Norovirus: A Common Cause of Stomach Upset

Norovirus and Group Infections

Norovirus is well-known for causing outbreaks, particularly in places where people gather in close quarters, such as kindergartens, schools, nursing homes, guesthouses, and cruise ships. The virus can spread in many ways: directly from person to person through contact, through contaminated food, from contact with infected surfaces (like doorknobs or utensils etc.), and potentially through drinking water. In Iceland, waterborne outbreaks in recent decades have mostly been due to Campylobacter or norovirus.

Symptoms and Course of Norovirus Infections

The most common symptoms of a norovirus infection are vomiting and/or diarrhea, often accompanied by abdominal pain, body aches, headache, and sometimes a mild fever. There is no specific treatment for norovirus, and in most cases, the illness resolves on its own within 1-2 days. However, elderly individuals and those who are already unwell can experience more severe illness, especially due to dehydration. There is no vaccine for norovirus. It is important to stay hydrated, and paracetamol can be used to relieve headache or body pain.

Norovirus is Highly Contagious

Norovirus is extremely contagious, as only a small number of viral particles are needed to cause infection. People with norovirus are contagious while they are symptomatic and typically remain so for 2-3 days after symptoms disappear. However, in some cases, individuals can continue to be contagious for up to 10 days after recovery.

Preventing Norovirus Infection

Good and frequent hand washing is the most effective way to prevent the spread of norovirus. People who are sick with norovirus should stay away from others and absolutely avoid cooking or serving food while they have symptoms and for at least two days after symptoms stop. Surfaces in the sick person’s environment should be thoroughly cleaned and disinfected. Clothing, bedding, and towels should be washed at high temperatures.

Effective Cleaning Methods

When cleaning areas where norovirus infections have occurred:

• Exercise caution when cleaning up after someone with a norovirus infection, especially if there has been vomiting or diarrhea, as these are highly contagious.

• The virus can survive on surfaces for an extended period (from several days up to two weeks), so infection from the environment is possible.

• Contaminated clothing, bedding, and towels should be removed and washed at the highest temperature the fabric can withstand, and ideally dried in a dryer. Be sure to wash your hands thoroughly afterward.

• Clean and disinfect contaminated surfaces: regular rubbing alcohol is not effective against norovirus. Wash the area with soap and water, then disinfect with a chlorine solution at a concentration of 1000 ppm (mix 1 part bleach with 50 parts water).

By following these guidelines, you can help prevent the spread of norovirus and protect yourself and others from infection.

Various guidelines on norovirus infection and general infection prevention and hygiene:

• Brochure on preventing infection with norovirus, guidelines for the general public (Icelandic)

• Heilsuvera website

• The Directoreate of Health

  (under the heading Norovirus)

• U.S. Center for Disease Control

The Chief Epidemiologist