There are increasing signs in many of parts of Asia that malaria parasites are becoming more resistant to drugs that until now have been extremely effective. The World Health Organization has stepped up its research.
Malaria is a mosquito-borne infectious disease
Global warming – and the consequent change in weather and rainfall patterns – is complicating matters for the World Health Organization in its fight against malaria in Asia.
The countries which are most at risk in the Asia-Pacific region are India, Myanmar, Bangladesh and Indonesia.
According to World Health Organization figures, two million people are at risk of contracting the illness. Overall, Asia accounts for more than 60 percent of the global population risk.
Migrant workers on the Thai-Cambodian border where there are growing signs of drug-resistance
Malaria parasite could spread
Increasingly extreme climate conditions are fueling fears the malaria parasite could spread. This was the topic of debate at a recent conference in Bangkok.
"Global warming is of course going to increase the conditions for mosquitoes to thrive." explained Dr Eva-Maria Christophel, a WHO official based in the Philippines.
"There is a lot of reason to worry," she said, explaining that the change in weather conditions could lead to the areas where malaria can thrive becoming larger.
Right now, a more pressing concern for the WHO is that there are increasing signs of growing drug resistance to malaria in parts of Cambodia, Thailand, Myanmar and Vietnam.
Increasing resistance to artemisinin-based drugs
In recent years, the main frontline treatment for malaria has been a combination drug based on artemisinin, which is derived from the sweet wormwood plant.
But in early 2009, the WHO confirmed several cases of resistance to this powerful combination drug on the Thai-Cambodian border. Recent studies have found that as many as 20 percent of malaria patients in Myanmar's border areas still have parasites in their blood after a normal course of treatment.
Malaria patients at a Cambodian hospital
Clinical trials are currently being conducted to see whether artemisinin-resistant malaria is becoming even more widespread. The authorities are already working on containment measures in case this turns out to be critical.
Poor quality drugs on the market
Dr Charles Delacollette, from the Bangkok-based WHO Mekong Malaria Program, explained that the growing resistance was due in part to the poor quality of the drugs.
"The drugs are stored in very poor conditions and are becoming substandard. There are also counterfeit drugs for sale," he pointed out.
The authorities in China, Cambodia and Myanmar have recently stepped up their investigations and cracked down against "backyard" counterfeit drug makers.
Governments across the region are currently reviewing strategies for containing drug-resistant malaria, such as the distribution of insecticide-treated mosquito nets and free screening. The WHO has warned that millions could be exposed to a form of the disease which takes longer to treat.
Author: Ron Corben
Editor: Anne Thomas