CHOLERAArdal Koprulu 295-B

Cholera Cholera is an acute diarrheal illness

caused by infection of the intestine with the bacteria Vibrio cholerae.

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.

INCUBATION PERIODRanges from a few hours to 5 days. Universal I/P is 5 days. Shorter incubation period:

High gastric pH (from use of antacids)Consumption of high dosage of cholera

Period of CommunicabilityDuring acute stage

A few days after recovery

By end of week, 70% of patients non-infectious

By end of third week, 98% non-infectious

HOST FACTORS 1. Age: Children: 10x more susceptible than adults,

And Elderly also higher susceptible.2. Sex: Equal in both male and female.3. Immunity: Less immune higher risk.4. People with low gastric acid levels5. Blood types

O>> B > A > AB

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

Pathophysiology of choleraV. 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

Signs & Symptoms Most people remain asymptomatic. The

symptoms of cholera include :

profuse, watery

diarrhea

stomach pains

leg cramps

Mild fever

Vomiting Sunken eyes and cheeks

Dry mucous

membranes

Decreased urinary output

Signs & Symptoms The primary symptoms of cholera are

profuse, painless diarrhea and vomiting of clear fluid.

The diarrhea is frequently described as "rice water" in nature and may have a fishy odor.

An untreated person with cholera may produce 10 to 20 litres of diarrhea a day with fatal results.

patient's skin turning a bluish-gray hue from extreme loss of fluids.

Signs & Symptoms If the severe diarrhea is not treated with

intravenous rehydration, it can result in life-threatening dehydration and electrolyte imbalances.

The typical symptoms of dehydration include low blood pressure, poor skin turgor (wrinkled hands), sunken eyes, and a rapid pulse.

Complications

severe dehydration Shock

Renal failure Death

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

AmericaPoor 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 likelyType O blood

Causes (transmission mood)

Drinking contaminated water.

eating raw or undercooked shellfish

diagnosisClinical

diagnosisCholera 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.

Differential diagnosis

Enterotoxigenic e. Coli

Bacterial food poisoning

Viral gastroenteritis

Laboratory Diagnosis 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.

Treatment Continued eating speeds the recovery of

normal intestinal function. The World Health Organization recommends

this generally for cases of diarrhea no matter what the underlying cause.

A CDC training manual specifically for cholera states: “Continue to breastfeed your baby if the baby has watery diarrhea, even when traveling to get treatment. Adults and older children should continue to eat frequently

Treatment Fluids: In most cases, cholera can be

successfully treated with oral rehydration therapy (ORT), which is highly effective, safe, and simple to administer.

Electrolytes: As there frequently is initially acidosis, the potassium level may be normal, even though large losses have occurred.

Treatment Antibiotic treatments for one to

three days shorten the course of the disease and reduce the severity of the symptoms. Doxycycline is typically used first line,

Other antibiotics proven to be effective include cotrimoxazole, erythromycin, tetracycline, chloramphenicol, and furazolidone.

Prevention Basic health education and hygiene Mass chemoprophylaxis Provision of safe water and sanitation Comprehensive Multidisciplinary

Approach: water, sanitation, education, and communication

VaccinesParenteral 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-effectsLive, 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

Controlling choleraTreatment 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.

References http://www.mayoclinic.com/health/choler

a/DS00579/DSECTION=risk-factors http://www.safewater.org/PDFS/resources

knowthefacts/Cholera.pdf?noframe http://tropicaldisease.files.wordpress.co

m/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

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