What are noroviruses?
Norovirus is a virus that causes the "stomach flu," or vomiting and diarrhea,
What are the symptoms of illness caused by noroviruses?
Norovirus illness usually begins 12-48 hours after exposure, but can appear as early as 10 hours after exposure. Symptoms usually include nausea, vomiting, diarrhea, and stomach cramping. Sometimes people have a low-grade fever, chills, headache, muscle aches, and a general sense of tiredness. The illness is usually brief, with symptoms lasting only 1 or 3 days.
How serious is norovirus disease?
Norovirus disease is usually not serious, but people may feel very sick. Most
people get better within 1 or 3 days, and have no long-term health effects from
the illness. Sometimes people are unable to drink enough liquids to replace
what they lose from vomiting and diarrhea, and they can become dehydrated and
need to see a doctor. This problem usually occurs only among the very young,
the elderly, and persons with weakened immune systems.
How is norovirus spread?
Noroviruses are very contagious and spread easily from person to person. The
virus is found in the stool and vomit of infected people. People can become
infected in several ways, including eating food or drinking liquids that are
contaminated by infected food handlers, touching surfaces or objects contaminated
with norovirus and then touching their mouth before handwashing, or having direct
contact with another person who is infected and then touching their mouth before
handwashing. Outbreaks also have occurred from eating undercooked oysters harvested
from contaminated waters - cooking kills the virus. Drinking water contaminated
by sewage can also be a source of these viruses. Persons working in day-care
centers or nursing homes should pay special attention to children or residents
who have norovirus illness. This virus can spread quickly in these places.
How long are people contagious?
People infected with norovirus are contagious from the moment they begin feeling ill and for up to a month after recovery. Therefore, good handwashing is important. Persons infected with norovirus should not prepare food while they have symptoms and for at least two days after they recover. Infected people do not become long-term carriers of norovirus.
Who gets norovirus infection?
Anyone can become infected with these viruses. Because there are many different
strains of norovirus, norovirus infection and illness can re-occur throughout
a person's lifetime.
What treatment is available for people with norovirus infection?
Currently, there is no specific medication or vaccine for norovirus. Norovirus
infection cannot be treated with antibiotics. By drinking fluids, such as juice
or water, people can reduce their chance of becoming dehydrated. Sports drinks
do not replace the nutrients and minerals lost during this illness.
Do infected people need to be excluded from school, work or daycare?
Since the virus is passed in vomit and stool, children should not go to daycare or school while they have diarrhea or vomiting and for 24 hours once illness ends. When children return to daycare handwashing must be strictly monitored. Persons who work in nursing homes, take care of patients, or handle food should stay out of work while they are sick and for at least two days after symptoms end.
Can norovirus infections be prevented?
You can decrease your chance of coming in contact with noroviruses by: