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, herpes simplex 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 genital herpes, 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 antibodies for HSV-1 and HSV-2, or seroprevalence, 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 oral sex 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 herpes viruses.
1) A new study suggests that an increasing number of U.S. adolescents lack antibodies to herpes simplex virus type 1 (HSV-1), making them potentially more susceptible to genital herpes caused by the virus when they become sexually active in future years.
2) Using nationwide data, researchers found that the prevalence of antibodies for HSV-1, or seroprevalence, among 14 to 19 year olds 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.
3) With recent research suggesting that HSV-1 is an increasingly important cause of genital herpes in industrialized countries, continued surveillance of HSV-1 and HSV-2 and prevention strategies for new infections are needed.
NOTE: The study and related editorial are available online. They are embargoed until 12:05 a.m. EDT on Thursday, Oct. 17.
Published continuously since 1904, The Journal of Infectious Diseases is the premier global journal for original research on infectious diseases. The editors welcome major articles and brief reports describing research results on microbiology, immunology, epidemiology, and related disciplines, on the pathogenesis, diagnosis, and treatment of infectious diseases; on the microbes that cause them; and on disorders of host immune responses. The journal is an official publication of the Infectious Diseases Society of America (IDSA). Based in Arlington, Va., IDSA is a professional society representing nearly 10,000 physicians and scientists who specialize in infectious diseases. For more information, visit http://www.idsociety.org.
Jerica Pitts | EurekAlert!
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering