were screened in 23 villages; 5469 valid results were obtained. G6PD activities ranged from 0.1 to 20.0 IU/gHb; activity in males followed the expected bimodal distribution. Based on manufacturer’s activity thresholds, 841 (15.4%) subjects were diagnosed as G6PD deficient, 522 (9.5% of total, 17.9% of females) as G6PD intermediate and 4106 as G6PD normal. Genotype for Mahidol variant was performed on a representative subgroup of samples with deficient, intermediate and normal G6PD activities.
The Biosensor test was easy to use, provided results in 99.3% of sample tested and could reliably identify both intermediate and deficient phenotypes. Counselling was well received by the population and test results G6PD cards were provided to all subjects. Use of G6PD quantitative POC tests in future malaria elimination efforts will provide an extremely valuable tool to support radical cure with different hypnozoitocidal regimens, including single dose tafenoquine.