Norovirus: what is it?

The norovirus is a very commons cause of gastrointestinal diseases. Symptom such as diarrhea , nausea, and vomiting when the digestive tract is unbalanced are typical of norovirus infection .

According to the norovirus definition, the pathogen is distributed worldwide. Scientists characterized the pathogen from the calicivirus family for the first time in 1972. The norovirus used to be called "Norwalk-like virus". Man is his only host. Infections with noroviruses can occur year-round, but are more common in the cool months of October to March.

Norovirus causes gastrointestin flu

The norovirus trigger the majority of diarrheal disease that are not caused by bacteria. In children it is responsibles for around 30 percent of gastrointestinal inflammation (gastroenteritis), in adults even for up to 50 percent. The vernacular also speaks of gastrointestinal flu , stomach flu or vomiting diarrhea.

An infection with the norovirus is subject to notification. Doctors also know that the norovirus particularly often affects children under the age of five and people over the age of 70. Regular norovirus outbreaks often occur in community facilities (daycare centers, kindergartens, schools) as well as old people's and nursing homes.

You can only prevent an infection through thorough hygiene measures, because there is no vaccination against the highly contagious virus.

Magnified illustration of a norovirus in the gastrointestinal tract of the human body

Norovirus: symptoms set in quickly

The first signs of a norovirus infection are usually not long in coming. The following symptoms often occur just a few hours after being infected:

• Nausea and gushing, violent vomiting
• severe diarrhea (the stool odor with a norovirus infection is often pungent, sometimes bloody mucus is visible)
• pronounced feeling of illness, fatigue, exhaustion
• stomach pain
• headache
• Muscle pain , body aches
• Mild fever , but the norovirus usually does not cause a fever

Severe, mild and even symptom-free courses of norovirus infection are known. Some experience norovirus infection without vomiting and only have diarrhea. Conversely, some patients only vomit and the disease proceeds without diarrhea. Very rarely do patients experience norovirus infection without any symptoms.

The symptoms usually last between twelve and 48 hours. The diarrhea and the violent vomiting lead to a considerable loss of fluid, which you have to compensate for as quickly as possible.

Is the norovirus contagious?

The norovirus is considered highly contagious . Just a few (around 10 to 100) virus particles are enough to trigger the infection. The incubation time for norovirus is six to 50 hours. This tells you how much time passes between the norovirus infection and the appearance of the first symptoms. The incubation period therefore varies considerably from person to person.

Norovirus: transmission in different ways

The norovirus is transmitted in several ways, mostly from person to person:

• Smear infection: Infected people excrete large amounts of noroviruses in their stool. Most of the time, the pathogens are passed on through the hands . If you put your hands in the eyes, mouth or nose, the virus can enter the body through the mucous membranes. However, noroviruses can also stick to objects and surfaces , for example bathroom fittings, door handles or handrails. If you touch them with your hands and then your mouth, you can also get infected.
• Droplet infection : When sick people vomit, catapult very fine droplets into the air, in which the noroviruses sit. If you inhale these tiny droplets from the vomit, you can become infected.
• Contaminated food : You can get a norovirus infection through the consumption of contaminated food (e.g. salads, fruit, crabs, mussels) or drinks (contaminated water).

The greatest risk of infection for others is when the patient shows the first signs of the disease. But even if the symptoms have subsided after a day or two, the risk of infection is still high. Because the sick excrete noroviruses in the stool for a few days (sometimes even two weeks and longer). You should therefore ensure that your hands and sanitary facilities are well hygienic even after the symptoms have disappeared.

Norovirus: treatment relieves symptoms

There is no causal norovirus treatment that goes straight to the root of the problem - the viruses. There are no targeted drugs against the norovirus. By the way, antibiotics cannot do anything against noroviruses because they only work against bacteria. Doctors can only relieve the uncomfortable symptoms that accompany norovirus infection. Otherwise, however, the body will have to deal with the virus on its own.

Norovirus therapy depending on severity

There are some things you can do to help patients with norovirus infection and get through the disease better. Some examples:

• Sick people should take it easy , avoid physical exertion and limit contact with other people to what is necessary.
• Due to the often severe diarrhea and vomiting, a norovirus infection quickly leads to high fluid and electrolyte losses. Therefore, drink enough (e.g. herbal tea, ginger tea, water) and consume salts, for example in the form of a salty broth, in spite of the nausea. Sometimes ready-made electrolyte solutions from the pharmacy also help to bring the electrolyte balance back into shape.
• What to eat with norovirus? The answer to this question is simple: easily digestible foods such as rusks, pretzel sticks or crispbread. This way you don't put any more strain on your stomach and intestines and the intestinal mucosa can recover. Food that is rich in fat or high in fiber is rather unsuitable for a norovirus infection, as it puts additional strain on the digestive system.

Norovirus: treatment of risk groups

Especially small children, pregnant women, the elderly or weakened people should seek treatment from a doctor. This is specially true in the case of frequent and long-lasting diarrhea, but also if fever and vomiting occur. For these people, the loss of fluids and electrolytes can be dangerous and lead to complications.

• An electrolyte-rich substitution solution, which is available in the pharmacy as a powder for self-mixing, is helpful.
• Medicines - so-called antiemetics - are a possibility against nausea and severe vomiting when infected with the norovirus.
• If the norovirus infection is particularly severe, hospitalization may be necessary. Doctors then deliver the fluid and electrolytes via infusion solutions.