WEDNESDAY, SEPTEMBER 28, 2016

Drug-resistant malaria getting dangerously close to India

Malaria parasites that are immune to the drug artemisinin are a serious threat to the worldwide control and elimination of the disease, according to a report released this week by researchers who project that if drug resistance spreads from Asia to the African sub-continent or Africa itself, millions of lives will be at risk.

Recently, a collection of samples was taken from Myanmar and its border regions by Dr. Kyaw Myo Tun of the Defense Services Medical Research Centre, Napyitaw, Myanmar, and coordinated by the Mahidol-Oxford Tropical Medicine Research Unit in Bangkok, Thailand.

The researchers looked at parasite samples collected at 55 malaria treatment centers across Myanmar and whether they carried mutations in specific regions of the parasite's kelch gene (K13), which is a known genetic marker of artemisinin drug resistance. The researchers confirmed resistant parasites in the Homalin, Sagaing Region about 15 miles from the Indian border.

"Myanmar is considered the front line in the battle against artemisinin resistance as it forms a gateway for resistance to spread to the rest of the world," Oxford University's Charles Woodrow, the study's senior author, said. "With artemisinins, we are in the unusual position of having molecular markers for resistance before resistance has spread globally. The more we understand about the current situation in the border regions, the better prepared we are to adapt and implement strategies to overcome the spread of further drug resistance."

Of the 940 samples Myo Tun’s team found, 371 (39 percent) carried a resistance-conferring K13 mutation.

"We were able to gather patient samples rapidly across Myanmar, sometimes using discarded malaria blood diagnostic tests, and then test these immediately for the K13 marker and so generate real-time information on the spread of resistance," Mahidol University's Mallika Imwong said.

With the information gathered from the samples, the researchers created maps to display the predicted extent of artemisinin resistance as determined by the prevalence of K13 mutations, suggesting that the overall prevalence of K13 mutations was greater than 10 percent in large areas of east and north Myanmar, including areas close to the Indian border.

"The identification of the K13 markers of resistance has transformed our ability to monitor the spread and emergence of artemisinin resistance," Philippe Guerin, Director of the Worldwide Antimalarial Resistance Network and co-author of the study, said. "However, this study highlights that the pace at which artemisinin resistance is spreading or emerging is alarming. We need a more vigorous international effort to address this issue in border regions."

Professor Mike Turner, Head of Infection and Immunobiology at the Wellcome Trust, added his thoughts.

"Drug resistant malaria parasites in the 1960s originated in Southeast Asia and from there spread through Myanmar to India, and then to the rest of the world where it killed millions of people,” Turner said. “The new research shows that history is repeating itself with parasites resistant to artemisinin drugs, the mainstay of modern malaria treatment, now widespread in Myanmar. We are facing the imminent threat of resistance spreading into India, with thousands of lives at risk."

Researchers say a combined effort with policy makers, doctors and funding partners will allow the global health community to lessen the threat of drug resistance to malaria.