The recent European E. coli O104:H4 Outbreak is now reporting over 2,000 ill (nearly 70% women) and 19 dead in what has now become the world’s most deadly E. coli Outbreak and its third largest.  However, what is most staggering are the numbers of people who have developed Hemolytic Uremic Syndrome – over 550 to date – an attack rate of over 27%.   In some respect it reminds me of the 2006 Dole Spinach E. coli O157:H7 Outbreak, which, according to the CDC:

Among the ill persons, 102 (51%) were hospitalized and 31 (16%) developed a type of kidney failure called hemolytic-uremic syndrome (HUS). One hundred forty-one (71%) were female and 22 (11%) were children under 5 years old. The proportion of persons who developed HUS was 29% in children (<18 years old), 8% in persons 18 to 59 years old, and 14% in persons 60 years old or older.

Whether it is E. coli O104:H4 or E. coli O157:H7 caused Hemolytic Uremic Syndrome, it is a very nasty outcome.  So, lets get some answers:

What is the Hemolytic Uremic Syndrome and What Do I Need to Know about It?    

Post-diarrheal Hemolytic Uremic Syndrome (D+HUS) is a severe, life-threatening complication that occurs in about 10% of those infected with E. coli O157:H7 or other Shiga toxin (Stx) producing E. coli.  D+HUS was first described in 1955, but was not known to be secondary to E. coli infections until 1982.   It is now recognized as the most common cause of acute kidney failure in infants and young children.  Adolescents and adults are also susceptible, as are the elderly, who often succumb to the disease.

How did these otherwise harmless E. coli become such killers?  It seems likely that DNA from a Shiga toxin producing bacterium known as Shigella dysenteria type 1 was transferred by a bacteriophage (a virus that infects bacteria) to harmless E. coli bacteria, thereby providing them with the genes to produce one of the most potent toxins known to man.  So potent, that the Department of Homeland Security lists it as a potential bioterrorist agent.  Although E. coli O157:H7 are responsible for the majority of cases in America, there are many additional Stx producing E. coli strains that can cause D+ HUS.

The following is a comprehensive description of the hemolytic uremic syndrome (HUS), its symptoms, and the complications and long-term risks associated with HUS.  (A glossary of terms can be found at the bottom of this entry).

Hemolytic uremic syndrome is a severe, life-threatening complication of an E. coli bacterial infection that was first described in 1955, and is now recognized as the most common cause of acute kidney failure in childhood. E. coli O157:H7 is responsible for over 90% of the cases of HUS that develop in North America. In fact, some researchers now believe that E. coli O157:H7 is the only cause of HUS in children. HUS develops when the toxin from E. coli bacteria, known as Shiga-like toxin (SLT) [1,2], enters cells lining the large intestine. The Shiga-toxin triggers a complex cascade of changes in the blood. Cellular debris accumulates within the body’s tiny blood vessels and there is a disruption of the inherent clot-breaking mechanisms. The formation of micro-clots in the blood vessel-rich kidneys leads to impaired kidney function and can cause damage to other major organs.


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