HUS is often preceded by which event?

HUS is often preceded by which event?

• A. Bloody diarrhea caused by E. coli
• B. Viral hepatitis
• C. Pneumonia
• D. Urinary tract infection

Answer: (A)

The key concept is that classic HUS almost always follows a diarrheal illness caused by Shiga toxin–producing E. coli. After ingesting the toxin-producing strain (often from undercooked meat or contaminated foods), a child typically develops bloody diarrhea. The Shiga toxin injures the vascular endothelium, especially in the kidneys, leading to microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. This makes bloody diarrhea caused by E. coli the best antecedent for HUS. The other events listed are not the usual triggers for classic HUS.

The key concept is that classic HUS almost always follows a diarrheal illness caused by Shiga toxin–producing E. coli. After ingesting the toxin-producing strain (often from undercooked meat or contaminated foods), a child typically develops bloody diarrhea. The Shiga toxin injures the vascular endothelium, especially in the kidneys, leading to microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. This makes bloody diarrhea caused by E. coli the best antecedent for HUS. The other events listed are not the usual triggers for classic HUS.