How accurate are HSV PCR tests?

PCR assays or other NAATs are the most sensitive test currently available to detect HSV in clinical samples. The detection rates of the PCR assays were shown to be 11–71% superior to virus culture [26,41-44].

Can a PCR herpes test be wrong?

Variations in quality. In a recent study of 27 coded samples tested by 66 labs, 30 false positive HSV PCR results were reported, as well as 30-50% false negative results for samples containing low titers of 0.2-7 copies/µL.

How accurate are herpes swab tests?

The herpes culture test (swab test) has a 0% chance of a false-positive test result. This means that a person who tests positive can be 100% sure that they have the herpes infection. The commercially available herpes IgG test (HerpeSelect) has up to a 19% probability of revealing false-positive test results.

What is a PCR test for herpes?

A PCR test can be done on cells or fluid from a sore or on blood or on other fluid, such as spinal fluid. PCR finds the genetic material (DNA) of the HSV virus. This test can tell the difference between HSV-1 and HSV-2. Using the PCR test on skin sores isn’t common.

How long does it take to develop HSV IgG antibodies?

The time required for the development of IgG antibodies following HSV infection varies from 21 to over 42 days with most individuals having detectable IgG 21–28 days after exposure to the infection and probably lasting for life.7–,9 IgM antibodies are usually detectable 9–10 days after exposure and last 7–14 days.

Can herpes be dormant and not show up in a blood test?

If you have the herpes virus and your body has produced antibodies, it can be detected on a blood test, even if you have no symptoms. The only time the virus might not be detected on a test (after you’ve contracted it) is if you’ve been tested too early.

What does PCR stand for in a blood test?

PCR means polymerase chain reaction. It’s a test to detect genetic material from a specific organism, such as a virus. The test detects the presence of a virus if you have the virus at the time of the test. The test could also detect fragments of the virus even after you are no longer infected.

What is the sensitivity of a herpes simplex 1 test?

While the test has 100% specificity for HSV-1 or HSV-2, the sensitivity depends on the stage of the lesion at the time of specimen collection. The sensitivity also varies from 75% for first episodes to 50% for recurrences (18,19). Once received in the laboratory, the specimen should be vortexed.

How is the specificity of a PCR assay dependent?

For instance, it is known that the sensitivity and specificity of a PCR assay is dependent on target genes, primer sequences, PCR techniques, DNA extraction procedures, and PCR product detection methods.

Which is the gold standard for herpes simplex virus?

Standard viral culture: Tube culture isolation is the traditional gold standard for HSV detection and the reference method against which all other tests are measured ( 16, 17 ). While the test has 100% specificity for HSV-1 or HSV-2, the sensitivity depends on the stage of the lesion at the time of specimen collection.

Why is PCR used to diagnose CNS infections?

Thus, the available amount of CSF and numbers of samplings for diagnosis are limited. Therefore, performing PCR using a CSF specimen will become the first-line diagnostic test for CNS infections (11, 33), due to a sensitivity requiring only a limited amount of CSF, the specificity of the assay, and speed.