Cytomegalovirus colitis in a critically ill, dialysis-dependent, acute kidney injury patient without immunosuppressive therapy.

Background: Historically, cytomegalovirus (CMV) infection in immunocompetent patients has been considered to have a relatively indolent and self-limited course, not warranting specific treatment. Case presentation: We are presenting a 72-year-old African-American male transferred to our intensive care unit (ICU) with methicillin-resistant Staphylococcus aureus bacteremia, respiratory failure, and dialysis-dependent acute kidney injury. While he recovered from bacteremia, he remained difficult to wean from respiratory support, had labile blood pressure, and manifested persistent diarrhea. Stool antigen testing for C. difficile colitis returned repeatedly negative. Flexible sigmoidoscopy described diffuse ulceration, attributed to ischemic colitis. The colon biopsy specimen, however, described tissue-invasive cytomegalovirus (CMV) infection. Polymerase chain reaction (PCR) testing confirmed viremia with 8,900 copies/mL viral DNA. Human immunodeficiency virus antibody and PCR testing were both negative. Absolute lymphocyte count varied between 80 and 450/mm(3) during the admission. After IV ganciclovir initiation, diarrhea and respiratory failure resolved, while renal function recovered to the patient's baseline. Conclusion: The combination of critical illness and recent bacteremia likely represented a state of profound immunosuppression in this formerly healthy patient. CMV colitis may be under-diagnosed in sick ICU patients with renal failure and otherwise unexplained diarrhea. Serum PCR testing may aid the diagnosis.