People with reservations in the affected cabins are not being notified before arrival, but they are being warned during check-in to report any sightings of mouse feces.
"This is a serious public health issue and we want to be transparent, but at the same time we don't want people to alter their plans, because we are taking the necessary precautions," Gediman said.
Since the first illness was reported earlier this month, employees of Delaware North disinfected all 408 canvas-sided and wood-sided cabins in Curry Village. Workers are in the midst of shoring up the cabins in an attempt to keep mice from have easy access.
Epidemiologists say none of the victims had anything in common other than staying in Yosemite cabins.
A 37-year-old man from the San Francisco Bay area was the first person to die. Further details have not been released because of medical privacy laws.
Of the 587 documented U.S. cases since the virus was identified in 1993, about one-third proved fatal.
Deer mice were determined to be the main carriers of the virus, though other rodents can be infected, according to the Centers for Disease Control. Most of the cases occur in the West, though researchers are not sure why.
This year's deaths mark the first such fatalities of park visitors, although two others were stricken in a more remote area of the park in 2000 and 2010.
There have been at least two other fatal cases in national parks in the past few years, including a deputy superintendent at Glacier National Park who died in 2004, and a tourist at the Grand Canyon who was stricken in 2009.
Wong said health officials never were able to determine whether the victims contracted hantavirus inside the park grounds.
CDC on hantavirus: http://www.cdc.gov/hantavirus
Follow Tracie Cone on Twitter: www.twitter.com/TConeAP
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.