Cholera - including symptoms, treatment and prevention
Cholera is an acute diarrhoeal illness caused by some strains of the bacterium Vibrio cholerae.
The cholera organism is known to be present in some rivers along the eastern Australian coast, but cholera acquired in Australia is very rare. In Australia, because of our high standards of sanitation, water and food quality, cholera outbreaks do not occur. Typically, cholera is seen only in travellers arriving from countries where the disease is still common, such as Africa, Central Europe, Latin America and Asia.
How cholera is spread
Infection occurs when the bacteria are taken in by mouth, usually in food or water contaminated by human faeces.
Cholera is spread by:
drinking contaminated water
eating food contaminated by dirty water, soiled hands or flies
eating fish or shellfish from contaminated waters.
The cholera organism can survive for long periods in water and ice.
Signs and symptoms
Infection is often mild, or without any symptoms, but it can be severe.
sudden onset of painless, profuse, watery diarrhoea
nausea and vomiting early in the illness
In severe untreated cases, death may occur within hours, but with simple treatment full recovery can be expected.
Diagnosis is suspected on clinical signs and confirmed by growing Vibrio cholerae from afaecal specimen.
(time between becoming infected and developing symptoms)
A few hours to 5 days, usually 2 to 3 days.
(time during which an infected person can infect others)
During the acute stage and for a few days after recovery. However, some people (called 'carriers') who do not have symptoms may still carry the bacteria and be infectious, sometimes for months to years.
Anyone who has been in a high-risk region within the previous 5 days and develops severe vomiting and diarrhoea should seek urgent medical assessment.
Although cholera can be life-threatening, it is easily treated by immediate rehydration, that is, replacement of the fluid and salts lost through diarrhoea.
Oral rehydration fluid is recommended. This can be obtained from pharmacies.
Patients with severe dehydration or who are unable to keep oral fluids down require hospitalisation and intravenous fluid replacement.
Antibiotics shorten the duration of the illness and lessen the severity, but they are not as important as rehydration.
Severely ill patients should be isolated in hospital.
People who are less severely ill can be nursed at home. Faeces and vomit can be disposed of into the toilet except in areas where there is not an adequate sewage disposal system.
All linen and articles used by the patient should be washed in hot soapy water and the room thoroughly cleaned when the person has recovered.
Vaccines are available but are recommended only for travelers to high-risk countries. They may not protect against all strains of cholera bacteria and protection is for several months only.
When traveling to high-risk countries, seek advice from a travel medical clinic or an experienced general practitioner on how to protect yourself from cholera and other diarrhoeal illnesses. In particular, drink only water that has been boiled or disinfected with iodine or chlorine tablets. Carbonated bottled drinks are usually safe, if no ice is added.
Contacts (for example, family members) of a case should be observed for 5 days from the date of the last exposure to the infected person. A contact is any person who has been close enough to an infected person to be at risk of having acquired the infection from that person.