Between August 28th and October 30th 2012, A total of ten cases of hantavirus infection including three deaths were confirmed in people who had visited Yosemite National Park in June through August, according to the CDC. The California Department of Public Health, the CDC, and the National Park Service took measures to identify all infected individuals and to prevent further infection. Though hantavirus infection is relatively uncommon in the US, we can learn from this event in order to avoid further occurrences.
Hantaviruses have existed for a long time, in several different strains. The Yosemite infections were due to a newer strain of the virus called the Sin Nombre strain, which was first identified in 1993 and causes a severe respiratory illness called Hantavirus Pulmonary Syndrome (HPS). Hantavirus strains in the United States are carried by rodents: the White-Footed Mouse, Deer Mouse, Rice Rat, Cotton Rat, and other rodents which have not been identified, according to the CDC. The virus is excreted in the animals’ urine and feces, and becomes airborne in small droplets that can be inhaled by humans and cause infection. The virus is also excreted in rodent saliva, and can be transmitted by bites and by contact with contaminated surfaces. The US strains cannot be transmitted from human-to-human. There have been less than 600 identified cases of hantavirus in the US, 36% of which have been fatal.
Symptoms of hantavirus infection are similar to the flu and include:
- body aches
- breathing problems
The virus’ incubation period is one-to-six weeks, meaning that symptoms can occur long after someone has been exposed. If infection is suspected by a physician it can be confirmed by a blood test, but there is no reason to get tested if you have not been exposed and are not sick. Care for infection is only supportive as there is no “cure” for the disease. Once respiratory illness from the virus becomes severe, death is very likely.
Nine of the Yosemite cases were from guests who stayed in undeveloped tent-cabins which were later found to have Deer Mouse infestation. The other case was in someone who stayed in the undeveloped high sierra camps, which are deep in the wilderness at high altitude.
Hantavirus infection is not a big worry in developed areas. Warehouses, vacant buildings, and poorly maintained structures are the most at-risk locations in civilization. Watch for rodents or droppings, and have any suspected infestation treated by a professional exterminator. While enjoying the wilderness you should avoid potential rodent dens and only drink sanitized water. If you have been exposed you should see your doctor at the first sign of illness. For further information watch the video above, visit the CDC.gov, or leave questions and comments below.
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Written content © Jake Schulke