Norovirus Takes to the Great Outdoors

Norovirus Takes to the Great OutdoorsNorovirus, the highly contagious “Winter Vomiting Bug1” or “Stomach Flu2” has taken to the great outdoors, hitch-hiking with travelers on the Appalachian Trail (AT) and accompanying tourists to Yellowstone and Grand Teton National Parks.  This virus, the bane of cruise ship vacationers, can also ruin a land-based vacation.

Norovirus on the “AT”

According to a recent report, “the worst viral outbreak to strike hikers in Appalachian Trail history is traveling north from Georgia into Pennsylvania.”  Norovirus is spread via the fecal-to-oral route, so appropriate hand-washing is a must for controlling transmission.  But hot water and soap are not mainstays along AT facilities, so hikers may be inadvertently spreading the virus by hand contact.  Hand sanitizer, so often carried and used by hikers and tourists on the move, may not be as effective against norovirus as a good old “lather up” with soap and warm water.  Additionally, according to a National Park Service Hiking Alert, “Outbreaks occur more often where people share untreated water sources and facilities for sleeping, dining, showering, and toileting. The virus can spread rapidly in crowded shelters and hostels.”

Norovirus “Does Yellowstone”

On June 7, two tourist buses arrived at Yellowstone National Park’s Mammoth Hot Springs area.  Some of the tourists “complained of stomach flu symptoms,” according to one article, and evidently passed the infection on to park employees, who exhibited symptoms within 48 hours. The report quoted a healthcare professional as characterizing the outbreak as “one of the most significant ones he’s seen.”  A June 24 report noted at least 100 visitors have been infected and that “the problem continues to grow.” The outbreak has spread to Grand Teton National Park as well.

Staying One Step Ahead of Norovirus on Your Outdoor Vacation3

  1. Treat all water by boiling, filtering, and/or treating with chemicals. To learn how best to treat your water, visit:
  2. Do not eat out of the same food bag, share utensils, or drink from other hikers’ /tourists’ water bottles.
  3. Wash your hands with warm (or cold water if warm is unavailable), soapy water whenever possible after using the bathroom and before and after handling food.  “Paper soap” is lightweight and convenient. Hand sanitizer is better than nothing, but it may not be effective against norovirus.
  4. Follow “Leave No Trace” guidelines for disposing of human waste:  Use only sanitary facilities or bury four to six inches deep in an area not frequented by the public, not visible from trails, campsites or developed areas, and at least 100 feet from any water source. For best practices visit  
  5. Consider carrying chlorine bleach-based disinfectant wipes to apply to frequently touched hard surfaces such as a toilet handle or cabin food preparation or eating surfaces.
  6. If you have a diarrhea or vomiting incident clean up as well as possible using the steps listed on this poster.
  7. Stay home if you are sick and wait at least three days beyond the time of symptoms to prevent spreading norovirus—it’s the right thing to do.

Here’s wishing you a happy, healthy, norovirus-free outdoor vacation!

1Norovirus is more common in late Fall through early Spring, but outbreaks in warm weather are also common.
2Although it is commonly called the “Stomach Flu,” norovirus is not a flu.
3Tips are based on a National Park Service Hiking Alert at: