Norovirus a Threat to Elderly, Infants

Published by Contra Costa Times

Posted on Wed, Feb. 07, 2007

By Susan Farley, RN, PHN

A family recently called the Public Health Department to complain about food poisoning they thought they had gotten from a restaurant. They turned out to have a norovirus infection, an intestinal virus that causes nausea, vomiting and diarrhea.

Norovirus is highly contagious. Outbreaks tend to increase in the winter and spring, and occur in nursing homes, cruise ships and catered events where groups of people have close contact.

Contra Costa and other Bay Area counties currently are experiencing outbreaks of norovirus.

Though the symptoms can be severe and extremely unpleasant, the illness isn't usually serious for a person who is healthy overall. However, norovirus can be very serious for the frail elderly and very young because these groups are more at risk for severe dehydration.

The following information may help you protect yourself and your loved ones from norovirus.

What is norovirus?

Norovirus is a highly contagious stomach virus that was originally identified in an outbreak in a school in Norwalk, Ohio, in 1968.

Though sometimes referred to as the stomach flu, norovirus is not an influenza virus, which causes a respiratory illness. Norovirus also isn't usually spread by food itself, though infected food handlers can infect others by contaminating food.

What are the symptoms of norovirus?

The sudden onset of nausea, vomiting and/or diarrhea, headache, chills and less commonly fever. Symptoms usually start one to two days after exposure and last one to three days in most healthy people, though some will feel weak for several days.

A lab test can confirm an outbreak, but it is not used for individual cases.

How is norovirus treated?

The best treatment is rest and fluid replacement. In most cases, sports drinks such as Gatorade are sufficient. Those who become quite ill, including the frail elderly and very young will need to be monitored closely, and may need intravenous fluids.

How is norovirus spread?

Nororvirus is spread through vomit and stool. It takes only a small amount of the microscopic viral particles to make someone sick, which usually happens after a person gets the particles on their hands and then puts their hands in their mouth, ingesting the virus.

Vomiting causes the virus to be spread through the air, contaminating people and surfaces.

Norovirus can survive for days on surfaces and can remain in a person's stool for a week after symptoms are gone.

Infected people also can spread the virus before they get symptoms and even if they never get sick.

People who prepare and handle food can spread the illness if infected, especially if they don't wash their hands regularly after using the restroom or don't wear gloves when handling food.

How is norovirus prevented?

You can help protect yourself and your family by avoiding contact with anyone who is ill. If you do have contact with a person who is ill, then make sure to wash your hands frequently, especially before eating.

Clean and disinfect soiled surfaces as soon as possible, including bathrooms and door handles. Change clothes if soiled by vomit.

An infected person will develop a temporary immunity to norovirus but after six months can get sick again if exposed to the virus.

For information on norovirus, visit the Center for Disease Control and Prevention Web site.

Farley is the public health nurse program manager for Contra Costa Public Health's communicable diseases programs.