Researchers on Thursday reported the first clinical evidence that drug-resistant mutations in the malaria-causing parasite are gaining ground in Africa.
Experts have long been concerned about the emergence of drug resistance across the continent, which accounted for more than 90% of malaria deaths globally in 2019.
A new study published in The Lancet seems to confirm these fears.
In clinical trials, the disease persisted longer in children receiving standard malaria treatment if they were infected with mutant strains of the disease, according to the study.
The effectiveness of artemisinin-based combination therapies (ACT) remained high, but the researchers said there was an “urgent need” for increased surveillance in Rwanda, where the study was being conducted, as well. than in neighboring countries.
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There are approximately 229 million cases of malaria worldwide, according to the World Health Organization (WHO).
The disease killed more than 400,000 people in 2019, more than two-thirds of whom were children.
Malaria is caused by the parasite Plasmodium falciparum, which is carried by female mosquitoes of one of dozens of species of the genus Anopheles.
“Our study shows that resistant isolates are starting to become more common,” said lead author Aline Uwimana, researcher at the Rwanda Biomedical Center in Kigali.
Introduced in the early 2000s, ACTs are the most effective and widely used treatments for malaria.
The drug combines an artemisinin component that eliminates most pathogens from the patient’s body within three days, and a long-acting partner drug that eliminates remaining parasites.
Resistance to the artemisinin component is suspected if P. falciparum is still present after the third day of treatment.
Currently, ten mutations in one of the genes of the parasite, known as pfk13, have been confirmed as markers of partial resistance, and several more are being marked as potential markers.
Partial resistance to artemisinin was first identified in Cambodia in 2008 and is now well documented in many countries in Southeast Asia.
Data from the Mekong River region showed that once artemisinin resistance becomes widespread, resistance to the partner drug often follows, leading to ACT treatment failure.
In 2006, Rwanda introduced the most widely used antimalarial as a first-line treatment for the disease.
A study in 2013 and 2014 showed mutations, but no evidence that the drug combo was less effective.
However, follow-up research in 2018 showed for the first time mutations in the pfk13 gene and so-called delayed parasite clearance in patients, although the efficacy of ACT remained above the critical threshold of 90%. .
In the trial, more than 200 children aged six months to five years infected with the parasite received standard three-day treatment and then were followed for 28 days.
About 15% had detectable parasites three days after treatment.
“Recent data suggests that we are on the brink of clinically significant artemisinin resistance in Africa,” wrote Philip Rosenthal, professor at the University of California at San Francisco, in a commentary, also in The Lancet.
The loss of effectiveness of key ACTs “can have dire consequences, as happened when chloroquine resistance led to huge increases in malaria deaths in the late 20th century,” he said. -he declares.