It’s 2 a.m. when your 5-year-old daughter’s cry jolts you awake: “Mommy, I’m sick!” The next few hours are a blur of clean-up and comfort as you battle the dreaded norovirus, aka the stomach bug, aka the stomach flu, aka the “winter vomiting bug.”
The Centers for Disease Control and Prevention (CDC) reported 97 cases of the highly contagious virus in the U.S. during the week of Jan. 6, double the number as in previous years during early January. The actual number is likely much higher because state and local health departments aren’t required to report norovirus cases.
Dr. Mohammad Ali, an infectious diseases physician at Penn State Health’s Hampden and Holy Spirit medical centers, explains why norovirus cases are rising lately and why hand sanitizer can’t prevent it.
What is norovirus?
Norovirus is the culprit behind gastroenteritis, an inflammation of the stomach and intestines, causing severe vomiting, diarrhea and stomach cramps. While anyone can catch norovirus, young children, older adults and people with weakened immune systems are more vulnerable to severe illness. “It can be pretty debilitating and even put you in the hospital,” Ali said.
Despite being called the “stomach flu,” norovirus is unrelated to influenza. It spreads easily from person to person through contaminated food, surfaces like doorknobs and bathroom fixtures, and close contact with infected individuals. Outbreaks are more common between November and April when people spend more time indoors. Schools, day cares, nursing homes and cruise ships are frequent hotspots.
Common sources of norovirus infection include raw or undercooked shellfish, contaminated fruits and vegetables, contaminated water and food handled by infected people. The virus can live on hard surfaces for up to two weeks and soft surfaces such as carpet for up to 12 days. Even a small amount of the virus can cause infection.
How does norovirus spread?
Norovirus spreads by consuming contaminated food or water or by touching contaminated surfaces and then touching your mouth. The contagious period starts when someone feels ill and lasts for at least three days after recovery ─ sometimes longer.
More outbreaks of norovirus are occurring lately because a particular variant that isn’t common in the U.S. is spreading, meaning fewer people have immunity, Ali explained.
Why hand sanitizer doesn’t work against norovirus
Alcohol-based hand sanitizers are ineffective against norovirus.
“Norovirus has a thick capsule around it. It’s a hardy virus, which means it’s difficult to eradicate, and you need only a few particles to cause illness,” Ali said.
Washing hands with soap and water is the gold standard for preventing a norovirus infection. Wash your hands for at least 20 seconds, especially after using the restroom, before eating and after handling food. Unlike hand sanitizers, proper handwashing creates friction that removes the virus particles from your skin.
How to prevent norovirus
The CDC also recommends these steps:
- Wash fruits and vegetables thoroughly under running water.
- Cook food to the proper temperature.
- Keep raw and cooked foods separate to prevent cross-contamination.
- Avoid preparing food when you are ill.
- Clean regularly, especially during outbreaks. Use a bleach-based cleaner or a disinfectant approved by the U.S. Environmental Protection Agency to sanitize high-touch areas like kitchen counters, bathroom fixtures and doorknobs.
- Wear gloves when cleaning. Wipe surfaces with paper towels and throw them away in a plastic trash bag.
- Wash clothes and linens that may have been exposed to norovirus with detergent and hot water at the maximum available cycle length, and then machine dry them at the highest heat setting.
When to seek medical attention
Most people recover from norovirus with rest and hydration. Start with clear liquids and slowly reintroduce bland foods. Avoid dairy, caffeine and high-fat foods to help ease gastrointestinal upset.
“Most people start to feel better in 24 to 48 hours, but they might feel wiped out for four to five days afterward because of being dehydrated and behind on nutrition,” Ali said.
However, symptoms like persistent vomiting, severe abdominal pain, high fever or blood in the stool may signal a more serious norovirus infection. One major risk is dehydration, especially in children.
“Signs of dehydration are irritability, dizziness, decreased urine production and sunken eyes, in the case of kids,” Ali said. Oral rehydration solutions can help, but when a person is severely dehydrated, he recommends taking them to the nearest emergency department so they can get intravenous fluids quickly.
Related content:
- The Medical Minute: 10 health tips for parents during cold and flu season
- The Medical Minute: Hand sanitizers effective, but handwashing is better
The Medical Minute is a weekly health news feature produced by Penn State Health. Articles feature the expertise of faculty, physicians and staff, and are designed to offer timely, relevant health information of interest to a broad audience.
