# Clinical Diagnosis of Cytomegalovirus Colitis Enhanced With Multiplex Polymerase Chain Reaction Panel Using Stool Sample: A Case Report

## TL;DR

A 71-year-old man with suspected CMV colitis was diagnosed using a stool-based PCR test when colonoscopy was not possible, enabling timely treatment.

## Contribution

Demonstrates the utility of stool-based multiplex PCR for diagnosing CMV colitis when colonoscopy is infeasible.

## Key findings

- CMV was detected in a stool sample using the BioFire® FilmArray® ME Panel.
- Timely ganciclovir treatment improved the patient's condition.
- Stool-based PCR can aid in diagnosing CMV colitis when standard methods are not feasible.

## Abstract

A 71-year-old man was admitted because of acute exacerbation of interstitial pneumonia following a right upper lobectomy for lung cancer. His respiratory failure worsened after admission, and he required mechanical ventilation. He was undergoing intensive immunosuppressive treatment, including high-dose corticosteroids and cyclosporine, and had watery diarrhea six times a day. White blood cells were found in the stool, and an intestinal infection was suspected. Fecal cultures showed no pathogenic bacteria. Multiplex polymerase chain reaction for gastrointestinal infection yielded negative results. Based on the increasing number of cytomegalovirus (CMV) antigen-positive cells in the CMV antigenemia assay, we suspected CMV colitis. However, the patient was still undergoing mechanical ventilation, and colonoscopy was difficult to perform. After explaining the procedure to the patient and obtaining his consent, the BioFire® FilmArray® Meningitis/Encephalitis (ME) Panel was performed using a fecal specimen. CMV was detected. Intravenous infusion of ganciclovir at 5 mg/kg was immediately commenced and administered every 12 hours for three weeks. Intravenous infusion at 5 mg/kg was continued every 24 hours thereafter for a further three weeks. When CMV colitis is suspected but the patient’s condition prevents tissue collection through colonoscopy and standard diagnosis by histopathology, the addition of CMV PCR using a stool sample may assist in the clinical diagnosis of CMV colitis. The use of multiplex polymerase chain reaction is expected to contribute to prompt and appropriate treatment.