Containing a drug-resistant strain of malaria

The area of Pailin in western Cambodia is well-known to health experts as a source of drug-resistant strains of malaria.

So there was major concern recently when studies showed that the malaria parasite in Pailin was showing tolerance to the usual combination drug therapy, known as ACT.

"It's been scientifically proven that the parasites that are drug-resistant in Africa came from Cambodia," explains Dr. Steven Bjorge, a malaria specialist who works for the World Health Organization in Phnom Penh. "That was with the chloroquine resistance. And so the fear is that again the drug-resistant parasite, for example from western Cambodia, will move to Africa, and Africa is a malaria problem many magnitudes worse than anything in southeast Asia."

Drug resistance could spread

Each year malaria kills one million people – mostly in Africa – making the disease a significant global health problem.

The studies from Pailin showed that the ACT drugs were taking twice as long as the usual two or three days to clear the body of the parasite.

Experts worried that this resistance could spread, with catastrophic consequences.

Dr Duong Socheat heads the Cambodian government’s National Center for Malaria Control.

He says experts and donors devised a containment strategy that divided Cambodia into three zones. Zone 1, about 5 percent of the country, is centered around Pailin, and has been the focus of an aggressive effort to combat the resistant strain.

Zone 2, which comprises half of the country lying beyond Zone 1, is a buffer in which the usual ACT treatments are used. The rest of Cambodia makes up Zone 3.

Measures and strategy

The government and its partners have distributed mosquito nets throughout Zone 1, and Dr. Duong Socheat says local people have also been educated about the dangers of using counterfeit or substandard drugs, or of using just one drug to beat malaria – so-called monotherapy.

Among other measures, every village in Zone 1 now has at least one volunteer trained to provide free malaria tests to any villager suffering from fever.

One year after the containment strategy was implemented, he says, the situation seems to be stable.

"There is no new increase in Zone 1 due to the containment strategy. And no deaths in Zone 1, only in Zone 2 and Zone 3."

Proactive steps

There are more proactive moves underway too. Next week health workers will head to a dozen of the most malarious villages in Pailin, take blood samples from every villager and test them in Phnom Penh, then provide pre-emptive treatment.

Dr. Duong Socheat says the goal is to eliminate all deaths caused by the disease by 2020. "We hope that there will be no more deaths in the villages as we create our network of volunteers over there."

But should the containment strategy fail, an already serious global health problem could worsen dramatically.

Author: Robert Carmichael (Phnom Penh)
Editor: Grahame Lucas