Oral and Vaginal Sex Indicate Higher Herpes Infection Rates, Recent Research Reveals
(Adapted by ScienceDaily.com from materials gathered from University Of Pittsburgh Medical Center.)
ScienceDaily (Mar. 12, 2005) — PITTSBURGH, Feb. 28 – The first clinical research conducted to determine the likelihood of contracting HSV-1 based on studying sexual activity has found a connection between oral sex and vaginal intercourse with an evidently higher infection rate, especially in young women, University of Pittsburgh researchers reported in the February edition of Sexually Transmitted Diseases, the journal of the American Sexually Transmitted Diseases Association.
HSV-2 is one of the most common STDs in America. Across the nation, at least 45 million people over the age of 12 (one out of five adolescents and adults) have genital herpes. Between the late 1970s and the early 1990s, the amount of people in the U.S. who had HSV-2 increased by 30%, the U.S. Centers for Disease Control and Prevention reported. There is no cure, but antiviral drugs have been proven to decrease and prevent outbreaks. Also, daily practice of suppressive therapy can decrease, but not remove, the chance of passing the virus to sexual partners who do not have it.
It is protocol to teach medical students that HSV-1 is most common above the waist, while HSV-2 occurs below the waist. There is new evidence, however, that HSV-1 also is a key pathogen in genital herpes, especially in younger women. HSV-1 is traditionally known to infect the mouth and lips, as evident by fever blisters or cold sores. Viral shedding and contracting the virus can occur even when there is no sign of an outbreak.
"[Oral and vaginal sex] were … significant risk factors for ... HSV-1," said Thomas Cherpes, M.D., an infectious diseases fellow at the University of Pittsburgh School of Medicine and the study's first author. "… HSV-1 infections are less frequent in childhood and adolescence, future prevention strategies [must] consider increased susceptibility for HSV-1 among young adults … to the growing genital herpes epidemic."
Between 1998 and 2000, 1207 non-pregnant women from the ages of 18 to 30 were admitted to three Pittsburgh health clinics. Participants were instructed to return for three follow-up visits at four-month intervals. During each study visit, blood samples were tested for HSV-1 and HSV-2-specific antibodies. Researchers also administered sexual behavior surveys and collected demographic information from participants.
At first, HSV-1 was detected in 38% of women aged 20 or younger. During the follow-up period, however, analysis found that females who participated in vaginal intercourse had more than six times higher risk of transmitting HSV-1 than women who did not engage in sexual activity, or 6.8 compared to 1.2 cases. For women who only engaged in receptive oral sex and abstained from vaginal intercourse, the study revealed the risk was even greater – 9.8 compared to 1.2 cases.
"[This] …is consistent with other research indicating a reduction in HSV-1 [in] younger people," said Sharon Hillier, Ph.D., professor in the departments of obstetrics, gynecology and reproductive sciences and molecular genetics and biochemistry at the University of Pittsburgh School of Medicine and the study's chief author. "… a significant number of young adults are [vulnerable] to oral or genital HSV-1..."
This is significant because most of the new studies being conducted on vaccine development for genital herpes only researches HSV-2, Dr. Hillier said. Dr. Hillier is also is a chief investigator at the Magee-Women’s Research Institute.
The evident decrease in childhood HSV-1 cases confounds the situation because it leaves more young people at risk of contracting a genital infection of HSV-1, Dr. Cherpes believes, especially with surveys indicating higher rates sexual activities, which increases the risk.
"[Recurrence]…among sexually active women is 75 percent," he said. "In our group, more than 90 percent of …participants reported a history...."
Both Dr. Cherpes and Dr. Hillier believe that subsequent vaccine development initiative must deal with HSV-1 targets in order to decrease occurrences.
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In addition to Drs. Cherpes and Hillier, Leslie A. Meyn, M.S., Magee-Womens Research Institute, contributed to the study, which was funded by the National Institutes of Health.
University Of Pittsburgh Medical Center (2005, March 12). Risk Of Herpes Infection Rises With Oral Sex. ScienceDaily. Retrieved March 20, 2008, from http://www.sciencedaily.com/releases/2005/03/050308100931.htm