Drug-resistant malaria is spreading in Asia, experts warned, as a high-level conference opened yesterday with the aim of hammering out an action plan to strengthen the region's response.
Resistance to the drug used everywhere to cure the life-threatening disease has emerged in Cambodia, Thailand and Myanmar, said Richard Feachem, director of global health at the University of California in the United States.
"In the Mekong Basin there is a growing and spreading problem of resistance ... to the drug artemisinin which is the frontline drug worldwide," he said ahead of "Malaria 2012: Saving Lives in the Asia-Pacific" in Sydney.
"I think we've undoubtedly slowed it down, the international efforts have had a positive effect, but as far as we can tell it is still growing and it is still spreading.
"The danger is that at some time this resistance may break out of Southeast Asia and crop up in Africa," added Feachem, the former founding head of the Global Fund to Fight Aids, Tuberculosis and Malaria.
Some 22 countries in the Asia-Pacific region still had malaria, but enormous progress had been made in combatting the devastating disease with the number of infections falling by about 50 per cent in the past decade, he said.
Yet there were still an estimated 30 million cases in the Asia-Pacific in 2010, and more than 40,000 deaths in Southeast Asia and the Western Pacific, according to the World Health Organisation (WHO).
Drug-resistant malaria was found on the Thailand-Cambodia border eight years ago, and has also been found along the Thailand-Myanmar frontier and in parts of Vietnam, prompting an urgent call for action from the WHO in September.
Resistance to artemisinin currently does not prevent patients being cured, thanks to other drugs it is used in concert with, but treatment typically takes longer than normal.
It is not known why the resistance emerged in Cambodia, one of the first countries to deploy the treatment some 30 years ago. But Ric Price, from the Centre of Tropical Medicine in Oxford, Britain, said high levels of counterfeit drugs and people not taking the full course of treatment could be factors.
"Artemisinin still remains the treatment of choice, but it's under threat and we have to monitor where those areas are, where it is declining," he said.