A previously healthy 36-year-old woman is brought in by ambulance following a seizure. Her husband reports that she has no history of seizures but had been complaining of diarrhea and vomiting for almost a week. She went out of town to a family reunion 10 days ago and had talked to several other family members who also became ill, some even needed to go to the hospital. On examination the patient is confused with diffuse abdominal tenderness. Vitals are within normal limits. Although in the ED she experiences an episode of grossly bloody diarrhea. Significant laboratory results include:
Peripheral blood smear shows a large number of schistocytes.
Which of the following statements is true regarding this patient’s disease process?
A. Early antibiotics have been shown to improve outcomesCorrect Answer: D
Enterohemorrhagic Escherichia coli (EHEC or Shiga toxin producing E. coli) is a cause of bloody, infectious diarrhea commonly associated with ingestion of contaminated food such as fresh produce, undercooked beef, or various prepackaged products. Although most infections resolve without complications, occasionally patients go on to develop the triad of nonimmune hemolytic anemia, thrombocytopenia, and AKI known as hemolytic-uremic syndrome (HUS). Although HUS is more commonly associated with children, some newer outbreaks have preferentially affected adults. The most common serotype is E. coli O157:H7; however, outbreaks associated with non-O157 serotypes have also been reported. The incubation period is 2 to 12 days. Stool culture is the gold standard for diagnosis, but a presumptive diagnosis can be made based on the presence of bloody diarrhea and the triad of HUS. Central nervous system involvement is common and can include seizures, stroke, coma, hemiparesis, or cortical blindness. Management of the gastroenteritis is generally supportive care including IV fluids. Antimotility agents should not be given and may be associated with increased risk of developing HUS. Antibiotics have not been found to be helpful. For patients who develop HUS, admission with close monitoring is recommended with the use of IV fluids, antihypertensives, renal replacement therapy, and red blood cell transfusions as clinically indicated. Anticoagulation, fresh frozen plasma, steroids, or Shiga toxin binders have not been shown to offer benefit. Unlike with thrombotic thrombocytopenic purpura or nondiarrheal (atypical) HUS, plasmapheresis has also not been shown to improve outcomes. Overall prognosis is good, even for patients that require dialysis. EHEC-associated HUS has a mortality rate of <5%.
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