Post-Diarrheal Hemolytic Uremic Syndrome (D+HUS)

1. Post-Diarrheal Hemolytic Uremic Syndrome (D+HUS) • Richard L. Siegler M.D. • Professor Emeritus • University of Utah School of Medicine

2. What is Post-Diarrheal Hemolytic Uremic Syndrome (D+HUS) and where did it come from ? • The syndrome includes: • Acute kidney failure • Hemolytic anemia • Thrombocytopenia (low platelet count) • Most common cause of acute renal (kidney) failure in young children; also occurs in older children and adults

3. How did these otherwise harmless E. coli become such killers? • DNA from a Stx producing bacterium (Shigella dysenteriae type 1) transferred by bacteriophage to E. coli • This provided E. coli with genes to produce Shiga toxin (Stx), one of the most potent toxins known to man  

4. Pathogenic Cascade;from diarrhea to dialysis • Chain of events: • ingestion of Stx producing E. coli • multiplication in bowel • absorption of Stx into circulation

5. pathogenic cascade, cont. • Chain of events, cont.: • attachment of Stx to receptors in kidney, and occasionally other organs • movement of toxin into cells • cell injury or death

6. pathogenic cascade, cont.the end result is: • hemorrhagic colitis (bloody diarrhea) • kidney injury, causing acute renal failure • damage of red blood cells causing anemia • trapping and destruction of platelets causing bleeding • occasional damage to other organs (brain, pancreas, heart, lungs, eyes)

7. Signs and Symptoms • diarrhea (usually bloody) with severe pain; can be mistaken for appendicitis • pallor • bruises • seizures and/or coma (occasionally) • little (oliguria) or no (anuria) urine • high blood pressure • pancreatic damage (diabetes)

8. Hospital course and Treatment • meticulous attention to salt and water balance • dialysis for kidney failure • blood transfusions for anemia • Platelet transfusions for bleeding • aggressive nutritional support (e.g., total parenteral nutrition [TPN]) • treatment of high blood pressure • treatment of seizures

9. Outcomes • Death in 3-5%, due to: • brain damage (stroke and/or brain swelling) • bowel necrosis and perforation • heart damage • lung injury • multiorgan injury (seen in most fatal cases)

10. outcomes, cont. • Those who survive may be left with: • permanent kidney damage • brain damage • hypertension • diabetes

11. Monitoring • Chronic kidney failure may occur decades later (due to hyperfiltration injury) • most common in those who had prolonged kidney failure (oligoanuria) >10 days • proteinurea (protein in the urine) is an early sign

12. monitoring, cont. • Hypertension may begin years later (in those with chronic kidney damage) • Diabetes can latter occur (in those with pancreatic injury)

13. Summary • D+ HUS is a life threatening complication of Stx producing E. coli • It occurs primarily in infants and young children, but also affects adults • Is fatal 3-5% of victims • Survivors (30-50%) are left with chronic kidney damage that can be progressive later in life • Life long monitoring is necessary