Cholera, a deadly, life-threatening disease that affects 3 to 5 million people worldwide. I previously did not know how widespread and lethal this disease was, but after reading a detailed article in this month’s Biological Sciences Review magazine I found out exactly how the toxin causes such devastating effects.
Having had the cholera vaccine in order to travel to the Dominican Republic and Ecuador, I did not realise the consequences that cholera could have. It is actually endemic in various parts of Asia and is responsible for 100,000 to 120,000 deaths annually. Essentially it is an infection of the small intestine by the bacterium Vibrio cholera which thrives in contaminated water. Hence, the disease occurs in areas of poor sanitation, particularly after natural disasters or war.
There is excessive transport of chloride ions and water into the small intestine as a result of the toxin being released. This leads to severe diarrhoea causing rapid dehydration. In 50% of cases, if untreated, it can cause death in just a few hours. Fortunately, there are new therapies to counteract dehydration by delivering a mixture of sugars and salts dissolved in water. Sufferers can therefore revive their immune system and recover. Nevertheless, the majority of people do not have access to such treatments as Figure 1 shows 70% of all cases occur in Southeastern Asia, Northern and Central Africa. The territory size on this map indicates the proportion of all cholera cases in that country. The United Kingdom (top centre) and United States (top left) are almost unnoticeable. Hence, most people infected are likely to live in poor conditions and so are likely to die if they become severely dehydrated.
Indeed, there are no drugs currently which can specifically block the cholera toxin, and so even in economically advanced countries, recovery is only ensued by oral-rehydration therapy. Nevertheless there are a multitude of clinical trials being carried out in cholera-affected areas. To find out about specific clinical trials visit: http://www.nhs.uk/Conditions/Cholera/Pages/Clinical-trial.aspx?&Condition=Cholera&pn=1&CT=0&Rec=0 .
In conclusion, always check to see if you are travelling to a cholera-affected area to ensure you take the necessary precautions. A cholera vaccine is administered as a drink and it lasts for 2 years. While in the affected area you should also avoid ice cream and any ice in drinks, ensure you drink bottled water, avoid uncooked food unless you have washed it yourself and avoid seafood. While making sure that your health is protected from cholera, we also need to support those who are disadvantaged from such privileges. The most recent severe outbreak of cholera was in South Sudan and charity MSF has so far treated 46,900 people. They do this by simply replacing the fluids and salts the patient has lost having developed cholera treatment kits to provide rapid assistance. The MSF has managed to limit the case fatality in South Sudan to less than 1%. Working in Angola, Cameroon, Haiti, India, just to name a few more countries; the charity is hugely responsible to providing a future where cholera can be controlled and contained. Their website includes an interactive guide to how they treat cholera (http://www.msf.org.uk/cholera,) and you can also donate online.
Cholera is just one of the few diseases that effects less economically developed countries around the world. It is important to remember in the midst of wars and natural disasters, how such diseases can thrive and spread so quickly affecting millions who are deprived from medical facilities that we take for granted each day.
Biological Sciences Review, Volume 28, November 2015