Norovirus – Symptoms, Prevention, Treatment and More

17 mins read

Norovirus symptoms are unpleasant. It can cause inflammation of the intestines and stomach, resulting in the patient experiencing pain, sickness, and diarrhea.

The first norovirus outbreak

Back in 1929, before it became recognized, Zahorsky described this type of stomach inflammation as the “winter vomiting disease.” This terminology is still in use today.

It was back in 1968 when a place called Norwalk in Ohio experienced the first notable attack of this virus with its many norovirus symptoms.

It took four years before the discovery of the agent causing the problem, the norovirus, was isolated. This is why it has the name ‘norovirus’ because of its first appearance in Norwalk.

As a result, if not treated, dehydration will quickly occur. The virus spreads to others by getting into the body via the mouth, nose, or eyes with the original infection coming by being in contact with contaminated water or food.

Norovirus infection and norovirus symptoms

There is no cure as such because this is a virus. Sufferers with norovirus symptoms need to be comfortable and supplied with plenty of fluids while they wait for it to pass, which takes between one and three days.

Antibiotics are useless as it is not an infection but a virus.

Norovirus infection can run rife in close, crowded environments. Norovirus symptoms can be found in hospitals, nursing homes, schools, nurseries, and even cruise ships.

The first sign of norovirus symptoms is people vomiting and experiencing diarrhea. It is very contagious and spreads quickly via food and water that is contaminated while being prepared.

Infected people can also pass the virus to each other. Once exposed to the virus, people will quickly succumb to becoming ill. People who are already sick, such as in-hospital patients, the elderly, and the very young are very susceptible to dehydration. They may need to have medical treatment in the form of extra fluids.

Norovirus incubation

The norovirus incubation period usually is 12 – 48 hrs. Norovirus symptoms appear very quickly and can intensify until they reach a worrying state. (1)

At its worst, this includes projectile vomiting, severe watery diarrhea, cramps in the abdomen, and even a fever, coming together to reach a peak.

Norovirus transmission

Those who are infected with norovirus symptoms can shed billions of viral particles in a short period. Seen by using a microscope, it takes only a few to make people sick. Sufferers are at their most contagious and able to transmit the virus when:

  • They have been in touch with others that have the illness or have taken contaminated food or drink recently.
  • They are within the first few days of recovery. The virus can be carried for up to two weeks, even when the patient feels well.


Because the virus is very infectious, it takes only a few particles to infect food and water and create norovirus symptoms. (2)

Contamination can occur when:

    • Someone already infected touches food with dirty hands contaminated with vomit or feces particles
    • Food touches a surface covered with vomit or feces particles.
  • Clean water is contaminated with already tainted water.
  • Vomit spray passes via the air, landing on food.
  • Food is grown or prepared using contaminated water i.e., oysters from tainted water or vegetables irrigated with polluted water.


The norovirus is the leading cause of illness from contaminated food or water. These can quickly occur in restaurants where correct food preparation processes are not followed.

The people preparing the food may have dirty hands. When they touch the food that is ready to eat and does not need to be cooked further, contamination occurs.

Norovirus symptoms will then occur. Affected items may be fruit and salads, but any raw food or ready-to-eat i.e., handled after being cooked, can become tainted.

Drinking bottled water only is one way of ensuring that water is clean. The top should not be tampered with or the bottle refilled from a tap.

Preventing norovirus symptoms

Keeping norovirus at bay is not a difficult thing to do. Prevent norovirus symptoms by washing hands thoroughly and keeping all kitchen surfaces free from infection. (3)

Hand washing

Wash hands before eating or preparing food or drinks and always after going to the toilet or changing a baby’s nappy. Also, cleanse your hands before dispensing medicine to yourself or someone who is sick.

The problem with norovirus is that people may be contaminated without knowing it and before norovirus symptoms occur. If you are recovering from the virus or helping people who have it, hand washing carefully is vital for recovery.

If facilities like soap and water are not around, hand sanitizers do not substitute. You can use it after washing but not instead.

Also, using disposable towels as fabric ones will become contaminated quickly, acting as an invisible breeding ground for the virus. If this happens, washing your hands will do nothing to help prevent the spread of the virus or the norovirus symptoms.

Food preparation

Wash all fruit and vegetables in clean water before eating. Cook all shellfish fully. The norovirus seems to be able to resist heat as high as 145°F, so steaming shellfish is not adequate.

If you suspect food is already contaminated, put it in the bin. If people are sick, they should not enter the kitchen. Wait for a minimum of 48hrs, if you are recovering from the norovirus symptoms after all norovirus symptoms have gone before preparing food.

This applies not only at home but also if you work in an environment such as a school, nursery, care home, or hospital.

Disinfect surfaces

When you are in the same room as someone with norovirus symptoms, frequently disinfect all surfaces. Wear disposable gloves, clean with paper towels, and then dispose of them.

Make a disinfectant solution using bleach, as shown on the product label. Leave the disinfectant on the surfaces for a minimum of five minutes, and then clean again with hot soapy water. Wash soiled laundry in very hot water, separate from other garments.

Kitchen surfaces should also be cleaned and sanitized in the same way, including all surfaces, utensils, counters and serving trays, etc.

Norovirus treatment

Norovirus is a virus, and antibiotics will not kill it. These only fight bacteria, so they are ineffective. The only way to care for infected patients with norovirus symptoms is to keep them comfortable and fully hydrated with plenty of liquids.

People in the hospital, the elderly, and the very young will succumb quickly to dehydration and may need hospital treatment to give them fluids intravenously.

Signs of dehydration with norovirus symptoms are the skin becoming dry and tight in the elderly, lacking energy and children crying, and being overly sleepy.

As well as drinking plenty of water, sports drinks can help. Do not use caffeine or alcohol. While these drinks can help with water retention, they do not contain essential nutrients and minerals.

To replenish these, you will need to introduce oral rehydration fluids, obtained from the doctor or chemist.

Norovirus vaccine

Previously considered as just an annoying virus, norovirus is taken far more seriously nowadays. It results in unpleasant norovirus symptoms and hundreds of thousands of hospital visits and hundreds of deaths each year, mainly among the elderly.

Worldwide, the World Health Organization estimated that in 2015, 685 million cases occurred, with 200 million of these being children. Two hundred thousand resulted in deaths, and this was in developing countries. (4)

It is, therefore, now crucial to find a norovirus vaccine to treat norovirus symptoms. The problem is that the virus comes in many strains, and it does not prompt a strong immune response.


In 2012, researchers in Sydney worked with Genotype II, which is the most common strain responsible for outbreaks. (5)

They were able to isolate antibodies from previously infected patients, finding that they bound to three antigenic sites on the virus. These are the first steps toward finding a vaccine, but it could take a while.

More recently, a biotech operation in Durham, NC, tested a molecule called CMX521 in Phase One of their trials.

This attacks an enzyme called RNA-dependent RNA polymerase (RdRp), which creates the base pair units that make up the genome required to produce new viruses and the norovirus symptoms.

RdRp is found in all strains of the norovirus, so CMX521 may be used to tackle various strains, even though the spikes (surface protein binding sites) vary across each strain. (6) (7)

They are still testing on mice and need to decide when it would be taken. Would this be before being infected with the virus or when a person feels ill and has norovirus symptoms?

The problem is that once you begin to feel sick, the vomiting follows quickly. You would only know that you might come down with the bug if others around you already have it. Anti-viral medicines are generally not used in a prophylactic (preventative) way.

Preventative measures – stop norovirus symptoms

  • Before preparing food, wash your hands thoroughly and always after using the toilet.
  • Suffers should be isolated, if possible.
  • Kitchens, fridges, toilets, washrooms, and areas where vomiting has taken place all need to be disinfected.
  • Wear masks and gloves when cleaning and dispose of them after use.
  • Anyone with symptoms should remain absent for a minimum of 48 hrs after recovery.
  • Those involved in health care should disinfect their hands for 14 days after norovirus symptoms have disappeared.

Any immunity that is given by an attack is strain-specific, so it offers little protection. People can be infected many times in their lifetime and at any age.

It is felt that susceptibility to infection could be genetically determined. Recent studies have shown that those with blood group 0 are more at risk of showing norovirus symptoms.

As we can see, the norovirus creates a very unpleasant illness all over the world with distressing norovirus symptoms.


It is found in third-world countries and in developing countries too. Difficult to control and tackle, sufferers can feel unwell, spreading the virus from person to person even before they show symptoms.

Known by a mixture of names – norovirus, winter sickness, vomiting bug, or merely sickness and diarrhea, it can wreak havoc very quickly in hospitals and other confined spaces every year with the norovirus symptoms taking hold in a short space of time.

Until a vaccine is found to treat norovirus symptoms, all that we can do is apply stringent preventive procedures and keep all food preparation areas and kitchens spotlessly clean.

Once food and water are contaminated and people infected, there is nothing to do but wait for the virus to burn itself out.


In summary, we can see that the norovirus creates a gastrointestinal illness in humans. This results in norovirus symptoms that include vomiting, abdominal pain, and diarrhea.

Some sufferers may have a fever, headache, and chills. It can hit very suddenly, creating a dramatic fluid loss. For this reason, babies, the elderly, and those with limited immune systems can be at high risk.

Recovery from norovirus symptoms takes between one and three days, with the incubation period being between 12-48 hours. Infection is often present long before the sickness begins.

Symptoms may drag on and last for a week. More common in the winter, this virus is often called the “winter vomiting disease.”

The virus is sturdy, able to withstand freezing conditions as well as high temperatures. When present on a surface, the virus can remain alive for an extended period.

Adding chlorine to the drinking water does not destroy it, as the general levels of chlorine used are not high enough to eradicate it.

Highly contagious

Highly contagious, it does not take many particles to create an infection. Transmission of norovirus symptoms is via the fecal-oral route or by consuming contaminated food or water.

When vomiting takes place, (sometimes projectile) particles enter the atmosphere, contaminating both surfaces and people, remaining around for a long time.

To give some idea, during a single outbreak of norovirus Gastroenteritis, transmission can take place in many ways, and the origin of the outbreak can be complicated to pin down.

The infection of the food or water may then be followed by person-to-person transmission. Shedding of the virus takes place via vomiting and diarrhea and may continue even after the infected person feels recovered.

Some food items seem to be more associated with outbreaks of norovirus. Oysters and raspberries have caused both international and national outbreaks of the virus along with norovirus symptoms.

Any food can be contaminated if the person touching it is infected and has norovirus symptoms.

The infection spreads quickly from person to person. It is most rife in contained areas such as hotels, hospitals, schools, and nursing homes.

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