Artemisinin-resistant malaria reported in southeast Thailand

Thailand and Cambodia – epicenters of drug-resistant malarias – started using artemisinin based treatments years ago. Thailand made it their policy in 1995, Cambodia in 2003. According to an advisory committee to the WHO, the artemisinin-based treatments – which the WHO and other agencies are currently pressing African and Asian governments to implement – have already started to fail. (That the parasite would figure out how to circumvent the drug was apparent some years ago, when genetic studies revealed that the genes that the drugs target were mutating rapidly.)

In a province of southeast Thailand (Trat), artemisinin combo treatments failed in 20 percent of cases in a 2003 study. In a western province of Cambodia, they failed in 10% to 14% of cases. In other studies cited by the committee, artemether-lumefantrine failed in up to 29 percent of cases!

Historically, drug-resistant strains have first emerged in this area of the world, and they don’t take long to spread. Chloroquine-resistant falciparum, for example, emerged in the early 1960s in southeast Asia and by the 1990s was present everywhere in the world. How fast will artemisinin-resistant malaria spread, in this era of accelerated globalization? Will the pace of drug development keep up with the need for an artemisinin replacement? Will the WHO and other’s noble efforts to stave off resistance with novel combinations buy enough time before the parasite breaks out? The most popular malaria drugs, before artemisinin, were developed in the 1950s. Artemisinin, an extract from the sweet wormwood tree, is the latest thing, but it is not a novel drug: it’s a 2,000 year old Chinese remedy, revamped for modern use.

For more:

World Health Organization, “Containment of malaria multi-drug resistance on the Cambodia-Thailand border,” report of an informal consultation, Phnom Penh, January 29-30, 2007

www.who.int/malaria/docs/drugresistance/ReportThaiCam.pdf
Global Malaria Programme: Drug resistance http://www.who.int/malaria/resistance.html