Washington: International experts raised the alarm Wednesday over the spread of drug-resistant malaria in several Southeast Asian countries, saying it endangers major global gains in fighting the mosquito-borne disease that kills more than 600,000 people annually.
While the disease wreaks its heaviest toll in Africa, it's in nations along the Mekong River where the most serious threat to treating it has emerged.
The availability of therapies using the drug artemisinin has helped cut global malaria deaths by a quarter in the past decade.
But over the same period, resistance to the drug emerged on Thailand's borders with Myanmar and Cambodia and has spread. It has been detected in southern Vietnam and likely exists in southern Laos, said Professor Nick White of the Thailand-based Mahidol Oxford Tropical Medicine Research Unit.
White, a leading authority on the subject, said that while there's no confirmed evidence of resistance in Africa, there's plenty of risk of transmission by air travelers from affected countries, such as construction labourers, aid workers or soldiers serving on peacekeeping missions.
"We have to take a radical approach to this. It's like a cancer that's spreading and we have to take it out now," White told a conference at the Centre for Strategic and International Studies think tank in Washington. He said no alternative anti-malarial drug is on the horizon.
The UN World Health Organisation, or WHO, is also warning that what seems to be a localised threat could easily get out of control and have serious implications for global health. Mosquitoes have developed resistance to antimalarial drugs before.
It happened with the drug chloroquine, which helped eliminate malaria from Europe, North America, the Caribbean and parts of Asia and South-Central America during the 1950s. Resistance first began appearing on the Thai-Cambodia border, and by the early 1990s it was virtually useless as an antimalarial in much of the world.
Scientists have been working for decades to develop a malaria vaccine, a complicated endeavour since the disease is caused by five different species of parasites. Dozens of candidate vaccines are being researched worldwide.
Nowhere are the challenges in countering the threat to drug resistance greater than in Myanmar, also known as Burma. Some 70 per cent of its 55 million people live in malaria-endemic areas, and as a nation, it accounts for about three-quarters of malaria infections and deaths in the Mekong region, according to a report for the conference by Dr. Christopher Daniel, former commander of the US Naval Medical Research Centre.
White said resistance has been found in the east, centre and south of the country, but it's unknown if it has reached the country's north and its northwestern border with densely populated India. "In my view, once it gets into the northeast part of India, that's it, it's too late, you won't be able to stop it," White said.