Some 10,000 people who recently stayed in tent cabins at Yosemite National Park risk having contracted the often fatal hantavirus pulmonary syndrome, the U.S. Centers for Disease Control and Prevention said Saturday.

"People who stayed in the tents between June 10 and August 24 may be at risk of developing HPS in the next six weeks," the CDC said in a communique.

In the past few hours at least two more cases have been detected of the disease that up to now has taken two lives, raising the number of confirmed infections to six, according to the authorities.

Other suspected cases are currently undergoing diagnosis.

The CDC urged anyone in that situation to have medical exams in case they feel symptoms associated with the hantavirus pulmonary syndrome, a fairly rare infection but one that can be fatal. It is spread by rats and mice.

The symtoms include fatigue, fever, muscle ache - especially in the thighs, hips and back - headache, chills, dizziness, nausea, vomiting, diarrhea, abdominal pains, coughing and shortness of breath.

The rodents expel the virus in the urine, feces and saliva. According to the Web site medline Plus, small drops of the virus can float in the air and humans can contract the illness by inhaling the infected air or by coming in contact with the rodents or their excrement.

It added that a person infected with the disease cannot transmit it to another.

Most of the victims are believed to have been infected by the virus while staying at one of the 91 tent cabins in Curry Village, which were later closed to the public. However, one of the victims could have caught it in another part of the park.

"Our investigation is trying to determine which area of the park that person visited," California Department of Public Health spokeswoman Anita Gore said.

Though no cure exists for the hantavirus, treatment after a swift diagnosis greatly increases chances of survival.

"The earlier it's caught and supportive care is given, the better the survival rate," Dr. Vicki Kramer, chief of vector-borne diseases at the California Department of Public Health, said.

In 2011, half the cases diagnosed with hantavirus in the United States ended in death, but since 1993, when the virus was identified, the average death rate in detected cases has been 36 percent, according to the CDC.

Some 4 million people visit Yosemite National Park every year. Close to 70 percent of those tourists go to Yosemite Valley, where the Curry Village tent cabins are located. EFE