Cholera is acute diarrheal infection of the intestine caused by Vibrio cholerae. The infection is often mild or without symptoms, but sometimes can be severe and fatal.
Mode of Transmission of Cholera
• Transmission is through faecal –oral route but almost all cholera infections are waterborne.
o Vibrio cholera can live in water for 2 weeks and prefer salty water
• Vibrio may survive for longer period and multiply in shellfish
The reservoir of infection is formed mainly by carriers excrete vibrio in small numbers posing danger to the community
Signs and Symptoms of Cholera
• The incubation period is 2-3 days
• The clinical presentation of cholera is caused by water and electrolyte loss and develop in 3 stages described below:
o First stage (last for 3-12 hours)
+ Characterized by passage of profuse watery stool
+ The stool comprises of clear fluid with flakes of mucous (rice water appearance)
+ Severe cramps in the abdomen and limbs develop from loss of electrolytes
o Second stage:
+ There is collapse from dehydration
+ The body becomes cold, the skin dry and inelastic
+ The blood pressure is low and the pulse is rapid and feeble
+ Urine production stops and the patient may die of shock
o Third stage:
+ Stage of recovery, either spontaneously or with treatment
+ Diarrhoea decreases
+ Patient is able to take fluids and general condition improves
Treatment of Cholera
• Patients should be hospitalized
• Cholera is cured by appropriate and timely re-hydration o Patients of all ages who are strong enough to drink will take a lot of glucose/electrolyte solution needed for re-hydration and maintenance
• It is essential to use oral re-hydration solution (ORS) or appropriate intravenous (IV) fluids to replace the necessary electrolytes.
• Patients in shock or who are too weak to drink require intravenous fluids until they can take in oral fluids.
• Antimicrobial agents have been shown to shorten the period of diarrhoea and the amount of fluid loss.
o Tetracycline or doxycycline are the drugs of choice
o Erythromycin is an effective alternative both in children and adults
o Cotrimoxazole is also another alternative
• Strict isolation is not necessary as only vomitus and stool are infectious Patients are treated on ‘Cholera bed’ (beds with central hole) through which the continuous stool can pass into a bucket and fluid loss be measured.
Prevention and Control of Cholera
• Improve quality of public water supply by chlorination in large scale
• Encourage individuals to boil drinking water
• Milk products should be pasteurized
• Avoid eating half cooked food
• Leftovers should be protected against contamination by flies
• Markets and food premises should be free from contamination
• Improvement of sanitation facilities e.g. proper excreta and refuse disposal
• Give health education to public on how cholera is spread, clinical features, preventive measures, ways of making water safer (e.g. by boiling), proper food handling, sanitation and hand washing
• The vomitus and stool should be properly deposited in pit latrine or a septic tank system
• Hospital equipment should be cleaned with disinfectant such as 5% Lysol