Virus Attack Continuing at Yosemite Natl. Park

July 8, 2013 by · 2 Comments 

Deer mice (Peromyscus maniculatus) are carriers of hantavirus pulmonary syndrome (HPS) in Yosemite and other parts of the U.S. Photo from Centers for Disease Control and Prevention.

The weapons of choice against the tiny mice that run around Yosemite National Park carrying a potentially fatal virus include disinfectant, peanut butter and 20 years’ worth of animal science.

Last year 10 people became ill with hantavirus, an outbreak concentrated among a cluster of canvas-walled tent cabins in Yosemite’s Curry Village, a popular destination on the valley floor, the Orange County Register reported. Three people died in what is the largest rash of cases related to the Sin Nombre strain of the virus, which was discovered in 1993. The other seven victims survived.

DNC Parks and Resorts of Yosemite, which operates the lodgings and other businesses in Yosemite National Park, has gone to great lengths to prevent another outbreak. Ninety-one Signature tent cabins, the relatively new structures that turned out to be well-suited for harboring infected mice, were torn down earlier this year.

Park employees now take more time to clean structures — at least 15 minutes for the Curry Village tent cabins — and watch for mouse droppings. Park authorities also have redoubled efforts to educate visitors about the importance of stowing food so mice, as well as bears, deer and other animals, can’t get to it. All over the park, there are fliers urging guests to take precautions.

The preventive surge has brought a comeback for one of the nation’s greatest natural treasures, thanks in part to a massive outreach campaign. And the visitors are undeterred by last summer’s unprecedented outbreak.

“The transparency of the National Park Service reinforces my confidence that they’re eradicating the problem and keeping everyone safe,” said Kevin Kearn, 45, a retired Army lieutenant colonel from Huntington Beach.

No one, not even the biologists who poured into the valley after the first hantavirus cases were reported, can explain exactly why so many people developed infections in such a short time. And despite the intense preventive efforts, there’s no guarantee there won’t be more cases.

“When you have that many humans, chances are there’s going to be a food source,” said Danielle Buttke, a veterinary epidemiologist at the National Park Service in Fort Collins, Colo.

The “reservoir” for the outbreak was traced to the deer mouse, which is common all over the West. About 14% of the deer mice in Yosemite have the Sin Nombre strain of the hantavirus.

The virus doesn’t spread to any other animals, and the virus doesn’t exist in common house mice.

But it’s in the deer mouse feces, urine and saliva, and if any of those substances gets stirred up — say, by sweeping along a floor — it can get aerosolized. If enough of it is inhaled, infection can occur.

In 2009, the park built 91 Signature tents, which featured canvas on the outside, then a layer of insulation, then a layer of sheet rock. The goal was to have a warmer-cabin option in wintertime for guests who wanted it. Mice were able to get into the insulation and hide, and the virus came from the walls.

“That particular kind of structure, we hadn’t anticipated a rodent infestation would be there, but that was the smoking gun in this case,” said Barbara Knust, an investigator with the Centers for Disease Control and Prevention’s infectious-disease branch in Atlanta.


A Closer Look at Yosemite Hantavirus Fight

May 28, 2013 by · 1 Comment 

Curry Village has become ground zero of a multimillion-dollar effort to make Yosemite National Park safe — or as safe as any rural place can be — from an illness carried by mice who can burrow into a hole the width of a pencil. Changes to the park’s far-flung facilities will get tested this summer, as an expected 1.8 million visitors fan out across its 1,200 square miles and share turf with all sorts of wild beasts, the Los Angeles Times reported.

The park visitors who contracted hantavirus had inhaled large quantities of dust containing urine, saliva and fecal matter from infected deer mice. To try to keep that from happening again, workers have been plugging crannies in buildings, hanging screens on staff and guest lodgings, and reinforcing “bear boxes,” all to keep the little critters from nesting anywhere near people.

It’s an undertaking that’s considerably more difficult than guarding against ferocious predators, said Mark Gallagher, environmental manager at Yosemite for Delaware North Cos., which operates Curry Village and other lodging facilities in the park.

“Keeping a bear out is easy — your enclosure just has to be strong,” Gallagher said. “With a mouse, you really have to pay attention to detail.”

Click here to read the entire story.




Feds: Hantavirus Outbreak Response Proper

May 21, 2013 by · Comments Off on Feds: Hantavirus Outbreak Response Proper 

Federal investigators probing the hantavirus outbreak blamed for three deaths at Yosemite National Park recommended on Monday (May 20) that design changes to tent cabins and other privately run lodging first be reviewed by National Park Service (NPS) officials.

The report released by the Interior Department’s Office of Inspector General found that park officials responded to last summer’s outbreak appropriately and within department policy, the Macon (Ga.) Telegraph reported.

“When the outbreak was identified, NPS mobilized to contain and remediate the outbreak and to prevent further outbreaks,” Mary Kendall, a deputy inspector general, wrote in a letter attached to the report.

Still, the report found that current policy didn’t require park officials to approve design changes made to the “Signature tent cabins” by concessionaire Delaware North Cos. Parks and Resorts, which added rafters and wall studs to the structures.

Investigators determined that deer mice, which can carry the illness, nested inside the double walls of the new tents in Yosemite’s family friendly Curry Village.

At least eight of the nine tourists who fell ill stayed in the tent cabins.

Because the changes to the cabins were considered routine maintenance, current park service policy did not require prior approval, the report found.

The report also recommended that the park service begin cyclical pest monitoring and inspections of all public accommodations.

While there is a current pest monitoring program at Yosemite, Delaware North was responsible for Curry Village, which was not considered at high risk for hantavirus.

The company issued a statement late Monday saying it would follow the recommendations in the report.

“DNC Parks & Resorts at Yosemite has consistently worked hand-in-hand with the National Park Service and public health officials on this issue,” spokeswoman Lisa Cesaro said in the statement. “The Signature Tent Cabins have been removed from Curry Village. We are following the recommendations by the National Park Service, which were developed in consultation with the California Department of Public Health and the Centers for Disease Control and Prevention.”

Prior to the outbreak, Delaware only responded to pests in the cabins when visitors or housekeeping staff complained, the report said.


Suit Filed Over Yosemite Hantavirus Outbreak

April 30, 2013 by · Comments Off on Suit Filed Over Yosemite Hantavirus Outbreak 

A multi-million dollar lawsuit has been filed over the hantavirus outbreak inside Yosemite National Park last year, KFSN-TV, Fresno, Calif., reported.

The first court date is set for May 30. The lawsuit alleges Cathy Carrillo of Chino, Calif., contracted the virus while staying in Curry Village last June.

Carrillo claims she has a million dollars’ worth of medical bills and now suffers from diminished lung capacity and low energy.

Carrillo is seeking $3.25 million from DNC Parks and Resorts at Yosemite. The hantavirus outbreak caused a worldwide scare among Yosemite visitors. Three died and several others were sickened by the illness.

230,000 people around the world were warned that they may have been exposed to the virus while visiting Yosemite.

Click here to read a story summarizing the hantavirus outbreak at Yosemite.


A Look Back at Yosemite’s Hantavirus Outbreak

December 19, 2012 by · Comments Off on A Look Back at Yosemite’s Hantavirus Outbreak 

Sunset over Half Dome, Yosemite National Park

On Dec. 10, Yosemite National Park in California began demolishing 91 tent cabins in Curry Village, a rustic encampment of 408 canvas-sided cabins jammed into a pine-and-cedar glade near the sloping shoulders of Half Dome. It was here that an outbreak of hantavirus began last summer, infecting at least 10 people and killing three, reported.

But on Sunday, June 10, 2012, the campground seemed idyllic. That weekend held all the promise of early summer. The Curry Village swimming pool was open. The smell of hot dogs and nachos curled out of the snack bar. The sun bounced off the face of Glacier Point. Kids in “Go Climb a Rock” T-shirts shouted and chased each other on bikes.

Sometime that day, a 49-year-old woman from the Los Angeles area arrived at Curry Village’s front desk, a plain wood-floor office that’s often cacophonous with the sound of staffers checking guests in and out. A clerk handed her a key to one of the 91 “signature tent cabins” that opened three years ago — the “new 900s” as they were collectively known. Unlike the older cabins, which are sided with single-ply vinyl-coated canvas, the signature cabins boasted double-wall plywood construction and propane heaters, making them warmer and quieter than the older units.

Off she went, this Southern California lady, to enjoy her Yosemite vacation. We’ll call her Visitor One.

About the same time, another guest checked into Curry Village. He was a 36-year-old man from Alameda County, Calif., which encompasses Berkeley, Oakland, and the East Bay region. He was given the key to a cabin close to Visitor One’s. He dropped off his things and went about his business. We’ll call him Visitor Two.

We don’t know exactly how Visitors One and Two spent their four days in the park. Medical confidentiality laws forbid public-health officials from releasing their names, and they and their families have chosen to keep their stories private. Maybe they hiked to the top of Half Dome or enjoyed the giant sequoias of the Mariposa Grove. By the following Wednesday, June 13, both visitors had checked out of their Curry Village tent cabins and left the park.

Around Yosemite the summer unfolded quietly. The search-and-rescue team went out on minor events: an ankle fracture on the Panorama Trail, a fallen hiker on the Half Dome cable route. Rangers kept a wary eye on the Cascade Fire, a lightning-sparked wilderness blaze that smoldered through a red fir forest.

Then, in late June, Visitor One fell ill. She might have felt like she had the flu: chills, muscle aches, fever, headache, dizziness, fatigue. The flu goes away after a few days. This didn’t. We do know that, back home, she went to see her doctor. When presented with Visitor One’s symptoms, most physicians would have dismissed it as the flu or, at worse, low-level pneumonia. Her doctor didn’t.

They talked about what she might have picked up and where. She mentioned her Yosemite trip. The doctor took the unusual step of calling Charles Mosher, a public-health officer for Mariposa County, which encompasses Yosemite, and asking if there were any known hantavirus cases in the area. “Based on her history and symptoms, [hantavirus] was a definite possibility,” Mosher recalled, so he and Visitor One’s doctor agreed that starting treatment for the virus while awaiting lab confirmation was the prudent way to go.


Yosemite Park Campers Still Very Trepidatious

September 14, 2012 by · Comments Off on Yosemite Park Campers Still Very Trepidatious 

A stone’s throw from the cluster of tent cabins in Yosemite National Park where three victims of a deadly rodent-borne virus stayed earlier this summer, two tourists from the New York area were meticulously sorting their trash into sealed garbage bins while making sure that a ravenous-looking squirrel did not slip inside.

Like many of the thousands of other visitors to Yosemite National Park last weekend, Johanna Dieguez and Mildred Bennett came here with trepidation after the authorities announced last week that the third person had died from the worst outbreak of hantavirus in this park’s history.

The 91 affected “signature tent cabins” — located in Curry Village in Yosemite Valley, the park’s most popular area — have been closed indefinitely. But tourists like Dieguez and Bennett have been staying in the 413 other cabins in Curry Village that remain open.

The two had decided not to cancel a long-planned annual “girls’ trip” together. “They told us this area was not affected,” said Dieguez, who is from New Jersey.

Click here to read the entire story.

NPS: 9th Yosemite Camper Got Hantavirus

September 14, 2012 by · Comments Off on NPS: 9th Yosemite Camper Got Hantavirus 

Deer mice (Peromyscus maniculatus) are implicated as carriers of hantavirus pulmonary syndrome (HPS) in Yosemite and other parts of the U.S. Photo from Centers for Disease Control and Prevention.

Another person was sickened by hantavirus traced to Yosemite National Park, the latest in an outbreak that has grown to nine cases and has killed three visitors since mid-June, the Los Angeles Times reported.

The latest case, which sickened a California resident, is believed to have originated in one of Curry Village’s signature tent cabins in early July, park spokesman Scott Gediman said. A total of eight cases have been linked to the insulated signature tent cabins; the other to the High Sierra Loop that connects Yosemite Valley with Tuolumne Meadows and other areas.

But the latest case differs from the others in that it was considered a “hantavirus infection,” officials said. Although very rare, some hantavirus cases don’t show the respiratory symptoms found in hantavirus pulmonary syndrome, according to the California Department of Public Health.

The eight other cases tied to Yosemite developed into the full-fledged hantavirus pulmonary syndrome.

The person with the hantavirus infection has since recovered, Gediman said. The park received confirmation of the case Thursday morning (Sept. 13).

Spread through urine, droppings or saliva of infected rodents, hantavirus takes one to six weeks before causing flu-like symptoms in humans, officials said. The disease generally is transmitted when people come in contact with an enclosed area that has been infested by mice.

The disease is rare — 587 cases were diagnosed nationwide from 1993 to 2011, of which about one-third were fatal, according to the national Centers for Disease Control and Prevention.

But the cases at Yosemite are more unusual. Public health authorities said they had not heard of more than one case of the disease in the same location within a year.

The newest case was announced a day after Yosemite officials said they were again broadening their outreach efforts, sending emails to some 230,000 people who reserved lodging throughout the park since early June.

“We heard some concerns from visitors, and people read about it in the media, so we felt that we wanted to be proactive and transparent and get the word out to additional overnight visitors,” Gediman said. “We want to get out all the information we can.”

News of the outbreak has rattled visitors, who travel across the globe to the national park. Park rangers have fielded thousands of calls through an emergency hotline. The World Health Organization has issued a global alert, and the U.S. Department of Health and Human Services has notified 39 countries whose citizens were at risk.

Meanwhile, public health authorities and park officials are continuing their investigation into what prompted the outbreak. A larger-than-normal deer mouse population could be a contributing factor, officials said Wednesday.

Virus Claims Life of Third Yosemite Camper

September 7, 2012 by · Comments Off on Virus Claims Life of Third Yosemite Camper 

Deer mice (Peromyscus maniculatus) are implicated as carriers of hantavirus pulmonary syndrome (HPS) in Yosemite and other parts of the U.S. Photo from Centers for Disease Control and Prevention.

The National Park Service confirmed Thursday (Sept. 6) that a third camper has succumbed to the hantavirus since staying this summer at Yosemite National Park and the number of confirmed cases has now risen to eight.

Three of these cases have resulted in the death of the individual concerned, while the five remaining victims are said to be improving or recovering, reported. The confirmed cases include six individuals from California, one from Pennsylvania and one from West Virginia. Seven of the eight cases of HPS have been linked to the “Signature Tent Cabins” – operated by DNC Parks and Resorts – located in Curry Village in Yosemite Valley.

However, in a somewhat worrying turn of events, the California Department of Public Health (CDPH) has also advised the National Park Service that one of the eight confirmed victims likely contracted HPS after staying in multiple Yosemite High Sierra Camps in July.

While the High Sierra Camps – at Sunrise, May Lake, Glen Aulin, Tuolumne, Vogelsang and Merced Lake – are all located in areas other than Curry Village, the locations also use tent cabins and dining tents. The CDPH is of the opinion that the stay in the High Sierra Camps is the most likely source of that person’s infection. Fortunately the individual concerned only exhibited mild symptoms of HPS and is now recovering.

In a sign of the continued severity and seriousness of the HPS outbreak Yosemite National Park Superintendent Don Neubacher said in a statement that: “we urge visitors who may have been exposed to hantavirus to seek medical attention at the first sign of symptoms.”

These symptoms – which generally begin one to five weeks after exposure – include fatigue, fever, chills, and muscle aches. About half of patients will experience headaches, nausea, vomiting, dizziness and abdominal pain. The disease progresses rapidly (4-10 days after initial symptoms) to include coughing, shortness of breath and severe difficulty breathing. If you visited Yosemite National Park recently and are displaying the above symptoms you should seek immediate medical attention.


Reuters: Campers from 39 Countries Warned

September 5, 2012 by · Comments Off on Reuters: Campers from 39 Countries Warned 

Deer mice (Peromyscus maniculatus) are implicated as carriers of hantavirus pulmonary syndrome (HPS) in Yosemite and other parts of the U.S. Photo from Centers for Disease Control and Prevention.

U.S. health officials have sent warnings to 39 other countries that their citizens who stayed in Yosemite National Park tent cabins this summer may have been exposed to a deadly mouse-borne hantavirus, a park service epidemiologist said on Tuesday (Sept. 4).

Of the 10,000 people thought to be at risk of contracting hantavirus pulmonary syndrome from their stays in Yosemite between June and August, some 2,500 live outside the United States, Dr. David Wong told Reuters in an interview.

Wong said U.S. Department of Health and Human Services officials notified 39 countries over the weekend, most of them in the European Union, that their residents may have been exposed to the deadly virus.

The lung disease has so far killed two men and sickened four other people, all U.S. citizens, prompting the U.S. Centers for Disease Control and Prevention to issue a health alert.

Officials are concerned that more Yosemite visitors could develop the lung disease in the next month or so. Most of the victims identified so far were believed to have been infected while staying in one of 91 “Signature” tent-style cabins in the park’s popular Curry Village camping area.

There is no cure for the disease, but early detection through blood tests greatly increases survival rates.

“I want people to know about this so they take it seriously,” Wong said. “We’re doing our due diligence to share the information.”

Last week, park officials shut down the insulated “Signature” tent cabins after finding deer mice, which carry the disease and can burrow through holes the size of pencil erasers, infesting the double walls.

Officials are continuing to investigate additional possible cases of the disease, which has killed 64 Californians and about 590 Americans since it was identified in 1993, Wong said.

Early symptoms include headache, fever, muscle aches, shortness of breath and coughing. The virus may incubate for up to six weeks after exposure and can lead to severe breathing difficulties and death.

Experts say hantavirus, which kills 36 percent of those it infects, has never been known to be transmitted between humans.

Four of those known to be infected at Yosemite this summer slept in the insulated tent cabins. One slept elsewhere in Curry Village, located in a valley beneath the iconic Half Dome rock formation, and the sixth case remains under investigation.

One man from northern California and another from Pennsylvania died, while three victims have recovered and a fourth remains hospitalized, the state Department of Public Health said.

Nearly 4 million people visit Yosemite each year, attracted to the park’s dramatic scenery and hiking trails. Roughly 70 percent of those visitors congregate in Yosemite Valley, where Curry Village is located.

Hantavirus is carried in viral particles inhaled from rodent feces and urine. People also can be infected by eating contaminated food, touching contaminated surfaces or being bitten by infected rodents.

Hantavirus previously infected two Yosemite visitors, one in 2000 and another in 2010, but at higher elevations.

Rodent Virus Claims 2nd Yosemite Camper

August 28, 2012 by · Comments Off on Rodent Virus Claims 2nd Yosemite Camper 

A second person has died of a rare, rodent-borne disease after visiting one of the most popular parts of Yosemite National Park earlier this summer, and park officials were warning past visitors to be aware of some flu-like aches and symptoms and seek medical help immediately if they appear, the Associated Press reported.

Health officials learned this weekend of the second hantavirus death, which killed a person who visited the park in June, spokesman Scott Gediman said in a statement.

There was one other confirmed case of the illness, and a fourth is being investigated.

Yosemite officials said the four visitors might have been exposed while vacationing at the park’s Curry Village, and are warning those who stayed in the village’s tent cabins from mid-June through the end of August to beware of any symptoms of hantavirus, which can include fever, aches, dizziness and chills. An outreach effort is under way to contact visitors from that period who stayed in “Signature Tent Cabins,” which have more insulation and amenities than other tent cabins.

Federal health officials say symptoms may develop up to 5 weeks after exposure to urine, droppings or saliva of infected rodents, and Yosemite advised visitors to watch for symptoms for up to six weeks.

Of the 587 documented U.S. cases since the virus was identified in 1993, about one-third proved fatal. There is no specific treatment for the virus.

After-hours calls to Yosemite officials seeking further details were not immediately returned Monday night.

Following the first death, which was reported earlier this month, state health officials advised anyone with symptoms to seek medical attention and let doctors know if they were camping in Yosemite. Officials said thousands of people visit the park every month, so it would be impossible to track everyone who had set foot in Curry Village.

Curry Village is the most popular and economical lodging area in the park, a picturesque assemblage of rustic cabins at the base of the 3,000-foot promontory Glacier Point.

Gediman told the San Francisco Chronicle that of the 408 tent cabins in the village, 91 are of the “signature” variety where the four cases had stayed, which feature more insulation and amenities than the others.

It was not clear how many people stayed in the cabins in the period in which park officials are warning visitors.

Gediman said contractors are working on the signature cabins to protect park-goers.

“They’re doing everything they can to eliminate areas where mice can get into the cabins,” Gediman told the Chronicle. “This was never because the cabins were dirty, it was never because we didn’t take care of them. This is just because approximately 20 percent of all deer mice are infected with hantavirus. And they’re here in Yosemite Valley.”

This year’s deaths mark the first such deaths in park visitors, although two others were stricken in a more remote area in 2000 and 2010, officials said.


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