Cholera is an acute diarrheal illness caused by the bacteria Vibrio cholerae. It spreads when the feces of an infected person come into contact with food or water. Symptoms include profuse watery diarrhea, vomiting, and leg cramps. Treatment focuses on oral rehydration salts or intravenous fluids for severe cases. Prevention emphasizes basic hygiene, provision of safe water and sanitation, and vaccination programs. With prompt treatment, mortality rates from cholera can be reduced to about 1%.
2. LEARNING OBJECTIVES
• Define cholera.
• State epidemiology of cholera.
• Describe the causative organism.
• Explain the pathophysiology of cholera.
• Mention the sign & symptom, complication, risk
factors, causes, diagnosis, treatment, prevention,
& prognosis of cholera.
• Describe the ways of controlling the spread of
cholera.
3. CHOLERA
Cholera is an acute diarrheal illness caused by infection
of the intestine with the bacteria Vibrio cholerae.
4. EPIDEMIOLOGY
• Cholera was prevalent in the 1800s, but due to
proper treatment of sewage and drinking water,
has become rare in developed countries.
• Cholera is a fecal disease, meaning that it
spreads when the feces of an infected person
come into contact with food or water.
• Incidence: 1 in 100,000 worldwide.
• Over 1 million cases and nearly 10,000
fatalities.
5. VIBRIO CHOLERAE
• Gram negative.
• Type of Gammaproteobacteria
• Distinguishing factors: Oxidase-
positive, motile via polar
flagellum, and both respiratory
and fermentative metabolism.
• Organism can multiply freely in
water
6. PATHOPHYSIOLOGY OF CHOLERA
V. cholerae
activation of ion
accumulates in increase cAMP
channels
stomach
NaCl influx into
G- protein stuck intestinal lumen
Produces toxins
in "on" position to drag water
into lumen
Toxins will bind
Inactivation of lead to watery
to G-protein
GTPase diarrhea
coupled receptor
7. SIGNS & SYMPTOMS
Most people remain asymptomatic. The symptoms of
cholera include :
profuse, watery stomach leg cramps Mild fever
diarrhea pains
Vomiting Sunken eyes Dry mucous Decreased
and cheeks membranes urinary output
9. RISK FACTORS
Poor sanitary • Rare in developed countries
conditions • Common in Asia, Africa, & Latin America
Raw or • Contaminated seafood, even in developed
countries.
undercooked food • Especially shellfish.
• People with low levels of stomach acid
Hypochlorhydria • Such as children, older adults, and some
medications.
• Reasons aren't entirely clear
Type O blood • Twice more likely
11. DIAGNOSIS
Clinical diagnosis Differential diagnosis
Cholera should be considered Enterotoxigenic e. Coli
in all cases with severe watery
diarrhea and vomiting.
Bacterial food poisoning
Traveling to affected areas and
eating shellfish
Viral gastroenteritis
No distinguishing clinical
manifestations for cholera.
12. LABORATORY DIAGNOSIS
• Vibrios often detected by dark
field or phase contrast
microscopy of stool
• Organisms are motile,
appearing like “shooting stars”
• Microscopy show sheets of
curved Gram negative rods.
• When plated on sucrose
dishes, yellow colonies appear
confirming cholera present
14. TREATMENT
Oral rehydration salts
• Up to 80% of cases can be treated through this.
Intravenous fluids (Ringer lactate)
• For severe cases.
Antimicrobial Therapy
• can diminish duration of diarrhea, reduce volume
of rehydration fluids needed, and shorten duration
of V. cholerae excretion.
15. PREVENTION
• Basic health education and hygiene
• Mass chemoprophylaxis
• Provision of safe water and sanitation
• Comprehensive Multidisciplinary
Approach: water, sanitation, education,
and communication
16. VACCINES
Parenteral Vaccine :
• 2 doses administered 2 weeks apart
• Efficacy of approximately 50% and hardly exceeds 6 months
• Not recommended
Killed WC/rBS Vaccine :
• Killed whole-cell V.cholerae in combination with a recombinant B-subunit of cholera toxin
• Safe in pregnancy and breastfeeding
• Efficacy of approximately 50% after 3 years
• Only mild side-effects
Live, attenuated CVD 103-HgR Vaccine :
• Protection as early as 1 week after vaccination, with >90%
• Unknown efficacy for children under 2
• No adverse side-effects
17. PROGNOSIS
The prognosis of cholera can range depending
on the severity of the dehydration and how
quickly the patient is given and responds to
treatments.
Death (mortality) rates in untreated cholera can
be as high as 50%-60% during large outbreaks
but can be reduced to about 1% if treatment
protocols are rapidly put into action.
18. CONTROLLING CHOLERA
Treatment
centers Set up treatment centers for prompt
treatment.
Sanitary
measures. food safety and animal health measures
Comprehensive
surveillance (adapt to each situation) for a
data comprehensive multidisciplinary approach.