Evaluation of the Wondfo G6PD/Hb Test for glucose-6-phosphate dehydrogenase deficiency: preliminary performance, matrix equivalence, and usability

(2025) 24:201 Green et al. Malaria Journal https://doi.org/10.1186/s12936-025-05436-0 Malaria Journal Open Access RESEARCH Evaluation of the Wondfo G6PD/Hb Test for glucose‑6‑phosphate dehydrogenase deficiency: preliminary performance, matrix equivalence, and usability Rebecca K. Green1*, Stephanie Zobrist1, Gornpan Gornsawun2, Paw Khu Moo2, Laypaw Archasuksan2, Huyen Nguyen3, Huong Nguyen3, Cindy S. Chu2,4, Emily Gerth‑Guyette1, Podjanee Jittamala5, François Nosten2,4, Sampa Pal1, Germana Bancone2,4 and Gonzalo J. Domingo1 Abstract Background Current treatment guidelines for radical cure of Plasmodium vivax malaria recommend the use of 8-ami‑ noquinolines, which can result in life-threatening complications in people with glucose-6-phsophate dehydrogenase (G6PD) deficiency. Testing for this condition is recommended prior to administering such drugs. The Wondfo G6PD/ Hb Test (Guangzhou Wondfo Biotech Co., Ltd., China) is a novel, quantitative point-of-care (POC) G6PD test that may help decentralize testing, expanding access to safe treatment options. Methods Two studies were conducted: a retrospective diagnostic accuracy study on frozen venous whole blood specimens and a prospective matrix equivalency study. First, 300 frozen specimens from Mae Sot, Thailand were tested from July–August 2022 using the Wondfo test in laboratory and simulated field conditions. Reference testing for G6PD and Hb (spectrophotometer [Pointe Scientific, USA] and HemoCue [HemoCue AB, Sweden], respectively) was completed in the laboratory. Usability was evaluated among 10 intended users. Next, 225 participants were enrolled into a prospec‑ tive matrix equivalency study from March–May 2023 in Memphis, Tennessee, USA. The Wondfo test was conducted at the POC with fingerstick capillary blood, and Wondfo and HemoCue tests were completed on fresh venous ( K2EDTA) blood within 12 h. Remaining specimens were shipped to PATH for repeat Wondfo and reference testing. Results The Wondfo G6PD measurement showed strong correlation under both laboratory and field conditions (R2>0.9). The area under the curve was 1.00 for deficient (95% CI: 1.00–1.00) and 0.99 for intermediate individuals (95% CI: 0.99–1.00). Sensitivity was high (1.00) across all conditions and groups (lower bound of the 95% CI ≥0.85). Good correlation was observed in both capillary and fresh venous blood against the reference and each other ( R2>0.75). McNemar’s test showed no significant differences in classification between venous and capillary specimens. The Wondfo test achieved 98.2% (95%CI: 95.5–99.5%) overall agreement. All usability participants successfully completed quality control and test procedures, rating the test system highly for ease of use. Conclusions The Wondfo G6PD/Hb Test demonstrates good diagnostic performance using current manufac‑ turer thresholds across various conditions and both venous and capillary specimens. Comparable performance in both specimen types supports matrix equivalence. Usability is acceptable for end users, though refinements were recommended. *Correspondence: Rebecca K. Green Full list of author information is available at the end of the article © The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Green et al. Malaria Journal (2025) 24:201 Page 2 of 10 Keywords Plasmodium vivax, Glucose-6-phosphate dehydrogenase (G6PD), Point-of-care testing, Radical cure, Primaquine, Tafenoquine Background Malaria remains a significant global health challenge, with an estimated 249 million cases and 608,000 deaths reported in 2022 [1]. This burden is disproportionately high in Africa, which accounts for 94% of malaria cases and 95% of malaria deaths [1]. While Plasmodium falciparum is the most prevalent and deadly of the malaria parasites, Plasmodium vivax also poses a significant threat due to its ability to cause recurrent infections from the dormant liver stage parasite [2]. Plasmodium vivax is most common in Asia and Latin America, contributing significantly to the overall malaria burden and causing severe illness as well as economic disruption in affected regions [2]. A variety of options exist for the treatment and prevention of malaria, including drugs in the 8-aminoquinoline family such as primaquine and, more recently, tafenoquine. These drugs are the only ones capable of radical cure, preventing relapse and eliminating liver stage parasites in P. vivax infections. People deficient in the glucose-6-phosphate dehydrogenase (G6PD) enzyme, however, are particularly susceptible to adverse health outcomes from radical cure treatments, including acute haemolytic anaemia. Due to these risks, the World Health Organization (WHO) recommends that “the G6PD status of patients should be used to guide administration of either primaquine or tafenoquine for preventing relapse [3].” Specifically, for administration of tafenoquine as well as high dose primaquine (1 mg/kg/day for 7 days), individuals should have G6PD activity above the threshold corresponding to 70% of normal [3, 4]. To date, a few qualitative tests for G6PD deficiency are available, including the fluorescent spot test as well as some lateral flow rapid diagnostic tests (CareStart G6PD RDT, AccessBio, USA and BinaxNOW G6PD Test, Alere, USA). These qualitative tests, however, cannot distinguish between normal and intermediate activity in heterozygous females, limiting safe treatment access for half the population [5–7]. Other assays, such as genetic and quantitative assays as well as qualitative assays such as the fluorescent spot test, require laboratory equipment and facilities, making them ill-suited to point-of-care (POC) testing. To date, only one commercially available quantitative POC G6PD test, the STANDARD™ G6PD Test (SD Biosensor, Republic of Korea), has been WHO Prequalified and widely used to support administration of radical cure treatments in endemic countries at the POC [8–13]. The availability of additional POC G6PD testing platforms is needed to enable radical cure treatment and support elimination efforts [14–16]. To address this gap, Guangzhou Wondfo Biotech Co., Ltd. (China) has developed the Wondfo G6PD/Hb Test, a quant (...truncated)