The Appalachian Trail is experiencing a norovirus outbreak. Here’s everything hikers need to know.

In mid-May, hikers on the Pacific Crest Trail near Wrightwood, California, began falling seriously ill with similar symptoms: stomach cramps, vomiting, diarrhea. By the end of the month, at least two dozen hikers had contracted the bug, one of whom became so sick that he had to be airlifted off the trail to a local emergency room.

Now, it’s the turn of the Appalachian Trail. On June 17, the National Park Service warned visitors that It was tracking a group of cases of stomach disease With similar characteristics in Shenandoah National Park. The suspected cause of the outbreak: norovirus, a family of viruses that are notorious for sickening cruise ship passengers, nursing home residents and hikers on America’s increasingly popular long trails.

These are not the first suspected cases of norovirus on the AT this year. according to A timeline of the outbreak on the Appalachian Trail Conservancy’s trail updates pageThe first reported cases occurred in early May, when several hikers came down with the disease near the Virginia Triple Crown, at mile marker 697.5 to mile 731.1, and at mile marker 823.9 to 865.1 of the Blue Ridge Parkway, ending at Rockfish Gap. In the group’s next update, a month later, ATC reported more cases at miles 809.8 to 865.3 between Buena Vista and Waynesboro, VA. In its latest update on June 15, ATC said it had received a report of suspected norovirus from Shenandoah’s Blackrock Hut at mile marker 885.8.

No one wants to get sick on the trail, but enduring a gastrointestinal bug in the middle of a hike is a uniquely unpleasant experience, because backpacker Author Corey Buhay found out after suffering food poisoning on the John Muir Trail. Without easy access to indoor plumbing, it is difficult to deal with frequent diarrhea and vomiting; ATC writes in its informational page on the subject that some pedestrians They become so dehydrated that they have to call for evacuation.. It is much easier to prevent an illness than to treat its symptoms once they occur – but to avoid it, there are a few things you need to know.

How do hikers get norovirus?

Prepare yourself, because it’s disgusting: Norovirus is spread when hikers come in contact with the feces or vomit of an infected person, either through direct contact or through tiny, aerosolized droplets containing the virus. This means that hikers are at risk of infection through shared sanitation facilities, dining areas, or anywhere they have close contact with groups of people. Private spaces, dormitories, water sources and shelters are all potential hotspots for the spread of the virus.

Complicating matters are pedestrians’ hygiene habits, or lack thereof. Without access to running water, many hikers rarely wash their hands after using the bathroom or before eating, relying instead on alcohol-based hand sanitizers. But while alcohol can kill insects like E. coli bacteria, most research shows that it is largely ineffective at destroying norovirus due to the structure of the virus.

How can I avoid getting sick from norovirus?

Practicing good hygiene on the trail is the most important thing hikers can do to avoid stomach bugs. Your hands are probably dirtier than you think: A CDC investigation after 2022 outbreak A trail cabin on the PCT and a nearby outhouse were tested and found to have particles of human feces on nearly every surface that the backpackers had touched, from walls to door handles.

Instead of relying on hand sanitizer after going to the bathroom or before eating, hikers should wash their hands with soap and water. as Patricia Cameron, a wilderness emergency medical technician, wilderness first responder instructor, and founder of blackpackerswrote in backpacker In 2024, washing your hands for at least 20 seconds with biodegradable soap is one of the most effective ways to protect yourself from disease. Don’t assume that just because you haven’t been around someone who is sick, you’re safe: Cameron says infected hikers usually don’t show symptoms for 12 to 48 hours after being infected with norovirus, and can spread the virus for several weeks even after recovery. Avoid sharing water bottles, utensils or food with other hikers, whether they are sick or not.

It is also important to treat your water properly. Most water filters, including popular models like the Sawyer Squeeze, are unable to filter out norovirus or other viruses from contaminated water, because the germs are so small. While the NPS notes that boiling water is the most effective way to kill the virus, most hikers, especially fuel-conscious or drenching hikers in the cold, will likely not find this a practical solution.

Luckily, you have other options. A mild and simple way is to add chemical treatment such as aquamira Or add iodine tablets to your water after filtering it; The combination of those two treatment methods will remove most of the substances capable of making you sick. (Chemical treatments have an iffy record with parasites like Giardia and Cryptosporidium.) Another option is to carry a water purifier: While usually on the heavy side, these filters can filter out viruses. The Grail GeoPress (15.9 ounces) can handle even poor water sources, and also works as a bottle.

What should I do if I get norovirus while traveling?

Unfortunately, there is no cure for norovirus, and since it is not caused by bacteria, antibiotics will not help. All care is helpful: ATC recommends for sick hikers separate yourself from other hikers While the disease shows its effect and after that for two to three days, either live alone in a tent or take a room in a hotel or hostel. Dehydration is a serious threat: the The CDC recommends that sufferers drink plenty of fluids. And seek medical care if they start showing signs of dehydration or remain ill for more than a few days.