Malaria parasites may be resisting effective drugs: Study

A clinical study of treatment with the artemesinin family of drugs was carried out by separate British and American research teams in Cambodia. The trials revealed that artemesinin that cleared all malaria parasites from the blood within two or three days, now took four or five days for clearance, a clear indication of emerging resistance.

The UK study
In the UK study, patients living in Cambodia took almost twice as long to clear the malaria parasite as opposed to a group in Thailand.

Professor Nick Day, director of the Mahidol-Oxford Tropical Medicine Research Unit, the UK team investigating malaria spread in the Combodia, stated, "Twice in the past, South East Asia has made a gift, unwittingly, of drug resistant parasites to the rest of the world, in particular to Africa."

"That's the problem. We've had chloroquine and SP (sulfadoxine pyrimethamine) resistance, both of which have caused major loss of life in Africa," he said in reference to earlier generation anti-malarial drugs.

"If the same thing happens again, the spread of a resistant parasite from Asia to Africa, that will have devastating consequences for malaria control," he said.

Dr Glenn McConkey, a malaria expert at Leeds University felt that the malaria’s resistance to artemesinin could become as widespread as that to chloroquine, which used to be a frontline defense against the disease.

"This could be a major threat in terms of drug resistance. The concern is that it will spread before we can develop a new drug to replace it," said McConkey.

The US study
The US study also found a delayed clearance of the parasite. Dr. Delia Bethell, an investigator working on the clinical trials as part of the US Armed Forces Research Institute of Medical Science (AFRIMS), stated that out of the 90 patients in the study, nearly a third to a half were still positive for malaria parasites after three to five days.

Referring to the artemesinin family of drugs, she explained, "This is by far the most effective drug we have. And there are no new drugs coming through the system in the next few years.”

Cause for concern
The World Health Organization says that malaria is a major concern for people living in Cambodia's hilly and forested regions.

In a report, the health agency declared "Of particular concern is the high level of multi drug resistance present in affected areas. Strains of P. falciparum are resistant to most antimalarial drugs, and the quality and usage pattern of antimalarial drugs are suboptimal.”

Scientists believe that Cambodia's poor public health system and the availability of cheap 'pirate' drugs, which contain small amounts of the real drug in order to pass detector tests, are helping nurture resistance.