Nasty Norovirus

Gastrointestinal illness is never pleasant—but norovirus is particularly distasteful. A norovirus infection can cause repeated bouts of diarrhea and vomiting, which further spreads the virus on contaminated surfaces, foods, and through close contact with infected people. People who are infected with norovirus shed billions of virus particles in their feces and vomit.¹ And it takes fewer than 100 tiny virus particles to make someone else sick.¹

That’s why the idea of a norovirus outbreak strikes fear into the staff of daycare centers, schools, healthcare facilities, cruise ships, and other group settings.

What is norovirus?

Norovirus is a highly contagious virus that is a common cause of diarrhea and acute gastroenteritis. Norovirus causes gastroenteritis in 19–21 million people per year in the United States, according to the Centers for Disease Control and Prevention (CDC).¹ More seriously, the virus is responsible for 56,000–71,000 annual hospitalizations and 570–800 deaths in the U.S. every year.¹

How is norovirus spread?

Noroviruses can linger on surfaces for days, and they are difficult to eradicate because they can withstand both hot and cold temperatures and most disinfectants.²You can acquire a norovirus infection by:^1,2

Eating contaminated food or drinking contaminated liquids
Touching contaminating surfaces and then touching your hand to your mouth
Being in direct contact with a person sick with norovirus
Sharing plates, cups, and utensils with someone who is infected

What are the symptoms of norovirus?

If you have acquired a norovirus infection, you’ll probably go quickly from feeling completely normal and healthy to total discomfort. Signs and symptoms usually begin 12–48 hours after exposure to norovirus and last one to three days.²

Typical norovirus symptoms include nausea, vomiting, watery diarrhea, and stomach cramps. Other norovirus symptoms include:²

Low-grade fever
Chills
Headache
Muscle aches
Fatigue

For most people, a norovirus infection is unpleasant but clears up within just a few days. However, older adults, pregnant women, and immunocompromised people may experience severe illness leading to dehydration, malnutrition, and even death.²

How long is norovirus contagious?

Those infected with norovirus can continue to shed the virus in their feces for up to two weeks after recovery. This shedding can last weeks to months in those who have an underlying health condition. Some people with the norovirus infection may be asymptomatic—however, they are still contagious and can spread the virus to others.²

Syndromic testing pouch loaded into BioFire® System.

How is norovirus diagnosed?

Many pathogens can cause symptoms like diarrhea and vomiting, making it difficult for clinicians to know what’s causing gastrointestinal illness based on symptoms alone. Traditional testing methods are time consuming and may not even reveal the etiology of a patient’s gastrointestinal symptoms.

Fortunately, syndromic testing from the BioFire^® FilmArray^® Gastrointestinal (GI) Panel is fast, accurate, and comprehensive, offering results on 22 gastrointestinal pathogens—including viruses, bacteria, and parasites—in about an hour.

The BioFire GI Panel takes a syndromic approach to infectious disease diagnostics, using multiplex PCR technology to simultaneously test for multiple potential pathogens in one quick test. Quickly identifying the causative pathogen may help guide appropriate treatment and may improve patient management.

How is norovirus treated?

There is no specific treatment for norovirus infection, and recovery generally depends on the health of your immune system. In most people, the illness usually resolves within a few days. When sick with a gastrointestinal illness, it’s important to stay hydrated. If you are unable to drink enough fluids to prevent dehydration, you might need to receive intravenous fluids.^1,3

5 tips from the CDC for preventing norovirus¹

1. Practice proper hand hygiene. Make sure to wash your hands thoroughly with soap and water after using the toilet and before eating or preparing food. While alcohol-based hand sanitizer may be used in addition to handwashing, it is not a substitute for washing with soap and water.

2. Wash fruits and vegetables and thoroughly cook shellfish. Noroviruses are relatively resistant and can survive temperatures up to 140°F, including the quick-steaming processes that are often used to cook shellfish. Discard any food that may be contaminated with norovirus.

3. Do not prepare food or care for others when you are sick. Wait for two or three days after you recover before preparing food or caring for others. This includes in settings like schools, daycares, and restaurants.

4. Clean and disinfect contaminated surfaces. The CDC recommends using a chlorine bleach solution with a concentration of 1000–5000 ppm (5–25 tablespoons of household bleach [5.25%] per gallon of water) or other disinfectant registered as effective against norovirus by the Environmental Protection Agency (EPA).

5. Wash contaminated laundry thoroughly. When you wash clothing or bedding that may be contaminated with vomit or stool, be sure to handle them carefully (to avoid spreading the contamination) and wear rubber or disposable gloves. Wash with detergent at the maximum cycle length and machine dry them. Wash your hands thoroughly after handling the laundry.

References:

Norovirus Illness: Key Facts. CDC. Retrieved from https://www.cdc.gov/norovirus/downloads/keyfacts.pdf. Accessed 27 Dec 2021.
Norovirus Infection: Symptoms & Causes. The Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/norovirus/symptoms-causes/syc-20355296. Accessed 27 Dec 2021.
Norovirus Infection: Diagnosis & Treatment. The Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/norovirus/diagnosis-treatment/drc-20355302. Accessed 27 Dec 2021.

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