Until the 1980s serological tests for antibodies to HSV were rarely useful to diagnosis and not routinely used in clinical practice. The older IgM serologic assay could not differentiate between antibodies generated in response to HSV-1 or HSV-2 infection. However, a glycoprotein G-specific (IgG) HSV test introduced in the 1980s is more than 98% specific at discriminating HSV-1 from HSV-2.
Human herpes virus 2 (HHV2) is also called herpes simplex virus 2 (HSV2). It typically causes genital herpes, a sexually transmitted infection. However, it can also cause cold sores in the facial area. Like HHV1, the HHV2 infection is contagious and is spread by skin-to-skin contact. The main route of transmission is through sexual contact, as the virus does not survive very long outside the body.
Herpes viruses typically infect the oral or genital mucosa. When herpes affects the mouth, it causes the typical "cold sores," which are painful sores or blisters that form on the lips, mouth, or gums. Prior to the development of the blisters, there may be a prodrome (early symptoms indicating onset of a particular disease) consisting of an itching, burning, or tingling sensation in the affected area. The virus remains dormant in the nervous system throughout life, and this is the reason that cold sores often recur in the same location.
A 2004 study in the New England Journal of Medicine found that suppressive therapy decreases the risk of HSV-2 transmission from symptomatic, infected partners to uninfected partners by 48%. So “the risk of transmission is significantly reduced, but cannot be eliminated even with suppressive therapy,” Johnston explains, and she stresses that the virus can be passed along even without signs or symptoms.