Viral
Gastroenteritis
Article provided by the National Digestive Diseases
Information Clearinghouse
On this page:
Symptoms of Viral Gastroenteritis
Causes of Viral Gastroenteritis
Transmission of Viral Gastroenteritis
Diagnosis of Viral Gastroenteritis
Treatment of Viral Gastroenteritis
Prevention of Viral Gastroenteritis
Hope Through Research
Points to Remember
For More Information on Viral Gastroenteritis
Viral gastroenteritis is an intestinal infection caused by
several viruses. Viral gastroenteritis is highly contagious
and causes millions of cases of diarrhea each year.
Anyone can get viral gastroenteritis and most people recover
without any complications. However, viral gastroenteritis
can be serious for people who cannot drink enough fluids to
replace what is lost through vomiting and diarrhea,
especially infants, young children, the elderly, and people
with weak immune systems. Complications from vomiting also
can occur, even in healthy people.
Symptoms of Viral
Gastroenteritis
The main symptoms of viral gastroenteritis are watery
diarrhea and vomiting. Other symptoms are headache, fever,
chills, and abdominal pain. The symptoms may appear within
hours or a few days of infection. They usually last for 1 to
2 days, but may last as long as 10 days.
Causes of Viral Gastroenteritis
The viruses that cause viral gastroenteritis damage the
cells in the lining of the small intestine. As a result,
fluids leak from the cells into the intestine and produce
watery diarrhea. Four types of viruses cause most viral
gastroenteritis. Rotavirus is the leading cause of gastroenteritis among children
3 to 15 months old. Most children have been exposed to the virus
by age 2. Children with rotavirus have vomiting and watery
diarrhea for 3 to 8 days, along with fever and abdominal pain.
- Rotavirus can also infect adults who are in close contact with
infected children, but the symptoms in adults are milder.
Symptoms of rotavirus infection appear 1 to 2 days after
exposure. In the United States, rotavirus infections are most
common from November to April.
- Adenovirus serotypes 40 and 41 cause gastroenteritis mainly in
children younger than 2 years old. Infections occur all year
round; vomiting and diarrhea appear approximately 1 week after
exposure.
- Caliciviruses cause infection in persons of all ages. This
family of viruses is further divided into the noroviruses
(example, Norwalk virus) and the sapoviruses (example, Sapporo
virus). Caliciviruses are transmitted from person to person and
also through contaminated water or food--especially oysters from
contaminated waters. The noroviruses are often responsible for
epidemics of viral gastroenteritis. In addition to vomiting and
diarrhea, people infected with caliciviruses may have muscle
aches. The symptoms appear within 1 to 3 days of exposure.
- Astrovirus also infects primarily infants, young children, and
the elderly. This virus is most active during the winter months.
Vomiting and diarrhea appear within 1 to 3 days of exposure.
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Viral gastroenteritis is often mistakenly called "stomach flu,"
but it is not caused by the influenza virus and it does not
infect the stomach. Also, viral gastroenteritis is not caused by
bacteria or parasites. For information about bacterial
infections, please see the Bacteria and Foodborne Illness fact
sheet from the National Institute of Diabetes and Digestive and
Kidney Diseases (NIDDK).
Transmission of Viral Gastroenteritis
Viral gastroenteritis is highly contagious. The viruses are
often transmitted on unwashed hands. People can get the viruses
through close contact with infected individuals, such as sharing
their food, drink, or eating utensils, or by eating food or
drinking beverages that are contaminated with the virus. People
who no longer have symptoms may still be contagious, since the
virus can be found in the stool for up to 2 weeks after they
recover from their illness. Also, people can become infected
without having symptoms, and they can still spread the
infection.
Outbreaks of viral gastroenteritis can occur in child care
settings, schools, nursing homes, cruise ships, camps,
dormitories, restaurants, and other places where people gather
in groups. If you suspect that you were exposed to a virus in
one of these settings, you may want to contact your local health
department, which tracks outbreaks.
Diagnosis of Viral Gastroenteritis
If you think you have viral gastroenteritis, you may want to see
your doctor, although many people don't bother. Doctors
generally diagnose viral gastroenteritis based on the symptoms
and a physical examination. Your doctor may ask for a stool
sample to test for rotavirus or to rule out bacteria or
parasites as the cause of your symptoms. No routine tests are
currently available for the other types of viruses.
Treatment of Viral Gastroenteritis
Most cases of viral gastroenteritis resolve over time without
specific treatment. Antibiotics are not effective against viral
infections. The primary goal of treatment is to reduce the
symptoms, and prompt treatment may be needed to prevent
dehydration.
Your body needs fluids to function. Dehydration is the loss of
fluids from the body. Important salts or minerals, known as
electrolytes, can also be lost with the fluids. Dehydration can
be caused by diarrhea, vomiting, excessive urination, or
excessive sweating, or by not drinking enough fluids because of
nausea, difficulty swallowing, or loss of appetite.
In viral gastroenteritis, the combination of diarrhea and
vomiting can cause dehydration. The symptoms of dehydration are
-
dry mouth
- little or no urine or dark yellow urine
- decreased tears
- severe weakness or lethargy
- dizziness or lightheadedness
If you notice any of these symptoms, you should talk to your
doctor. Mild dehydration can be treated by drinking liquids.
Severe dehydration may require intravenous fluids and
hospitalization. Untreated severe dehydration can be life
threatening.
Children present special concerns. Because of their smaller body
size, infants and children are at greater risk of dehydration
from diarrhea and vomiting. Oral rehydration solutions such as
Pedialyte can replace lost fluids, minerals, and salts.
You can take several steps to help relieve the symptoms of viral
gastroenteritis.
Allow your gastrointestinal tract to settle by not eating for a
few hours.
Sip small amounts of clear liquids or suck on ice chips if
vomiting is still a problem.
Give infants and children oral rehydration solutions to replace
fluids and lost electrolytes.
Gradually reintroduce food, starting with bland, easy-to-digest
food, like toast, broth, apples, bananas, and rice.
Avoid dairy products, caffeine, and alcohol until recovery is
complete.
Get plenty of rest.
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Prevention of Viral Gastroenteritis
Prevention is the only way to avoid viral gastroenteritis. There
is no vaccine available. You can avoid it by
washing your hands thoroughly after using the bathroom or
changing diapers
washing your hands thoroughly before eating
disinfecting contaminated surfaces
not eating or drinking foods or liquids that might be
contaminated
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Hope Through Research
NIDDK's Division of Digestive Diseases and Nutrition supports
basic and clinical research into gastrointestinal diseases,
including epithelial cell injury in the gastrointestinal tract.
New vaccines under development may decrease the risk of
infection, especially among infants and young children.
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Points to Remember about Viral Gastroenteritis
Viral gastroenteritis is a highly contagious infection of the
intestines caused by one of several viruses.
Although it is sometimes called "stomach flu," viral
gastroenteritis is not caused by the influenza virus and does
not affect the stomach.
The main symptoms are watery diarrhea and vomiting.
Anyone can get viral gastroenteritis through unwashed hands,
close contact with an infected person, or food and beverages
that contain the virus.
Diagnosis is based on the symptoms and a physical examination.
Currently only rotavirus can be rapidly detected in a stool
test.
Viral gastroenteritis has no specific treatment; antibiotics are
not effective against viruses. Treatment focuses on reducing the
symptoms and preventing dehydration.
The symptoms of dehydration are excessive thirst, dry mouth,
dark yellow urine or little or no urine, decreased tears, severe
weakness or lethargy, and dizziness or lightheadedness.
Infants, young children, the elderly, and people with weak
immune systems have a higher risk of developing dehydration due
to vomiting and diarrhea.
People with viral gastroenteritis should rest, drink clear
liquids, and eat easy-to-digest foods.
For infants and young children, oral rehydration solutions can
replace lost fluids, minerals, and salts.
Avoid viral gastroenteritis by washing hands thoroughly after
using the bathroom or changing diapers, disinfecting
contaminated surfaces, and avoiding foods or liquids that might
be contaminated.
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For More Information
Centers for Disease Control and Prevention
1600 Clifton Road
Atlanta, GA 30333
Phone: 1-800-311-3435 or (404) 639-3534
Internet: www.cdc.gov
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