The spread of drug-resistant malaria in Asia and Africa complicates the fight against the killer. In Cambodia, the government has tightened its grip on private drug stores, often the source of resistance-enhancing fake drugs and improper treatment. There is concern, though, that the effort may shut down the pharmacies upon which Cambodians most rely.
Mom Va, who lives in Pailin in western Cambodia, says her malaria symptoms appeared a week ago, and she still has not recovered. Va worries that she has a strain of malaria called falciparum, which has become resistant to some of the most effective treatments.
In Cambodia's war against malaria, village health volunteers are at the frontline. Trained volunteers, such as Mak Saeun, screen for Falciparum malaria and can treat other strains.
He says there used to be a lot of malaria in the region. But as the trees have been cut down on the hills, and people have begun to use insecticide-treated mosquito nets, the numbers are down. Between 2006 and 2008, Cambodia almost halved its malaria cases, to about 54,000.
Now the appearance of the drug-resistant Falciparum in Cambodia, however, raises concerns that it will spread across Southeast Asia. The World Health Organization gathered regional experts and health workers to find ways to ensure success in the fight against malaria.
Major Stuart Tyner is with a U.S. Army medical team studying malaria. He says the malaria parasite eventually adapts to a single medicine. So using two or more drugs can stem resistance.
"There's always a concern that when resistance to any kind of medicine develops … that it's going to spread," said Tyner. "So, the idea that by changing the drug, you will be able to kill parasites that are becoming resistant to the old drug with a new drug. Once you do that, you are back to a level playing field, where the old drug can still work."
Fake drugs and the unregulated use of single drug treatments help create resistance. Both are common in poor areas of the world, like Pailin. The Cambodian government has flooded the region with combination drugs, called ACTs, and is cracking down on unregistered drug stores.
But aid workers worry that many private drug stores and health care providers are left out.
Cris Jones is with Population Services International, which distributes anti-malaria kits and trains drug sellers on proper treatments. He says unregistered sellers must have access to ACTs.
"Seventy-five percent of Cambodians, when they go to seek access for treatment for malaria, they do so in the private sector," said Jones. "It is important that we support the private sector to make sure they've got high-quality government approved ACTs, that they are treating properly, that they are diagnosing properly."
Although the WHO and Cambodia's Center for Malaria Control say the effort to contain the resistant strain is paying off, they warn the fight is far from over.