Hantavirus: Be careful, not fearful

August 30, 2012 by Jeffrey Norris
Charles Chiu, MD, PhD. Photo: Susan Merrell

(Medical Xpress)—Hantavirus, a potentially fatal virus transmitted by rodents such as deer mice, is making news following an unusual outbreak at a popular tourist area of Yosemite National Park. The recent cases are a reminder for campers to be cautious, but not necessarily fearful, according to UCSF infectious diseases expert, Charles Chiu, MD, PhD.

Previous cases in had originated at , which are favored by the deer mouse that carries the virus, said Chiu, who directs the UCSF-Abbott Viral Diagnostics and Discovery Center. Other rodents, including , are rarely if ever carriers of the virus.

"For whatever reason, it appears that the range of the deer mouse is moving to include lower elevations," he said. "Over the past two decades, most exposures to the virus have been in very rural areas. Now we are starting to see potentially more people at risk perhaps due to changing of the deer mouse."

Hantavirus has been fatal in more than one-third of the nearly 600 cases reported since it was first recognized in 1993 in the Four Corners region of New Mexico. Three—possibly four—cases of infection, including two deaths, have been linked to June stays at tent cabins in Yosemite's Curry Village.

Chiu prescribes precautions for those who want to be happy, virus-free, Labor Day campers at Yosemite and other favored camping destinations. But there is no reason to ruin your vacation out of fear, he said.

The virus is often deadly but infection is very rare, and potential exposures occur much more often than infection, Chiu said. The virus is not spread by infected humans or by other animals. Furthermore, the virus does not survive long in dust after the mice that carry it have been eradicated, Chiu said.

Contamination depends on continual exposure to infected . "The mice most likely must have been around within hours or days of infection," Chiu said.

Humans may become infected by inhaling dust contaminated by the droppings or urine of an infected mouse, which does not exhibit any symptoms when carrying hantavirus. The deer mouse nests in wood, and may nest in the logs of wooden cabins or stacks of firewood. The virus does not fare well in sunlight, but survives well in dark, musty environments, which may include seldom-used cabins that have not recently been aired out or cleaned.

Infection may occur up to six weeks before symptoms become apparent, Chiu said. Initial flu-like symptoms from hantavirus infection can include fever, fatigue, muscle aches, and stomach upset. Respiratory symptoms occur later and may progress to pneumonia that requires that patients be on a breathing tube in the intensive care unit, to secondary bacterial infections, and to multi-organ failure. 

According to Chiu, there is no known effective anti-viral treatment for hantavirus infection, but early detection and medical care that includes close monitoring, fluids, oxygen and antibiotics to treat secondary infections increase the likelihood of survival. 

Chiu suggested that continuing outbreaks of hantavirus infection might spur greater interest in the development of new treatments or a vaccine.

Lower Your Risk for Hantavirus Infection

  • Stay away from wild rodents and do not pitch tents near logs or mouse droppings.
  • Open doors and windows of cabins upon arriving and allow at least 30 minutes for airing out.
  • Do not raise dust by sweeping or vacuuming.
  • Wipe down floors and surfaces with a solution of one part bleach and 10 parts water using a sponge, sponge mop or rags. Wear rubber, vinyl or latex gloves, as well as a dust mask while cleaning.
  • Seal up all food tightly to keep mice away. Clean dishes and utensils promptly after use. Close garbage containers securely.

Explore further: Hantavirus found in African wood mouse

Related Stories

Hantavirus found in African wood mouse

April 18, 2006

Scientists have reported the discovery of the first African hantavirus, a type of rodent-borne virus that can cause life-threatening infections in humans.

Can hantavirus infection spread among humans?

January 18, 2008

In connection with last year's epidemic, a research team at Umea University in Sweden has managed for the first time to show that hantavirus exists in human saliva. This raises the question of whether this contagion can spread ...

2nd Yosemite visitor dies of rodent-borne illness

August 28, 2012

(AP)—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.

Yosemite officials say 1,700 visitors risk disease

August 28, 2012

(AP)—Yosemite officials told 1,700 past visitors on Tuesday they may have been exposed to a rodent-borne disease already blamed for the deaths of two people who stayed in cabins at the national park.

Yosemite officials say 1,700 visitors risk disease

August 29, 2012

(AP)—The rustic tent cabins of Yosemite National Park—a favorite among families looking to rough it in one of America's most majestic settings—have become the scene of a public health crisis after two visitors died ...

Recommended for you

Immune breakthrough: Unscratching poison ivy's rash

August 23, 2016

We all know that a brush with poison ivy leaves us with an itchy painful rash. Now, Monash University and Harvard researchers have discovered the molecular cause of this irritation. The finding brings us a step closer to ...

Zika infection may affect adult brain cells

August 18, 2016

Concerns over the Zika virus have focused on pregnant women due to mounting evidence that it causes brain abnormalities in developing fetuses. However, new research in mice from scientists at The Rockefeller University and ...

Monkeys with Sudan ebolavirus treated successfully

August 22, 2016

Scientists funded by the National Institutes of Health (NIH) have successfully treated monkeys several days after the animals were infected with Sudan ebolavirus (SUDV). The study is important, according to the researchers, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.