by Arneb » Sat Jun 04, 2011 10:06 pm
What gives you the idea that Cholera, of all things, is at work here?
Cholera, caused by a special strain of the bacterium Vibrio cholerae, is characterized by vomiting and watery diarrhea. The last cholera epidemic in Gemany was in Hamburg, in 1892. The history of Cholera in Germany ends with the 19th century. It did not even come back under the catastrophic circumstances of post-WWII. Cholera is usually transmitted by drinking water contaminated with Cholera patients' excrement, which contains V. cholerae in excessive numbers. The number of bacteria needed to cause Cholera is high (10^6), and direct human-to-human transfer or contaminated food is rare.
Enterohaemorrhagic Escherichia coli (EHEC) is the bug you are asking me about. It is an infection by a ubiquitous denizen of the human gut (E. coli), which has acquired several so-called virulence factors. It causes a disease characterized by bloody diarrhea, abdominal pain, sepsis (severe general reaction to an infection: fever, shortness of breath, low blood pressure, rapid pulse, weakness), haemolysis (the destruction of red blood cells in the blood stream) and uncontrolled clotting of blood platelets. The latter, by obstructing blood flow in the small vessels of the kidney, causes acute kidney failare. The full-blown disease is therefore called haemolytic-uraemic syndrome (HUS). The bacterium also carries the so-called ESBL plasmid, which makes it highly resistant to comonly-used antibiotics (which is not the point in this disease, as HUS is not usually treated antibiotically; however , it is a hint that the causative organism is from an environment in which antibiotics are used).
The dose for infections is extremely low (less than 10^2). The main source is contaminated food. The first patients (typically young, previously healthy women taking good care of their diet and usually eating little or no meat, plus their families) hinted at raw vegetables as the source of the infection, hence the ruckus about Spanish organic cucumbers being fertilized with manure.
This epidemic is extremely interesting: With the low infection dose, the source of the contamination can be extremely subtle. In the early days, there was speculation that the epidemic was caused by a single palette of cucumbers falling over in the Hamburg central food market, and hitting contaminated ground. Living in a country where serious infectious disease or serious food hygiene incidents are rare, we do not, of course, have a "Peel it, boil it, cook it or forget it" attitude towards food - except when we travel. Thus, what is considered the healthiest food of all, a salad, could have become the source of an epidemic that has, to date, killed 11 people (1213 reported cases of EHEC infection; 502 HUS cases).
I have not personally treated any patients with the disease, but our canteen has since removed fresh vegetable from the menu, according to the new customer protection guidelines (which are basically, and sensibly, "peel it, boil it..." and "wash your hands"). I've had a lot of pickled kraut salad during those last days, I can tell you.
This is the most severe EHEC epidemic EVER in the world. The causative organism was known beforehand, it occurred worldwide, but was very rare. Something extraordinary must have happened to make this thing the cause of an epidemic in a usually hygiene-obsessed rich country.
I'll keep you informed, if there is interest.
And, tubeswell, don't call it cholera. Please.
Non sunt multiplicanda entia praeter necessitatem