09-06-2007, 09:56 PM
A 32-year-old former heroin addict has a history of being treated for Pneumocystis carinii pneumonia twice in the past year. Over the past 2 weeks, he has developed bloody diarrhea, which occurred up to 12 times daily and is associated with urgency and the sensation of incomplete evacuation. He also complains of left lower quadrant cramping. He denies any history of homosexual activity. Which of the following organisms would most likely be responsible for his symptoms?
A. Cryptosporidium
B. Cytomegalovirus
C. Entamoeba histolytica
D. Enterotoxigenic Escherichia coli
E. Escherichia coli 0157
A. Cryptosporidium
B. Cytomegalovirus
C. Entamoeba histolytica
D. Enterotoxigenic Escherichia coli
E. Escherichia coli 0157