Table 1.

Definitions and risk factors of the described CMV clinical entities in the general, IBD, and liver transplant patient populations.

Disease manifestation	Definition	Risk factors
General population
Latent CMV	Asymptomatic, no clinically detectable active replication	Female sex, older age, high crowding index, and low household income or education [2]
Mononucleosis-like syndrome	Predominant constitutional, mononucleosis-like symptoms with intact immune system	Blood transfusions, second or third decades of life, exposure to bodily fluids of infected host [14]
Tissue-invasive CMV	Predominant symptoms localizable to a specific tissue site	Critical illness (especially with sepsis or intubation at time of admission), active malignancy (especially with low BMI, lymphopenia, or steroid use), hematologic malignancy, blood transfusion [27]
Inflammatory bowel disease ∗
Tissue-invasive CMV	Predominant symptoms typically localizable to the GI tract, mimicking IBD flare	Endoscopic inflammation [107], immunosuppressant-refractory ulcerative colitis
Liver transplant ∗∗
CMV syndrome	Positive CMV serum PCR with 2 of the following: (i) Fever ≥ 38°C for at least 2 days (ii) New fatigue or malaise (iii) Leukopenia or neutropenia (iv) ≥5% atypical lymphocytes (v) Platelets < 100,000 cell/μL or >20% decrease (vi) >2 xULN ALT or AST	R-/D+ status, acute allograft rejection, immunosuppression with antilymphocyte antibodies, mycophenolate dose > 2 grams/day, viral coinfection, toll-like receptor polymorphisms [108]
Tissue-invasive CMV	Predominant symptoms localizable to a specific tissue site

^∗Latent CMV and mononucleosis-like syndrome definition and risk factors are as with the general population. ^∗∗Latent CMV definition and risk factors are as with the general population.