A Case of Cytomegalovirus Colitis in an Immunocompetent Host Complicated by Relapsing Clostridium difficile Colitis

Abstract

Background: Cytomegalovirus (CMV) colitis typically occurs in immunocompromised patients. Clinical presentation is characterized by watery or bloody diarrhea often associated with fever. The clinical course can carry significant morbidity and mortality, with complications including perforation and gangrene. We report a case of CMV colitis in an immunocompetent host. Methods: A case report is presented. Clinical History: A 56-year old female with a history of Hashimoto's thyroiditis, hyperlipidemia, hypertension, and osteopenia presented with diffuse abdominal pain, fevers, nausea, vomiting, and diarrhea. She had a colonoscopy, which revealed ulceration at the splenic flexure and was diagnosed with ischemic colitis. She was treated with metronidazole and ciprofloxacin, which failed to alleviate her symptoms. She was readmitted one week later and a CT abdomen revealed transverse colonic wall thickening. Sigmoidoscopy was normal at that time. She was treated with another course of antibiotics. Further workup included an MRA of the abdomen, which revealed a 10-12 cm segment of circumferential thickening of the mid-transverse colon. Her symptoms worsened, with persistent abdominal pain, diarrhea, malaise, and fevers. Work-up including Clostridium difficile (C. difficile) toxin, stool culture, stool crypto, and stool giardia were negative. A colonoscopy showed a segmental area of friable, ulcerated mucosa. Biopsies revealed several fragments of ulcer exudates, acute inflammatory granulation tissue and scattered cytomegalovirus inclusions in the transverse colon. She was treated with IV ganciclovir followed by oral valganciclovir for a total of three weeks. Her symptoms resolved completely. Workup for immunodeficiency including HIV testing was normal. Her course was subsequently complicated by severe C. difficile colitis requiring ICU admission. She completed a course of vancomycin and had a normal follow up sigmoidoscopy three weeks later without evidence of either CMV or C. difficile. She then had a relapse of C. difficile colitis and was treated with another course of vancomycin. Discussion: CMV colitis is rare in immunocompetent patients. This case highlights several important points. First, CMV colitis can easily be confused for more common diagnoses, such as ischemic colitis. Second, misdiagnosis can lead to inappropriate use of antibiotics, subsequently predisposing the patient to further complications, including C. difficile colitis, which can be difficult to eradicate. Third, antiviral therapy is effective for CMV colitis.