Herpes labialis, or oral herpes, is also known as HSV-1 (herpes simplex virus one). The virus is quite common, affecting 80-90% of adults by the age of 50. Once the virus has been introduced, it will remain in the body for life. The virus will become latent (dormant) in the central nervous system, and reemerge as cold sores or fever blisters through varying triggers. These sores are highly contagious, and can spread to other parts of the body as well as to other people.
The herpes sores are the active virus shedding cells. In this state, the virus can infect other people through direct contact. Therefore, if oral sex is performed while a herpes oral sore is active, the virus can easily spread to the contacted area. It is more common for oral herpes to be transmitted from mouth to the genitals through oral sex, than it is for genital herpes (HSV-2, herpes simplex virus two) to be transmitted to the mouth. But it is clear, if a person has HSV-1 sores and performs oral sex on the partner, then it is possible for that person to transmit the virus to the genitals by this action, and vice versa.
The typical duration of a cold sore outbreak lasts two weeks. The initial onset will begin with a tingling or itchy feeling, followed by a reddening of the area. This will lead to the lesions, which are the body’s red blood cells trying to combat the virus, generally displayed as fever blisters or cold sores. When the cold sores are present, the virus is at its most contagious. A crusting or scab will appear, indicating the healing process. Finally, the scab will drop away and redness will remain. Although the worst of the infection has passed by this state, the virus still is shedding cells, and can still be contagious. It is only once all signs of the infection are gone that the herpes virus is safe from spreading to others.
Since more than a majority of the population will contract HSV-1 in their lifetime (many before reaching adulthood), how does that stop the spread of HSV-2? In general, after the initial HSV-1 infection, those with the virus will experience fewer and fewer outbreaks throughout their lifetime. Likewise, the longer it has been in the system, the shorter the individual outbreaks will last. On average, most people will experience only between one and three occurrences a year. While the virus is latent, the ability to spread the virus is halted. Only in very rare cases does the virus spread when no symptoms are visible. Therefore, oral sex performed while the virus is inactive will not spread the herpes infection to the partner’s genitals.