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.

Ms. Arakawa, the wife of the actor Gene Hackman, died from the effects of a disease often caused by contact with droppings from infected rodents.