Cholera is an acute, highly transmissible intestinal infection caused by Vibrio cholerae bacteria. It is characterized by sudden onset of severe watery diarrhea that can lead to rapid dehydration and death if untreated. It is most commonly transmitted through contaminated drinking water or food. In 2020, over 300,000 cases and 800 deaths from cholera were reported globally. Control measures focus on access to clean water and sanitation, handwashing, food and household hygiene, oral cholera vaccination, and oral rehydration therapy for treatment. Surveillance of cases is also important for outbreak response.

1. CHOLERA AND ITS CONTROOL
MEASURES
Gowtham selvaraj - 403

2. INTRODUCTION
WHAT IS CHOLERA ?
Cholera is an acute, highly transmissible, intestinal infection
caused by toxigenic bacteria Vibrio cholerae O1 and O139.
In its severe form, cholera is characterized by a sudden
onset of acute voluminous watery diarrhoea that can
rapidly lead to dehydration and death if left untreated.
Vibrio cholerae is a gram-negative, curved rod-
shaped, motile, non-invasive bacterium.
It produces a toxin which is responsible for the
voluminous diarrhoea characteristic of the illness.

3. Cholera is most commonly acquired from drinking
water in which Vibrio cholerae is found naturally or
that has been contaminated by the faeces of an
infected individual.
Transmission may also occur by eating food that has
come into contact with human faeces.
Food may be contaminated when prepared with
contaminated water or kitchen utensils, or mixed
with other contaminated food, or handled by
infected persons in unhygienic conditions.
Low temperatures favour the survival of Vibrio
cholerae in food.
Foods including cold rice, raw vegetables, ice cream
and fruits, have been implicated in cholera
outbreaks.
MODES OF TRANSMISSION

4. Usually 24-72 hours (range 2 hours - 5 days)
but is dependent on the dose ingested
Incubation period:

5. EPIDEMIOLOGY, RISK FACTORS, AND DISEASE BURDEN
Cholera can be endemic or epidemic, with a cholera-endemic area containing confirmed cases
within the last three years.
Outbreaks can occur in both endemic and non-endemic countries, with endemic countries
experiencing a greater than expected number of cases.
In non-endemic countries, outbreaks are defined by at least one confirmed case with local
transmission in an area not usually prone to cholera.
Cholera transmission is linked to inadequate access to clean water and sanitation facilities
particularly in peri-urban slums and camps for internally displaced persons or refugees.
Humanitarian crises can increase the risk of cholera transmission.
The number of cholera cases reported to WHO has been high, with 323,369 cases and 857 deaths
in 2020.

6. CHOLERA CONTROOL MEASURES
1) Hand hygiene
Faecal-oral transmission of Vibrio cholerae
may be prevented by hand washing with
soap and clean water , at "critical times".

7. The risk of transmission is
associated with food that is
contaminated during handling or
with eating raw (or insufficiently
cooked) fish products
contaminated in the environment.
The risk of transmission through
food can be reduced by ensuring
that: food is well cooked, eaten hot,
stored covered; fruit and vegetables
are washed in potable water or
peeled (by oneself just before
eating); the area where food is
prepared and the utensils used are
cleaned and dried.
2)Food hygiene 3)Household hygiene
Cleaning potentially soiled surfaces and
materials (water storage receptacles, areas where
food is prepared and served, latrines/toilets) with
local dish detergent prevents transmission.
Soiled clothes, linens and other articles can be
washed with local laundry detergent and then
left to dry in the sun b . Items that cannot be
washed (e.g. soiled unprotected mattresses) may
be disinfected by drying in the sun.
If floors or surfaces are soiled by patient faeces or
vomit, faeces or vomit should first be wiped away
and disposed of in the latrines or buried. Then,
the area should be cleaned with local household
detergent c .

8. Stop cholera with clean water and hygiene practice

9. SANITATION ACTIVITIES
Safe excreta disposal
1.
These provide a very short term (first few days) solution that can be set up in hot dry climates if
there is enough space available and the population accepts them.
Trench latrines require less space and contain the faecal matter better (the stools are covered by
soil located alongside the trench).
This option can only be considered if the following is organised: distribution of bags specifically
designed for this purpose (biodegradable, single use, adapted size); information campaign on how
to use them correctly; effective and safe collection, transport and disposal of bags by burial in an
appropriate place.
Defecation fields
Trench latrines
Defecation in plastic bags

10. Domestic waste water contaminated with
human faeces may get in direct contact with
potable water and lead to point source
outbreaks.
Such water systems often work intermittently,
allowing waste water flowing into the system
via broken pipes at times of low pressure in
the system.
It is imperative to determine the source of the
contamination in order to remedy it (e.g.
repair pipes) and disinfect the potable water
networks polluted by the leaks.
2)Waste water disposal
A) Prevention of cross contamination
Stagnant, undrained waste water is a
permanent source of environmental
contamination. Water pooling often
happens in low lands or along coastal
areas where waste water naturally
collects and is difficult to evacuate.
In urban areas, water pooling is often
aggravated by discharge of domestic
waste water by households, absent or
obstructed drainages and, during rainy
season, a raise in standing water levels.
B) Water drainage

11. Cholera surveillance should be integrated into a global disease surveillance system, involving
local feedback and global information sharing.
Cases are detected based on clinical suspicion in severe acute watery diarrhea, confirmed by
identifying V. cholerae in stool samples.
Rapid diagnostic tests (RDTs) facilitate detection, and samples are sent for confirmation.
Local capacity to detect and monitor cholera occurrence is crucial for effective surveillance
and control measures.
Countries affected by cholera should strengthen disease surveillance and national
preparedness to respond to outbreaks.
SURVEILLANCE

13. TREATMENT
Cholera is an easily treatable disease.
The majority of people can be treated successfully through prompt administration of oral
rehydration solution (ORS). The WHO/UNICEF ORS standard sachet is dissolved in 1 litre (L) of clean
water.
Adult patients may require up to 6 L of ORS to treat moderate dehydration on the first day.
Severely dehydrated patients are at risk of shock and require the rapid administration of intravenous
fluids.
These patients are also given appropriate antibiotics to diminish the duration of diarrhoea, reduce the
volume of rehydration fluids needed, and shorten the amount and duration of V. cholerae excretion in
their stool.

14. oral cholera vaccines
Currently there are three WHO pre-qualified oral cholera vaccines (OCV)
Dukoral® is administered with a
buffer solution that, for adults,
requires 150 ml of clean water.
Dukoral can be given to all
individuals over the age of 2 years.
There must be a minimum of 7
days, and no more than 6 weeks,
delay between each dose.
Children aged 2 -5 require a third
dose. Dukoral® is mainly used for
travellers.
Two doses of Dukoral® provide
protection against cholera for 2
years.
Shanchol™ and Euvichol-Plus® have the
same vaccine formula, produced by two
different manufacturers.
They do not require a buffer solution for
administration.
They are given to all individuals over the
age of one year.
There must be a minimum of two weeks
delay between each dose of these two
vaccines.
Two doses of Shanchol™ and Euvichol-
Plus® provide protection against cholera
at least for three years, while one dose
provides short term protection.