RI, MA EHS Pest Control Blog

A West Virginian is the third person to die so far from a rodent-borne illness linked to some tent cabins at Yosemite National Park that has now stricken eight people in all, health officials said Thursday.

Five people are ill from the outbreak reported last week by park officials, who said that up to 10,000 guests could have been exposed to hantavirus pulmonary syndrome from sleeping in the cabins since June 10.

Alerts from the U.S. Centers for Disease Control and Prevention sent to public-health agencies, doctors and hospitals have turned up other suspected cases that have not yet been confirmed. This week, the European CDC and the World Health Organization issued global alerts for all travelers to avoid exposure to rodents.

Dr. Rahul Gupta, director of the Kanawha-Charleston Health Department, said the West Virginia victim had visited the park since June but declined to give more details, citing the family's wish to grieve in private.

The other deaths occurred in California and Pennsylvania. Those who were sickened also were from California, and the National Park Service said Wednesday they were either improving or recovering.

Seven of the cases involved guests at the insulated "signature" cabins in the park's historic Curry Village section. The California Department of Public Health said the other case involved someone who stayed in several High Sierra Camps in a different area of Yosemite in July.

Yosemite officials said the cabins have been closed and the park is reaching out to guests who have stayed in the cabins.

Gupta declined to elaborate on whether anyone was traveling with the Kanawha County victim, although he said his department knew of no other cases.

"The time has lapsed in a way that it should not be a concern," Gupta said.

Health officials say the disease isn't spread from person to person. There is no cure for the virus, which can affect people of any age. The disease is carried in the feces, urine and saliva of deer mice and other rodents and carried on airborne particles and dust.

People can be infected by inhaling the virus or by handling infected rodents. Infected people usually have flulike symptoms, including fever, shortness of breath, chills and aches. The illness can take six weeks to incubate before rapid acute respiratory and organ failure.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

A Bay Area man has died after contracting the rare hantavirus - a viral infection carried by mice and passed to humans by the rodents' feces or urine - that he was probably exposed to while staying in Yosemite's popular Curry Village tent cabins, public health officials said Thursday.

The 37-year-old man, whose name and hometown were not released, died in late July, about six weeks after his stay in Yosemite National Park. Another visitor to the park, a woman in her 40s who lives in Southern California, also became sick with hantavirus but is expected to survive, according to the state Public Health Department.

The woman and the Bay Area man were in Yosemite at the same time in mid-June and staying in cabins about 100 feet from each other, but did not know each other, Yosemite officials said.

Lab tests taken after the two fell ill confirmed that the virus was present in fecal matter from mice trapped near Curry Village, a collection of tents and cabins in the eastern end of Yosemite Valley.

"The mice shed the virus in urine, in feces, and when the urine or feces, or nests, are disturbed, the virus can become airborne and infect people," said Vicki Kramer, chief of the state health agency's vector-borne disease section.

Both victims suffered from hantavirus pulmonary syndrome. It can take up to two weeks for symptoms to appear after exposure to hantavirus.

Most people suffer flu-like symptoms first, including fever, headache and muscle pains, often in the thighs, back and hips. After two to seven days, many patients have severe difficulty breathing and can die.

There is no cure or virus-specific treatment for hantavirus. Patients typically are hospitalized and get help breathing while their body tries to fight off the virus.

'Bad options'

"It's supportive treatment only. We have pretty unacceptably bad options for treating hantavirus," said Dr. D. Scott Smith, chief of infectious disease and geographic medicine at Kaiser Permanente Medical Center in Redwood City.

"By the time someone comes in with a bad cough and a fever, sometimes it's too late."

There have been about 60 cases of hantavirus pulmonary syndrome reported in California since the virus was identified in the United States in 1993. About a third of those patients died. So far this year, there have been four cases of hantavirus reported in California.

The virus is most commonly seen in the eastern Sierra and is rare in lower-elevation parts of the state. These two most recent cases are the first ever to be reported from Yosemite Valley, although the national park has had two cases in past years, both in visitors to the higher-elevation Tuolumne Meadows, said park spokesman Scott Gediman.

In California, the virus is spread primarily via deer mice, which have solid-colored backs and white bellies and generally live at higher elevations. Yosemite officials regularly monitor the activity of deer mice in the park, and crews that clean tent cabins are instructed to inspect rooms for mouse droppings, Gediman said.

No infestations

After the recent hantavirus cases were connected to the park, officials with the state Public Health Department and the U.S. Centers for Disease Control and Prevention visited Yosemite and found no evidence of mouse infestations or unclean lodgings, Gediman said.

He and public health officials advised visitors to Yosemite and elsewhere in the Sierra to take precautions against contracting hantavirus.

People should avoid leaving food in the open, which can draw mice, and they should avoid contact with mouse feces or nests.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

One of the first things I was taught when I first became a “PMP” (Pest Management Professional) back in the 70’s was to always look up! Come to think of it, we were “Exterminators” back then.

In many situations this holds true for keeping rodents out of your home.

Mice are excellent climbers and our native mice (White-Footed and Deer Mice) are exceptional climbers. I remember camping once and I woke up at 1:30AM to attend to some business. As I exited the camper with my trusty flashlight (PMP’s always carry quality flashlights) I observed a White-Footed mouse climb the truck of a large Eastern Hemlock onto a large branch and disappear into the dark woods!

If you want complete mouse proofing, seal everything larger than 1/4” all the way up to and including the gutter line. Our company has always struggled to be competitive in offering this service to our clients due to the cost of enormous amount of labor and it’s tedious nature. We do offer it though if anyone is interested in it.

John Stellberger
President - Environmental Health Services, Inc.

Pest Control, RI, Pest Control, MA 

More Rodents Carrying Hantavirus Found

Six more rodents trapped by County Vector Control technicians last week have tested positive for the sometimes-deadly hantavirus, County officials said this week.

The rodents, four Harvest mice and two California Meadow Voles, were trapped in Fairbanks Ranch and northern Escondido near the San Luis Rey River bringing this year’s total to 16 rodents testing positive for hantavirus, a news release stated. In 2010, a total of 21 rodents tested positive for hantavirus.

“Recent rains have created an abundance of food for rodents, which can increase the rodent population,” said County Environmental Health Director Jack Miller. “More rodents can lead to more hantavirus.” People should never sweep up or vacuum rodent droppings and nesting materials. Instead, ventilate closed areas and use wet cleaning methods with a 10 percent bleach solution or other full strength disinfectant. The best way to prevent the disease is to keep mice out of houses, garages and sheds by sealing all holes larger than the size of a dime, the news release stated.

Wild rodents, primarily deer mice, carry hantavirus. People can contract it by inhaling dust particles from rodent droppings and nesting materials that contain the virus. The virus can cause hantavirus pulmonary syndrome (HPS), which begins with flu-like symptoms, but can graduate to severe breathing difficulties and even death, according to the news release. There is no vaccine or specific treatment for hantavirus and the national Centers for Disease Control and Prevention report that HPS has killed 36 percent of all the people known to have contracted the disease.

How to Avoid Exposure:

• Eliminate rodent infestations immediately.
• Avoid rodent infested areas. Do not stir up dust or materials that may be contaminated with feces and urine.
• Clean up rodent droppings and urine using the wet cleaning method described below.

Use “wet-cleaning” methods to prevent inhaling the virus:

• DO NOT SWEEP OR VACUUM INFESTED AREAS.
• Ventilate affected area by opening doors and windows for at least 30 minutes.
• Use rubber gloves. Spray a 10 percent bleach solution (2 tablespoons bleach to 1 cup of water), or other full strength disinfectant onto dead rodents, rodent droppings, nests, contaminated traps, and surrounding areas and let the disinfectant stand for at least 15 minutes before cleaning. Clean with a sponge or a mop.
• Place disinfected rodents and debris into two plastic bags, seal them and discard in the trash.
• Wash gloves in a bleach solution, then soap and water, and dispose of them using the same double-bag method. Thoroughly wash your bare hands with soap and water.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA