cholerae Serogroup O1
is responsible for Asiatic or epidemic cholera Environmental
studies have demonstrated that strains of this organism may
be found in the temperate estuarine and marine coastal areas
surrounding the United States.
1991 cholera was reported for the first time in this century
in South America, starting in Peru. The outbreaks quickly
grew to epidemic proportions and spread to other South American
and Central American countries, and into Mexico. 1,099,882
cases and 10,453 deaths were reported in the Western Hemisphere
between January 1991 and July 1995.
the South American strain of V. cholerae O1 has been isolated
from Gulf Coast waters, presumably transmitted by ships off-loading
contaminated ballast water, no cases of cholera have been
attributed to fish or shellfish harvested from U.S. waters.
However, over 100 cases of cholera caused by the South American
strain have been reported in the United States. These cases
were travelers returning from South America, or were associated
with illegally smuggled, temperature-abused crustaceans from
the Autumn of 1993, a new strain, a non-O1 never before identified,
was implicated in outbreaks of cholera in Bangladesh and India.
The organism, V. cholerae serogroup O139 (Bengal), causes
characteristic severe cholera symptoms. Previous illness with
V. cholerae O1 does not confer immunity and the disease is
now endemic. In the U.S., V. cholerae O139 has been implicated
in one case, a traveller returning from India. The strain
has not been reported in U.S. waters or shellfish
is the name of the infection caused by V. cholerae
of Asiatic cholera may vary from mild, watery diarrhea to
an acute diarrhea, with characteristic rice water stools.
Illness is generally sudden, with incubation varying from
6 hours to 5 days. Abdominal cramps, nausea, vomiting, dehydration,
and shock; after severe fluid and electrolyte loss, death
may occur. Illness is caused when bacteria attach to the small
intestine and produce cholera toxin. The production of this
cholera toxin by the attached bacteria results in the watery
diarrhea associated with this illness.
consumption markedly lowers the infective dose.
is confirmed only by isolation of cholera bacteria from the
diarrheic stools of infected individuals.
is generally spread by poor sanitation, and contaminated water
supplies. This is the main mechanism for its spread in poor
communities in South America.
cases occur when shellfish harvested from fecally polluted
coastal waters are consumed raw.
may also be transmitted by shellfish harvested from nonpolluted
waters since V. cholerae O1 is part of the normal
microbiota of these waters
patients require fluids either intravenously or orally with
a solution containing sodium chloride, sodium bicarbonate,
potassium chloride, and glucose. The illness is generally
self-limiting. Antibiotics shorten the illness. Death occurs
from dehydration and electrolyte loss.
44(20):1995 , MMWR
44(11):1995 , MMWR
42(33):1993 , MMWR
42(26):1993 , MMWR
cholerae Serogroup Non-O1
only humans and primates. It is related to V. cholerae
Serogroup O1, the organism that causes Asiatic or epidemic
cholera, but causes a less severe disease than cholera. Strains
of the organism are normal inhabitants of marine and estuarine
environments of the United States. It has been referred to
as non-cholera vibrio (NCV) and nonagglutinable vibrio (NAG)
in the past.
V. cholerae gastroenteritis is the name associated
with this illness.
rare, septicemic infections have been reported and deaths
have resulted. Some cases are similar to the primary septicemia
caused by V. vulnficus
abdominal cramps, and fever are symptoms associated with this
illness, and vomiting and nausea occurring 25%. Diarrhea occurs
within 48 hours after eating these bacteria. Diarrhea may,
be severe, lasting 6-7 days. Antibiotics shorten the severity
and duration of the illness.
caused by V. cholerae O139 is indistinguishable from cholera
caused by V. cholerae O1
of a V. cholerae non-Ol infection is made by culturing
the organism from an individual's diarrheic stool or from
the blood of patients with septicemia.
harvested from U.S. coastal waters frequently contain V.
cholerae serogroup non-Ol. So eating raw, improperly
cooked or cooked, re-contaminated shellfish may lead to infection.
can occur in individuals with cirrhosis of the liver, or who
42(26):1993 ; MMWR
44(11):1995 ; MMWR
older cholera vaccine was about 50% effective and causes local
reactions such as; fever, flu symptoms, and headache.
A newer cholera vaccine is now available with minimal side
Immunization is felt to be effective in controlling cholera
epidemics but is not recommended for travelers because of
Cholera is characterized by severe diarrhea (early to rapid
dehydration), and if left untreated death occurs within 24
hours. Cholera is transmitted through food or water contaminated
by cat, dog or human faeces.
is also transmitted by direct person-to-person contact.
avoid transmission of cholera drink provided water and consume
well cooked food.
help early on if symptomatic. Rehydration with oral or IV
fluids may be necessary.
Other countries may require proof of vaccination for travelers
arriving from countries where cholera is endemic. Although
the WHO does not suggest that a certification of immunization
be necessary some countries like Uganda occasionally will
insist a letter for arriving travelers.
with each countries Embassy in advance of travel will confirm
any recent changes to requirements.
for Disease Control http://www.cdc.gov/ncidod/dbmd/diseaseinfo/cholera_g.htm
Snow Home Page http://www.ph.ucla.edu/epi/snow.html
is one of the most historically important links on our site
and celebrates the life of a famous epidemiologist and how
he fought against cholera)
World Health Organaization Who http://www.who.int/health_topics/en/