Rabies, bubonic plague, monkeypox, West Nile encephalitis, Legionnaires' disease, bird flu. Living in proximity to animals means that we are often susceptible to zoonosis — diseases or infections that are naturally transmissible between species or from animals to humans.


The recent widespread outbreak of mosquito-borne West Nile virus has been burning up the Web, but now there’s another zoonotic disease vying for attention: Hantavirus.


Two people have recently died from the virus after camping at Yosemite National Park. That makes three confirmed cases from the area, with a fourth being investigated.


Since the virus was identified in 1993, fewer than 600 cases of hantavirus pulmonary syndrome (HPS) have been reported nationwide; but it is an ugly disease, and has a mortality rate of 38 percent, according to the Centers for Disease Control and Prevention (CDC).


Hantavirus is carried by rodents, especially deer mice. The virus is found in rodents’ urine, droppings and saliva, however, the animal do not get sick. Humans can become infected with the virus when they come in contact with contaminated dust from mice nests or droppings.


Although the incubation time is not completely understood, it appears that symptoms may develop between one and five weeks after exposure to fresh urine, droppings or saliva from infected rodents.


Early symptoms:

  • Fatigue
  • Fever
  • Muscle aches (especially in the large muscle groups — thighs, hips, back and sometimes shoulders)
  • Headaches
  • Dizziness
  • Chills
  • Abdominal problems, such as nausea, vomiting, diarrhea and abdominal pain

Late symptoms (appear four to 10 days after the first symptoms):

  • Coughing
  • Shortness of breath

Complications of hantavirus may include kidney failure, heart failure and lung failure.


Potential risk activities for HPS (as described by the CDC):

Opening and cleaning previously unused buildings: Opening or cleaning cabins, sheds and outbuildings, including barns, garages and storage facilities, that have been closed during the winter is a potential risk for hantavirus infections, especially in rural settings.


Housecleaning activities: Cleaning in and around your own home can put you at risk if rodents have made it their home too. Many homes can expect to shelter rodents, especially as the weather turns cold. 


Work-related exposure: Construction, utility and pest control workers can be exposed when they work in crawl spaces, under houses, or in vacant buildings that may have a rodent population.


Campers and hikers: Campers and hikers can also be exposed when they use infested trail shelters or camp in other rodent habitats.


People with hantavirus are usually admitted to the hospital, often to the intensive care unit. Treatments include oxygen, breathing tube or breathing machine, a medication called ribavirin to treat kidney-related problems and reduce the risk of death



Hantavirus is a serious infection that gets worse quickly. Lung failure can occur and may lead to death. Even with aggressive treatment, more than half of people who have this disease in their lungs die.


Needless to say, call your health care provider if you develop flu-like symptoms after you come in contact with rodent droppings or rodent urine, or dust that is contaminated with these substances. For more information, visit the CDC page on the virus.


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