What is norovirus?

Gastrointestinal illnesses, such as norovirus, are defined by irritation of the mucous membrane of the intestinal tract. Common symptoms of gastrointestinal illness include:

  • Acute diarrhea
  • Nausea
  • Vomiting
  • Abdominal pain

The most common viral causes are Norwalk-like viruses (Norovirus), of which there are several different strains. These viruses commonly occur during the winter months in New England.

  • Among adults, these viruses account for 40-80% of gastroenteritis outbreaks, and they are more common during the winter months
  • Immunity to these organisms is poorly understood and appears to be short-lived
  • Transmission is via the fecal-oral route (from inadequate hand washing after bathroom use) and direct person-to-person contact, as well as through contaminated food or water
  • A very small amount of virus can cause illness — aerosolized particles of virus (small particles dispersed into the air) from vomitus can infect others, so it is important to take care when assisting those who are ill or when helping to clean up vomitus
  • Shared common surfaces can easily become contaminated leading to the infection of others — those living in communal settings (dorms) or sharing confined environments (cruise ships) have an increased risk
  • The incubation period is usually 16 to 72 hours
  • Confirmatory diagnosis requires stool cultures obtained during the first 48 hours of acute illness and the organism may be hard to identify in the lab
  • There is no specific therapy available for these viral agents — gastroenteritis is considered a self-limiting condition (usually lasting 24 to 48 hours) and treatment is supportive care with fluid replacement and symptomatic relief

How do you prevent the spread of Norovirus?

Prevention is centered on good hygiene practices, which include:

  • Washing hands frequently with soap and water — alcohol-based products can be used in addition, but not as a substitute, because this virus is not as susceptible to alcohol-based products
  • Not sharing eating utensils, glasses, water bottles, etc. with others
  • Taking precautions when assisting someone who is ill or has vomited, and if at all possible, avoiding any contact with vomitus