A FRONT-LINE anti-malaria drug currently used around the world could become useless unless an emerging pocket of drug resistance in Southeast Asia is contained, an expert has warned.
Artemisinin therapy is widely used to treat malaria, which is caused by a blood-borne parasite.
“We rely on it in Ireland where it would be used as a treatment for people who present with malaria, and also in many Asian and sub-Saharan African countries it’s the first-line, nationally-recommended treatment for malaria,” explained Prof Sam McConkey, head of the Department of International Health and Tropical Medicine at the Royal College of Surgeons in Ireland.
Artemisinin compounds are usually used in combination with other drugs to kill off parasites that develop resistance to one of the agents, but extensive single-use of the compound artesunate in Western Cambodia appears to have led to the development of drug-resistant parasites, as outlined in a recent New England Journal of Medicinereport.
“This is the first time in the world that convincing, scientifically-documented resistance to artesunate has been described,” said McConkey. “They described it in two patients in a total of 60 in this study so it’s relatively infrequent, but it’s very convincing that it did occur.”
The area has previously been a breeding ground of resistance against other anti-malaria drugs that eventually spread around the world, said McConkey.
“The worst-case scenario is that resistance in Cambodia might gradually grow perhaps to 80 per cent over a period of five or 10 years in that location. Then parasites that are resistant might start to appear in other parts of the world, in Papua New Guinea, and Africa and it might spread around the world. That would mean artesunate would become useless for treating malaria.”
Measures to contain the resistance include using the drug in combination with other anti-malarial agents and using insecticide-dipped bednets to help prevent mosquitoes from spreading the drug-resistant parasite between humans, said McConkey. “That goes a long way to preventing resistance, because if you don’t have the parasite in the first place then drugs aren’t an issue.”
