90-Second Read: Hantavirus in the U.S.: How easily does the Andes strain spread?

At least 11 passengers from the MV Hondius cruise ship are reported to have the Andes strain of Hantavirus. The latest confirmed cases are all among people who had direct contact with other patients who were on the ship, although concerns about how easily, or not, the Andes strain spreads are growing. Only one of the dozens of Hantavirus strains is known to spread among people: the Andes strain. Andes is the only type of Hantavirus that can pass from person to person.

While experts maintain that the risk of Hantavirus' spreading widely is extremely low, they say there's still much to learn about the virus and how it infects people. Just 2% to 5% of all Andes cases are estimated to stem from person-to-person transmission. Rachael Lee, chief health care epidemiologist at the University of Alabama at Birmingham, said the problem with Hantavirus is that patients are identified only when they're sick enough to be hospitalized. Of the 18 Americans who were on board and are now in quarantine facilities in the U.S., at least three are being closely watched for possible infection.

Researchers were able to piece together how an infected person might have spread the virus at the birthday party. In one instance, the infected person spread the virus to somebody at a table roughly 1 to 2 meters away. Jackson said there's no documented evidence that infected people can spread the virus if they don't have any symptoms, like coughing or sneezing. Jackson of the CDC acknowledged that there's a lot more to learn about Hantavirus.

Three people from the cruise ship have died from the virus. Some experts now suggest it's possible it may be more contagious than thought. When it does, it typically involves household members that are doing things like sharing beds or sharing eating utensils or having contact with body fluids.