* "This is serious"
* Disease carried by wild deer mice
(Updates with fourth confirmed hantavirus case)
By Ronnie Cohen
Aug 29 Yosemite National Park has closed part of
a popular campground over a deadly rodent-borne lung disease
that has already killed two visitors to the California park, and
officials said on Wednesday more cases could emerge.
Two park visitors who stayed in the cabins in June in Curry
Village, a popular camping area tucked below the park's sheer
granite walls, have died after being infected by the illness
known as hantavirus, while a third visitor was sickened but is
A fourth person who visited the park this summer was found
to be suffering from the illness, which is carried by wild
rodents, but investigators were still trying to confirm the
source of that infection. Officials said more cases could
"This is serious. This is something we haven't seen before
and we're all working together to control this disease," said
Dr. David Wong, medical epidemiologist with the National Park
The National Park Service has already sent emails to nearly
3,000 people who slept in the tent cabins this summer, warning
them that they may have been exposed to the virus, Wong said.
Nearly 4 million people visit Yosemite each year, drawn from
around the world by the park's dramatic scenery and hiking
trails. Roughly 70 percent of visitors congregate in the
Yosemite Valley, where Curry Village is located.
Captain Charles Higgins, director of the National Park
Service public health office, said that park officials decided
to close 91 tent cabins after finding rodents nesting between
the double walls of the cabins.
"Our current thinking is that the design of these tents --
double walls -- provides rodent space," Higgins said. "We can't
get to it to clean it."
PREVIOUS HANTAVIRUS CONCERNS
Park and public health officials were also examining guest
lists to see whether they should widen a physician alert to
other countries, Higgins said. The virus kills slightly more
than one-third of those infected.
Twice before, public health officials warned the park about
hantavirus after it struck visitors. But it was not until this
week that the hiding place for the deer mice carrying the virus
was found, Higgins said.
After determining that those stricken had all stayed in the
tent cabins during the same week, park officials began reaching
out to others who stayed there and warned public health
officials across the nation.
Wong said investigators were looking into whether other
visitors were suffering from the illness, which is carried by
wild deer mice. Hantavirus symptoms include fever, headache and
muscle aches, and appear one to six weeks after exposure.
California has reported 60 cases of hantavirus
cardiopulmonary syndrome since it was first recognized in 1993.
Nationwide, 587 people were sickened with hantavirus between
1993 and 2011, according to government data.
Public health officials believe that only deer mice carry it
in California. As many as 20 percent of Yosemite's deer mice
carry hantavirus, park spokesman Scott Gediman estimated.
Most hantavirus infections result from breathing air
contaminated with rodent urine or droppings, usually in small,
confined spaces with poor air circulation. People can also be
infected by eating contaminated food, touching contaminated
surfaces or being bitten by infected rodents.
Blood tests can diagnose the virus. There is no treatment,
but supportive care can improve survival chances.
(Editing by Dan Whitcomb, Cynthia Johnston and Peter Cooney)