Fatima Al-AwadhCHOLERA

• 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.

LEARNING OBJECTIVES

Cholera is an acute diarrheal illness caused by infection of the intestine with

the bacteria Vibrio cholerae.

CHOLERA

• 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.

EPIDEMIOLOGY

• 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

VIBRIO CHOLERAE

V. cholerae accumulates in stomach

Produces toxins

Toxins will bind to G-

protein coupled

receptor

Inactivation of GTPase

G- protein stuck in "on"

position

increase cAMP

activation of ion channels

NaCl influx into

intestinal lumen to

drag water into lumen

lead to watery

diarrhea

PATHOPHYSIOLOGY OF CHOLERA

Most people remain asymptomatic. The symptoms of cholera include :

SIGNS & SYMPTOMS

profuse, watery

diarrhea

stomach pains

leg cramps

Mild fever

Vomiting Sunken eyes and cheeks

Dry mucous

membranes

Decreased urinary output

severe dehydration Shock Renal failure

Death

COMPLICATIONS

• Rare in developed countries• Common in Asia, Africa, & Latin

America

Poor sanitary conditions

• Contaminated seafood, even in developed countries.

• Especially shellfish.

Raw or undercooked food

• People with low levels of stomach acid

• Such as children, older adults, and some medications.

Hypochlorhydria

• Reasons aren't entirely clear• Twice more likely

Type O blood

RISK FACTORS

Drinking contaminated water.

eating raw or undercooked shellfish

CAUSES (TRANSMISSION MOOD)

DIAGNOSIS

Clinical diagnosis

Cholera should be considered in all cases with severe watery diarrhea and vomiting.

Traveling to affected areas and eating shellfish

No distinguishing clinical manifestations for cholera.

Culture• 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

LABORATORY DIAGNOSIS

Additional methods of detection include PCR and monoclonal antibody-based stool tests.

LABORATORY DIAGNOSIS

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.

TREATMENT

• Basic health education and hygiene• Mass chemoprophylaxis

• Provision of safe water and sanitation

• Comprehensive Multidisciplinary Approach: water, sanitation,

education, and communication

PREVENTION

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

VACCINES

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.

PROGNOSIS

Treatment centers Set up treatment centers for

prompt treatment.

Sanitary measures. food safety and animal health

measures

Comprehensive surveillance data

(adapt to each situation) for a comprehensive multidisciplinary approach.

CONTROLLING CHOLERA

• http://www.mayoclinic.com/health/cholera/DS00579/DSECTION=risk-factors

• http://www.safewater.org/PDFS/resourcesknowthefacts/Cholera.pdf?noframe

• http://tropicaldisease.files.wordpress.com/2008/01/cholera-rose-ricardo-compatible-v.ppt

• http://cti.itc.virginia.edu/~whg2n/biom204/ppt/cholera.ppt

• http://www.socgastro.org.pe/biblioteca/presentacion/archivos/diarrea/2007Cholera3.ppt

REFERENCES

THANK YOU