Table 4:

Definitions of congenital/neonatal CMV infections¹²²

Congenital CMV infection	Cytomegalovirus infection acquired in utero. Diagnosis can be made within the first three weeks of life by detection of CMV in newborn’s urine or saliva
Postnatal CMV infection	Cytomegalovirus infection acquired in the postnatal period. After three weeks, CMV detection in urine or saliva may indicate either congenital or postnatal CMV infection. Postnatal CMV infection usually is clinically benign or self-limited
Symptomatic cCMV disease	Defined as a newborn with CMV detected in urine or saliva samples collected within 3 weeks of life, presenting with at least one of the clinical findings at birth: purpura/petechiae, jaundice, hepatosplenomegaly, microcephaly, unexplained neurological abnormality, elevated liver enzymes (alanine aminotransferase >100 IU), conjugated hyperbilirubinemia (direct bilirubin >2mg/dL), or thrombocytopenia (platelet count <100,000/mm3)
Asymptomatic cCMV infection	Defined as a newborn with CMV detected in urine or saliva samples collected within 3 weeks of life, who has a normal newborn examination, that is, none of the symptoms defining symptomatic cases
Primary neurophenotype	Refers to patients with only central nervous system manifestations. They lack the typical somatic manifestations and may appear completely healthy at birth or may have microcephaly. On follow-up, they develop neurologic manifestations and neuroimaging shows polymicrogyria or other cortical dysplasia
Asymptomatic with isolated hearing loss	Refers to infants with isolated hearing loss at birth but no other symptoms. Categorization of these infants as “symptomatic” or “asymptomatic” is inconsistent, hence considered as a distinct category because they are not truly asymptomatic, but their disease is milder than that of symptomatic infants
Virologically confirmed congenital CMV infection	Diagnosed on the basis of any of the following: Detection of CMV by viral culture in urine or saliva samples obtained within the first 3 weeks of life Detection of CMV by shell vial assay in urine or saliva samples obtained within the first 3 weeks of life, with a positive confirmatory test (viral culture or PCR) Detection of CMV via PCR in urine, saliva, or blood samples obtained within the first 3 weeks of life, confirmed on repeat testing Detection of CMV via PCR in the newborn screening dried blood spot
Possible congenital CMV infection	A diagnosis of “possible” congenital CMV infection may be made if all of the following criteria are met: One or more signs or symptoms of congenital CMV Other conditions that cause these abnormalities have been excluded Cytomegalovirus is detected in urine or saliva samples (via viral culture, shell vial assay, or PCR) or in the blood after the first three weeks of life
Not infected	Infants in whom CMV is not detected in urine or saliva (via viral culture, shell vial assay, or PCR) during the newborn period do not have congenital CMV. Because of the high sensitivity and specificity of these tests, a negative result excludes the diagnosis of congenital CMV infection. Congenital cytomegalovirus infection can be excluded beyond the newborn period if CMV IgG antibody testing is negative