What is Vibrio
What type of illness
is caused by V. parahaemolyticus?
How does infection with V.
How common is V. parahaemolyticus
How is V. parahaemolyticus diagnosed?
How is V. parahaemolyticus
How do oysters get
contaminated with V. parahaemolyticus?
How is V. parahaemolyticus
How can I find out more
about V. parahaemolyticus?
is Vibrio parahaemolyticus?
Vibrio parahaemolyticus is a bacterium
in the same family as those that cause cholera. It lives in
brackish saltwater and causes gastrointestinal illness in humans.
V. parahaemolyticus naturally inhabits coastal waters
in the United States and Canada and is present in higher concentrations
during summer; it is a halophilic, or salt-requiring organism.
type of illness is caused by V. parahaemolyticus?
When ingested, V. parahaemolyticus causes
watery diarrhea often with abdominal cramping, nausea, vomiting
fever and chills. Usually these symptoms occur within 24 hours
of ingestion. Illness is usually self-limited and lasts 3 days.
Severe disease is rare and occurs more commonly in persons with
weakened immune systems. V. parahaemolyticus can also
cause an infection of the skin when an open wound is exposed
to warm seawater.
does infection with V. parahaemolyticus occur?
Most people become infected by eating raw or undercooked
shellfish, particularly oysters. Less commonly, this organism
can cause an infection in the skin when an open wound is exposed
to warm seawater.
common is infection with V. parahaemolyticus?
In Asia, V. parahaemolyticus is a common
cause of foodborne disease. In the United States, it is less
commonly recognized as a cause of illness, partly because clinical
laboratories rarely use the selective medium that is necessary
to identify this organism. Not all states require that V.
parahemolyticus infections be reported to the state health
department, but CDC collaborates with the Gulf Coast states
of Alabama, Florida, Louisiana, and Texas to monitor the number
of cases of Vibrio infection in this region. From those states,
about 30-40 cases of V. parahaemolyticus infections are
reported each year. The Foodborne Diseases Active Surveillance
Network, Food Net, also tracks V. parahaemolyticus in
regions outside the Gulf Coast. In 1997, the incidence of diagnosed
V. parahaemolyticus infection in Food Net sites was .25/100,000.
is V. parahaemolyticus infection diagnosed?
Vibrio organisms can be isolated from cultures
of stool, wound, or blood. For isolation from stool, use of
a selective medium that has thiosulfate, citrate, bile salts,
and sucrose (TCBS agar) is recommended. If there is clinical
suspicion for infection with this organism, the microbiology
laboratory should be notified so that they will perform cultures
using this medium. A physician should suspect V. parahaemolyticus
infection if a patient has watery diarrhea and has eaten raw
or undercooked seafood, especially oysters, or when a wound
infection occurs after exposure to seawater.
is V. parahaemolyticus treated?
Treatment is not necessary in most cases of V.
parahaemolyticus infection. There is no evidence that antibiotic
treatment decreases the severity or the length of the illness.
Patients should drink plenty of liquids to replace fluids lost
through diarrhea. In severe or prolonged illnesses, antibiotics
such as tetracycline, ampicillin or ciprofloxicin can be used.
The choice of antibiotics should be based on antimicrobial susceptibilities
of the organism.
do oysters get contaminated with V. parahaemolyticus?
Vibrio is a naturally occurring organism commonly
found in waters where oysters are cultivated. When the appropriate
conditions occur with regard to salt content and temperature,
V. parahaemolyticus thrives.
is V. parahaemolyticus infection prevented?
Most infections caused by V. parahaemolyticus
in the United States can be prevented by thoroughly cooking
seafood, especially oysters. Wound infections can be prevented
by avoiding exposure of open wounds to warm seawater. When an
outbreak is traced to an oyster bed, health officials recommend
closing the oyster bed until conditions are less favorable for
can I learn more about Vibrio parahaemolyticus?
You can discuss your medical concerns with your
doctor or other health care provider. Your local health department
can provide information about this and other public health problems.
Information about problems associated with raw seafood consumption
can be obtained from the FDAs Center for Food Safety and
Applied Nutrition (telephone 1-800-332-4010). At this number
recorded information is available on many subjects including
seafood consumption and handling. A public affairs specialist
is available 12:00 p.m.-4:00 p.m. Eastern Standard Time. Seafood
safety information is also available on the world wide web at
There is more information about other Vibrio infections, such
as Vibrio vulnificus at http://www.cdc.gov/ncidod/dbmd/diseaseinfo/vibriovulnificus_g.htm.