Cytomegalovirus colitis in intensive care unit patients: difficulties in clinical diagnosis

Cytomegalovirus (CMV) infection occurs increasingly in critically ill patients in intensive care units (ICUs). We reported CMV colitis which has rarely been recognized in the ICU patients.

CMV DNA was detected by polymerase chain reaction (PCR) for blood and/or stool samples. Definite diagnosis of CMV colitis required histopathology or CMV immunohistochemical staining of colorectal biopsies. We reviewed ICU patients characterized by positive blood or stool CMV-PCR with colorectal bleeding or water diarrhea.

We identified 18 patients (biopsy-proved, n=8; probable cases, n=10). The most common comorbidities were chronic renal disease, diabetes mellitus, and coronary artery disease. Stool CMV-PCR was positive in 7 of 10 patients (2 of 3 biopsy-proved and 5 of 7 probable cases). Colonoscopy was performed for 15 patients, revealing ulcerative or polypoid lesions. The endoscopists obtained colonic biopsies from 9 patients. Yet, the pathologists reported CMV colitis for 4 patients. Additional 4 patients were confirmed using immunohistochemical stain by the request of clinical physicians. Pseudomembranous colitis was found in 4 patients.

Diagnosis of CMV colitis seems difficult in clinical practice and need persistent communication between clinicians. The positive stool CMV-PCR result was a useful hint for adding immunohistochemical stain in mucosal biopsies to make a definite diagnosis of CMV colitis.