Cholera is an infection in the small intestine caused bythe bacterium Vibrio cholerae. The main symptoms areprofuse, watery diarrhea and vomiting. Transmissionoccurs primarily by drinking water or eating food that hasbeen contaminated by the feces of an infected person,including one with no apparent symptoms.
Acute infectious disease is often fatal characterized by severe vomiting, diarrhoea, and collapse
Caused By: Vibrio cholerae •Indirect transmission Vehicle borne •Reaches water through: Vomiting Diarrhoea •Carriers active or passive •Produces toxins in sml intestines that cause severe diarrhoea and dehydration
Through: Contaminated water Contaminated food Eating with unwashed hands Also house flies and otherinsects
The primary symptoms of cholera are profuse, painless diarrheaand vomiting of clear fluid. These symptoms usually start suddenly,one to five days after ingestion of the bacteria. The diarrhea isfrequently described as "rice water" in nature and may have a fishyodor.An untreated person with cholera may produce 10 to 20 liters (3 to5 US gal) of diarrhea a day with fatal results. For every symptomaticperson, 3 to 100 people get the infection but remain asymptomatic.Cholera has been nicknamed the "blue death" due to a patientsskin turning a bluish-gray hue from extreme loss of fluids.
If the severe diarrhea is not treated with intravenous rehydration, itcan result in life-threatening dehydration and electrolyteimbalances.The typical symptoms of dehydration include low bloodpressure, poor skin turgor (wrinkled hands), sunken eyes, and arapid pulse. A person with severe dehydration due to cholera - note the sunken eyes and decreased skin turgor which produces wrinkled hands
Host drinks water Bacteria moves through the stomach Reach the intestine & produce flagella Propel through mucus of the sm. intestine Produce toxin causing diarrhea Feces carry new bacteria into drinking water
When consumed, most bacteria do not survive the acidic conditions ofthe human stomach. The few surviving bacteria conserve their energyand stored nutrients during the passage through the stomach byshutting down much protein production.When the surviving bacteria exit the stomach and reach the smallintestine, they need to propel themselves through the thick mucus thatlines the small intestine to get to the intestinal walls where they canthrive. V. cholerae bacteria start up production of the hollow cylindricalprotein flagellin to make flagella, the cork-screw helical fibers theyrotate to propel themselves through the mucus of the small intestine.
Once the cholera bacteria reach the intestinal wall they no longerneed the flagella to move. The bacteria stop producing the proteinflagellin to conserve energy and nutrients by changing the mix ofproteins which they express in response to the changed chemicalsurroundings. On reaching the intestinal wall, V. cholerae startproducing the toxic proteins that give the infected person a waterydiarrhea.This carries the multiplying new generations of V. cholerae bacteriaout into the drinking water of the next host if proper sanitationmeasures are not in place. Advanced Mechanism Structure Next
Stage 1 Stage 3 Vomiting Start to recover Muscle cramps Mild to severe diarrhoea Sudden onset and watery, Shock and dehydration painless diarrhea Loss of important minerals Stool has a characteristic “rice and electrolytes water” appearance (gray, slightly cloudy with bits of Intense thirst mucus, and a slightly sweaty Reduced urination odor) Muscle cramps/weaknessStage 2 Dehydration, Thirst and Shock Cold Skin, sunken Eyes, weak pulse and feint high-pitched voice Reduced urine Muscle cramps and Muscle weakness
Oral Rehydration Therapy (ORT) Solution of salts and sugars, taken by the mouth Also homemade solutions (water, sugar, table salt, baking soda, and fruit) Sometimes intravenous
Tetracycline Shortens the course of the disease Weaken the symptoms.
Squatter camps Bad hygiene Unsafe preparation of food Drinking contaminated water To bathe / swim in contaminated water
Immunization Boiling water, covering food Education Personal and domestic hygiene Prevention of contamination of water supplies Improvement of sewage systems Access to health care
Although cholera may be life-threatening, prevention ofthe disease is normally straightforward if propersanitation practices are followed. In developed countries,due to nearly universal advanced water treatment andsanitation practices, cholera is no longer a major healththreat.