Stomach bugs are expected in the winter, but they can make us sick during warmer months as well. Norovirus is the most common cause of acute gastroenteritis, which is inflammation in the stomach and/or intestines that causes diarrhea and vomiting.
It’s extremely contagious and known to spread at resorts, day care centers, nursing homes, summer camps, cruise ships and other similar, enclosed spaces.
“Anyone can be infected with norovirus and there are many different strains, so being infected with one type may not protect you against others,” said Evangelia Papageorge, MD, family medicine specialist at Southern Hills Hospital and Medical Center and WellHealth Primary Care.
Because many summer activities — from casual potlucks to long-awaited vacations — can be affected by norovirus, it’s important to take precautions against it.
What is norovirus?
There are more than 25 strains of norovirus. Common symptoms include stomach pain, nausea, vomiting, diarrhea, fever, headache and body aches.
The symptoms are similar to those that occur from food poisoning or the “stomach flu,” and the terms often are used interchangeably, even though they’re not necessarily the same.
Food poisoning can be caused by norovirus but it also can be caused by other germs and contaminants, such as bacteria. Meanwhile, the flu refers strictly to a respiratory infection caused by the influenza virus, which is entirely separate from norovirus. The “stomach flu” isn’t a flu at all — it’s simply a colloquial term that describes symptoms of gastroenteritis. Unfortunately, this means that getting an annual flu vaccine won’t help to fend off gastrointestinal diseases.
The symptoms of norovirus typically develop quickly (within 12-48 hours) following exposure and typically last for one to three days.
How does it spread?
Norovirus can be spread through direct contact with an infected person, touching contaminated surfaces or objects, or by consuming contaminated foods/drinks.
Norovirus is the leading cause of foodborne disease outbreaks in the United States. These outbreaks can be caused by an infected service worker handling food or, in some cases, the food (especially shellfish, fruits and vegetables) may be contaminated at the source.
Why is it so contagious?
Norovirus is a tenacious bug with multiple characteristics that make it easily transmittable and prone to outbreaks.
1. Infected patients are most contagious while they’re still experiencing symptoms and during the first few days following recovery, Papageorge said. However, they’ll continue to “shed” the virus in their stool for two to four weeks after symptoms subside.
2. Some patients with norovirus won’t show any symptoms, but they can still transmit it to others.
3. It doesn’t take much to make you sick. Someone can become infected after being exposed to less than 100 norovirus particles, while patients with the illness shed billions of particles through stool and vomit.
4. Norovirus can live on surfaces and objects for several days or weeks, and can withstand many disinfectants. Its resilience to disinfectants, combined with a low number of virus particles required for transmission, makes it difficult to sanitize contaminated areas.
5. There is no vaccine to prevent it, no medication to treat it and patients can get it more than once.
Norovirus can cause complications
Anyone can contract norovirus, but most healthy adults will be able to recover without medical treatment. However, norovirus is responsible for 56,000 to 71,000 hospitalizations and up to 800 deaths each year — mostly in young children and the elderly.
“People 65 years and older, infants, children and other patients with suppressed immune systems (such as those with diabetes, kidney disease, COPD/emphysema or who are undergoing chemotherapy) have an increased risk,” Papageorge said.
Severe dehydration is the most common complication associated with norovirus, so it’s necessary to replenish your system with plenty of fluid and electrolytes. This is especially important during summer, when temperatures are high and many people may be slightly dehydrated to begin with. If you’re unable to keep fluids down and/or are showing signs of dehydration, seek medical attention immediately.
How can I prevent norovirus transmission?
• Practice proper hand hygiene: Wash hands with soap and water for at least 20 seconds before and after using the restroom, changing diapers, and eating/handling/preparing food.
• Take extra care with food prep: Wash fruits and veggies well. Avoid consuming raw shellfish, and cook seafood thoroughly because norovirus can withstand temperatures up to 140 degrees.
• Clean contaminated surfaces: Use a chlorine bleach solution on any surface or object that may be contaminated. To make the solution, combine 5-25 tablespoons of bleach (5.25% solution) per gallon of water. Some disinfectants may be registered as effective against norovirus as well.
• Launder any clothes or linens that may be contaminated and wear gloves when disposing of any soiled items.
• If you have norovirus, do not prepare food, provide care or come into close contact with others for at least two to three days after symptoms subside. During this time, it’s also best to stay home and avoid public areas, so you don’t infect others.
Source: Centers for Disease Control and Prevention