I just learned about the potential of oral HSV-1 to spread to the genital region, and I feel a little freaked out and worried about my girlfriend of 3 years. I don’t believe I’ve ever kissed her or performed oral sex anywhere near the time of a cold sore break out, as they are rather infrequent for me (once every 1-2 years), but I have performed oral sex on her several times without protection. On top of that, she has never had an outbreak of HSV-1 anywhere as far as I know, but what are the chances that I have given it to her, either orally and/or genitally?
More generally, why is genital HSV-1 on the rise? I read that it’s because more college-aged people are performing oral sex these days, so the incidence is increasing. But does this mean that it has always carried the potential to spread to the genitals, or is this a mutation or a new strand of HSV-1? Last, when they say that HSV-1 can spread to the genitals, what sort of probability are they talking about?
Please give me some more information to help put my mind to rest.
As we covered in a recent post, the old way of thinking about Herpes Simplex Virus – that type 1 (HSV-1) only causes cold sores on the lips while HSV-2 only infects the genitals – isn’t really applicable anymore. While HSV-1 does prefer to live above the belt and HSV-2 below, both can infect the mouth or genitals. So unfortunately, you’re right to be a little freaked out. But let’s go through your questions to hopefully put you at ease.
Why is genital HSV-1 on the rise? Has it has always carried the potential to spread to the genitals, or is this a mutation or a new strand of HSV-1?
Genital HSV-1 is on the rise. In fact, among sexually active adults, new genital HSV-1 infections are as common as new oral HSV-1 infections. This is especially true for college aged people. A study done at the University of Wisconsin in 2003 showed that the proportion of newly diagnosed genital herpes infections resulting from HSV-1 increased from 31% in 1993 to 78% in 2001 in college students. A 2011 study involving college students showed that this trend continues; HSV-1 accounted for 78% of female and 85% of male genital herpes infections.
This is not because of any new strand of Super Herpes, but because of changing beliefs in what constitutes “safe” sex. College students report having vaginal intercourse and oral sex at about the same frequency, but the problem is that because they assume oral sex is safer, they are much less likely to use a condom. While it certainly eliminates the risk of pregnancy, oral sex doesn’t eliminate the risk of transmitting sexually transmitted infections and in fact, increases the risk of transmitting HSV-1 because it is spread by direct contact. So HSV-1 has always had the ability to spread to the genitals, it’s just getting more of an opportunity nowadays.
When they say that HSV-1 can spread to the genitals, what sort of probability are they talking about? What are the chances that you have passed HSV-1 on to your girlfriend, either orally or genitally?
Unfortunately, it’s really impossible to say. The closest thing to an answer that I could find came from a 2006 study that showed that transmission of HSV-2 can occur pretty quickly in new sexual relationships. In 199 people who acquired HSV-2 genital infection after beginning a new relationship, the median length of the relationship was 3.5 months and the median number of sex acts before transmission was 40. But the most important finding is that it took a lot longer for participants whose partners told them up front that they had genital herpes to acquire the infection compared with participants whose partners didn’t – 270 days vs. 60 days. So even though it’s kind of an awkward conversation to have at the beginning of a new relationship, talk to your partner about this stuff – it’s the best way to keep you both as safe as possible.
If you have any questions about HSV or any other sexually transmitted infections, make an appointment to see us at the Student Health Center. We can answer your questions, take a look at what’s worrying you and perform any necessary lab testing.
John A. Vaughn, MD
Student Health Services
The Ohio State University
 Langenberg AG et al. A prospective study of new infections with herpes simplex virus type 1 and type 2. N Engl J Med. 1999;341(19):1432.
 Roberts CM, Pfister JR, Spear SJ. Increasing proportion of herpes simplex virus type 1 as a cause of genital herpes infection in college students. Sex Transm Dis. 2003;30(10):797.
 Horowitz , et al. Herpes simplex virus infection in a university health population: clinical manifestations, epidemiology, and implications. J Am Coll Health. 2011;59(2):69.
 Wald A et al. Knowledge of partners’ genital herpes protects against herpes simplex virus type 2 acquisition. J Infect Dis. 2006;194(1):42.