Vibrio cholerae serogroups O1 and O139 cause cholera, an acute bacterial enteric disease characterized by sudden onset of profuse watery diarrhea and vomiting that can lead to rapid dehydration and death if untreated. Cholera is typically diagnosed by isolating V. cholerae O1 or O139 from a patient's stool. While outbreaks are associated with consumption of unsafe water and poor sanitation, the main reservoir of cholera is humans. Transmission occurs through ingestion of food or water contaminated with feces from infected individuals. Preventive measures include access to safe water and proper sanitation.

1. Cholera And Other Vibrios

2. VIBRIO CHOLERAE
(SEROGROUPS O1 AND O139)
Identification
• An acute bacterial enteric disease characterized in its severe form
by sudden onset, profuse painless watery stools (rice-water stool),
nausea and profuse vomiting early in the course of illness. In
untreated cases, rapid dehydration, acidosis, circulatory collapse,
hypoglycaemia in children, and renal failure can rapidly lead to
death.
• In severe dehydrated cases , death may occur within a few hours,
and the case-fatality rate may exceed 50%.
• With proper and timely rehydration, this can be less than 1%.

3. Diagnosis
• is confirmed by isolating Vibrio cholerae of the serogroup O1
or O139 from feces.
• V. cholerae grows well on standard culture media, the most
widely used of which is TCBS agar.

4. • The strains are further characterized by O1 and O139
specific antisera.

5. • If laboratory facilities are not nearby or immediately
available, Cary Blair transport medium can be used
to transport or store a fecal or rectal swab

6. • For epidemiological purposes,
a one-step dipstick test for
rapid detection of V. cholerae
O1 and O139 has been
developed and should soon
be available on the market to
improve application of
effective public health
interventions.

7. • In epidemics, once laboratory confirmation and antibiotic
sensitivity have been established, it becomes unnecessary to
confirm all subsequent cases. Shift should be made to using
primarily the clinical case definition proposed by WHO as
follows:
• Disease unknown in area: severe dehydration or death from acute
watery diarrhea in a patient aged 5 or more
• Endemic cholera: acute watery diarrhea with or without vomiting
in a patient aged 5 or more
• Epidemic cholera: acute watery diarrhea with or without vomiting
in any patient.

8. Infectious agent
• Only Vibrio cholerae serogroups O1 and O139 are associated
with the epidemiological characteristics and clinical picture of
cholera.
• Serogroup O1 occurs as two biotypes– classical and El Tor.
• each of which occurs as 3 serotypes (Inaba, Ogawa and rarely
Hikojima).
• In any single epidemic, one particular serogroup and biotype
tends to be dominant

10. Occurrence
• Cholera is one of the oldest and best understood epidemic
diseases.
• Epidemics and pandemics are strongly linked to the
consumption of unsafe water, poor hygiene, poor sanitation
and crowded living conditions.
• Man-made or natural disasters such as complex emergencies
and floods resulting in population movements as well as
overcrowded refugee camps are conducive to explosive
outbreaks with high case fatality rates.

11. Reservoir
The main reservoir is humans.
Incubation period
From a few hours to 5 days, usually 23 days.

12. Mode of transmission
• Cholera is acquired through ingestion of an infective dose
of contaminated food or water and can be transmitted
through many mechanisms.
• Water usually is contaminated by feces of infected
individuals and can itself contaminate, directly or
through the contamination of food.
• Outbreaks or epidemics as well as sporadic cases are
often attributed to raw or undercooked seafood.

13. Period of communicability
• As long as stools are positive, usually only a
few days after recovery.
• Occasionally the carrier state may persist for
several months.

14. Susceptibility
• Variable; gastric achlorhydria increases the risk of
illness, and breastfed infants are protected.
• Cholera occurs significantly more often among
persons with blood group O.
• Infection with either V. cholerae O1 or O139
results in a rise in agglutinating and antitoxic
antibodies, and increased resistance to
reinfection.

15. VIBRIO CHOLERAE
SEROGROUPS OTHER THAN
O1 AND O139
• Organisms of V. cholerae serogroups other than O1 and O139
have been associated with sporadic cases of foodborne
outbreaks of gastroenteritis, but have not spread in epidemic
form.
• They have been associated with wound infection and also,
rarely, isolated from patients (usually immunocompromised
hosts) with septicemic disease.
• Non-O1/non-O139 V. cholerae strains are associated
• with 2%–3% of cases (including travellers) of diarrheal illness
in tropical developing countries.

16. VIBRIO PARAHAEMOLYTICUS
ENTERITIS
• An intestinal disorder characterized by watery
diarrhoea and abdominal cramps in nearly all cases,
usually with nausea, vomiting, fever and headache.
• About one quarter of patients experience a dysentery-
like illness with bloody or mucoid stools, high fever and
high WBC count.
• Typically, it is a disease of moderate severity lasting 1–
7 days; systemic infection and death rarely occur.

17. • Diagnosis is confirmed by isolating Vibrio parahaemolyticus
from the patient’s stool on appropriate media (typically TCBS
media).
• or identifying 105 or more organisms per gram of an
epidemiologically incriminated food (usually seafood).

18. Methods of control
Preventive measures
• Traditional injectable cholera vaccines based on
killed whole cell microorganisms provide only partial
protection (50% efficacy) of short duration (3–6
months) they do not prevent asymptomatic infection
and are associated with adverse effects. Their use
has never been recommended by WHO.

19. Control of patient, contacts and the
immediate environment
• Isolation: Hospitalization with enteric precautions is desirable
for severely ill patients; strict isolation is not necessary.Less
severe cases can be managed on an outpatient basis with oral
rehydration and an appropriate antimicrobial agent to prevent
spread.
• Concurrent disinfection: Of feces and vomit and of linens and
articles used by patients, using heat and disinfectant.
• Management of contacts: Surveillance of persons who shared
food and drink with a cholera patient for 5 days from last
exposure

20. Epidemic measures
• Adopt emergency measures to ensure a safe water
supply. Chlorinate public water supplies, even if the
source water appears to be uncontaminated.
• Initiate a thorough investigation designed to find the
vehicle of infection and circumstances (time, place,
person) of transmission, and plan control measures
accordingly.
• Provide appropriate safe facilities for sewage disposal.