Researchers have found for the first time ‘disturbing’ evidence that a life-saving malaria drug becomes less effective in young African children with serious infections.
A study of children treated in hospital for malaria in Uganda, presented at a major conference on Thursday, found signs of resistance to artemisinin in one in ten patients.
Antimicrobial resistance, in which pathogens such as parasites, bacteria and fungi develop ways to evade the drugs used to combat them, is a growing global problem. It is predicted that more than 39 million people will die by 2050.
Children are the most vulnerable to malaria about 450,000 In sub-Saharan Africa, children under the age of 5 die every year from the disease. Of the 100 children studied, 11 showed partial resistance to the treatment. They were all infected with malaria parasites that carried genetic mutations that have been linked to artemisinin resistance.
Dr. Chandy John, from Indiana University, who co-authored the study with international colleagues, said: “This is the first study from Africa to show that children with malaria and clear signs of severe disease experience at least partial resistance to artemisinin. ”
Another ten of the children studied, who were thought to have been cured of the infection, had a repeat attack of the same strain of malaria within a month. The results suggest that the ‘gold standard’ treatment they had been given, which combined artemisinin with a second malaria drug called lumefantrine, did not work as well as it should.
John said the study was started after researchers noticed a slow response to treatment in some children who were already being followed for a project on severe malaria in young patients.
“The fact that we started seeing evidence of drug resistance before we even started specifically looking for it is a worrying sign,” John said.
“We were further surprised that after shifting our focus to resistance, we also ended up finding patients who relapsed after we thought they were cured.”
The study will be presented at the annual meeting of the American Society of Tropical Medicine & Hygiene in New Orleans and published in the Journal of the American Medical Association.
John said it was too early to determine how widespread resistance to artemisinin was in Africa, although there were indications that resistance was spreading. He pointed to studies showing partial resistance in children with uncomplicated malaria – a milder form that does not affect organs – in countries such as Rwanda and Uganda.
However, he said: “I think our study is the ‘canary in the coal mine’ for children with severe malaria.”
Resistance to artemisinin therapies emerged rather in Southeast Asiawhere the first signs were identified in similar studies. The number of treatment failures in that region increased as resistance to drugs used in combination with artemisinin also emerged. Dr. Richard Pearson of the Wellcome Sanger Institute, who was not involved in this research, said the situation in East Africa was reminiscent of the situation in Southeast Asia 15 years ago.
Artemisinin is used in various forms to treat the disease. For children with severe malaria, this consists of an intravenous infusion of artesunate, a derivative of artemisinin, followed by an oral drug that combines a second derivative with another antimalarial drug.
Artesunate replaced quinine as the recommended treatment for children with severe malaria more than a decade ago The trial revealed fewer deaths with the newer drug. “Returning to quinine would be a step backwards,” John said.
Dr. Alena Pance, associate professor of genetics at the University of Hertfordshire, said any indication of resistance to the “critical drug” is extremely worrying and that high transmission rates in Africa “pose a dangerous risk of rapid spread of resistance within the continent.” making these findings even more alarming.”