An indicator of inequity

Cholera is a highly contagious disease caused by infection with bacteria. It occurs in poor remote villages to overcrowded cities. Not having access to clean water and improper sanitation are the main drivers behind cholera epidemics. Cholera is a global problem and an indicator of inequity and lack of developed infrastructure.

Cholera is an extremely virulent disease that can cause severe dehydration and if left untreated can kill within hours.



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What causes Cholera

Cholera is caused by the bacterium Vibrio cholerae serogroup O1 or O139 and infects the small intestine. The bacteria are spread via water or food contaminated by feces of infected persons.

It prevails in regions with inadequate water treatment and poor sanitation, brackish (partly saline) rivers and coastal waters. Although rare, raw shellfish has been a source of infection in the past.

Casual contact with infected people is not considered a risk factor, since person-to-person direct transmission is unlikely.

Photo: Vibrio cholerae Scanning electron microscope image.

Where is Cholera found

Descriptions of cholera can be found as early as the 5th century BC in Sanskrit. In the past two centuries, seven cholera pandemics have been recorded – six from the Gangetic delta and one from Indonesia – killing millions of people. The last pandemic started in 1961 and is still considered ongoing, making it the longest pandemic recorded to date. Strain O1 was found to have caused all the earlier pandemic, and strain O139 was discovered in 1992 in Asia.

An estimated 2.9 million cases and 150 000 deaths occur around the world each year. People who don’t have access to safe drinking water and food and live in poor sanitary conditions are at the highest risk for cholera. 60% of infections and 68% of deaths occur in Africa.

Image: Cholera case fatality rates

What are the symptoms of Cholera

Infected people typically take 2-3 days to show symptoms, although this can vary from a few hours to five days.

The infection is often mild and infected individuals do not show any symptoms, but it can be severe in about 10% of cases.

Profuse diarrhea and vomiting of clear fluid are the primary symptoms. An untreated person with cholera may produce 10 to 20 liters. The diarrhea is frequently described as resembling rice water and may have a fishy odor.

Severe cholera, without treatment can lead to dehydration and death within hours if not treated in time.

Fever is rare. Patients can be lethargic and might have sunken eyes, dry mouth and cold clammy skin. A deep and labored breathing pattern, can occur because of acidosis. The blood pressure drops due to dehydration and is accompanied by a rapid pulse.

Photo: Typical cholera diarrhea that looks like rice water.

How can Cholera be prevented

It is important to be aware of the prevalence of cholera in areas you live or plan to visit. The bacterium spreads through the fecal-oral route and infected individuals might shed the bacteria for up to two weeks.

Travellers from the USA can take the FDA-approved vaccine Vaxchora (lyophilized CVD-103-HgR). Vaccines cuh as Dukoral, Shanchol and Euvichol-Plus/Euvichol in other countries.

Since no vaccine is 100% effective and in the absence of vaccine availability, it is additionally important to follow basic safety precautions which can prevent infections to a large extent:

  • Drinking only bottled/ boiled/ chemically treated water for all purposes including drinking, cooking, brushing, washing dishes and making ice.
  • Washing hands thoroughly with soap and water (or hand sanitizers if these are not available) before cooking or eating and after using the toilet.
  • Eating only packaged or freshly prepared food.
  • Disposing of feces in a sanitary manner to prevent contamination of food and water.

How is Cholera diagnosed

If you recently travelled to an area with a cholera outbreak and suspect you could have been infected, diagnosis can be done by a laboratory by analysing a stool sample or rectal swab. A rapid dipstick is available too to get an initial diagnosis. Polymerase chain reaction (PCR) tests, such as the one available at WoIDMo, can detect V.cholerae O1.

How is Cholera treated

Dehydration is the biggest risk in case of cholera, so in case of infected individuals showing symptoms such as diarrhea and vomiting, a simple and effective solution is to have them drink an “oral re-hydration solution” (ORS; a packaged mixture of sugar and salt diluted in 1 liter of water). Medical care should be sought in severe cases, since intravenous fluid replacement may be necessary. With prompt re-hydration, less than 1% of cholera patients die from cholera.

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