Mon June 27, 2011

The German Disease

Most strains of E. coli bacteria are harmless. But a new, more virulent strain has the medical community perplexed as to its origins. This has caused a lot of finger pointing which KUNC commentator Dr. Marc Ringel says is rather pointless.

Not so long ago the French called it the “Spanish Disease” while the Spanish called it the “French Pox.”  I’m referring to syphilis, caused by a bacterium that in reality shows no more national preference than the folks who spread that venereal disease show when they choose whom to have sex with.

Since May there’s been an epidemic of severe, sometimes fatal, diarrhea that began in Germany.  Initially the Germans blamed the infection on Spanish cucumbers, causing huge economic losses for Iberian vegetable farmers and a giant legal kerfuffle between the government of Spain and their German brothers in the European Union.

Then German public health authorities reported, “Sorry.  We think the problem was really caused by vegetable sprouts grown on an organic farm in Lower Saxony.”

This is a very bad bug.  As of June 16 (the latest statistics I could find), the infection had caused well over 3000 confirmed cases of bloody diarrhea to people in 16 nations, complicated by hemolytic-uremic syndrome (a type of kidney failure) in more than 800 patients.  There had been 39 deaths.  Five infections with this germ, officially known as E. coli O104, occurred in the United States.

This particular bacterium is a new variant of a very old germ.  Microbiologists have been studying Escherechia coli, a family of bacteria that got its first name from the German bacteriologist, Theodor Escherich, who discovered it in the1885.  The second name, “coli,” derives from the large intestine, where the bug thrives.

About 30% of human stool is composed of excreted bacteria, a large proportion of which, literally billions of organisms, is E. coli.  The colon provides a nutrient rich, warm niche for about a dozen-and-a-half different bacterial species.  Digestive health depends on having the right proportions of the right bacteria, which is why antibiotics often cause diarrhea by upsetting the balance among the critters that live in the large intestine and why eating active yogurt cultures can sometimes cure antibiotic-associated diarrhea by adding more “good bacteria” to the mix.

Some E. coli are not so benign.  They produce toxins that inflame the intestinal lining, affect distant organs like the kidneys, and provide an entrée for spread of infection into the bloodstream and to other parts of the body.

E. coli O104 produces shiga toxin, like that produced by the Shigella bacillus (discovered by a Japanese bacteriologist, Dr. Shiga, of course).  Shigellosis is a form of dysentery, characterized by bloody diarrhea and fever.

Nobody knows how this new bad E. coli germ came into being.  Nor has there been time to completely characterize the organism and to understand exactly how it sickens humans.  We do know that, like the Spanish accuse the French and the French accuse the Spanish, E. coli is quite promiscuous.  This bacterium exchanges genetic material with all sorts of other germs, occasionally including blueprints to produce toxins.

E. coli infections start with swallowing bad bugs that probably came from someone else’s colon.  We don’t know how sprouts from the culprit farm were contaminated with the bad bug.  Once the tainted sprouts were removed from the market, subsequent infections probably started with people picking up the germ from the tiniest bit of contamination left on a sink, a plate or a hand by someone with an infection. Which is why you should always, always wash your hands well before cooking or eating.

And, much as I love the Spanish, don’t take them seriously when they call this the “German Disease.”


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