Gastroenteritis means inflammation of the stomach
and small and large intestines. Viral gastroenteritis is
an infection caused by a variety of viruses and
results in vomiting or diarrhea.
It is often called the "stomach flu," although it is not caused by the
What causes viral gastroenteritis?
Many different viruses can cause gastroenteritis,
A group of Noroviruses
Although the symptoms may be similar viral gastroenteritis is not caused by:
Bacteria (such as Salmonella or Escherichia coli)
Parasites (such as Giardia)
Other medical conditions
Your doctor can determine if the
diarrhea is caused by a virus or by something else.
What are the symptoms of viral
The main symptoms of viral gastroenteritis are:
The affected person
may also have:
cramps ("stomach ache")
In general, the symptoms
begin 1 to 2 days following infection with a virus
that causes gastroenteritis and may last for 1 to 10 days, depending on which virus causes the illness.
Is viral gastroenteritis a serious illness?
For most people, it is not. People who get viral
gastroenteritis almost always recover completely
without any long-term problems.
Gastroenteritis is a serious illness, however, for people who are unable
to drink enough fluids to replace what they lose
through vomiting or diarrhea.
Those at risk for dehydration from loss of fluids include:
The disabled or elderly
compromised people are at risk for dehydration
because they may get a more serious illness, with
greater vomiting or diarrhea. They may need to be
hospitalized for treatment to correct or prevent
Is the illness contagious? How are these
Yes, viral gastroenteritis is contagious.
that cause gastroenteritis are spread through close
contact with infected people (for example, by sharing food, water, or eating utensils). Individuals
may also become infected by eating or drinking
contaminated foods or beverages.
How does food get contaminated by
Food may be contaminated by food preparers or
handlers who have viral gastroenteritis, especially if
they do not wash their hands regularly after using the bathroom.
Shellfish may be contaminated by
sewage, and people who eat raw or undercooked
shellfish harvested from contaminated waters may get diarrhea.
Drinking water can also be
contaminated by sewage and be a source of spread
of these viruses.
Where and when does viral gastroenteritis
Viral gastroenteritis affects people in all parts of the
world. Each virus has its own seasonal activity.
example, in the United States, rotavirus and astrovirus infections occur during the cooler months
of the year (October to April), whereas adenovirus
infections occur throughout the year.
Viral gastroenteritis outbreaks can occur in institutional
settings, such as:
Child care facilities
Viral gastroenteritis can also occur in other group settings, such as:
Who gets viral gastroenteritis?
Anyone can get it. Viral gastroenteritis occurs in
people of all ages and backgrounds. However, some
viruses tend to cause diarrheal disease primarily
among people in specific age groups.
infection is the most common cause of diarrhea in
infants and young children under 5 years old.
Adenoviruses and astroviruses cause diarrhea
mostly in young children, but older children and
adults can also be affected.
Noroviruses are more likely to cause diarrhea in
older children and adults.
How is viral gastroenteritis diagnosed?
Generally, viral gastroenteritis is diagnosed by a
doctor on the basis of the symptoms and medical
examination of the patient.
Rotavirus infection can
be diagnosed by laboratory testing of a stool
specimen. Tests to detect other viruses that cause
gastroenteritis are not in routine use.
How is viral gastroenteritis treated?
The most important part of treating viral gastroenteritis
in children and adults is to prevent severe loss of
fluids (dehydration). This treatment should begin at home. Your doctor may give you specific
instructions about what kinds of fluid to give.
recommends that families with infants and young
children keep a supply of oral rehydration solution
(ORS) at home at all times and use the solution when
diarrhea first occurs in the child. ORS is available at pharmacies without a prescription. Follow the
written directions on the ORS package, and use clean
or boiled water.
Medications, including antibiotics (which have no effect on viruses) and other
treatments, should be avoided unless specifically
recommended by a doctor.
Can viral gastroenteritis be prevented?
Yes. People can reduce their chance of getting
Frequent hand washing
disinfection of contaminated surfaces with
household chlorine bleach-based cleaners
Prompt washing of soiled articles of clothing
or water that is thought to be contaminated
Is there a vaccine for viral gastroenteritis?
There is no vaccine or medicine currently available
that prevents viral gastroenteritis. A vaccine is being
developed, however, that protects against severe
diarrhea from rotavirus infection in infants and