Drug-resistant malaria may be emerging in Africa, according to a study that suggests the most powerful drugs against the disease are losing potency on the continent most affected by it.
Genetic mutations in the parasite that causes malaria are starting to make the bug resistant to artemether, the key ingredient in Novartis AG (NOVN)’s Coartem, researchers at the University of London wrote in the Malaria Journal today.
Studies in Cambodia and Thailand have shown that drugs based on artemisinin, the class of remedies to which artemether belongs, are becoming less effective there. The World Health Organization has been leading efforts to contain the resistant strain amid concerns it may spread to Africa, rendering the best treatments useless and endangering millions of people.
“This study confirms our fears,” Sanjeev Krishna, who led the research, said in a statement. “Drug resistance could eventually become a devastating problem in Africa, and not just in southeast Asia where most of the world is watching for resistance.”
Malaria kills a child in Africa every minute, according to the Geneva-based WHO. It strikes about 216 million people each year and kills about 655,000.
Krishna and colleagues studied blood samples taken from 28 people who contracted malaria while traveling in sub-Saharan Africa, discovering resistance in 11 of them. In those cases, artemether’s effectiveness was reduced by about half, they found.
Ancient Chinese Remedy
Artemether is based on artemisinin, an ancient Chinese remedy derived from the leaves of the sweet wormwood tree. Artemisinin-based drugs such as Coartem are the most powerful treatments against malaria after the parasite developed resistance to several previous generations of medicines. The increased use of artemisinin-based drugs may have contributed to resistance, the researchers wrote.
The effectiveness of other artemisinin-based drugs, such as artesunate, wasn’t significantly affected by the mutations, they wrote.
“At the moment, we do not know if the other artemisinins will follow suit, but given the shared chemistry they have with artemether, it is tempting to think that they would,” Krishna said in the statement.
Novartis of Basel, Switzerland, is among the companies working on new malaria treatments, though they’re not expected to be available for years. GlaxoSmithKline Plc (GSK) is developing a product that would be the first malaria vaccine if approved. The shot, known as RTS,S, safely reduced illness in African infants by more than half in a study, the London-based company said in October.
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