For the first time in Africa, researchers said on Wednesday they have detected a malaria parasite that is partially resistant to the top anti-malaria drug, artemisinin, raising concern about efforts to fight a disease that sickens hundreds of millions of people each year.
The discovery means that Africa now joins south-east Asia in hosting such drug-resistant forms of the mosquito-borne disease. Malaria infected more than 200 million people and killed some 438,000 people world-wide in 2015, most of them children in Africa.
"The spread of artemisinin resistance in Africa would be a major setback in the fight against malaria, as ACT (artemisinin-based combination therapy) is the only effective and widely used antimalarial treatment at the moment," said lead author Arnab Pain, professor at the King Abdullah University of Science and Technology.
"Therefore, it is very important to regularly monitor artemisinin resistance world-wide."
The drug-resistant malaria parasites were detected in a Chinese patient who had travelled from Equatorial Guinea to China, said the report led by Jun Cao from the Jiangsu Institute for Parasitic Diseases in China.
Combination therapy with artemisinin usually clears malaria from the blood in three days.
In south-east Asia, strains of the malaria-causing agent, Plasmodium falciparum, have grown relatively tolerant to artemisinin, in what is known as "partial resistance."
Researchers said they found the parasite carried a new mutation in a gene called Kelch13 (K13), which is the main driver for artemisinin resistance in Asia.
They then confirmed the origin of the resistance was Africa, by using "whole-genome sequencing and bioinformatics tools we had previously developed - like detectives trying to link the culprit parasite to the crime scene," he said.