( CNN ) -- Two Californians , one of whom died , may have been exposed to mice droppings or urine that contained hantavirus while vacationing at Yosemite National Park , health officials said Thursday . The visitors contracted hantavirus cardiopulmonary syndrome , a rare but often fatal lung disease . The two had stayed at the popular Curry Village in mid-June , according to the California Department of Public Health . An unidentified 37-year-old man from the San Francisco Bay area died in late July , said Dr. Vicki Kramer , chief of the department 's vector-borne disease section . A Southern California woman in her 40s survived and is recovering , Kramer told CNN . The two stayed in separate locations at the village , which contains about 400 canvas tent and wooden cabins . `` They are very sparse but comfortable , '' Yosemite ranger and spokesman Scott Gediman said of the tent cabins where the man and woman stayed . Officials have focused on deer mice , common in the high-elevation eastern Sierra Nevada region . The mice are gray or brown on top , with white bellies . Their ears have no fur . `` Rodents can infest a whole range of these structures , '' Kramer said . `` Deer mice can get in a hole one-quarter inch in diameter . '' In the United States , the carriers of hantavirus are deer mice , cotton rats , rice rats and white-footed mice , according to the U.S. Centers for Disease Control and Prevention . The virus can be present in the rodents ' urine , droppings and saliva , and is spread to people when they breathe in air contaminated with the virus , the CDC says . The virus is not communicable from person to person . Explainer : What is hantavirus ? Rodent control is the primary strategy for preventing the hantavirus syndrome , according to the CDC . California 's health department has worked with Yosemite National Park for years to reduce the risks to visitors , Kramer said . The agency and park public health officers routinely conduct rodent surveillance , and the park inspects buildings and facilities , it said . The battle begins with workers routinely disinfecting floors and removing mouse droppings . Once park officials learned of the two cases , all 400 camp structures were thoroughly cleaned , Gediman said Thursday . Yosemite National Park has increased routine measures to reduce the hantavirus risk , according to officials . `` You can not eliminate all the mice , '' Kramer said . `` There are a lot of people and snacks that people bring into their tents or cabins . '' Gediman said officials consider Curry Village safe and guests have not canceled lodging reservations in the busiest month of the year at Yosemite . Officials urge people to clean areas of rodent infestation with caution . It 's best not to vacuum or sweep , because that can push hantavirus particles into the air , where they can enter the lungs . Rather , people should wear gloves and use bleach where they see mouse droppings . They should let the bleach sit for 15 minutes before using a mop or sponge to clean up . Opening shuttered areas to air and sunlight also is suggested . The two recent hantavirus cases bring the 2012 total in California to four . About one-third of the 60 cases reported in the state since 1993 have been fatal , the department said . Yosemite National Park saw one hantavirus case each in 2000 and 2010 . There is no specific treatment for hantavirus infection , according to the CDC , but the earlier the patient is brought to intensive care , the better . Diagnosis is difficult , because early symptoms of fever , muscle aches and fatigue often are confused with the flu . `` However , if the individual is experiencing fever and fatigue , and has a history of potential rural rodent exposure , together with shortness of breath , ( that ) would be strongly suggestive of HPS , '' the CDC says . Boy drowns , another missing in Yosemite National Park river .
Park said it disinfected 400 cabins . Man , woman in June visited camping area in Yosemite National Park . They may have been exposed to deadly hantavirus . Deer mice might be to blame .