Researchers have confirmed early signs of malaria parasites in Africa becoming more resistant to drugs, leading one person working on the study to fear a grave situation in future.
The traditional anti-malarial drug quinine has already been sidelined as the parasites carried by certain mosquitos became resistant to it over time. Now, other drugs commonly in use have been shown to be less effective than they once were.
Researchers at the London School of Hygiene & Tropical Medicine found that the most deadly form of the malaria parasite, Plasmodium falciparum, with a mutation to the gene ap2mu, was less sensitive to the antimalarial drug artemisinin.
A study in 2013, also led by the School, suggested an initial link between a mutation in the ap2mu gene and low levels of malaria parasites remaining in the blood of Kenyan children after they had been treated.
In the new study, published in Antimicrobial Agents and Chemotherapy, researchers genetically altered the malaria parasite in the laboratory to mutate the gene in the same way that had been observed in Kenya. They found the altered parasite was significantly less susceptible, needing a 32 percent higher artemisinin dose to be killed. The genetically altered parasite was also 42.4 percent less susceptible to quinine.
Much worse to come?
Earlier this year, a different research group discovered mutations in the gene kelch13. These were linked to reduced effectiveness of artemisinin treatment in South East Asia, where resistance usually begins, before spreading to Africa. However, there are now signs that a different route to drug resistance may be developing independently in Africa.
Lead researcher Dr. Colin Sutherland, Reader in Parasitology at the London School of Hygiene & Tropical Medicine, said: “Our findings could be a sign of much worse things to come for malaria in Africa. The malaria parasite is constantly evolving to evade our control efforts. We’ve already moved away from using quinine to treat cases as the malaria parasite has become more resistant to it, but if further drug resistance were to develop against our most valuable malaria drug, artemisinin, we would be facing a grave situation.”
Reason for optimism
However, there is optimism that the work will lead to greater understanding of how resistance occurs.
“We now know that the gene ap2mu is an important factor in determining how well our drugs kill malaria parasites,” Dr. Sutherland said. “We will be conducting laboratory and field studies to more accurately measure the impact of mutations in the ap2mu gene. We hope our findings will help understand resistance of malaria to drugs, and potentially be an important tool for monitoring malaria treatment in the future.”
Meanwhile, the International Business Times recently reported that a fast-working, single dose malaria drug developed in India was proven to be safe and effective in a series of tests on animals. The drug, triaminopyrimidine, is said to work against drug resistant strains of the malaria pathogen and has no known side-effects. After a few more lab tests, it will go for clinical trials in humans.
The World Health Organization estimates more than half a million people die from malaria every year, mostly children under five.
Published: April 19, 2015. By John Hopton
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