A 6-year-old boy is brought to the emergency department because of fever, abdominal pain and diarrhea for the past 3 days. This morning he also had nausea and his stool had a dark red stool. The patient attends daycare and a few children there have developed diarrhea over the past week as well. His immunizations are up-to-date. His temperature is 38.0°C (100.4°F), pulse is 140/min, and blood pressure is 80/45 mm Hg. Examination shows dry mucous membranes. The abdomen is soft, and there is tenderness to palpation of the left lower quadrant with rebound. Which of the following is the most likely causal organism?

Question

Quizplus · Accepted Answer

Eductional Objective: Acute-onset bloody diarrhea is most commonly due to Escherichia coli O157:H7, Shigella, or Campylobacter infection.  Shigella infection also classically causes high fever and left-sided abdominal tenderness (due to rectosigmoid involvement) and often occurs in outbreaks (eg, day care center).

A 6-Year-Old Boy Is Brought to the Emergency Department Because