Testing for herpes and other types of sexually transmitted diseases is important, but how do you know which test you should take? The American Sexual Health Association (ASHA) has a handy infographic that you can use as a reference, especially if you or someone you know may have herpes.1
Undergo a Herpes Viral Culture of Lesions Test
If you observe symptoms of herpes such as lesions or sores,2 take a herpes viral culture of lesion or a swab test of the sores3 within the first 48 hours after these become visible. In about a week, you will receive your results and know if you have herpes or not.4
According to ASHA, this herpes viral culture of lesion has a major pro and con. The test is typically known for its accuracy in generating a positive result — if you test positive for herpes, you can be certain that you have the virus. Moreover, the test is also able to classify if the infection is caused by the HSV-1 or HSV-2 virus.5
However, you should be aware that a herpes viral culture of lesion turns in a high rate of false negatives. This culture test needs an active virus, and if the sample you obtained is very small or is already starting to heal, there is a reduced possibility of getting an accurate culture.6
The amount of hours after a lesion first appears is also a factor — you might receive a false negative if you take a test more than 48 hours after these symptoms first appear. What’s more, if you get a herpes viral culture of lesion on your second herpes outbreak, the result may be less accurate.7
A NAAT Test Can Check If You Have Herpes or Not
Apart from a swab test, a Nucleic Acid Amplification Testing (NAAT) can also be performed to check for herpes. Because of its speed and accuracy to determine if a patient has an HSV-1 or HSV-2 virus, as well as its lower risk to yield a false negative result, NAATs are the preferred method in examining herpes cases.
Polymerase Chain Reaction or PCR tests are the most widely-used NAAT method. This test determines DNA from the virus and categorizes if it’s either the HSV-1 or HSV-2 virus. Your physician will recommend a PCR test for you if there’s active viral shedding.
This test is usually performed on cells or fluids from a sore, on blood or other bodily fluids (such as the spinal fluid).8
PCR tests are also known for their accuracy because they produce multiple copies of the viral genetic material in four hours, so even just a small amount of the virus can diagnose herpes. Unfortunately, PCR tests are both expensive and not widely available, so you might have to search extensively for a physician who can perform this type of test.9
If you don’t feel any symptoms but decide to have yourself checked anyway, your physician will first do a visual examination of the visible sores. Sometimes, a laboratory test may also be performed, but it’s not always necessary.
Ask About Antibody or Blood Tests as Well
You can also ask your physician to perform an antibody or blood test, since it could find the herpes simplex virus even before an outbreak occurs.10,11 This blood test is supposed to search for immunoglobulin (IgG) antibodies, which can be further broken down to know which of the two viruses cause a case of herpes.
While this antibody test is known for its accuracy, the periods when the IgG antibodies can be detected are different from person to person. Someone may have detectable IgG antibody levels in just weeks, but another person may have these levels in months. If a patient takes this test too long after he or she gets the virus, there’s a chance that the test will yield a false negative.12
ASHA advises to wait for at least 12 to 16 weeks from the final possible date of exposure before undergoing a type-specific blood test to ensure that the antibodies can be fully detected.13
You can avail of various FDA-approved and IgG-based blood tests that can show if you have herpes or not. They don’t discover if the infection site is oral or genital in nature, but they do provide accurate results. For example, as most cases of genital herpes are triggered by the HSV-2 virus, if you get a positive result for type-2 antibodies, you most likely have genital herpes.14