Herpes Simplex Virus I/II Past Infection Blood Test

Herpes is a very common virus that has two forms - HSV I and HSV II. It causes cold sores (in the case of HSV I) and genital herpes (mostly in the case of HSV II).

It is estimated that up to 70% of the global population is infected with the HSV I form of the virus which is usually acquired during childhood. HSV I is not usually something to worry about. HSV II is also widespread (affecting over 10% of people in the UK) and is almost exclusively transmitted by sexual contact. It causes genital herpes, but this can also be caused by HSV I in certain circumstances. There is no cure for herpes and once infected the virus will remain with you for life.

Many of those with genital herpes don't know they are infected because there are often no noticeable symptoms or the symptoms are so mild that they are interpreted as something else. If symptoms do appear they may include small blisters around the genitals, stinging, burning or itching around the genital area and pain when urinating. Genital herpes tends to recur in cycles with each outbreak milder than the previous ones.

This blood test checks for the presence of two different antibodies - to confirm an infection and also distinguish which form of the virus is present. This test will not detect a current active infection because it can take time for the IgG antibodies to herpes to reach detectable levels. To avoid false negative results it is usually recommended to wait 12-16 weeks from the date of last possible exposure.