Immunity to Norwalk and Noroviruses is strain-specific and
temporary, so everyone should take precautions to prevent
the spread of Norwalk virus to others.
Frequent hand washing with soap and running water is important,
especially after using the washroom and before handling food.
Prompt disinfecting of contaminated surfaces and soiled clothing
will also help prevent the spread of the disease. Regular
household bleach based cleaners are effective.
Thorough cooking destroys Norwalk virus, so make sure the
food you eat is cooked completely. Remember that the virus
can survive for 30 minutes at 60°C. When preparing food,
do not cross-contaminate. If you suspect that the water supply
is polluted while travelling, choose to drink pasteurized
milk or bottled beverages without ice.
There is currently no vaccine available for prevention of
Norovirus infection. Factors that make creation of a Norwalk
vaccine difficult include:
- Noroviruses are currently non-cultivatable in
any tissue culture or animal system.
- There are multiple genetic and antigenic types
- Immunity to Noroviruses are short-term
and strain-specific. Re-infection can occur.
Food handlers with symptoms of Norwalk and Norovirus-related
illness should be excluded from food handling and preparation.
Programs that educate and train food handlers and people who
work in places where there is a high risk of Norwalk virus
outbreaks will help to prevent disease and transmission. Regulation
and enforcement of proper disposal of human sewage will help
prevent outbreaks caused by contamination of shellfish, etc
Prevention of outbreaks in institutions depends on good food
handling practices, and compliance with hand washing on the
part of staff. Hand hygiene procedures should be reviewed
by all staff members. Common touch surfaces (door handles,
handrails, sink/toilet handles) should be disinfected.
Health care precautions for staff dealing with Norwalk patients
include wearing gloves and gowns to protect them from contact
transmission. Use of a mask is advised if there is potential
for airborne transmission involving areas where gross contamination
with feces and/or vomit has occurred. Since Norwalk virus
can still be shed in feces up to 48 hours after symptoms disappear,
ill patients must remain in their rooms until 48 hours after
symptoms have disappeared. Ill staff members must be excluded
from work, and should not return within 48 hours after symptoms
of Norwalk have stopped.
Movement of patients and staff within the institution should
be restricted. Patient transfers into and out of areas with
Norovirus should be avoided. Use of part-time and casual staff
who work in other areas or institutions should also be avoided.
Nurses and other staff who do work in areas with Norovirus
should be grouped to work exclusively in those areas. Group
activities should be decreased or discontinued until the outbreak
Hospitals and nursing homes should also maintain surveillance
for clusters of gastroenteritis, so that more stringent precautions
may be taken if there is evidence of transmission within the
facility. Visitors and personnel should be informed of how
Norwalk is spread and the personal precautions they can take.