CMV PCR Test, Normal Range, Levels, Positive, Negative, Interpretation

Cytomegalovirus, also known as CMV, is regarded as the most prevalent prenatal viral infection in humans. It is also considered as a major contributor of morbidity and mortality in immunosuppressed patients. This understanding of the clinical significance of invasive CMV illness in immunosuppression and in infants with parental CMV infection has led to the creation of new diagnostic techniques for the quick detection of immunocompromised persons with CMV disease and fetuses and babies with parental infection.

The CMV PCR Test on saliva is the standard laboratory test for identifying congenital CMV infection. Urine is typically collected and analyzed for validation once the saliva test is done. Most CMV-positive women shed the virus in their breast milk, which necessitates a urine test for confirmation. When saliva is collected soon after the newborn has breastfed, this may result in a false-positive CMV test.

CMV PCR Test

The following are detailed instructions for properly collecting saliva specimens from a newborn:

Collect a sample of the baby's saliva more than an hour after nursing and within 3 weeks of birth. If CMV is found after three weeks, it could be because of a post-partum infection. Swirl sterilized cotton or swab between the baby's gums and cheeks for several seconds. After removing the swab, place it in a buffer intended for PCR diagnostic testing. If CMV is present, the infectious agent will transfer from the swab to the liquid.

The liquid is handled in accordance with the manufacturer's guidelines, and PCR testing is conducted in the lab in accordance with the protocol. Depending on the laboratory, different processes and test interpretations apply.

CMV PCR Test Ranges and Levels

Patients who have CMV disease have a peak viral load that is considerably greater than those who have asymptomatic infection. The median peak viral load for patients with CMV disease is 55,000 copies/ml, whereas the peak viral load for patients with asymptomatic infection is 1820 copies/ml. By analyzing the data from the receiver-operator characteristic curves, specialists find that the best viral load for diagnosing clinically relevant CMV illness is between 2000 and 5000 copies/ml of plasma. As the viral load cutoff level for finding CMV disease goes up, the sensitivity goes down, but specificity goes up.

CMV PCR Test Positive and Negative

This test assesses the amount of Cytomegalovirus (CMV) viral genetic material in the blood. If this PCR test produces positive results, a quantitative numerical value will be provided to indicate the amount of viral DNA that was found (viral load). The word "negative" will be reported for negative outcomes. For the CMV DNA PCR test, the permissible range is 200–1 million units/ml. If the result is positive but the value is lower than the notifiable range, the result will be reported as <200.

CMV PCR Interpretation

Testing for CMV DNA viral loads is an essential tool for determining illness risk, making a diagnosis, and tracking treatment outcomes. The interpretation of CMV DNA viral load levels can be complicated, and several viruses and host parameters must be taken into account when determining the risk of CMV illness. For accurate interpretation of test results, it is vital to comprehend the performance characteristics of the viral load test.