Your Health: Despite Yosemite scare, deer mouse-borne infection rare

There has been a lot of news recently about Hantavirus infections involving visitors to Yosemite National Park. Six cases, including fatal infections, have occurred in park visitors who stayed in “signature cabins” in the Curry Village this summer.
In these cabins, the virus is found in the fecal droppings of deer mice, which can become aerosolized and breathed into the lungs of a potential victim. The incubation period for this infection is usually two to four weeks, with a range of one to six weeks.
The involved cabins have been closed and disinfected. About 3,000 camp visitors have been sent letters to warn them to seek treatment immediately if they show any of the usual symptoms of Hantavirus infection.
The symptoms are similar to an influenza-like illness, including fever and chills, severe achiness, headache, nausea, vomiting, diarrhea and stomach pain. Unlike influenza, Hantavirus infection rarely causes sore throat or nasal congestion. After a while, a cough can develop, which may become a severe and possible deadly pneumonia-like infection.
There is no cure or vaccine for the infection. Doctors and medical personnel provide care thorough hospital intensive-care units and support the patient’s immune system to help it fight off the infection.
It should be emphasized that this infection, as serious as it may be, is also very rare. Only 587 cases have been reported in the U.S. since 1993, including 63 cases in California. However, about one third of the California cases were fatal.
Fortunately, most people who were exposed in Yosemite and who become sick will ultimately be found to be sick with a more common, non-Hantavirus infection.
Whereas about 20 percent of deer mice in the Sierras test positive for the Hantavirus, none or less than 1 percent do in Santa Cruz County. Also, deer mice are much less prevalent in our area compared with the common gray-brown house mice, which do not carry this disease.
 As rare as this infection is, especially in our locale, one should follow these guidelines:
– Keep mice away by tightly sealing food containers and cleaning up food spills and debris.
– Seal even the smallest of holes in walls to keep mice out.
– Do not touch or handle live mice, and wear gloves when handling dead mice. 
– When cleaning out a room with mouse droppings, open all windows for up to two hours to air it out. Wear a mask and gloves. Instead of sweeping up dry droppings, spray them with a 10 percent bleach solution, wait 15 minutes and then dispose of the droppings by placing them in a double sealed plastic bag in the trash. Wash hands thoroughly.
I want to emphasize that this infection is as yet unheard of in our communities, so there’s no cause for alarm. But there may come a time when it arrives here and the above preventative measures will serve us well.
– Terry Hollenbeck, M.D., is an urgent-care physician at Palo Alto Medical Foundation Santa Cruz in Scotts Valley. Readers can view his previous columns on his website, http://valleydoctor.wordpress.com, or email him at

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. Information in this column is not intended to replace advice from your own health care professional. For any medical concern, consult your own doctor.