Malaria is caused by Plasmodium parasites, carried by mosquitoes that are resistant to two key anti-malarial medicines. They are becoming more dominant in Vietnam, Laos and northern Thailand after spreading rapidly from Cambodia.
The clinical trial looked at 140 patients who received malaria treatment in those countries and found that around half were not cured by first-line antimalarial drugs.
Researchers say the findings raise the “terrifying prospect” drug-resistance could spread to Africa. However, experts said the implications may not be as severe as first thought.
“The spread of drug-resistant strains… provides a warning signal,” said Dr. Michael Chew, infection and immunobiology portfolio manager at the Welcome Trust. “It serves as a reminder that we must not show complacency with the response to malaria.
“It also shows we have the tools to effectively track drug resistance across borders, which can be used to inform co-ordinated elimination and control efforts,” he said.
Using genomic surveillance to track the spread of drug-resistant malaria, the scientists found that the strain, known as KEL1/PLA1, has also evolved and picked up new genetic mutations which may make it yet more resistant to drugs.
“We discovered [it] had spread aggressively, replacing local malaria parasites, and had become the dominant strain in Vietnam, Laos and northeastern Thailand,” said Roberto Amato, who worked with a team from Britain’s Welcome Sanger Institute and Oxford University and Thailand’s Mahidol University.
>Juthy Saha
