This assay should be used with other criteria including symptoms and clinical presentation. 

Newborn Screen: The neonatal saliva swab is intended to screen for CMV DNA and provide early identification of at-risk congenitally infected infants.  This would allow for targeted monitoring and/or intervention during critical stages of speech and language development.  High titers of CMV are shed in saliva of infected newborns, and a swab of saliva specimen is an easy and non-invasive sample type for newborn screening.

Cytomegalovirus is a ubiquitous human herpes virus that establishes latency in cells of the myeloid lineage after primary infection.  Seroprevalence studies have shown that 60-70% of adults in the US have been exposed to the virus at some time during their lives and that prevalence increases with age.  The virus can be transmitted in-utero or spread through direct contact with body fluids as occurs throughout child care, breast feeding, during intimacy, or via certain blood transfusions.  Most immunocompetent individuals do not experience symptoms during primary infection.  A small portion of patients will develop a self-limited mononucleosis-like illness characterized by fever, pharyngitis, and lymphadenopathy.  For immunosuppressed patients, however, primary infection may be devastating.  Similarly, in the setting of significant immunosupression, the virus may reactivate from latency, disseminate, and cause invasive end organ disease.

Clinically significant CMV disease frequently develops in patients immunocompromised by low CD4 counts and HIV, solid organ transplantation, and bone-marrow transplantation.  Symptomatic disease in immunocompromised individuals can affect almost every organ of the body, resulting in fever of unknown origin, pneumonia, hepatitis, colitis, myelitis, retinitis, neuropathy, and encephalitis.  CMV can infect parenchyma in both the peripheral and central nervous systems.  Additionally, congenital transmission from a mother with acute infection during pregnancy is a significant cause of neurological abnormalities and deafness in newborns.  CMV-caused meningoencephalitis is a common complication in newborns congenitally infected with the virus and in adults with a profound cellular immunodeficiency, as in transplant recipients and AIDS patients.  Other neurological manifestations of CMV disease include ventriculitis, myelitis, radiculoganglionitis, and peripheral neuropathies.  Untreated CMV encephalitis progresses to death.

Congenital transmission from a mother with acute infection during pregnancy has the potential for the development of CMV infection in the newborn.  Congenital CMV infection occurs most often in fetuses infected during the first half of gestation.  CMV may be transmitted to about 50% of fetuses after maternal primary infection, and about 10% of these will be clinically affected.  The route of transmission of CMV from mother to fetus has not yet been well elucidated.  It is possible that the spread is hematogenous, through the cord blood or placental tissue and amniotic cells.

Reliable results are dependent on adequate specimen collection, transport, storage, and processing procedures.  A negative result does not preclude active disease. 

Specimens grossly contaminated with blood may inhibit the PCR and produce false negative results. 

The high sensitivity of PCR amplification requires that the specimens be processed in an environment where contamination of the specimens by CMV DNA is not likely to occur.

Saliva from newborns must be collected PRIOR to breastfeeding.  CMV may be shed in breast milk and confound the results of the screen.

Detection of CMV does not indicate the viability or non-viability of the CMV virus.

This is a qualitative assay that uses an automated extraction of nucleic acid and real-time PCR amplification.



CMV DNA extraction and purification is accomplished with the MagNA Pure Compact instrument/Nucleic Acid Extraction Kit (Roche Applied Science)or with the NucliSENS easyMAG instrument (BioMerieux), depending on the specimen type.  this provides highly purified nucleic acid ready for amplification and detection.



CMV DNA PCR using the MGB Alert CMV 3.0 assay is based on the amplification of a selected target region on the CMV genome (Major Immediate Early Gene (IE1)) using target-specific complementary primers and specific fluorescent labeled probes.  Detection occurs concurrently with amplification in a cycle-by-cycle monitoring format during the log-linear phase of amplification.  The LightCycler 2.0 (Roche Applied Science) monitors fluorescent intensities during PCR, allowing for the real-time detection of CMV amplicons. The proprietary CMV Primer/Probes are designed to be exclusively complementary to the target DNA; therefore, cross-reactivity with other viruses is not expected and was not observed.



This test was developed and its performance characteristics determined by the Duke University Health System Clinical Microbiology Laboratory. It has not been cleared or approved by the U.S. Food and Drug Administration.