Study calls for rapid sharing of data to monitor artemisinin resistance

The paper, Mapping genetic markers of artemisinin resistance in Plasmodium falciparum malaria in Asia: a systematic review and spatiotemporal analysis, was published in the Lancet Microbe today.

The study, conducted in Asia, aimed to develop up-to-date spatial distribution visualisations of the Kelch-13 (K13) markers of artemisinin resistance for policymakers to guide policy decisions. Researchers collated data from 72 studies published between 1 January 2010 and 31 March 2021, comprising K13 markers from 16,613 blood samples collected from 1991 to 2020 from 18 countries. Findings showed a steady increase in the prevalence of 'WHO-validated' K13 markers, reaching 62·9 per cent in 2018. Overall, the prevalence of C580Y mutation increased from 48·9 per cent in 2002 to 84·9 per cent in 2018. Data showed that from 2002 to 2018, there has been a steady increase in geographic locations and the proportion of infected people with 'validated' artemisinin resistance markers.

The emergence and spread of artemisinin and artemisinin-based combination therapy (ACT) partner drug resistance in the Greater Mekong Subregion (GMS) poses a significant threat to global efforts to eliminate malaria and with the potential to spread or emerge further afield, including to India, Africa and Latin America, and highlights its immediate relevance to Africa.  A recent report showed independent emergence and local spread of clinically artemisinin-resistant P. falciparum, while Professor Philip Rosenthal, of the University of California, San Francisco, and an IDDO board member recently raised the issue in an editorial in the American Journal of Tropical Medicine and Hygiene.

This is the first study to use the 2020 revised WHO classification for K13 markers and the first to aggregate all published K13 marker data in Asia and map them by province and district. It highlights that non-uniform, patchy and delayed reporting are crucial challenges in K13 surveillance.

Prior to this study, a 2014 multicentre study showed the worldwide map of K13 markers, which aggregated K13 markers per country. In addition, the WWARN K13 surveyor charts K13 global maps with study sites drawn as points using an IPD meta-analysis classification.

Currently, data in the literature are reported in an unstructured way leading to difficulties in pooling and interpretation. Researchers conclude that more consistent data collection over extended periods in the same areas with the rapid sharing of data are needed to map the spread and evolution of resistance to better inform policy decisions. A tool, developed by scientists from WWARN, Mahidol-Oxford Tropical Medicine Research Unit (MORU) and the University of Cape Town (UCT), with a set of minimum criteria for reporting future studies can overcome this issue, researchers say.

Read the full paper.