King County Public Health Department officials are advising residents not to panic but to still take precautions after an Issaquah man died of Hantavirus Pulmonary Syndrome last month.

The disease, caused by exposure to hantavirus, has been reported twice in King County since December; the other case involved a woman from Redmond who has since recovered.

The Issaquah man, who was in his 30s, went to the emergency room on Feb. 23 and died the next day, according to the Public Health Department. Test results received the following week showed that the man had hantavirus.

Hantavirus is rare, but without proper precautions, it can be spread through rather ordinary activities, such as camping or housecleaning. In Washington state, the virus is primarily carried by the deer mouse.

Dr. Jeff Duchin, health officer for Public Health — Seattle and King County, said that hantavirus is a “very, very rare disease,” but that “it’s not impossible” to contract, especially for people who live in wooded areas — the environment of deer mice.

Humans can contract hantavirus by coming into contact with rodent droppings, urine, saliva or nesting materials, either by breathing in dust from those materials that has been stirred up, or by touching the materials and then touching their eyes, nose or mouth. A person can also catch the illness after being bitten by a rodent. Humans cannot pass the disease to one another.

Symptoms show up within one to eight weeks of exposure and begin like a normal flu, with fatigue, fever, head and body aches, nausea and vomiting.

“The symptoms early on are really hard to tell from other more common diseases,” Duchin said. The key, he explained, is to tell a health care professional right away if you develop these symptoms after having been around places infested with rodents. If this is done, “the outcome of survival will be much greater,” he said.

As the disease progresses, a person develops a cough, difficulty breathing and shortness of breath.

“It’s very serious,” Duchin said. “It causes the lungs and the blood vessels in the lungs to become leaky and the blood pressure to drop.”

According to national statistics, about one in three people who contract the disease die from it, though Duchin noted that these statistics were gathered around the world over many years, and that the survival rate in present-day Seattle may be higher.

Prime settings for contracting hantavirus include cleaning houses that might be infested with rodents, opening up buildings that had previously been closed, such as summer cabins, camping, hiking, and working in construction, utility and pest control.

“If there’s any concern at all … take precautions when you sweep up dusty areas,” Duchin said.

To prevent rodent infestations, remove potential sources of food, water and shelter for rodents. Seal all pet food, trim back trees growing next to your house and seal all cracks and gaps in buildings over a fourth-inch wide.

If you have an infestation, ventilate the space for 30 minutes before cleaning, wear gloves and a mask while cleaning, do not vacuum, sweep or stir up dust in any way, and clean with a mixture of bleach and water. For a full list of precautions, visit http://www.kingcounty.gov/depts/health/communicable-diseases/disease-control/~/media/depts/health/communicable-diseases/documents/hantavirus-info-sheet.ashx. For serious infestations, contact professional cleaners.

As the days start to get warmer and longer, Duchin said that people should not be afraid to take part in outdoor activities like camping and hiking. He only recommends taking precautions if camping in a cabin or a shelter, where deer mice could also be taking shelter.

“Being out in nature is perfectly safe … The risk factor isn’t nature, it’s the nesting area,” he said.

The first-known human cases of hantavirus in the U.S. occurred in 1993 in the Four Corners region, and has been referred to as the Four Corners outbreak.

The only other time that hantavirus was reported and acquired locally in King County was in 2003.