One of American's most pristine national parks has U.S. health officials warning its visitors over a deadly lung disease spread by deer mice.

Three people have died so far after staying in tents at Yosemite National Park in California that were infested with mice who carry the hantavirus.

Last week, U.S. health officials said that up to 10,000 people may have been at risk of contracting the disease after staying in the tents between June and August of this year.

Despite the warnings, though, tourists continue to visit the park, and even stay in the tents which have since been cleaned and disinfected.

Visitors say they're using common sense to stear clear of any possible danger.

(SOUNDBITE) (English) JADYN THEILEN, TOURIST AND DAUGHTER OF DAWN THEILEN, SAYING:

"My mom told me that if we see any mice poops, we'll just warn her and she'll find a way to get rid of them."

The virus is carried in rodent feces, urine and saliva that can be inhaled in spaces with poor ventilation.

There have been no cases of the disease spreading through human contact.