Norovirus Infection

The Norovirus Infection: Causes, Management, and Prevention

The Norovirus Infection: Causes, Management, and Prevention

Causative Agent

Norovirus is a faecal-oral virus which typically causes acute gastroenteritis. It is also a common cause of food poisoning and is often related to the consumption of undercooked shellfish. Norovirus can cause outbreaks of acute gastroenteritis in settings where numbers of people are together in close proximity including cruise ships. The disease affects people of all age groups and tends to be more common during winter months, which is why it is often referred to in the press as the winter vomiting bug.

Clinical Features

The disease is characterised by nausea, vomiting diarrhoea, abdominal pain, low grade fever (not always) and a general feeling of malaise. Symptoms appear after 12- to 48-hours and usually self-limiting, lasting typically for between 12- and 60-hours.

Modes of Transmission

The infection may be transmitted via the following:

  • Food, water or ice contaminated with the virus;
  • Contact with vomitus or faeces from infected persons;
  • Contact with contaminated objects; or
  • By aerosolisation of contaminated droplets of splashed vomitus and sneezing.

Incubation Period

The incubation period is usually from 24- to 48-hours. Food handlers are required to be isolated for a full 48-hours after symptom resolution.


Given adequate fluids to prevent dehydration and supportive treatment, the patient usually recovers within one to three days. Antibiotics are of no value in treatment.


  • Maintain high standards of personal, food and environmental hygiene.
  • Wash hands before handling food and eating; after going to the toilet and before putting anything to the mouth.
  • Use a clean tissue to touch the handles of exit doors from toilet facilities.
  • Cook all food, particularly shellfish, thoroughly before consumption.
  • Crew must refrain from working and seek medical advice if suffering from vomiting or diarrhoea;
  • Guests must be seen by the doctor and remain confined to cabin at least until symptoms desist.
  • Clean up vomitus and diarrhoeal accidents and disinfect the contaminated areas properly and immediately. Keep other people away from the area to prevent inhalation of germs.
  • Ensure that crewmembers attending to incidents wear appropriate personal protective equipment (PPE) including a face mask and gloves when disposing of, or handling vomitus and faecal matter.
  • Wash hands thoroughly directly after handling vomitus or faecal matter.
  • Clean and thoroughly disinfect soiled linens, clothes and environmental surfaces promptly and thoroughly. Wash hands thoroughly afterwards.
  • Note that no vaccine is available for the Norovirus infection.

Guidance in Disinfection of Areas contaminated by Norovirus

  • Keep other people away from contaminated areas.
  • Wear appropriate PPE including gloves and a face mask throughout the disinfection procedure.
  • Use disposable cloths or paper towels to wipe away all the vomitus from outside inward, then apply a <1,000ppm bleach solution (or other chemical disinfectant agent approved by the company) to the contaminated surface and all adjacent areas within 2m / 6ft of the vomit or diarrhoea spill.
  • Allow the bleach to air-dry on the contaminated surfaces to allow it to inactivate viruses.
  • Wash hand thoroughly afterwards.
  • NEVER use mops for cleaning up vomitus or diarrhoea.
  • Do not vacuum floors whilst virus is present as viral particles tend to be aerosolised by vacuuming. Brushing floors and carpets is the preferred method.