Scientists are expressing alarm at a thriving counterfeit industry that is producing fake drugs to treat malaria.   They worry the fake drugs are putting countless lives at risk, and could harm a highly effective anti-malaria drug.

Last year, a 23-year old Burmese man died after he took the drug, artesunate, to treat what was diagnosed as a routine case of malaria.  The drug is normally very effective. 

The case was investigated by Oxford University's Paul Newton and colleagues, and published in the public online journal PLoS Medicine.

"I think the death, the very sad death, of the Burmese man is the tip of an iceberg," said Mr. Newton

The artesunate tablets that were used to treat the man were found to contain 20 percent of the amount of the active drug in a genuine pill.

In the study, Newton and colleagues also reported the percentage of over-the-counter counterfeit pills containing no artesunate appears to have increased from 38 to 53 percent in southeast Asia from 1999 through 2004. 

Experts are also concerned about a growing problem in sub-Saharan Africa, where artemisinin is frequently used as part of a combination therapy to treat malaria.

Each year, the disease kills an estimated 1.5 million people, mostly children, and infects another 300,000 to 500,000 people. 

The malaria parasite has become resistant to most antibiotics and quinine-derived drugs.  Drugs become ineffective, or resistant, when they are not used the way they supposed to by people who take them.

The recent introduction of drugs made from the artemisinin plant, such as artesunate, has revolutionized the treatment of malaria.        

The problem is artesunate is in high demand and expensive relative to the old malaria drugs, and that has created a thriving counterfeit industry, according to U.S. biochemist Facundo Fernandez.

Fernandez, who is working with Newton to root out counterfeiters, says the fake drugs contain just enough artemisinin to fool a field litmus test. Fernandez worries that the counterfeiters will continue to reformulate their pills to elude detection.

"We will have to go to more high-tech answers to evaluate the quality in the field," he said.  "Make a quantitative test for the field and so on.  And so you have to be up to date constantly.  Sometimes I think the counterfeiters are reading our papers."

To stop counterfeiters, Oxford University's Paul Newton says international authorities must work together to secure the supply of artesunate through drug regulatory authorities.

For the sake of malaria victims, Newton says it is also going to be necessary to try to beat counterfeiters at their own game.

"And that is to enable rural poor in Asia and Africa to have access to anti-malarial drugs that are good quality and are inexpensive, so they don't have to go and buy the more expensive counterfeits in a shop or a pharmacy, so one can undercut the counterfeiters," he added.

Experts say controlling the supply of artesunate will also help keep it from being misused by patients, further guarding its effectiveness in the fight against malaria.