Betsy Arakawa, the wife of the late Gene Hackman, died of hantavirus pulmonary syndrome, New Mexico officials said Friday.

There are at least 38 recognized species of hantavirus across the world, 24 of which cause disease in humans. It’s considered a rare virus but it’s also likely to be underdiagnosed in many areas of the world because the initial symptoms can be mistaken for cold and flu-like viral infections.