Table 1.

Definitions: CMV syndrome and disease affecting different organs 19–22.

Disease	Presumed diagnosis	Confirmation
CMV syndrome	The presence of one or more of these signs: fever > 2 days, malaise, leukopenia, > 5% atypical lymphocytes, thrombocytopenia, and increased aminotransferases (> 2-fold, except in liver transplantation) plus evidence of active CMV infection	Clinical and laboratory evidence of CMV infection without confirmation of other etiology
Pneumonia	The presence of signs and symptoms of pneumonia (fever, cough, dyspnea, hypoxemia, X-ray changes) plus evidence of CMV infection in the blood and/or bronchoalveolar lavage	Lung disease manifestations plus the presence of CMV in lung tissue based on immunohistochemistry with or without evidence of active CMV infection in the blood or bronchoalveolar lavage
Gastrointestinal disease (esophagitis, gastritis, enterocolitis, colitis)	The presence of signs and symptoms of gastrointestinal compromise plus endoscopic signs of mucosal lesions and evidence of active CMV infection in the blood	Gastrointestinal manifestations plus the detection of CMV in gastrointestinal tissues by immunohistochemistry
Hepatitis	An increase in liver enzymes and bilirubin levels (> 2-fold) in the absence of other known causes plus evidence of CMV in the blood	The presence of increased liver enzymes and bilirubin levels plus the presence of CMV in liver tissue, as determined by immunohistochemistry; note that the presence of hepatitis and CMV in the blood, without histological confirmation of CMV in liver tissue, does not allow for the diagnosis of hepatic invasive disease
Central nervous system disease	Neurological signs and symptoms in the absence of other known causes plus evidence of CMV (as detected by RT-PCR) in the cerebrospinal fluid	Neurological signs and symptoms plus evidence of CMV in brain tissue, as detected by immunohistochemistry
Retinitis	Not applicable	Typical CMV lesions on the retina, as confirmed by an ophthalmologist
Invasive disease in other organs (e.g., nephritis, myocarditis, pancreatitis)	The presence of organ dysfunction in the absence of other known causes plus evidence of CMV in the blood	The presence of organ dysfunction plus the presence of CMV in the target organ tissue, as detected by immunohistochemistry

Evidence of active CMV in the blood: positivity of antigenemia or RT-PCR testing.