Rotavirus vs. Norovirus: Symptoms, Causes, Treatment

Rotavirus and norovirus infections are common causes of stomach flu, clinically referred to as viral gastroenteritis. This inflammation of the gastrointestinal tract causes diarrhea, nausea and vomiting, abdominal pain, and sometimes fever. Even though both infections cause these symptoms, there are critical differences between the two viruses.

Whereas norovirus is the most common source of infections in adults and people of all ages, rotavirus is more common among children and infants under age 5.

This article breaks down the differences between these viruses, as well as when to contact your healthcare provider, the treatments available, and how to prevent infection.       

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Symptoms of Rotavirus vs. Norovirus

Since both rotavirus and norovirus lead to viral gastroenteritis, the symptoms largely align. Both conditions cause:

Nausea and vomiting
Watery diarrhea
Abdominal pain
Loss of appetite
Dehydration
Fever (in some but not all cases)

However, there are some key differences in the ways that norovirus and rotavirus present, including:

Typical age of onset: While people of all ages are susceptible to both viruses, norovirus primarily affects adults, while rotavirus is more common in children under 5 years old.
Incubation period: The incubation period is the time it takes from contact with the virus to symptom onset. The incubation for norovirus is 12–48 hours, while signs of rotavirus arise at two days.   
Duration of symptoms: Norovirus symptoms don't last as long, about one to three days; whereas rotavirus infections linger longer, for about three to eight days.

Symptoms of Dehydration

While most cases of viral gastroenteritis aren't themselves dangerous or fatal, they can cause dehydration, which can be a potential complication of both rotavirus and norovirus. The symptoms include:

Severe thirst, very dry mouth
Less frequent and lower volume of urination
Fatigue
Very dark-colored urine
Reduced ability of the skin to go back to normal after being pinched or pressed
Feeling light-headed or faint
Recessed eyes or cheeks

Causes

Both norovirus and rotavirus are easily passed from person to person, and they have similar means of transmission. In terms of causes, however, there are a few key differences.

Norovirus

There are several types of norovirus, with humans contracting three types—G1, G2, and G4—that can be divided into over 25 subtypes. This virus is among the most contagious worldwide, leading to approximately 21 million cases of stomach flu, which is about 60% of those cases.

Noroviruses are spread by the fecal-oral route—when viruses shed in the feces are somehow ingested through the mouth. This occurs due to contact with an infected person or surface, or via contaminated food, drinks, or water. Additionally, droplets of norovirus arising from vomit can also be inhaled, leading to infection.

When Are You Contagious?

People are most contagious with norovirus when symptoms arise and about three days after they've subsided. Some are contagious for up to two weeks after recovery.

Rotavirus

The word "rotavirus" comes from the Latin "rota," meaning "wheel," because of this virus's characteristic circular appearance. Like norovirus, rotaviruses are transmitted via the fecal-oral route. This means through direct contact, touching contaminated surfaces, or consuming affected water or food can all cause infection.    

Generally affecting those under age 5—though adults can also be infected—rotavirus outbreaks can occur in daycare facilities, schools, at home, or in other areas where many people are in close quarters. As such, cases increase during colder months. Unlike norovirus, people may become contagious before the onset of symptoms, and up to 2 weeks afterward.

Diagnosing Rotavirus and Norovirus

When you have stomach flu, the goal of diagnosis is to determine whether norovirus, rotavirus, or another infection is causing symptoms. As such, diagnostic approaches for these viruses largely line up. Here's a quick breakdown.

Medical History

At your medical appointment, the healthcare provider will ask about what symptoms you're having, how long you've had them, as well as whether you've been traveling or in contact with others who may be sick. They'll also want to know about your medical history and any medications you're taking.

Physical Exam

Tests of breathing function, heart rate, and blood pressure help providers detect signs of dehydration associated with infection. In some cases, providers use a stethoscope to listen to the abdomen or tap it to check for pain. A digital rectal exam may be needed if there's blood in the stool (feces).

Laboratory Tests

In most cases, physical exams and medical history are enough for diagnosis, though providers may call for testing to confirm the cause of symptoms. You'll be asked to leave a stool sample in a special container and send it off for laboratory analysis. Using genetic tests, clinicians detect signs of rotavirus or norovirus. These may include:

PCR assays: Tests of polymerase chain reaction (PCR) detect viral genetic material in the feces. These tests may be able to detect multiple viruses or are sensitive to only one of them, the way reverse transcription real-time polymerase chain reaction (RT-qPCR) assays are for norovirus.
Enzyme immunoassays: These test kits detect viruses that have caused an immune response (antigens) in the stool, providing rapid results. However, enzyme immunoassays tend to be less sensitive than PCR assays, and providers may require them for confirmation.
Multiplex gastrointestinal assays: These relatively newer tests are able to detect up to five different viruses that cause viral gastroenteritis, including both rotavirus and norovirus. They do this by picking up nucleic acids that the viruses give off in the stool sample.

Treatment

Generally speaking, most cases of both norovirus and rotavirus resolve on their own, without the need for medical attention. Largely the treatments of these conditions are identical, and there are no specific medications that directly treat rotavirus and norovirus. The typical approaches to care include:

Getting enough rest: The key to getting over any viral infection is making sure you're getting as much sleep and rest as possible. Take time off of work and school to prevent spreading the disease and give your body a chance to fight it off.
Replacing fluids: Since dehydration is the biggest danger in stomach flu cases, emphasizing water intake and drinking beverages with electrolytes, such as Gatorade, other sports drinks, and fruit juices, are other necessary steps to take. Infants, children, older adults, and those with weakened immune systems may need rehydration solutions, such as Pedialyte and Naturalyte.
Diet: Since vomiting and nausea are often symptoms of infection, you may also have to keep up nutrition with bland and easy-to-digest foods to ensure you're getting nutrition. The BRAT diet—emphasizing bananas, rice, applesauce, and toast—may be recommended.
Managing symptoms: To help with diarrhea, over-the-counter medications like Imodium (loperamide) and Pepto-Bismol (bismuth subsalicylate) can be taken. However, such options may be unsafe for children or if there is blood in the stool.

Probiotics: Taking supplements with or boosting dietary intake of bacteria that live in your intestines, such as Lactobacillus acidophilus, may help with diarrhea symptoms. Your provider may recommend taking these or eating foods with them, such as yogurt, kefir, or kimchi.
Intravenous (IV) therapy:`In cases of severe dehydration—a medical emergency—you may require intravenous (IV) fluid replacement therapy. Especially if fluids can't be held in due to vomiting, rehydrating solutions may be delivered directly to the bloodstream via tubes.

Rotavirus Vaccines

To help prevent the spread of rotavirus, vaccines like RotaTeq or RotaTrix prevent infants and children from developing severe symptoms in 90% of cases, with 70% experiencing little to no signs of illness. These vaccines take multiple doses, and are given to infants, typically at 2, 4, and 6 months.

Learn More: 2-Month Vaccines: What You Should Know

When to Get Help

If you or your child have any of the symptoms of dehydration, you should seek medical care as soon as possible. Get help if you experience dry mouth, loss of energy, lack of urination or tears, reduced skin elasticity, and dizziness. Furthermore, call your provider if infants or young children have stomach flu, if you're older than 65, or have compromised immunity.

Prevention

Since both rotavirus and norovirus are transmitted via the fecal-oral route, the core of prevention is good hygiene. This means:

Clean hands: Washing your hands thoroughly and properly after going to the bathroom, changing diapers, and before and after handling food. This means making a lather with soap and rubbing your hands together for at least 20 seconds, before rinsing with lukewarm or hot water.
Clean surfaces: Since noroviruses and rotavirus can survive on surfaces, keeping these clean and sanitary is another important step. Clean them with a solution of up to 25 tablespoons of bleach to 1 gallon of hot water. Potentially contaminated clothing should be thoroughly laundered.
Safe food handling: Thoroughly wash any fruits or vegetables you're planning on eating or preparing. Since viruses can be transmitted via shellfish and meat, make sure these foods are cooked thoroughly. If you're sick, don't touch raw food or wear gloves before doing so.

Prevent the Spread

If you or your child is feeling sick, take extra steps to prevent spreading your norovirus or rotavirus infection to others. Stay home from work, keep kids home from school, preschool, or daycare, and be extra mindful about hygiene and sanitation.

Summary

Rotavirus and norovirus are the two of the most common causes of viral gastroenteritis, commonly known as stomach flu. These infections, which usually resolve on their own, cause inflammation of the intestinal tract, leading to watery diarrhea, nausea, vomiting, and sometimes fever. Dehydration, a serious medical issue, can also arise.

Rotavirus primarily affects children under 5 and has a slower onset, taking up to two days after exposure. Generally, symptoms last up to eight days, and you're contagious before they set on. In turn, norovirus affects people of all ages, sets on within 12 to 48 hours, and typically resolves within a couple of days. Infected people can transmit the disease only after symptoms set on, though you may still be contagious for up to two weeks after they've resolved.

Primarily, assessment of symptoms is enough for diagnosis, though tests of stool samples or vomit can confirm the underlying cause. These include PCR, immunoassays, or multiplex gastrointestinal assays. Treatment strategies for these viruses line up and focus on rest, rehydration, and managing symptoms. Over-the-counter medications, such as Imodium, Pepto-Bismol, and probiotics can also help with symptoms. Prevention of this condition primarily involves extra effort in handwashing, cleaning surfaces, and safe food handling.      

A Word From Verywell

The good news when it comes to both norovirus and rotavirus is that these illnesses usually resolve on their own. Staying hydrated and getting rest is usually sufficient for taking on the symptoms of infection. However, as with all aspects of health, vigilance is key, and it's important to know when it's time to get help. If you're concerned about your or your child's stomach flu symptoms, call your provider or get emergency medical attention.

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