Vibrio cholerae

These bacteria are known for causing cholera – a deadly disease which is often fatal. The symptoms of cholera are similar to those of food poisoning.

This gastrointestinal illness is contracted after consuming infected food or water.

The vibrio cholerae bacteria

These bacteria are shaped like a ‘comma’ (a punctuation symbol) with a distinctive tail and are the direct cause of cholera in humans.

They and the vibrio parahaemolyticus bacteria form part of the Vibrio genus of bacteria which are known to cause food poisoning, other gastrointestinal illnesses and blood poisoning (septicaemia).

Causes of vibrio cholerae

The Vibrio bacteria live in contaminated water where they are transmitted to various species of fish and seafood such as prawns, oysters and tuna.

These bacteria enter the human body as a result of eating infected fish which then cause symptoms which are similar to food poisoning such as nausea, vomiting and diarrhoea.

The vibrio cholerae bacteria transfer to humans via consumption of infected food or contaminated water. The majority of these bacteria are killed by stomach acid but a few manage to survive.

These remaining bacteria access the small intestine. Their aim is to invade the soft lining of the intestinal walls but to do so they produce a type of protein which grows their distinctive curly tails.

These tails are used to move through the thick mucus of these walls. Once they access these walls they thrive and multiply.

Once inside the intestinal walls they lose their curly tails and instead, produce a mix of proteins which are pathogenic. This means that they have the ability to cause disease and infection.

These toxins are responsible for causing watery diarrhoea and other symptoms. They produce copious amounts of fluid which is expelled from the body as diarrhoea and often results in serious dehydration.

There is also the risk of these bacteria infecting another person due to poor sanitation or if they have contact with infected water.

Symptoms of vibrio cholerae

These are the symptoms of cholera and include:

• Watery diarrhoea
• Nausea
• Vomiting
• Abdominal pain
• Severe dehydration

But the main risk is that of dehydration. Severe dehydration can be fatal so it is important that any treatment plan includes fluid replacement.

Treatment for vibrio cholerae

An initial diagnosis will have been made from a physical examination and a stool sample. A ‘stool sample’ is a medical procedure in which a small sample of faeces is analysed for signs of bacteria.

Treatment is based upon fluid replacement therapy. This means ensuring that the infected individual is given fluids and electrolytes to replace those lost due to severe diarrhoea.

These electrolytes are designed to replace minerals such as sodium and potassium which have been depleted due to this illness. An oral replacement drink or sachet contain an oral re-hydration powder which is added to drinking water will be sufficient.

These fluids will be given intravenously in serious cases.

Antibiotics are often prescribed as they help to shorten the recovery period as well as easing the symptoms. But, a few strains of the Vibrio bacteria have developed a resistance to them.

Oral re-hydration therapy is still the preferred form of treatment.

Preventing vibrio cholerae

This is not a problem in industrialised countries but still remains a risk in the developing world. If you are planning on travelling in areas where cholera still occurs then seek advice about prevention before you travel.