Antimalarial Drug Resistance in Southeast Asia


HO CHI MINH CITY, Vietnam — In 2017, there were 219 million malaria cases. More than 11 million of these cases were in Southeast Asia where new strains of drug-resistant malaria exist. There is a history of antimalarial drug resistance originating in Southeast Asia. It is resurging in the Mekong Delta region. With more than 1.6 billion people at risk of malaria in Southeast Asia, antimalarial drug resistance has the potential to become a major epidemic.

ACTs and Drug-Resistant Strains

The World Health Organization (WHO) is recommending artemisinin-based combination therapies (ACT) to treat malaria. These pills work by using both fast-acting artemisinin and a long-term antimalarial drug. Treatment consists of six doses, each of which requires approximately three days of treatment. ACTs have decreased malaria deaths to the lowest level in history.

Antimalarial drug resistance arises in two stages. The first stage is that there is a rare genetic mutation that produces a resistant strain of the disease. The second is that there is a selection process that allows the disease to compete, and win, against the original, dominant strain. Once resistance forms, it has the advantage of survival against antimalarial drugs.

Antimalarial Drug-Resistant Strains in Southeast Asia Compared to Africa

Malaria is different in the Mekong region than in Africa where transmission rates are the highest in the world. Consequently, the death toll is almost incomparable. Approximately 500,000 children die from malaria in Africa each year. Meanwhile, fewer than 200 people die from malaria in the Mekong region. Much of Mekong is malaria-free. In the Mekong, the lowlands are relatively malaria-free, but the risk rises in the mountains and forests. Consequently, the majority of malaria cases are adult men who work in the woods. The low levels of malaria in the region allow new resistant strains to develop without competing against a dominant nonresistant strain.

In the 1950s, people found a mosquito population resistant to chloroquine in the Mekong region. By the 1980s, the resistant strain spread around the world killing millions. However, the World Health Organization does not predict antimalarial drug resistance to ACTs will have the same consequences as chloroquine. There was little to no control of malaria in Africa in the 1980s. Less than 1 percent of the population used a bed net, a simple intervention that has saved more than six million lives over the past 15 years. However, even if ACT resistant malaria spreads to Africa in the future, new case management and improved health systems will alleviate the consequences. The WHO also predicts that new research and medicines will allow them to contain and overcome the antimalarial drug resistance in the Mekong region.

The Solution

The World Health Organization (WHO) has designed an action plan to eliminate malaria in Southeast Asia by 2030, and then maintain a malaria-free environment thereafter. Creating new strains of antibiotics or ACTs will not solve the problem, but it will delay the inevitable resistance cycle. Antimalarial drug resistance will remain a dangerous threat until the region completely eliminates the disease.

The WHO has set four strategic interventions and two supporting elements to achieve its goal by 2030. Each of the intervention strategies works to ensure universal access to malaria diagnosis, treatment and prevention by monitoring all malarial cases, improving community health systems and accelerating efforts towards complete elimination.

– Haley Myers
Photo: Flickr


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