Doctors at the London School of Hygiene and Tropical Medicine made the finding following the failure for the first time of malaria treatment with a combination of artemether and lumefantrine.
The report indicates that the drug combination was unable to cure four patients, who had all visited Africa.
However; the doctors said it was too early to panic, but warned that things could suddenly get worse and called for an urgent appraisal of drug-resistance levels in Africa.
