Studies reveal markers of malaria resistance

Parasites were more likely to survive exposure to piperaquine if they had 2 or more copies of the plasmepsin 2 and plasmepsin 3 genes, as well as the exo-E415G variant on chromosome 13.

Similarly, in a further analysis of 133 patient samples, the investigators found that individuals infected with parasites carrying multiple copies of the plasmepsin genes were much more likely to fail treatment with dihydroartemisinin-piperaquine, as were individuals who had parasites with the exo-E415G variant.

The team also noted that the prevalence of exo-E415G and plasmepsin 2-3 markers has risen substantially in recent years in Pursat and Preah Vihear, where artemisinin resistance is common and dihydroartemisinin-piperaquine has been the frontline treatment for at least 6 years.

“By surveying the piperaquine resistance marker across Southeast Asia in real-time, we can identify those areas where dihydroartemisinin-piperaquine will not be effective, and this could enable national malaria control programs to immediately recommend alternative therapies, such as artesunate-mefloquine,” Dr Fairhurst said.

“This approach will be crucial to eliminating multidrug-resistant parasites in Southeast Asia before they spread to sub-Saharan Africa, where most of the world’s malaria transmission, illness, and death occur.”