A 37–year–old Caucasian female with a history of hypothyroidism presented with acute, diffuse, cramping abdominal pain, bloody diarrhea and green mucous discharge. The patient was admitted to our institution for acute gastroenteritis. Physical exam was significant for diffuse tenderness to palpation in the abdomen. The hospital course consisted of nausea, non–bilious vomiting and multiple episodes of loose stools with blood for 3 days. She received intravenous (IV) hydration along with IV ciprofloxacin and metronidazole. Despite persistent diarrhea, laboratory findings showed no evidence of leukocytosis, and stools were negative for ova and parasites, Clostridium difficile and stool leukocytes. Computed tomography (CT) of the abdomen and pelvis was obtained and showed pancolitis and terminal ileitis, consistent with infectious or inflammatory bowel disease. A gastroenterology consult was obtained and a colonoscopy done, which showed friable mucosa and acute infectious colitis. Symptoms improved and the patient was discharged home on oral ciprofloxacin. Several days after discharge, stool cultures showed Vibrio parahemolyticus. Only after the patient was called with results did she recall eating raw oysters.
Most acute diarrheal illnesses occur in the winter months and are usually associated with noroviruses. A patient reporting mucous or blood in the stool should prompt stool testing for bacterial culture as well as ova and parasites. If diarrhea still persists greater than 7 days, then further testing for less common pathogens should be pursued. V. parahaemolyticus is the most common cause of seafood related diarrheal illness, and especially prevalent along the gulf coast in the United States. A review of records from the microbiology lab at our institution for the last 10 years shows that vibrio was isolated only 4 times. According to the MMWR, a surveillance of food borne disease outbreaks in the US in 2006 revealed that among 624 total outbreaks of infectious colitis, 8 cases of V. parahemolyticus surfaced, and of those, only 6 had positive stool confirmation. Imaging of patients with this condition may lead to confusion regarding diagnosis.
Organisms such as V. parahemolyticus can mimic conditions such as ulcerative colitis or Crohn’s disease. Detailed history of travel and ingestion should be elicited even in atypical regions. Although V parahemolyticus has rarely been documented nationally in hospitalized patients and can be self–limiting, it can mimic more serious illness.
Figure 1Mild diffuse thickening of the colon and terminal ileum