Table 3 Example of the cyclical work process of the Vivax Working Group (diagnostic theme)

Identify knowledge gaps

In May 2012 the VxWG convened a workshop in Incheon, Korea to identify key knowledge gaps in the detection of G6PD deficiency [17]. The lack of robust evidence for the distribution of G6PD deficiency, and the relationship of G6PD deficiency and drug-induced haemolysis was discussed. Without reliable, convenient and sensitive point of care diagnostics, primaquine radical cure is often not prescribed, undermining P. vivax elimination efforts.

Build consensus

The group identified 10 key areas that are of highest research priorities, including: the mapping of G6PD deficiency, understanding drug induced haemolysis in G6PD deficient individuals, the identification of desirable test characteristics and the cost benefit analysis of routine G6PD testing.

Gather the evidence

Research projects in Cambodia, the Republic of Korea [54], Indonesia, the Philippines and China are currently being supported by the VxWG to address the identified research priorities.

One of the hot spots of vivax malaria in Hainan, a province in southern China, is home to a number of ethnic minorities. In contrast Jiangsu province located in Central China is mostly inhabited by Han Chinese and has witnessed a great reduction of vivax malaria over the last decades and the complete elimination of P. falciparum since 1990.

In 2013 the VxWG supported a cross sectional survey in Hainan and Jiangsu provinces to assess the population specific prevalence of G6PD deficiency. Participants were recruited among healthy individuals as well as febrile patients attending a health care facility. One drop of blood was collected from every participant together with information on the participants’ ethnic background. G6PD status was assessed at a reference centre applying a recently modified test assay (WST 8/1 PMS: methoxy PMS, Dojindo, Japan) for mass screening. Preliminary analysis indicated significant differences in the prevalence of G6PD deficiency between different geographic areas and ethnic groups ranging from close to 0 % to above 10 %.

Change practice

The marked differences in G6PD deficiency prevalence among different ethnic groups living in close geographic proximity highlights the need for routine G6PD testing as part of the national treatment guidelines for the treatment of vivax malaria. The investigators are currently evaluating point of care diagnostics suitable for this task.