A highly contagious stomach virus, commonly known as the “vomit bug,” is spreading across much of the United States, including Southern California, where hikers have recently reported symptoms, according to the Pacific Crest Trail Consortium (PCT).
one norovirus Dr. Linda Yancey, an infectious disease specialist at Memorial Hermann Hospital, also reported to NBC on Friday about the outbreak in the San Francisco Bay Area.
The virus is a leading cause of foodborne illness in the United States and is of concern due to its ability to spread rapidly through contaminated food, water, surfaces and close contact between people.
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What is vomiting sickness?
Vomiting sickness, or norovirus, is not a new disease, but periodic spikes in infection often occur when highly transmissible strains of the virus circulate in communities. It is a highly contagious virus that causes acute gastroenteritis, an inflammation of the stomach and intestines. This illness is commonly known as the stomach flu.
“There’s really nothing unusual about what happened in California. They just had bad luck,” Yancey assured.
The Centers for Disease Control (CDC) reports that the virus is spread through direct contact with an infected person, contaminated food and drinks, or contact with contaminated surfaces and then the mouth.
The virus can infect people of all ages and is notorious for sudden outbreaks in schools, nursing homes, hospitals, restaurants and cruise ships, according to People magazine, citing health experts.
According to NBC, wastewater monitoring reports show “high” levels of norovirus in many areas of the United States, with levels rising significantly in the Northeast.
“On a national level, norovirus remains at high levels due to the high concentrations over the past 21 days,” Amanda Bidwell, science program manager for WastewaterSCAN, told PEOPLE.
According to statistics from the CDC’s NoroSTAT program, from August 1, 2025, to May 7, 2026, “1,194 norovirus outbreaks were reported in NoroSTAT participating states.”
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What are the symptoms of vomitus or norovirus?
Norovirus symptoms usually appear within 12 to 48 hours after exposure. The most common symptoms include
- sudden vomiting
- nausea
- diarrhea
- stomach cramps
- General fatigue.
In rare cases, some people may also experience fever, headache, chills, and body aches.
For most healthy people, symptoms improve within one to three days, according to the Mayo Clinic. However, dehydration remains the biggest problem, especially for children, the elderly, and people with underlying health conditions.
Medical experts recommend drinking water regularly and seeking medical attention if severe dehydration occurs. People magazine previously reported that several hikers on California’s Pacific Crest Trail were dehydrated and felt “weak” due to a norovirus outbreak, and one man was sent to the hospital.
CDCOn their norovirus awareness page, it is recommended to wash hands frequently with soap and water, clean contaminated surfaces thoroughly, handle food properly, and avoid preparing food if you are sick.
