Hantavirus Endangers 10,000 Yosemite Campers

In a recent article I reported that the National Park Service Office of Public Health confirmed that two people had died of hantavirus pulmonary syndrome (HPS) and a third and probably fourth case was discovered in individuals who camped at California’s Yosemite National Park during the summer.

“Signature” tent-style cabins in Yosemite’s popular Curry Village camping area. (Source: DNC Parks and Resorts at Yosemite, Inc/AP)

The park has seen two other cases of the hantavirus in a more remote area in 2000 and 2010, but this year’s deaths were the first.

It is now known that thousands of people could be at risk from the outbreak of this deadly virus which is thought to have been caused by mice nesting in the insulation of “Signature” tent-style cabins in Yosemite’s popular Curry Village camping area.

Deer mice which carry the disease can burrow through holes the size of pencil erasers, nesting between the double walls.

About 10,000 visitors stayed at the campsite from June 10 through August 24, 2012 and could be at risk of contracting the virus, the Centers for Disease Control and Prevention (CDC) said.

The CDC added that they were looking into suspected cases of the disease in “multiple health jurisdictions”.

Official examines one of the “Signature” tent-style cabins in Yosemite’s popular Curry Village camping area. (Source: DNC Parks and Resorts at Yosemite, Inc/AP)

They also urged lab testing of patients who exhibit symptoms consistent with this lung disease and recommend that Doctors report diagnosed cases of Hantavirus to local health authorities.

Earlier this week, park officials closed all 91 “signature” cabins.

A park spokesperson indicated that the outbreak of the virus has not led to a wave of cancellations of other facilities in the national park.

Nearly 4 million people visit Yosemite, one of the nation’s most popular national parks, each year, attracted by its dramatic scenery and hiking trails. Roughly 70 percent of those visitors congregate in Yosemite Valley, where Curry Village is located.

The park has contacted about 3,000 groups of visitors warning them to seek medical advice if they experience hantavirus symptoms.

The virus starts out causing flu-like symptoms, including headache, fever, muscle ache, shortness of breath, and cough; and can lead to extreme breathing difficulties and death.

The incubation period for the virus is typically two to four weeks after exposure, the CDC said, with a range between a few days and six weeks. Just over a third of cases are fatal.

Although there is no cure for hantavirus, which has never been known to be transmitted between humans, treatment after early detection through blood tests can save lives.

“Early medical attention and diagnosis of hantavirus are critical,” Yosemite superintendent Don Neubacher stated.

“We urge anyone who may have been exposed to the infection to see their doctor at the first sign of symptoms and to advise them of the potential of hantavirus.”

Yosemite spokeswoman Kari Cobb said rangers have answered some 1,500 phone calls from park visitors and others concerned about the disease.

Housekeeper Albert Gomez sprays the floors of a tent cabin with a bleach mixture to prevent the possible spread of viruses in Curry Village at Yosemite National Park. (Source: Michael Macor/San Francisco Chronicle/AP)

A national park spokesperson indicated that public health officials warned the park twice before 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.

Hantavirus is carried in rodent feces, urine and saliva, which dries out and mixes with dust that can be inhaled by humans, especially in small, confined spaces with poor ventilation.

People can also be infected by eating contaminated food, touching contaminated surfaces, or being bitten by infected rodents.

Four other cases of Hantavirus, a rare lung disease, have been reported.

When people are in wilderness areas or places that harbor mice, individuals can take the following steps to prevent HPS:

  • Avoid areas, especially indoors, where wild rodents are likely to have been present
  • Keep food in tightly sealed containers and store away from rodents
  • When cleaning an area, open windows to air out at least two hours before entering taking care not to stir up dust
  • Wear plastic gloves and spray areas contaminated with rodent droppings and urine with a 10 percent bleach solution or other household disinfectants and wait at least 15 minutes before cleaning the area
  • Place the waste in double plastic bags, each tightly sealed, and discard in the trash and wash hands thoroughly

For additional information on preventing HPS, visit the Centers for Disease Control and Prevention’s Hantavirus Web site page.

Worth Pondering…

Adventure without risk is Disneyland.

—Doug Coupland

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Hantavirus Claims Two Yosemite Campers

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.

Yosemite National Park (Source: cdc.gov)

Park officials are warning past visitors to be aware of flu-like aches and symptoms and seek medical help immediately if they appear, the Associated Press reported.

The National Park Service Office of Public Health recently learned of a confirmed third case, and probable fourth case, of hantavirus pulmonary syndrome (HPS) in individuals who visited Yosemite National Park in June.

Yosemite officials said the four visitors may 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.

Hantavirus is a rare but serious disease. Since HPS was first identified in 1993, there have been approximately 60 cases in California and 587 cases nationally. About one third of cases identified have been fatal. There is no specific treatment for the virus.

(Source: cdc.gov)

HPS is caused by a virus that individuals get through contact with the urine, droppings, or saliva of infected rodents, primarily deer mice. Not all deer mice carry hantavirus, but deer mice with hantavirus have been found throughout the United States and Canada.

Most infections are caused by breathing small particles of mouse urine or droppings that have been stirred up into the air. If the virus is contracted, the symptoms appear one to six weeks after exposure with fever, headache, and muscle ache, and progresses rapidly to severe difficulty in breathing and, in some cases, death.

Early medical attention can greatly increase the chance of survival, so it is important to seek medical attention immediately if an individual experiences any of these symptoms and may have been exposed to rodents.

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.

Ninety one of the 408 tent cabins in the village are of the “signature” variety where the four cases had stayed, which feature more insulation and amenities than the others.

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.

Yosemite National Park has set up a general, non-emergency phone line for all questions and concerns related to hantavirus in Yosemite National Park. The phone number is (209) 372-0822 and it will be staffed from 9 a.m. – 5 p.m. daily.

The National Park Service Office of Public Health has issued a call for cases to state and local health departments nationwide, and is working with the Centers for Disease Control and Prevention to heighten public health awareness and detection.

Rodent control (Source: cdc.gov)

The park and concessioner have also increased public education efforts geared towards visitors and park employees. This includes distributing information to all visitors entering the park, information at Curry Village registration area, and notifications throughout the park.

California Department of Public Health (CDPH) and Yosemite National Park Public Health Service officers conduct periodic rodent surveys to monitor deer mouse abundance and virus activity in mouse populations.

Yosemite National Park has conducted additional rodent trapping and is increasing rodent-proofing and trapping measures in tent cabins and buildings throughout the park. Structures throughout the park continue to be cleaned by following recommended practices and are inspected regularly. Yosemite also conducts routine rodent proofing of buildings and facilities throughout the park.

When people are in wilderness areas or places that harbor mice, individuals can take the following steps to prevent HPS:

  • Avoid areas, especially indoors, where wild rodents are likely to have been present
  • Keep food in tightly sealed containers and store away from rodents
  • When cleaning an area, open windows to air out at least two hours before entering taking care not to stir up dust
  • Wear plastic gloves and spray areas contaminated with rodent droppings and urine with a 10 percent bleach solution or other household disinfectants and wait at least 15 minutes before cleaning the area
  • Place the waste in double plastic bags, each tightly sealed, and discard in the trash and wash hands thoroughly
  • For additional information on preventing HPS, visit the federal Centers for Disease Control and Prevention’s Hantavirus Web site page.

Worth Pondering…

Clean-up tip: Do not sweep or vacuum up mouse or rat urine, droppings, or nests.  This will cause virus particles to go into the air, where they can be breathed in.

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