A sample from a skin lesion (often a genital sore) or blister is needed. The health care provider will collect the sample during an active outbreak and place it in a laboratory container. The sample must include cells, not just fluid from the blister, because the virus is in the skin cells of the blister or ulcer.
At the laboratory, the sample is placed in a special dish and watched for the growth of the herpes simplex virus, or substances related to the virus. Special tests may also be done to determine whether it is herpex simplex virus type 1 or 2.
Results are available within 16 hours to 7 days (usually 2-4 days), depending on the laboratory method used.
How to prepare for the test
The sample must be collected during the worst part of an outbreak. This is considered the acute phase of infection.
How the test will feel
When the sample is collected, you may feel an uncomfortable scraping or sticky sensation. Sometimes a sample from the throat or eyes is needed. This involves rubbing a sterile swab against the eye or in the throat.
Why the test is performed
The test is done to confirm herpes simplex infection. The diagnosis is often made by physical examination (the health care provider looking at the sores), and the cultures and other tests are used to confirm that diagnosis.
A normal (negative) result means that the herpes simplex virus did not grow in the laboratory dish and the skin sample used in the test did not contain any herpes virus.
However, a normal (negative) culture does not guarantee that you do not have a herpes infection or have not had one in the past.
What abnormal results mean
An abnormal (positive) result may mean that you have an active infection with herpes simplex virus. Herpes infections include herpes genitalis, which is genital herpes, or cold sores on the lips or in the mouth.
If the culture is positive for herpes, you may have recently become infected or you may have become infected in the past and are currently having an outbreak.
What the risks are
Risks include slight bleeding or infection in the area where the skin sample was removed.
The viral culture for herpes test is most likely to be accurate when a person is newly infected (during the first outbreak).
Schiffer JT, Corey L. Herpes simplex virus. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 136.
Usatine RP, Tinitigan R. Nongenital herpes simplex virus. Am Fam Physician. 2010 Nov 1;82(9):1075-82.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.