Thursday, February 11, 2010

Shiga Travels To Kidney. Commits Lethal Deed. (Part 3)

Part 1: Shiga Toxin: One Of Man's Most Lethal Poisons
Part 2: E. coli O157:H7 Just One Among Many Shiga Toxin-Making Bacteria
Part 4: Marler Clark Holds USDA To Their Food Safety Mission, Legally

Shiga toxins sicken and kill by entering cells and shutting down their protein-making machinery - their ribosomes. This is similar to how the deadly toxin ricin works. Shiga causes tiny blood vessels to rupture; you don't just get diarrhea, you get bloody diarrhea. Shiga can then travel to the kidney, destroy tiny blood vessels there, resulting in a life-threatening complication from shiga poisoning: HUS or Hemolytic Uremic Syndrome. HUS can progress to kidney failure.

So, we have:
  • A poison, shiga, thousands of times more deadly than snake venom or strychnine.
  • A potent poison. In the case of E. coli 0157:H7, you only need about 10 or 20 bacteria - what would fit on the head of a pin - to infect and generate lethal quantities of shiga.
  • There's no antidote for shiga toxin.
  • Thorough cooking won't protect against cross contamination, or against contamination of foods eaten raw like lettuce and spinach.
  • Antibiotics may not only be useless, they may in fact worsen illness.1
  • Antidiarrheal drugs like Imodium® may also worsen illness.2
Shiga is nasty. It's showing up in more and more types of bacteria. Richard Raymond, the USDA's former head of FSIS, its food safety arm, said a few months ago:3
"The number of illnesses reported [from shiga toxin-producing bacteria other than E. coli O157:H7] has risen every year since reporting became mandatory [in 2000].

In those states where testing includes both 0157 and non-0157 the results are very similar---non-0157 appears to cause food borne illnesses at the same rate as 0157 does.

Dr. Samadapour reported at the 7th International Symposium on Shiga Toxin producing E coli that his lab had found non-0157 in 1.9% of ground beef sampled from retail stores. One out of every 50 packages contained this pathogen. That is not zero tolerance.

We need it out of our food."
Since there is no effective treatment for infection from bacteria that make shiga, the goal of our nation's public health agencies is to keep shiga toxin-producing E. coli out of our food.

The USDA can help meet that goal by declaring bacteria that make this toxin to be adulterants. They've done that for one: E. coli O157:H7. The CDC says there are over a hundred more.

Part 4: Marler Clark Holds USDA To Their Food Safety Mission, Legally
1 The Risk Of The Hemolytic–Uremic Syndrome After Antibiotic Treatment Of Escherichia Coli O157:H7 Infections, New England Journal of Medicine, June 2000
"Antibiotic treatment of children with E. coli O157:H7 infection increases the risk of the hemolytic–uremic syndrome."
2 CDC: Escherichia coli
3 Comment by Richard Raymond, October 21 2009, on Petition for an Interpretive Rule Declaring all enterohemorrhagic Shiga Toxin-producing Serotypes of Escherichia coli (E. coli), Including Non-O157 Serotypes, to be Adulterants Within the Meaning of 21 U.S.C. § 601(m)(1)

Drawing showing shiga toxin (STX) traveling from the intestine to the kidney where it commits lethal deed is by Mad Scientist, Jr. EHEC is Enterohemorrhagic E. coli, of which O157:H7 is one. That's one great sketch.

1 comment:

Pila said...

Found your blog from Marler's site. Good stuff! :)