MALARIA kills and continues to exert a tremendous health burden on human populations, especially the rural poor. And countries in the ASEAN region are no exception.The disease is transmitted by the Anopheles mosquito and is caused by a parasite that lives part of its life in mosquitoes and part in humans. Among the four Plasmodium parasite species that cause malaria in humans, Plasmodium falciparium is the most deadly. This species causes the vast majority of deaths from malaria.
In the Asia-Pacific, malaria is present in 20 countries. It is also found in the ASEAN region, South Asia, Eastern Asia and the Western Pacific. More than 2.2 billion people are at risk of malaria in the Asia-Pacific, which represents 67 percent of the world population at risk of malaria. Five countries (India, Myanmar, Bangladesh, Indonesia and Papua New Guinea) account for approximately 93 percent of the death toll in the region.
For decades, the treatment of malaria depended on chloroquine, which was characterised by its rapid efficacy, low toxicity, availability and affordability. However, within a decade of its introduction, chloroquine resistance appeared in malaria parasites. Sulfadoxine-pyrimethamine, or SP, soon replaced chloroquine as first-line therapy, but SP-resistant Plasmodium parasites emerged not long after.
Parasites in the ASEAN region are now resistant to almost all anti-malarial drugs, with the exception of drug combinations containing derivatives of artemisinin (artemisinin-based combination therapy, or ACT). These provide fast and effective treatment. It is therefore critical to protect the artemisinins by stopping monotherapy and using them only in combination with effective partner drugs in ACTs.
Because artemisinin derivatives are remarkably rapid in their anti-malarial effects, they are much sought after. But as they are relatively expensive, a demand is created for cheaper versions amongst the poorest and most vulnerable people, upon whom the counterfeiters have preyed – with fatal results.
The counterfeits contain inadequate or no active ingredient and engender the selection and spread of the artemisinin resistant falciparum parasite. Falciparum malaria resistant to artemisinin has now emerged in Southeast Asia, especially along the Cambodia-Thailand border. This has raised strong concerns that renewed efforts to globally eradicate malaria can be imperiled.
As a body for regional socio-economic growth, it is important for ASEAN to show strong commitment and ownership in the regional containment and elimination of artemisinin-resistant falciparium malaria. It is well documented that where malaria prospers most, human societies have prospered least. There is a striking correlation between malaria and poverty and malaria-endemic countries also have lower rates of economic growth.
The persistent deadly production and use of counterfeit drugs and monotherapies in the region does not bring down malaria deaths, but rather contribute to the fast appearance of parasite resistance to drugs. ASEAN must make a common stand to ban the production of monotherapies and stop the illegal production of purposely made counterfeits.
The Cambodian government’s efforts to ban monotherapies and crack down on counterfeit anti-malarials are certainly commendable. In April the United States Pharmacopia – a non-governmental, official public standards-setting authority for prescription and over-the-counter medicines – stated that Cambodia has shut down nearly 65 percent of illegal pharmacies after receiving evidence showing that they were among the main sources of substandard and counterfeit medicines in the country.
Cambodia’s Ministry of Health has trained the “justice police”, who regularly check pharmacies, shops and markets to try to ensure that only recommended malaria drugs are sold.
Recently the Cambodian government’s National Centre for Parasitology, Entomology and Malaria Control, which receives technical assistance from the World Health Organization, and the Anti-Economic Crime Police Department completed a training workshop for more than 80 senior police officers. These senior Cambodian police officers will make sure that the nationwide ban on monotherapies is enforced together with a crackdown on manufacturers and retailers of counterfeit malarial medicines.
Also in Cambodia about 2,900 volunteer village malaria workers, or VMWs, have been trained and equipped to diagnose malaria in the villages using a rapid diagnostic test and to provide the patients with the appropriate drugs for free. This strategy – providing free anti-malarial drugs in the villages – also works to undermine the sale of counterfeit anti-malarial drugs from the private sector where Cambodians have usually sought treatment.
While Cambodia has shown the political will to crack down on counterfeits, it still needs support and more can be done at the ASEAN regional level.
In Cambodia and other developing ASEAN countries, there is lack of representative data on a national scale of the retail market, which is the last link in a distribution chain. Also, there are very few reliable published estimates of the prevalence of counterfeit, substandard or degraded medicines for any ASEAN country.
The rapid strengthening of monitoring systems for drug resistance is critical in ASEAN.
Dr Charles Delacollette is coordinator of the World Health Organisation’s Mekong Malaria Programme.