19:25

Online demand for the anti-malaria drug hydroxychloroquine surged by more than 1,000% after Donald Trump endorsed it as a potential treatment for Covid-19 without providing evidence it worked, a new study has found.

There are no proven prescription therapies to treat Covid-19, the disease caused by the coronavirus. Despite the lack of evidence, the presidential endorsement drove up online searches for buying hydroxychloroquine, and its chemical cousin chloroquine, by 1,389% and 442% respectively.

Internet searches remained high, researchers said, even after NBC News reported an American couple had accidentally poisoned themselves by taking a liquid containing chloroquine meant to treat parasites in fish tanks, following a Trump press briefing in which he promoted the drug.

“We know that high-profile endorsements matter in advertising, so it stands to reason that these endorsements could spur people to seek out these medications,” said Michael Liu, a graduate student at Oxford University and the study’s first author, in a statement.