Hantavirus is in the Hantaviridae family of viruses carried by rodents.

The animals harbour the virus without becoming ill, then shed it in their urine, droppings, and saliva. When those secretions are disturbed—during cleaning, farming, or simply entering an infested space—the virus can become aerosolised and inhaled by a nearby human.

The virus can also infect humans if they eat contaminated food, or touch a contaminated object and then their mouth.

The consequences of infection can be severe, especially for infections with New World strains.

Between 1 and 15 percent of infections lead to death in Asia and Europe, but about half of hantavirus cases in the Americas are fatal.