Cholera is an infection of the intestines caused by the bacterium Vibrio cholerae that causes severe watery diarrhea and dehydration. It spreads primarily through contaminated water supplies but can also be transmitted through foods like raw seafood, fruits, and vegetables. Cholera bacteria live naturally in coastal waters and attach to crustaceans, spreading globally through their movements and growth of algae fueled by sewage runoff. Preventing cholera involves excluding infected individuals until symptoms cease, thorough hand washing, and isolating severely ill patients.

2. Cholera
• Cholera is an infection
of the intestines by
the bacterium Vibrio
cholerae. Symptoms
may range from none,
to mild, to severe. The
classic symptom is
large amounts of
watery diarrhea that
lasts a few days.

3. Signs and Symptoms
• Profuse diarrhea sometimes called “rice water
stools”
• Abdominal pain
• Vomiting
• Leg cramps
• Sunken eyes
• low blood pressure
A person with severe dehydration due
to cholera. Note the sunken eyes and
decreased skin turgor which produces
wrinkled hands and skin

4. Causes of Cholera
• Contaminated water supplies are the main source of cholera
infection, although raw shellfish, uncooked fruits and vegetables,
and other foods also can harbor V. cholerae.
• Cholera bacteria have two distinct life cycles
– One in the environment
– One in humans.

5. Cholera bacteria in the environment
• Cholera bacteria occur
naturally in coastal waters,
where they attach to tiny
crustaceans called
copepods. The cholera
bacteria travel with their
hosts, spreading worldwide
as the crustaceans follow
their food source. Algae
growth is further fueled by
the urea found in sewage
and in agricultural runoff.

6. Cholera bacteria in people
• Surface or well water. Cholera bacteria can lie dormant in water for long
periods, and contaminated public wells are frequent sources of large-scale
cholera outbreaks. People living in crowded conditions without adequate
sanitation are especially at risk of cholera.
• Seafood. Eating raw or undercooked seafood, especially shellfish, that
originates from certain locations can expose you to cholera bacteria. Most
recent cases of cholera occurring in the United States have been traced to
seafood from the Gulf of Mexico.
• Raw fruits and vegetables. Raw, unpeeled fruits and vegetables are a
frequent source of cholera infection in areas where cholera is endemic. In
developing nations, uncomposted manure fertilizers or irrigation water
containing raw sewage can contaminate produce in the field.
• Grains. In regions where cholera is widespread, grains such as rice and
millet that are contaminated after cooking and allowed to remain at room
temperature for several hours become a medium for the growth of
cholera bacteria.

7. Prevention
• Exclude people with cholera
from childcare, preschool,
school and work until there
has been no diarrhoea for 24
hours. If working as a food
handler in a food business,
the exclusion period should
be until there has been no
vomiting for 48 hours.
• Follow good hand
washing procedures.
• Severely ill patients should
be isolated in hospital.