Foods & Pregnancy

What are Noroviruses

Noroviruses are viruses that are very resistant to adverse environmental conditions: they can survive at temperatures above 60°C and even in the presence of chlorine used to disinfect drinking water.

If swallowed, these agents can cause foodborne infections.

The virus is highly infectious: a few viral particles are enough to give rise to an infection. The particles can replicate and spread even for two weeks after the initial infection.

Symptoms include nausea, vomiting (especially in children), watery diarrhoea, abdominal cramps, and sometimes fever.

There is no specific cure: experts recommend taking plenty of fluids to compensate for dehydration due to vomiting and diarrhoea.

norovirus norovirus on the dish
food pregnancy risk norovirus

How the infection may occur

Transmission can take place directly through the consumption of contaminated water or food, by contact with contaminated surfaces, by direct transmission from person to person or finally, by aerosol.

The faeces of infected people can be a source of contamination even 72 hours after healing.

In most cases, the incubation period of the disease is about 12-48 hours. Usually the disease has no serious consequences, and most people heal in 1-2 days.


In Europe, Noroviruses are considered the leading agents of non-bacterial gastrointestinal infection.

Since 1997, most European countries have witnessed an increasing trend in cases of infection with these viruses, with a significant peak in 2006 in many countries.

In Italy, in 2006, the province of Taranto was affected by an epidemic of Norovirus. On that occasion, a study identified the cause as contaminated tap water from the aqueduct.

year of a Norovirus epidemic
in Taranto, Italy
Fish and seafood
Fruits and vegetables

What foods to be careful with

Foods that are most often implicated in cases of Norovirus infection are:

  • water;
  • seafood or fishery products consumed raw or undercooked;
  • poorly washed raw fruits and vegetables and their derived products.

Attention should also be paid to ready-to-eat foods that may be subject to the following kinds of cross-contamination:

  • direct, by contact with other foods that carry the pathogen;
  • undirect, by contact with contaminated and inadequately clean utensils or work surfaces.

How to reduce the risk of norovirus infection?

Unfortunately, it is not possible to recognise food contaminated by pathogenic microorganisms:
contaminated food shows no changes in colour, smell, appearance or taste.

Click on the button below to read the rules on foods to avoid and behaviours to be adopted
to reduce the risk of contracting diseases of microbiological origin transmitted by food.