Although the European Commission’s aggressive five-year campaign to cut malaria rates in Cambodia ended in December, mosquitoes are still biting and anti-malaria drugs are becoming less effective than ever, according to a study by World Health Organization officials.
Long-term use of chloroquine, a drug heavily relied upon to save victims of p falciparum malaria, is not as effective as a first-line monotherapy treatment as they have been in past years, Dr Reiko Tsuyuoka of the WHO said.
Drug resistance stems from drug pressure, a phenomenon caused by drug use, drug behavior and drug quality, Reiko said.
“Drug resistance is happening because of a molecular change in the parasites,” Reiko said. Drug pressure helps the microorganisms become resistant against drugs that are used too often.
“Drug resistance is bigger here than anywhere else in the world,” said Dr Mey Bouth Denis, co-director of the European Commission’s Malaria Control Program in Cambodia. The problem is particularly bad in Pailin, he said, where “people come who are not immune, who are drug resistant.”
He said mosquitoes pass the drug-resistant blood of miners, who have traveled from neighboring countries to an area where there is low immunity, to local villagers.
The result is that Cambodians’ blood is infected by small doses of the drugs, which are recognizable to mosquitoes, Denis said.
Although drug resistance is a growing problem, Denis said less than 10 percent of Cambodians using A&M, a common drug therapy, are immune to the treatment. He said he would not begin worrying until resistance reached 25 percent.
Improperly stored drugs—housed in hot pharmacies—also lose effectiveness, making users resistant to their effects.
Many patients ingest low-quality or fake drugs, which contain less than appropriate levels of medicine to combat the illness, Reiko said.
With low doses of the drug in their system, patients become immune to the drugs.
Patients also fall victim to inadequate educational systems, following treatment regimes based on faith rather than fact. Minimal access to health education leads many provincial residents to not carry out an entire treatment program, taking only half the dosage needed to kill the malaria-carrying parasites.
To remedy the situation, the WHO has worked to distribute all drugs in blister packets, with pills individually sealed and easy to see, Reiko said.
Malaria experts suggested that the biggest fix for drug resistance is using two drugs instead of one as a first line treatment. For simple case management, a combination of artemether/artesunate and mefloquine are recommended as a first-line treatment.
For complicated case management, artemether injections should be followed by a single dose of mefloquine or quinine injection, Denis said.
