FRESNO, Calif. - About 1,700 people who stayed in tent cabins at Yosemite National Park this summer were warned Tuesday they may have been exposed to a deadly rodent-borne virus blamed for the deaths of two campers.

Four people who spent time in Signature Tent Cabins at Curry Village around the same time in June have contracted hantavirus pulmonary syndrome, an illness spread by rodent feces, urine and saliva.

One of the people who died was from outside California. The Centers for Disease Control confirmed the death within the past few days. Two other people were infected and expected to survive.

The disease can incubate for up to six weeks before flu-like symptoms develop. It's fatal in 30 percent of all cases, and there is no specific treatment.

"This is certainly an issue and we're getting word out," said park spokesman Scott Gediman. "We're very concerned about visitors and employees, but we feel we are taking proactive steps in both cleaning the affected areas and in public education."

Rangers were handing out brochures about hantavirus to guests as they entered the park. In addition, guests checking into cabins at the family friendly Curry Village were being warned about the outbreak and what precautions they should take.

"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.

After word of the first death came earlier this month, employees of park concessionaire Delaware North Co. disinfected the 408 canvas-sided and wood-sided cabins in Curry Village. The 91 signature cabins where all four victims stayed were being shored up in an attempt to make them more rodent-proof.

Park officials said none of the victims had anything in common other than staying in Yosemite cabins between June 10 and June 20. A 37-year-old man from the San Francisco Bay area was one of the victims who died. Details about the others have not been released because of medical privacy laws.

Thousands of people visit the park every month, so it would be impossible to track everyone who had set foot in Curry Village, officials said.

"There are rodents and some are infected and that's what happens," Gediman said. "This is a wilderness setting. It has nothing to do with the cleanliness of the cabins."

Of the 587 documented U.S. cases since the virus was identified in 1993, about one-third proved fatal.

This year's deaths mark the first such fatalities of park visitors, although two others were stricken in a more remote area in 2000 and 2010, officials said.

The century-old Curry Village is a collection of cabins that, at roughly $140 a night, are the most economical lodging in the park. At the other end of the lodging spectrum is the historic Ahwahnee Hotel, where rooms can be $500 a night.

Located at the base of 3,000-foot Glacier Point, Curry Village has been in the news in recent years for being located in a rockfall hazard zone. After boulders rained down on the village in 2008, the park permanently closed some of the cabins. These newer, insulated Signature Cabins were built in 2009 to replace them.