Some brands of artemisinin

 

 

Scientists have discovered the emergence of artemisinin-resistant malaria in Africa, raising concerns over treatment failures associated with the medicine that turned around malaria treatment.

Artemisinin, isolated by Chinese scientists in 1972 from Artemisia annua plant is a fast-acting drug that clears the malaria parasite within three days. For over two decades, it has become the preferred therapy in combination with other long-acting components for malaria treatment after the commonly used Chloroquinne monotherapy was failing in Africa and other malaria endemic regions.

However, evidence in Africa that the malaria parasite Plasmodium falciparum has developed genetic variants that confer partial resistance to artemisinin is a warning of potential treatment failure on the horizon.

Partial resistance to artemisinin was first discovered in Cambodia in 2008. Since then it has become common in Southeast Asia. This was soon followed by resistance to the combination therapy.

In Africa, mutations of the malaria parasite found to be associated with delayed parasite clearance were earlier observed at low frequencies in four countries, including Ghana, Rwanda, Uganda and Tanzania.

In the recent study conducted in Northern Uganda published in the New England Journal of Medicine (NEJM), researchers from the School of Medicine, Juntendo University, Tokyo and Japan’s Institute of Tropical Medicine at Nagasaki University alongside colleagues at the Gulu University, Gulu, Uganda have found that such mutations are also causing a reduction in the ability of artemisinin based antimalarials to treat people as fast as is expected.

The study conducted from 2017 to 2019 found that the mutation in Uganda were substantially different from those in Southeast Asia, raising concerns of a potentially precarious situation in Africa where over 90% of malaria cases and deaths worldwide occur.

Fears are particularly rife that the resistant parasite strains in Africa might evolve to become super resistant.

“It is certainly a worrying finding, because we rely completely on these artemisinin-combination therapies,” Arjen Dondorp, Head of malaria research at the Mahidol Oxford Tropical Medicine Research Unit in Bangkok, was quoted by Nature as saying.

According to him, scientists fear that a similar scenario to the one in Southeast Asia will unfold in Africa, and in light of the lack of access to adequate health care in many parts of sub-Saharan Africa, it could exact a huge toll.

Although the mutations had already been detected in malaria parasites in Africa, “we didn’t know if these parasites were actually resistant to drugs in humans”, says Toshihiro Mita, a parasitologist at Juntendo University in Tokyo, and a co-author of the study told Nature.

The findings have been described as a major wake-up call, with the thinking that the parasites becoming resistant to lumefantrine could be disastrous, especially in Africa where the health system is already challenged.

Although the researchers have stated that resistance might not spread as quickly as was the case in Southeast Asia, adding that that to the rampant cases of immune tolerance to malaria parasite strains among Africans could be devastating.

Meanwhile the world is hoping that a malaria vaccine comes through soon. Some are already under development, with one showing huge promises in a small clinical trial earlier this year.

 

 

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