Cell culture test
This test has long been the “Gold standard” of laboratory testing for herpes and is by far the most widely available. The technique is similar to that you may have seen in your high school biology class, when bacteria are grown (cultured) in a petri dish. To perform a viral culture, the doctor will use a sterile swab to retrieve a sample from a lesion. A good swab will generally cause some discomfort when a sore or lesion is sampled. The sample is sent to a laboratory where it is grown for several days in a culture of healthy human cells. If the sample contains herpes, the virus will infect the cells of the culture, causing cellular changes that can be seen with a microscope.
Unlike the culture method, this test doesn’t require growing the virus but rather seeks to identify herpes by way of a reliable marker. The presence of antigens, fragments of the virus that are know to stimulate the immune response. A swab is taken similar to the method used for viral culture. In general, antigen detection assays are less sensitive than viral culture. Antigen–detection is usually done only in research labs or large reference laboratories. Antigen tests can produce results more quickly than culture and are sometimes less expensive. The potential downsides are that they require better samples than culture and many do not provide a way to determine whether the sample represents infection with HSV–1 or HSV–2.
|Test type||Specimen source||Advantages||Disadvantages|
|Tissue culture||Swab/scrape lesion.||Highly specific, widely available.||Sensitivity is a function of specimen quality and sample timing.|
|Serologic test||Finger stick/draw blood.||Test can be performed in absence of lesions, Type–specific tests are highly accurate.||Earliest time is 12 days post infection, some tests may not detect antibodies until 3 months post–infection. Tests that are not type specific have inadequate accuracy.|
|Antigen detection||Swab/scrape lesion.||Results more rapid than culture.||Sensitivity lower than culture.|
A Pap Smear examination usually is performed at the time of a pelvic examination, which can help detect signs of herpes in female organs. A Pap examination is a simple procedure in which your physician painlessly obtains cells from the surface of your cervix, often using a special brush. The cells are placed on a glass slide, which is sent to a laboratory.
At the laboratory, the cells are stained and then examined under a microscope. If an abnormality is found, a pathologist, a physician who specializes in laboratory medicine, studies the cells and makes the final interpretation.