More US teens susceptible to HSV-1 infection, a growing cause of genital herpes

October 17, 2013

A new study suggests a growing number of U.S. adolescents lack antibodies that may help protect them later in life against an increasingly important cause of genital herpes. Published in The Journal of Infectious Diseases and available online, the findings show that fewer of today's teens have been exposed in their childhood to herpes simplex virus type 1 (HSV-1), a common cause of cold sores, than U.S. adolescents in previous years. Without these antibodies, today's teens may be more susceptible—when they become sexually active—to genital infections also caused by the virus, particularly through oral sex.

HSV-1 and a related virus, type 2 (HSV-2), both cause lifelong infections, with no known cure, that can go through dormant periods after an initial outbreak. Most people contract HSV-1 in childhood, through skin-to-skin contact with an infected adult. HSV-2 is usually transmitted sexually. Though both viruses can cause , HSV-1 has been associated with fewer recurrences and less viral shedding than HSV-2. Recent research, however, suggests that HSV-1 is becoming a significant cause of genital herpes in industrialized countries, with one study finding that nearly 60 percent of genital herpes infections were attributable to HSV-1.

In this latest study, Heather Bradley, PhD, and colleagues from the Centers for Disease Control and Prevention examined HSV-1 and HSV-2 prevalence among 14 to 49 year olds in the United States, using data from the National Health and Nutrition Examination Surveys (NHANES), large nationwide surveys, including blood samples, that are representative of the U.S. population. Investigators estimated the prevalence of for HSV-1 and HSV-2, or , among different age groups, from the 2005 to 2010 time period and compared it to seroprevalence from the 1999 to 2004 period. They also examined trends in HSV-1 and HSV-2 from earlier time periods.

Dr. Bradley and her team found an overall HSV-1 seroprevalence of 54 percent during the period 2005 to 2010. Among 14 to 19 year olds, HSV-1 seroprevalence declined by nearly 23 percent from the 1999 to 2004 period compared to the 2005 to 2010 period. Among 20 to 29 year olds, HSV-1 seroprevalence declined by more than 9 percent. HSV-1 seroprevalence remained stable in the two oldest age groups (those in their 30s and 40s). HSV-2 seroprevalence was not significantly different across any of the age groups between these two time periods.

The data suggest that an increasing number of U.S. adolescents lack HSV-1 antibodies at their first sexual encounter and are therefore more susceptible to genital herpes resulting from that strain. "In combination with increased oral sex behaviors among young people," the study authors wrote, "this means that adolescents may be more likely than those in previous time periods to genitally acquire HSV-1."

In an accompanying editorial, David W. Kimberlin, MD, at the University of Alabama at Birmingham, wrote that the study's "key finding is that HSV-1 seroprevalence among 14 to 19 year olds has declined by nearly 23 percent from 1999-2004 to 2005-2010, from 39.0 percent to 30.1 percent, for an absolute difference of about 9 percent." This absolute difference that has occurred over the past 10 years, Dr. Kimberlin noted, represents an approximately 9 percent decrease in the percentage of adolescents who have already had oral HSV-1 as they enter their sexually active years, when exposure genitally is increasingly common: "Almost one in 10 adolescents who 10 years ago already would have acquired HSV-1 earlier in life now are vulnerable to getting a primary infection" as they become sexually active later in life.

Changes in sexual practices could make the problem worse: An unintended consequence of the success of public campaigns to limit the spread of HIV has led some to embrace the notion that oral sex is "safe," Dr. Kimberlin wrote, despite the fact that also carries risks, including significant risk of transmission of HSV-1 from the mouth to the genitals. Another serious potential consequence of increased susceptibility to genital herpes caused by HSV-1 is the risk of genital transmission of the virus from mother to baby during delivery, Dr. Kimberlin wrote. Both HSV-1 and HSV-2 can pose significant problems for newborn infants, who lack a mature immune system capable of fighting these viruses. Up to 30 percent of infected babies will die from this infection if they have the most severe form of the disease, Dr. Kimberlin noted.

The study authors stressed the importance of continued surveillance of HSV-1 and HSV-2 to monitor the changing epidemiology of these diseases and to help inform prevention strategies for genital herpes and vaccine development efforts against viruses.

Explore further: Herpes research turns up genetic combatant

Related Stories

Herpes research turns up genetic combatant

July 18, 2013
(Medical Xpress)—A molecule that could potentially be used to fight herpes simplex virus (HSV-1) has been discovered by Curtin University scientists.

Research shows progress toward a genital herpes vaccine

January 4, 2012
An investigational vaccine protected some women against infection from one of the two types of herpes simplex viruses that cause genital herpes, according to findings in the New England Journal of Medicine.

Persons with herpes simplex virus type 2, but without symptoms, still shed virus

April 12, 2011
Persons who have tested positive for herpes simplex virus type 2 (HSV-2) but do not have symptoms or genital lesions still experience virus shedding during subclinical (without clinical manifestations) episodes, suggesting ...

Study reveals new approach for stopping herpes infections

March 25, 2013
Researchers at Albert Einstein College of Medicine of Yeshiva University have discovered a novel strategy for preventing infections due to the highly common herpes simplex viruses, the microbes responsible for causing genital ...

Recommended for you

Google searches can be used to track dengue in underdeveloped countries

July 20, 2017
An analytical tool that combines Google search data with government-provided clinical data can quickly and accurately track dengue fever in less-developed countries, according to new research published in PLOS Computational ...

MRSA emerged years before methicillin was even discovered

July 19, 2017
Methicillin resistant Staphylococcus aureus (MRSA) emerged long before the introduction of the antibiotic methicillin into clinical practice, according to a study published in the open access journal Genome Biology. It was ...

New test distinguishes Zika from similar viral infections

July 18, 2017
A new test is the best-to-date in differentiating Zika virus infections from infections caused by similar viruses. The antibody-based assay, developed by researchers at UC Berkeley and Humabs BioMed, a private biotechnology ...

'Superbugs' study reveals complex picture of E. coli bloodstream infections

July 18, 2017
The first large-scale genetic study of Escherichia coli (E. coli) cultured from patients with bloodstream infections in England showed that drug resistant 'superbugs' are not always out-competing other strains. Research by ...

Ebola virus can persist in monkeys that survived disease, even after symptoms disappear

July 17, 2017
Ebola virus infection can be detected in rhesus monkeys that survive the disease and no longer show symptoms, according to research published by Army scientists in today's online edition of the journal Nature Microbiology. ...

Mountain gorillas have herpes virus similar to that found in humans

July 13, 2017
Scientists from the University of California, Davis, have detected a herpes virus in wild mountain gorillas that is very similar to the Epstein-Barr virus in humans, according to a study published today in the journal Scientific ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.