WHO prequalifies diagnostic test for safer administration of P. vivax malaria treatments
To improve efficiency, access
On December 18, 2024, the World Health Organization (WHO) prequalified the first diagnostic test for glucose-6-phosphate dehydrogenase (G6PD) deficiency. This breakthrough will help safely administer WHO-recommended treatments to prevent relapse of Plasmodium vivax (P. vivax) infection, a significant advancement in global malaria control efforts.
The pre-qualification of this G6PD diagnostic test represents a crucial step in ensuring the safe and effective treatment of P. vivax malaria. The test is expected to support the broader use of medicines that prevent relapses, including tafenoquine, a key medication now available to combat P. vivax. Malaria continues to claim over 500,000 lives annually, with children being the most vulnerable.
This milestone follows the early December prequalification of two tafenoquine products for anti-relapse treatment of P. vivax malaria. These medications, recommended in updated WHO guidelines released in late November 2024, are now more accessible due to WHO’s prequalification efforts.
This suite of actions by WHO reflects the organisation’s updated, streamlined processes for developing health product recommendations and overseeing their prequalification. While these processes remain separate, their alignment ensures faster access to essential treatments for low—and lower-middle-income countries. This shift is designed to speed up the delivery of life-saving health products and improve global health equity.
P. vivax malaria, endemic in most regions except Europe, was responsible for an estimated 9.2 million cases globally in 2023. It is the dominant malaria parasite in many countries outside sub-Saharan Africa.
However, treating P. vivax infections can be complicated by the widespread prevalence of G6PD deficiency, a genetic condition affecting over 500 million people worldwide. Without reliable testing for this deficiency, it has been challenging to provide anti-relapse therapies safely.
Certain medications used to prevent malaria relapses, such as primaquine and tafenoquine, can cause dangerous side effects in people with G6PD deficiency, including haemolysis (destruction of red blood cells). G6PD testing can help clinicians determine which patients are at risk and tailor their treatment plans accordingly, ensuring the safe administration of anti-relapse drugs.
“The prequalification of this G6PD enzyme test for patients with P. vivax malaria can help countries enhance access to much-needed, quality-assured tests, enabling safe and effective treatment,” said Dr Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products.
She encouraged the submission of more diagnostic tools to expand the options available to healthcare systems.
Dr Daniel Ngamije Madandi, Director of WHO’s Global Malaria Programme, added that broader availability of G6PD tests would strengthen global efforts to reduce P. vivax infections by preventing relapses and curbing transmission.
The Standard G6PD System, developed by SD Biosensor, Inc., is a semi-quantitative, near-patient tool that measures G6PD enzyme activity in whole blood. It operates with the Standard G6PD Analyzer, a handheld device that provides minute results and is suitable for laboratory and non-laboratory settings.
This WHO prequalification marks a significant step in the global fight against malaria and reinforces the organisation’s commitment to improving public health in the world’s most vulnerable regions.
Image: P. vivax malaria is the dominant malaria parasite in many countries outside sub-Saharan Africa. Credit: Jimmy Chan
