Malaria: Resistance to drugs

(From: Overcoming Antimicrobial Resistance, WHO publication CDS 2000.2)

A mosquito-borne infection that killed an estimated 1.1 million people in 1998, and with an estimated 300 to 400 million new cases globally each year, malaria promises to be a pre-eminent threat to development in endemic regions well into the new millennium.

Like other diseases once considered banished to the geopolitical margins, malaria is reappearing in areas of the world formerly deemed disease-free. In a 1999 report WHO warned of "a serious risk of uncontrollable resurgence of malaria" in Europe owing to civil disorder, global warming, increased irrigation (canals are important breeding grounds for mosquitoes) and international travel. In the United Kingdom 1 000 new cases of malaria are imported each year from malaria-endemic countries. In the former USSR, weakening public infrastructures have triggered large-scale epidemics in central Asian republics, while in Turkey numbers have increased tenfold since the disease was believed nearly defeated in 1989.

Resistance to chloroquine - the former treatment of choice - is now widespread in 8O% of the 92 countries where malaria continues to be a major killer, while resistance to newer second and third-line drugs continues to grow. Unfortunately, many of these new drugs are not only expensive and have serious side effects, but most will be eventually rendered ineffective by the malaria organism's complex epidemiology and facility for rapid mutation. Mefloquine resistance emerged in Southeast Asia almost as soon as the drug became a treatment option.

The challenge is to use already existing antimalarials more effectively to better control the disease. This means improving access to appropriate drugs and providing combinations of medications at lower cost. Increasing surveillance to guide the proper use of drugs and more attention to alternative prevention strategies such as insecticide-treated bednets is also vital. A renewed commitment to research and development of newer, more effective medications is likewise critical to the containment of drug-resistant malaria.

Figure 1. From: The Southeast journal of Tropical Medicine and Public Health. Mekong Malaria, Volume 30, Supplement 4, p 68, 1999

Back to the table of contents