G6PD testing for P. vivax malaria treatment

In September 2022, MedAccess and PATH partnered with SD Biosensor to secure supply of its G6PD testing devices and strips. This will help doctors administer the most effective treatment for P. vivax malaria to people with G6PD deficiency.

The partnership

  • MedAccess has provided a volume guarantee to SD Biosensor, meaning it will make up any shortfall in sales.
  • SD Biosensor will continue to produce and supply its G6PD testing devices and test strips globally, and offer both products at a reduced price in low-and-middle-income countries.
  • PATH will continue to work with countries with high P. vivax malaria incidence to increase use of G6PD testing and uptake of ‘radical cure’ treatment.

Following the exit of multiple products, SD Biosensor is currently the only point-of-care G6PD test manufacturer in the market. This partnership will ensure continued supply of SD Biosensor’s product and offer a reduced price in low-and-middle-income countries.

Development impact

Eradicating P. vivax malaria is challenging. Even when the infection is treated in the bloodstream, the parasite can stay in the liver, causing reinfection and relapse.

Specific treatment will address the liver infection but it can also cause a severe blood disorder known as haemolytic anaemia in patients who are deficient in the enzyme glucose-6 phosphate dehydrogenase (G6PD).

Many doctors have no access to G6PD testing kits, and so prescribe lower, less effective doses of the liver treatment or none at all. Available testing allows for optimal single-dose treatment and treatment for all.

We project that the total number of G6PD testing kits purchased under volume guarantee terms will contribute to:

  • 9,600 more people will receive any treatment
  • 288,000 more people will receive superior single-dose treatment
  • 35,000 malaria relapses will be averted
  • A weighted average 10% product price reduction across devices and test strips for LMICs
  • $134,400 in procurement savings.

How we calculate impact

Lives changed: Estimates for treatment eligibility were derived from projections by Watson et al. Estimates of treatment outcomes were derived from a 2020 meta-analysis by Rodrigo et al.

Money saved: Impact is based on actual price reductions for G6PD tests over the course of the volume guarantee.

Markets shaped: We work with partners, including donors, procurers and ministries of health, to track changes in health markets where our investments are supporting access to products. We monitor for changes to policy, procurement practices and supplier movement, all of which affect markets and contribute to the long-term sustainability of impact.

The G6PD testing device

The product

The G6PD point-of-care test allows doctors to test patients for G6PD deficiency and receive rapid results within two minutes.

The device requires taking a pin prick of blood which is then tested in the analyzer. This looks for quantitative glucose-6-phosphate dehydrogenase (G6PD) enzyme activity.

The analyzer is battery-operated and portable in size (small enough to be held in one hand) so it can be easily stored and moved.

Why we acted

P. vivax causes around 6.4 million cases of malaria every year. Eradication is challenging because despite treatment, the parasite often persists in the patient’s liver, causing reinfection and relapse.

For complete treatment of P. vivax malaria, known as ‘radical cure’, the World Health Organization (WHO) recommends chloroquine or artemisinin combination therapy followed by a course of 8-aminoquinoline drugs – primaquine or tafenoquine – to treat liver-stage infection. However, 8-aminoquinoline drugs can trigger a severe blood disorder known as haemolytic anaemia in patients who are deficient in the enzyme glucose-6 phosphate dehydrogenase (G6PD), a condition that affects over 400 million people worldwide.

To avoid administering 8-aminoquinoline drugs incorrectly to G6PD deficient patients, the WHO recommends conducting a G6PD deficiency test prior to treatment. This is especially critical for tafenoquine, as it is a single dose treatment, and the drug remains in the body for several days after intake.

However, this recommendation has not been adopted in many countries, as point-of-care G6PD tests are not widely available. As a result, doctors are often cautious, prescribing lower doses of 8-aminoquinoline drugs taken over longer periods or none at all. Longer treatment can lead to patients stopping when they feel better, despite the infection not being cleared.