Do you take a good look at the person? Do you ask and look straight in their eyes? Do you inquire about their sex lives? Well, my answer is no, maybe and maybe.
It may be a good idea to ask someone if they're aware of having genital herpes. The more sexual partners a person has had in their lives, the more likely they're to be infected by herpes. But these methods are quite insufficient. Did you know that the majority of people who have genital or oral herpes are not aware of it? So how do you explain that? Simple, many oral or genital herpes infected people just don't have any herpes symptoms, others have some symptoms which are mild enough to confuse them with a rash or a mosquito bite or anything that may cause, redness, swelling, itching, burning and blisters, and some may not even know what herpes symptoms are.
The fact that somebody doesn't have or recognize herpes symptoms doesn't mean they don't have it. About 25% of the US population is infected with genital herpes, with women being more affected than men. Studies have shown that the vast majority (80%-90%) of people who have genital herpes have not been diagnosed with the condition.
According to a recent paper published by Carnegie Mellon University in January 2006, most sexually active teenage girls know almost nothing about sexually transmitted diseases (STDs), except AIDS, until it is too late. Another 2006 study led by Dr. Herbert Kaufman, Boyd Professor of Ophthalmology at Louisiana State University Health Sciences Center in New Orleans, found herpes virus-1 in 98 percent of healthy participants. None of them displayed any symptoms; however they shed the herpes virus in their saliva and tears at least once during the course of the 30-day study. Even though this study didn't target genital herpes directly, it demonstrates that most people can be totally unaware of carrying the virus and being infected by herpes.
Shed or shedding means that the virus is present on the skin and ready to be transmitted. Herpes is transmitted through skin contact 98% of the time. Studies have shown that shedding may occur in almost 40% of HSV-2 (usually associated with genital herpes) infected people. Asymptomatic viral shedding may last 1 to 5 days, meaning that a person can be contagious without presenting any symptoms at the time. The average duration of each period of viral shedding has been assessed through laboratory studies but is just an estimate.
So how can you tell for a fact if someone has genital herpes? The only way to know is to look at blood, PCR or swab test results. Swab and PCR tests are very accurate when they detect herpes. However, if a test was performed late or delivered to the lab late, it may return a false negative result. Western blot test, a blood test, is the most accurate test available but may return a false negative if the person tested was first infected within the past 3 months. So it is not easy to know if a person has genital herpes or not.
One last consideration, herpes Simplex 1 or HSV-1 usually causes oral herpes and cold sores and herpes simplex-2, genital herpes. But herpes virus-1 genital herpes is becoming more and more prevalent nowadays. It is mostly transmitted during oral sex from a person who's having an oral herpes infection with or without symptoms. So if getting genital herpes is a concern to you, you should consider oral herpes as well as genital herpes when asking a partner.
As you can see, it is very difficult to assess if a partner has genital herpes. There are no proven products to prevent genital herpes transmission at the moment. Some are currently undergoing testing for FDA approval and will hopefully be marketed soon. In the meanwhile, the best option is using a condom.