Counterfeit or cheap quality malaria drugs are boosting resistance in parts of Southeast Asia, a crisis predicted to worsen unless more rigid regulations are adopted, US experts said Monday.
"The malaria parasite has a history of adapting to drugs and adapting to insecticides," Regina Rabinovich, director of infectious diseases at the Bill and Melinda Gates Foundation, told a hearing of US lawmakers.
"Drug resistance to the most effective drug available, artemisinin-based combination therapy, is developing and has been recognized in southeast Asia."
Last month, the World Health Organization said resistance to artemisinin appeared to be spreading in the region from the Cambodia-Thailand border, where it was first detected in 2009, and possibly moving into Myanmar.
Half of the world's population is exposed to the mosquito-borne disease which kills 860,000 people every year, according to the WHO.
According to Roger Bate of the American Enterprise Institute, research has shown that about half the malaria drugs that failed quality control tests also contained some artemisinin.
"So they are directly contributing to resistance," he told lawmakers at the House subcommitee on Africa, Global Health, and Human Rights.
"Resistance is being noticed on the Thai, Cambodian, Burmese borders and resistance is likely to increase," he said.
"Fake and substandard antimalarial medications are a significant and probably growing problem."
While the actual number of poor quality drugs in circulation is unknown, "it is certainly not a negligible amount," he added, and the problem is festering because these medications are not illegal in the countries affected.
"Simply getting the medical regulatory authorities to control what is on the market for anti malarials I think is important," said Bate.
The sale and use of monotherapies, which contain just one active agent, have long been known to contribute to resistance. Experts favor combination therapies which last longer.
Bate said that coordinated action to get monotherapies off the market in Africa has shown some success, "but some companies in China, India and Vietnam are still producing them and this is a major contribution to resistance."
In addition to tougher regulations, researchers need to focus on developing new drugs against malaria, and consider making sure they cannot be sold or distributed as monotherapies, the panelists urged.
"The goal now going forward is the new drugs we develop need to be made as fixed dose combinations immediately, and never be sold or available as single entities," said Dennis Schmatz, president of Medicines for Malaria Venture North America, Inc.
"And that will definitely extend the life of any of those new drugs we develop going forward."
Rabinovich echoed that point, saying that the drugs of today will not be effective tomorrow.
"Research and development is essential because the preventive and curative tools that are available today and are so effective at controlling malaria are not sufficient to control malaria in the long term or for eradication due in part to the development of resistance," she said.