Such tests are not as effective for older ulcerated sores, recurrent lesions, or latency, since at these stages the virus may not be active enough to reproduce sufficiently to produce a visible culture. Microscopic Examination of Tissue Scrapings Quicker but less reliable tests use scrapings from lesions, which are then stained and microscopically examined. Other tests are occasionally performed that make use of the properties of the immune system and the genetic make-up of the virus. One test produces specific antibodies that hunt out and identify the herpes virus and often differentiate between types. Their accuracy is improving however.
Results are available in two hours.
This test appears to be very promising, particularly for newborns at high risk for HSV-although experts do not advise using this as the sole diagnostic test. Tests for HSV Encephalitis Diagnosis of HSV encephalitis may require a number of tests. New imaging techniques can detect swelling in affected lobes in the brain, although such abnormalities may not be detectable until late in the course of the disease. Brain biopsy is the most reliable method of diagnosing HSV encephalitis, but it is also the most invasive and is generally performed only if the diagnosis is uncertain. PCR uses a piece of the DNA of the virus and then replicates millions of times until the virus is detectable.