Malaria researchers are watching with alarm as once-effective drugs lose their punch in a flashpoint region, reports the Guardian. New studies show that drugs based on the plant extract artemisinin are losing potency on the Burma-Thailand border. The problem started in Cambodia and is apparently spreading as counterfeit versions spring up on the black market and dilute the real drugs' effectiveness. And it's happened once before: "Resistance to the previous mainstays of antimalarial treatment, namely, chloroquine and sulfadoxine-pyrimethamine, also arose in western Cambodia and spread across South-east Asia into Africa, resulting in the deaths of millions of children," notes one study.
"There is no doubt there has been quite significant reduction in susceptibility to artemisinin," says one researcher. "The problem is that once it gets to Burma, that is the gateway to the west. ... It's going to be much more difficult to contain it." There's some hope, though: A separate group of scientists identified a region on the malaria parasite genome linked to the problem. They warn, however, that failure to stop the spread of the resistance "would be catastrophic for malaria control."