Coexisting Gastrointestinal Cytomegalovirus and Herpes Simplex Virus Types 1 and 2 with Superimposed Clostridium difficile Colitis

Abstract

Purpose: The spectrum of morbidity and mortality caused by gastrointestinal cytomegalovirus (CMV) is classically determined by the host's immune response. Although self-limited in immunocompetent patients, multiple comorbidities, including age and malnutrition, can predispose a patient to debilitating opportunistic infections. We present a case of refractory pseudomembranous colitis with underlying gastrointestinal CMV and herpes simplex virus (HSV) infection. A 79-year-old Hispanic female was admitted for persistent diarrhea and vomiting. One month prior to admission, the patient had metastatic appendiceal mucinous adenocarcinoma, which was surgically excised. No chemotherapeutic regimen was initiated, and the patient was started on ampicillin and ciprofloxacin for a urinary tract infection. One week later, the patient described yellow, non-bloody diarrhea, averaging four bowel movements per day. Stool C. diff toxin assay was positive. Although oral metronidazole was prescribed, treatment was ineffective due to vomiting. On admission, the patient complained of fatigue and nausea, but denied fever, chills or abdominal pain. Past medical history was negative, and the patient's social and family history rendered no risk factors for either hereditary or acquired immunodeficiency. On examination, she was lethargic and cachectic. Her abdomen was distended with voluntary guarding but without peritoneal signs. Bowel sounds were present, and rectal exam showed positive fecal occult blood test. Laboratory showed WBC 10.1 K/uL with 14% bands and hemoglobin of 9.5 gm/dL. HIV was undetectable via PCR quantification. The patient was treated with intravenous metronidazole and oral vancomycin, but symptoms persisted. Rifampin was then added but rapidly discontinued as the patient developed hyperbilirubinemia. On hospital day four, a colonoscopy showed pancolitis with pseudomembranes. Biopsies confirmed the impression of C. diffinfection and demonstrated multiple viral inclusions within the epithelial cells. CMV and HSV immunostaining was positive and CMV DNA was detected in the serum via PCR quantification. Intravenous foscarnet was started with noticeable improvement in diarrhea within two days. With the increasing incidence and severity of C. diff-associated diarrhea, many patients develop infections refractory to standard treatment regimens. Whether this is due to resistance or co-infection needs to be determined. This case demonstrates an example of persistent diarrhea, despite appropriate antibiotics for C. diff colitis due to a viral co-infection. We suggest that this type of co-infection may arise in immunocompetent patients and should be taken into consideration when patients present with refractory colitis.