As the past few years have painfully made clear, infectious diseases remain one of humanityâs greatest perils. It only took weeks for scientists to identify the cause of the covid-19 pandemicâa previously unknown species of coronavirusâbut there have been plenty of outbreaks, past and present, whose true cause isnât so obvious. Here are six mysterious outbreaks that remain unsolved.
A version of this story was originally published April 2, 2021.
