a quick cholera review

2. Prepared by:
Faraja. S. Ramadhani
Dip. MLT
School of health and medical sciences-
SUZA
Zanzibar, Tanzania

3. Learning objectives
By the end of this lesson participants
are expected to:-
Explain on cholera (meaning, brief history,
global distribution)
Describe how cholera is transmitted
Describe the sign and symptoms of
cholera
Explain on cholera risk factors
Describe the treatment of cholera
Describe the prevention and control
measures on cholera

4. INTRODUCTION
Cholera is an acute secretory diarrheal illness caused
by toxin-producing strains of the gram-negative
bacterium Vibrio cholerae. Severe cholera is
characterized by profound fluid and electrolyte losses
in the stool and the rapid development of hypovolemic
shock, often within 24 hours from the initial onset of
vomiting and diarrhea. Administration of appropriate
rehydration therapy reduces the mortality of severe
cholera from over 10 percent to less than 0.5 percent
This topic discusses the epidemiology, clinical
manifestations, diagnosis, treatment, and prevention of
cholera.

5. HISTORY
During the 19th century, cholera spread
across the world from its original reservoir in
the Ganges delta in India. Six subsequent
pandemics killed millions of people across
all continents. The current (seventh)
pandemic started in South Asia in 1961, and
reached Africa in 1971 and the Americas in
1991. Cholera is now endemic in many
countries.

6. EPIDEMIOLOGY
Cholera is vastly underreported, and precise
measurements of the morbidity and mortality
attributable to V. cholerae infection are
lacking. However, there are an estimated 3
million cases of diarrheal illness and
approximately 100,000 deaths worldwide
caused by V. cholerae annually

7. GLOBAL DISTRIBUTION
Cholera primarily affects resource-limited
settings where there is inadequate access to
clean water sources. Cholera is endemic in
approximately 50 countries (defined as
having reported cholera cases in at least
three of the five past years), mostly in Africa
and Asia. In addition, epidemics due to V.
cholerae have occurred throughout Africa,
Asia, the Middle East, South and Central
America, and the Caribbean, and can be
particularly extensive.

9. TRANSMISSION
The bacteria are transmitted between humans
through the fecal-oral route; a bite of
contaminated food or a sip of contaminated
water can cause infection.
 Uncontrolled water sources such as wells,
lakes, ponds, streams and rivers pose a great
threat.
 Contaminated Food and Drinks: Ingestion
of contaminated food and drinks have been
associated with outbreaks of cholera. Bottle
feeding could be a significant risk factor for
infants. Fruits and vegetables washed with
contaminated water can be a source of
infection. After preparation, cooked food may
be contaminated through contaminated hands
and/or flies.

11. SIGNS AND SYMPTOMS
Symptoms of cholera infection may include:
 Diarrhea. Diarrhea due to cholera often has a pale, milky
appearance that resembles water in which rice has been
rinsed (rice-water stool).
 Nausea and vomiting. Occurring especially in the early
stages of cholera, vomiting may persist for hours at a time.
 Dehydration. Dehydration can develop within hours after
the onset of cholera symptoms. Depending on how many
body fluids have been lost, dehydration can range from
mild to severe. A loss of 10 percent or more of total body
weight indicates severe dehydration.
 Signs and symptoms of cholera dehydration include
irritability, lethargy, sunken eyes, a dry mouth, extreme
thirst, dry and shriveled skin that's slow to bounce back
when pinched into a fold, little or no urine output, low blood
pressure, and an irregular heartbeat (arrhythmia).
 Dehydration may lead to a rapid loss of minerals in your
blood (electrolytes) that maintain the balance of fluids in
your body. This is called an electrolyte imbalance.

12.  Electrolyte imbalance
An electrolyte imbalance can lead to serious signs
and symptoms such as:
 Muscle cramps. These result from the rapid loss of
salts such as sodium, chloride and potassium.
 Shock. This is one of the most serious complications
of dehydration. It occurs when low blood volume
causes a drop in blood pressure and a drop in the
amount of oxygen in your body. If untreated, severe
hypovolemic shock can cause death in a matter of
minutes.
 Signs and symptoms of cholera in children
In general, children with cholera have the same
signs and symptoms adults do, but they are
particularly susceptible to low blood sugar
(hypoglycemia) due to fluid loss, which may cause:
 An altered state of consciousness
 Seizures
 Coma

14. RISK FACTORS
 Poor sanitary conditions.
 Reduced or nonexistent stomach acid
(hypochlorhydria or achlorhydria)..
 Household exposure.
 Raw or undercooked shellfish and other
food stuffs

16. 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 diarrhea, reduce the volume of
rehydration fluids needed, and shorten the
amount and duration of V. cholerae excretion in
their stool.

17. Treatment continue….
reduce the volume of rehydration fluids needed, and
shorten the amount and duration of V.
cholerae excretion in their stool.
Mass administration of antibiotics is not
recommended, as it has no proven effect on the
spread of cholera and contributes to increasing
antimicrobial resistance.
Rapid access to treatment is essential during a
cholera outbreak. Oral rehydration should be
available in communities, in addition to larger
treatment centers that can provide intravenous
fluids and 24 hour care. With early and proper
treatment, the case fatality rate should remain
below 1%.
Zinc is an important adjunctive therapy for children
under 5, which also reduces the duration of
diarrhea and may prevent future episodes of other
causes on acute watery diarrhea.
Breastfeeding should also be promoted.

18.  PREVENTION AND CONTROL
A multifaceted approach is key to control
cholera, and to reduce deaths. A
combination of surveillance, water,
sanitation and hygiene, social mobilization,
treatment, and oral cholera vaccines are
used (there are three WHO pre-qualified
oral cholera vaccines (OCV): Dukoral®,
Shanchol™, and Euvichol®. All three
vaccines require two doses for full
protection).
Other Preventive measures include:
 Wash hands with soap and water
frequently.
 Drink only safe water Eat food that's
completely cooked and hot Avoid sushi.

20. REFFERENCE
 www.uptodate.com
 www.mayoclinic.com
 www.who.int
 www.cdc.gov
 www.medlineplus.com