Cholera (Vibrio cholerae)
Cholera is a completely preventable disease that is often prevalent in areas where there is a social development inequality. It is caused by consuming food or water contaminated with the vibrio cholerae bacterium. Annually, there are 1.3 - 4.0 million cases which result in up to 143,000 deaths. Cholera is an extremely life threatening serious disease which can cause severe acute watery diarrhea and severe dehydration.
Overview
In the 19th century, cholera spread from the Ganges river in India across the world causes six subsequent pandemics that killed millions. The current (seventh) pandemic recommenced in South Asia in 1961, then spread to Africa in 1971 and the Americas in 1991. There are many subgroups of the cholera bacterium however only two 01 and 0139 have caused outbreaks. Transmission is directly attributed to inadequate access to clean food and water as well as sanitation facilities. Uninfected dead bodies are not a source of cholera outbreaks. It can be spread through at risk areas such as slums, refugee camps and the like. Cholera outbreaks can occur in countries where cholera does not usually occur.
Prevention & Control
Cholera is completely preventable and predictable. It would be eliminated if the world had access to clean water, food and sanitation facilities as well as good hygiene practices. Health, food preparation and hygiene education through social public health initiatives can achieve this goal to elimination of cholera, but poverty, war, and lack of access prevent this from occurring in 3rd world countries. The basic practices of washing food, hands etc is not possible in areas where there is a lack of equality to clean water. Cholera vaccines are also essential to eliminate or prevent this disease as outbreaks, emergencies and hot spots.
Symptoms
Key symptoms of cholera include both diarrhea and dehydration. Often, symptoms of cholera can be mild, but people can experience pain in the abdomen, nausea, vomiting, severe watery diarrhea, dehydration, lethargy, and water electrolyte imbalance. Cholera is incredibly uncomfortable and painful as it can also cause leg cramps, irritability and the dehydration can further cause rapid heart rate, loss of skin elasticity, dry mucous membranes, low blood pressure.
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The severe dehydration can also cause kidney failure, and severe cases can lead to shock and seizures or death within hours.
Treatment
Cholera is an acute diarrhoeal disease that can cause death within hours if left untreated. Such cases require immediate administration of oral rehydration solution dissolved in clean water. Adult patients may require up to 6 litres of oral rehydration solution in the first day.
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If the patient presents with severe dehydration at risk of shock, intravenous fluids administered rapidly is required with antibiotics however mass administration of antibiotics is not recommended as there is no link between cholera and and antimicrobial resistance. For children under 5, zinc supplements are recommended and for infants, resume breastfeeding.
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Community engagement is critical to educate about protective hygiene measures are understood. This involves addressing local cultural practices and beliefs to ensure that hygiene is understood. Handwashing with soap, safe food preparation, sanitation practices, and safe funeral practices for those who died from cholera are essential. Often however, communities such as refugee camps or slums exposed to cholera do not have access to clean water due to extreme poverty or lack of infrastructure which presents a major issue.
Vaccines
There are 3 world health organisation approved oral cholera vaccines of which one is available in Australia: "Dukoral". Manufactured by CSL administered to those travelling to countries where there is a risk of cholera outbreaks. It is administered as follows:
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Avoid food 1 hour before and after.
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Children aged 2 - 6: Receive 3 doses of 75mL per dose with intervals between 1 - 6 weeks each. If the previous dose was more than 6 weeks ago, then they need to restart the primary dose. This dose is an oral solution dissolved with 150mL of water of which half is administered. If there are ongoing risks, then booster shots are recommended.
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Children aged 6 or over (including adults): Receive 2 doses of 150mL dissolved in water with booster doses every 2 years
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Travellers can received the cholera vaccine any time in conjunction with other travel vaccines such as yellow fever or typhoid vaccines however the oral live attenuated typhoid vaccine should be spaced at least 8 hours apart from the cholera vaccine administration.
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Contraindication: Anaphylaxis.
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Precaution: acute febrile illness or acute gastrointestinal illness with persistent vomiting and diarrhea.
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Immuno-compromised people can take the cholera vaccine.
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It is NOT recommended for pregnant or breastfeeding women however needs to be balanced against the risks
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Adverse Events: Cholera vaccine has a good safety profile but can occassionally cause mild abdominal pain, discomfort and diarrhea in up to 1% of patients.