Cholera


Clinical Features
Many people infected with the bacteria may not have any symptoms. Some people develop only mild diarrhoea and vomiting. In severe cases, there is rapid onset of frequent watery diarrhoea that typically resembles rice water, and dehydration can occur very quickly. If treatment is delayed or inadequate, death may follow.
Mode of Transmission
Cholera is transmitted by consumption of contaminated, inadequately cooked food or contaminated unboiled water. Cooked food may be cross-contaminated by raw food. High risk food items are raw or undercooked seafood, e.g. raw oyster and undercooked shrimps and crabs.
Incubation Period
Ranges from a few hours to 5 days, usually 2 to 3 days.
Treatment
For treatment of the patient, fluid and electrolyte replacement is important when there is watery or frequent diarrhoea. Antibiotics are useful to shorten the duration of the diarrhoea and reduce the duration of bacteria excretion. The excreta of the patient should be properly disposed of to prevent spread of the infection.
Prevention
  1. Maintain good personal hygiene, wash hands properly before eating and food handling.
  2. Keep the premises and kitchen utensils clean. Dispose rubbish properly.
  3. Clean and cook food thoroughly. Consume food as soon as it is done.
  4. Drinking water is preferably boiled.
  5. Purchase fresh food from reliable sources. Do not patronize illegal hawkers.
  6. Avoid high-risk food like shellfish, raw food or semi-cooked food. Scrub and rinse shellfish in clean water and immerse them in clean water.
  7. Handle and store raw and cooked food especially seafood separately (upper compartment of the refrigerator for cooked food and lower compartment for raw food) to avoid cross contamination.
  8. Clean and defrost refrigerator regularly and keep the temperature at or below 4oC.
  9. Cholera vaccination is not recommended because it cannot provide sufficient protection and will give a false sense of security to those vaccinated.
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