Today's teens may be more susceptible to contracting genital herpes because they have fewer disease-fighting antibodies than teens studied as recent as ten years ago, a new study reveals.
Research published in the Journal of Infectious Diseases on Oct. 17 shows that fewer U.S. teens today have been exposed to the cold sore-causing herpes simplex virus type 1 (HSV-1) than adolescents in previous years. When it gets to the time they become sexually active, their bodies lack the antibodies to fight off the virus.
Both HSV-1 and the sexually-transmitted herpes simplex virus type 2 (HSV-2) cause incurable lifelong infections. Both viruses can cause cold sores and genital herpes, but HSV-1 is associated with fewer recurrences of the genital-type infection. Most people get HSV-1 in childhood just by touching the skin of an infected adult.
But, HSV-1 has been seen increasingly as the cause of genital herpes in industrialized countries, with one study revealing that up to 60 percent of genital herpes cases were due to HSV-1.
For the study, researchers looked at HSV-1 and HSV-2 rates among U.S. 14 to 49-year-olds. From this data, they estimated the prevalence of antibodies (known as seroprevalence) for different age groups, and divided the data into two time periods: 1999-2004 and 2005-2010.
There was a 23 percent decline in prevalence of HSV-1 antibodies during the 2005-2010 period in teens aged 14 to 19 compared to those studied in the 1999-2004 period. During the same time periods, HSV-1 seroprevalence declined by more than 9 percent for 20 to 29 year olds. Numbers remained about the same for those in their 30s and 40s.
"In combination with increased oral sex behaviors among young people this means that adolescents may be more likely than those in previous time periods to genitally acquire HSV-1," the study authors wrote.
Dr. David W. Kimberlin, associate professor of pediatrics at the University of Alabama at Birmingham, wrote in an accompanying editorial that the most important finding revealed by the data is that almost one in 10 teens who a decade ago would have had antibodies to fight against HSV-1 would be more vulnerable to getting genital herpes.
"Three decades ago, HIV displaced HSV-2 as the principal virus competing for the attention of the public health community at a time when public awareness of genital herpes was just beginning to rise," he wrote. "Furthermore, the 'safe sex' educational advances that have contributed significantly to limiting the spread of HIV since then have contributed to modifications in sexual practices that now are poised to contribute to a resurgence in genital herpes, although this time with HSV-1. As a result, today we find ourselves once again confronting a scarlet letter, and the lives of many infants yet to be born may hang in the balance.
The authors mentioned that because of the success of public awareness campaigns about HIV, they believe that many people falsely believe that oral sex is safe. But, they forget that there is still a risk of getting the herpes virus.
"I tell patients herpes is like your credit history -- whatever you did you can never get rid of," Dr. Marcelo Laufer, a pediatric infectious disease specialist at Miami Children's Hospital, told HealthDay. He was not involved in the study.
Mothers with HSV-1 and HSV-2 can also put babies at risk during delivery, since newborns lack a mature immune system to ward off the virus. Up to 30 percent of infected babies will die if they contract the most severe form of the virus.
The authors called for more attention to HSV-1 and HSV-2 rates to see the changing nature of these viruses, asked health officials to create more prevention strategies for genital herpes and put more resources towards developing a vaccine.