Review Question - QID 107175

This clinical vignette is most consistent with Travelers’ diarrhea, which is associated with ingestion of unwashed fruits and vegetables.

Travelers’ diarrhea is a common gastrointestinal infection among those visiting developing countries. It may be caused by bacteria, viruses, and parasites. Symptoms generally begin within 4-10 days of travel and may include nausea, vomiting, abdominal cramps or pain, and passage of watery stool, usually 2-5 bowel movements per day. Given that the diarrheal illness is generally self-limited and resolves within 3 to 5 days, diagnostic testing is usually not needed nor informative.

This patient is at risk for infectious diarrhea given her recent travel to a developing country and intake of local food. In approaching this question, it is important to recognize the organisms associated with the answer choices. Vibrio vulnificus is associated with raw oysters; Listeria monocytogenes is associated with soft cheese; Bacillus cereus is associated with fried rice; Enterohemorrhagic E.coli (EHEC) is associated with ground meat; and Enterotoxigenic E. coli (ETEC) is associated with unwashed fruits and vegetables. Of these bacterial organisms, ETEC is the most common cause of Travelers’ diarrhea and most consistent with the patient’s onset and duration of self-limited watery diarrhea.

Incorrect Answers:
Answer 1: Vibrio vulnificus is associated with ingestion of raw oysters and can cause severe, life threatening septicemia most often in patients with underlying liver disease.
Answer 2: Listeria monocytogenes is associated with soft cheese and a rare cause of gastroenteritis, fever, watery diarrhea, and muscle aches.
Answer 3: Bacillus cereus is associated with ingestion of fried rice with preformed toxin, which leads to abdominal cramps and copious diarrhea. Symptoms generally start within 8 to 16 hours after ingestion and resolves within 1 day.
Answer 4: EHEC also known as E.coli O157:H7 is associated with ingestion of ground meat and can lead to bloody diarrhea or hemolytic-uremic syndrome (HUS)- a triad of thrombocytopenia, hemolytic anemia, and renal failure.

In Travelers’ diarrhea, antibiotics (usually a quinolone) and antimotility medications (like loperamide) may decrease the severity of diarrhea and duration of symptoms by one to three days. However, antibiotics and antimotility agents should not be used in patients with bloody or inflammatory diarrhea since they may block excretion of toxin and organism, and can lead to dangerous, prolonged illness (1).