I’m currently at 39,000 feet on my way to NY to have a fun weekend with my daughter. I slipped a few medical journals into my carry-on to review so that I could find an article to share in my weekly newsletter. The seat is cramped, the cabin is crowded, most of my fellow passengers are sleeping….I passed over articles on multiple therapies for tuberculosis (too much coughing going on around me), sepsis and organ failure, as well as AIDs – defining cancers (too depressing)…Each subject is critical to the progress of medicine and I did read up on them, but for this newsletter I selected an article in JAMA titled ” Genital Shedding of Herpes Simplex Among Symptomatic and Asymptomatic Persons with HSV-2 Infection”.
So here it is…answering the question: do individuals who don’t know they have genital herpes shed the virus (and hence can spread it to a partner) to the same extent as those that have recurrent lesions (and are aware of their diagnosis)?
A quick herpes review: Genital herpes (HSV-2) is unfortunately, extremely prevalent. Over half a billion people worldwide have the virus and it is estimated that 23.6 million persons aged 15 to 49 become infected annually. In the US, 16% of adults have had it as evidenced by the fact that they have antibodies to HSV-2, but only 10 to 25 % of persons with this “everlasting infection” know that they harbor it. As a result, individuals who don’t know they have had herpes spread most of the HSV-2 infections. The risk of sexual transmission doesn’t correlate with recognition of symptoms but is correlated with silent viral mucosal shedding (and obviously, sexual contact with a partner).
Researchers at the University of Washington enrolled participants who were 18 and older in this herpes study for the published study. They advertised for participants through word of mouth at the university, newspaper ads (and promises of payment), tested many and in the end found 498 individuals who had antibodies to herpes 2. They then divided them into 2 groups: those who were symptomatic (had a clinical history of genital herpes) and those who were not (never knew that they had a lesion, their diagnosis was made with the herpes antibody blood test). Each person then self-collected swabs of their genital secretions for at least 30 days. (The swabs were examined by quantitative polymerase chain reaction for HSV DNA…I had to add that for the purists.)
The results showed that those who had symptomatic genital lesions were twice as likely to shed the virus and 3 times more likely to develop lesions than those who were, on initial testing, asymptomatic. However in those with no symptoms, genital HSV shedding did occur on 10% of days, and almost all of it was subclinical (i.e. the person did not recognize a lesion). There was a similar shedding rate between men and women; which means that men can have sub-clinical shedding on normal appearing genital skin. (There goes the adage, look before you engage…)
What they also found was that many of those who were initially asymptomatic begin to recognize recurrent herpes once they had received the diagnosis through their blood tests. They may have felt that what they had in the past was just a mild irritation or itch and ignored it, now they didn’t.
I have frequently been the doctor who sees a patient with “something down there” and either through direct culture and/or a blood test have made the diagnosis of herpes. Often the first statement posed by my now horrified patient is “he never told me”, or “was he with someone else?” Neither may be correct…the partner may not have known that he (or she) had acquired herpes in the past, or the woman with the “new” herpes infection may have had it all along and only now has become aware of a clinical lesion. (Perhaps brought on by illness, stress or diminished immunity.)
It certainly would be helpful to have universal herpes 2- antibody testing. But this is not currently a part of “routine” blood tests, nor is it financially feasible. The best protection will continue to be the use of condoms. For those who have been diagnosed with herpes, daily prophylactic use of the antiviral medications such as Valtrex or acyclovir should decrease shedding as well as recurrent lesions. So far that’s the best advice that’s offered by the experts. Somewhat depressing at 39,000 feet (or for that matter at sea level)!