Background
Pathophysiology
Typical HUS is caused by Shiga toxin from enterohemorrhagic Escherichia coli (e.g. O157:H7)
Shiga toxin is absorbed systemically
Damages vascular endothelial cells leading to cytokine release and thrombus formation
Actives complement and binds Factor H (a complement regulator)
Risk Factors
Younger age
Exposure to antibiotics
Increased WBC count
Vomiting
Prolonged diarrhea
Presence of stx2a and eae genes
Clinical Manifestations
Abdominal pain and watery diarrhea about 4 days after exposure to toxin, progressing to bloody diarrhea with or without vomiting
Up to one third do not have bloody diarrhea
Fever is mild or absent
About 7 days after onset of diarrhea, HUS develops
Other preceding infections can include UTI , SSTI , or other causes of gastroenteritis
Management