Cholera

Cholera is a bacterial infection that produces a toxin and can cause profuse watery diarrhoea.

To give you some idea of the individual impact, symptomatic cholera patients with severe disease may be nursed in “cholera cots” with a strategic hole in the centre connected to a bucket. Without proper management, cholera can lead to severe dehydration. Fortunately, most infections are asymptomatic or mild.

The Centre for Disease Control and Prevention (CDC) estimates there are more than 2.9 million cases annually. These result in 95,000 deaths.

Cholera is transmitted by ingesting contaminated food (often seafood) or water and is much more common in low and low-middle income countries where there may be inadequate sanitation and a scarcity of clean water. It is a disease of poverty and poor public health infrastructure.

The cholera bacterium may live in the environment, in brackish rivers and coastal waters. It attaches to the carapaces of crustaceans (prawns, crabs, lobsters), shellfish and the skin of fish, which are sources of infection if not adequately cooked. The disease is unlikely to be spread from one person to another by casual contact.

Cholera outbreaks can also result from humanitarian crises where there may be a disruption of water and sanitation systems or the displacement of people into crowded camps with inadequate hygiene.

The overall risk of exposure for an educated traveller informed about safe and unsafe food and water, is less than 1 in 1 million per month of stay. Most cases relate to the consumption of raw or undercooked seafood or unsafe water.

Risk is probably highest for humanitarian workers in refugee camps or overpopulated communities.

Cholera is endemic in 50 countries, primarily Africa and South and Southeast Asia. In the period 2010-2014, 91 cases of cholera were identified in the USA in individuals who had travelled internationally. Of these, 75% were associated with travel to the Caribbean and 10% to India or Pakistan. Other destinations included Southeast Asia and West Africa.

Less than 10 cases are reported annually in Australia, with just 3 cases being reported year to date (November 2023). As of December 2022, 8 cases were reported in the USA. 

Two cholera vaccines are currently registered for use in Australia.