It's not just that hydroxychloroquine doesn't help Covid-19 patients. The drug makes them sicker.
A comprehensive study published yesterday in the medical journal The Lancet found that seriously ill Covid-19 patients who were treated with hydroxychloroquine or chloroquine were more likely to die or develop irregular heart rhythms.
"Our data has very convincingly shown that across the world in a real-world population that this drug combination, whichever way you slice it or dice it, does not show any evidence of benefit, and in fact is immutably showing a signal of grave harm," said Dr. Mandeep Mehra, the study's lead author.
It's not the first study to highlight the potentially harmful effects of the medication, but it is by far the largest. It analyzed data from more than 96,000 patients across six continents.
The study comes just days after US President Donald Trump revealed that he has been taking the medication himself, despite the Food and Drug Administration's stark 1,000-word warning about the risks.
Today's other developments
Latin America is the new hot spot: Brazil reported more than 20,000 cases yesterday in the previous 24 hours, as hospitals struggle to cope. President Bolsonaro continues to dismiss the threat, saying quarantines and lockdowns could have a worse impact on his country's battered economy.
In Peru, the government announced it was extending its state of emergency until the end of June. The Andean country has the second-highest number of confirmed Covid-19 cases in Latin America after Brazil. In Mexico, health officials announced the highest single-day surge in deaths.
80 million babies at risk: The WHO warns that 80 million babies worldwide could be at risk of preventable diseases like measles and polio because of missed vaccinations. The coronavirus pandemic has disrupted immunization programs in at least 68 countries.
Apples and oranges: The US Centers for Disease Control and Prevention acknowledged yesterday it had combined results from viral and antibody coronavirus tests on its website.
Experts say this is unhelpful and potentially misleading, because antibody tests aren't used to diagnose current infections or determine whether someone is potentially contagious. Instead, they indicate whether someone has been exposed to the virus in the past.
Information wars: Fighting misinformation is just as important as fighting the virus itself, says Dr. Mike Ryan of the WHO's Health Emergencies Program. Ryan says the WHO has invested heavily in myth-busting videos, infographics and cartoons.
Coronavirus conspiracy theories have spread rapidly on social media. But researchers from Carnegie Mellon University have discovered that nearly half the accounts propagating the Covid-19 conversations on Twitter could be automated bots.
Africa tops 100,000 cases: The coronavirus has spread to every country on the continent. But Africa's mortality rate is low compared to other parts of the world. Its young population might explain the low numbers. The WHO points to another possible explanation: Many governments there were quick to impose confinement measures, which helped slow the spread.
But lockdowns have spurred other hardships. In Ghana, bodies have piled up in morgues since a ban on public gatherings. Many families have opted to store corpses in morgues for longer than usual, until they can hold a traditional funeral with many mourners, Zaina Adamu reports
A version of this story appeared in the May 23 edition of CNN's Coronavirus: Fact vs. Fiction newsletter. Sign up here to receive the need-to-know headlines every weekday.