Preventing Sexually Transmitted Infections, 2008

In September 2008, data from what is purported to be the largest sexual health survey ever conducted in the United States, cataloging more than 1.2 million Internet responses to an “anonymous” questionnaire, were released.¹ There were the expected admissions from respondents concerning frequent use of behavioral disinhibitors-alcohol being the most popular-to manage anxiety and “have an excuse” to do what they wanted to do anyway, ie, have sex: One-third of the respondents-31% of men and 33% of women-said that in some circumstances they needed to become inebriated in order to have intercourse. Also, as expected, the responses showed that occasional sex with a stranger was quite common: 43% of men and 40% of women admitted having unprotected intercourse with someone unknown to them.

However, there were some unexpected findings. Given all those anonymous relationships, even when condoms were used, 22.5% of men and 17.5% of women experienced a condom break during sex. Approximately 1 of 4 women (27%) reported using emergency contraception with the “morning-after pill” (levonorgestrel) at least once, and 19.1% of respondents younger than 18 years had already taken it.

Setting aside the lack of controls in such a survey, including the likely skewing of demographics, the potential for multiple responses from the same respondent, and the need to have Internet access, the information bodes poorly for limiting the spread of sexually transmitted infections (STIs), including HIV infection, in the United States. At least it would seem to call for more intensive prevention methods targeting all adolescents and adults. Yet, a recent report from the US Preventive Services Task Force (USPSTF), an independent body funded through US congressional authorizations with a mandate to “make recommendations about preventive care services for patients without recognized signs or symptoms of the target condition,” suggests otherwise.²

The USPSTF recently reviewed the evidence for behavioral counseling interventions to prevent STIs in adolescents and adults.³ The data from 15 randomized controlled trials using such methods in primary care settings were examined. The panel concluded that only modest reductions in STIs-ranging from 2.6% to 11.1% at 12 months and only among “high-risk” adults and sexually active adolescents-were achieved. The interventions used in these studies did, however, accomplish 3 important goals, even though of modest magnitude: an increase in adherence to treatment recommendations for women; increased contraceptive use in adolescent boys; and decreased pregnancy in sexually active adolescent girls.³

The range of programs among these 15 studies was intensive, including a single 4-hour session, three 1-hour sessions over 3 consecutive weeks, four 4-hour sessions, or a 10-session intervention.² The USPSTF review found no evidence of behavioral or biological harm as a result of the risk-reduction counseling used in the studies, such as increases in unprotected sex, greater number of sexual partners, or earlier sexual debut. But, even though it was acknowledged that “clinicians may not be able to identify all adolescents who are sexually active,” intensive counseling for all adolescents, or for adults not perceived to be at increased risk, was not recommended.²

In terms of cost-benefit, this makes sense. Not all sexually active persons are at equal risk for HIV infection or other STIs, even with equivalent rates of unprotected sex. As noted in an Editorial here last year, apart from pregnancy and childbirth, women in the United States are disproportionately affected by health problems linked to sexual activity.⁴ A CDC study of adverse health events, deaths, and disability-adjusted life years (DALY) attributable to sexual behavior in 1998, the last year evaluated, showed 20 million such events.⁵ They included 29,782 deaths, or 1.3% of all deaths in the United States that year. But the majority of health events (62%) and DALY (57%) attributed to sexual behavior were among females; curable infections contributed to more than half of the events.⁵ In addition, disparities by race and ethnicity were stark in 1998 and appear to have continued unabated. In 2005, the rate of AIDS cases for female adults and adolescents was 2.0 per 100,000 population for non-Hispanic whites but 11.2 per 100,000 for Hispanics and 45.5 per 100,000 for blacks.⁶

As Jonathon Briggs, director of communications at the AIDS Foundation of Chicago recently wrote, in re-scripting a popular TV show and movie, “Though it is true that nearly every major character on ‘Sex and the City’ had an STD scare, the most severe disease any of the 4 white Manhattan women ever got was chlamydia. . . . If the show had been ‘Sex in the Inner City’ chronicling the sexually liberated adventures of 4 black women . . . one of the lead characters could credibly have tested positive for the virus that causes AIDS.”⁷

With a higher density of infected persons in a given region and with shared sexual networks, the likelihood of coming into contact with a sexual partner newly infected with HIV is greatly increased. Acute phase transmission events account for a large proportion of new HIV infections. This makes sense in terms of numbers of potentially infected contacts because, as in a study from Uganda, the average per-act transmission probability involving an acute infection was almost 40-fold greater than one involving a chronic infection (0.036 vs 0.0008).⁸

Presently, abstinence-based sex education programs receive federal priority, despite the fact that 22 states refuse to participate in this $50 million annual program using Title V funds and that 17 of these states have explicitly justified their decision on the basis that such sex education programs “are largely ineffective in reducing sexual onset and in promoting attitudes and skills consisting in sexual abstinence.”⁹ Abstinence programs can sometimes have some impact-one conducted among suburban Virginia students achieved a significant reduction in teen sexual initiation¹⁰-however, the long-term effectiveness of such programs, the extent of their impact in reducing STIs and HIV infection, and their cost-effectiveness have never been documented. In addition, certain long-held concepts about sexual behaviors among adolescents used as attempts to limit pregnancy and STIs appear to be incorrect. It was recently shown that “technical virgins,” ie, persons engaging in oral and/or anal sex in place of penile-vaginal intercourse, do not remain true virgins for very long. In a federal survey of more than 2200 youths aged 15 to 19 years, noncoital behaviors commonly co-occurred with coital behaviors.¹¹ Both oral and anal sex were much more common among adolescents who had initiated vaginal sex as compared with true virgins, and the initiation of either oral sex (50% of both girls and boys) or anal sex (10% of participants) preceded the first episode of penile-vaginal intercourse by a mean of only 6 months.¹¹

In terms of USPSTF considerations for targeting of prevention messages, one must also be aware of the changing demographics of the HIV epidemic in the United States and Canada. For example, 16% of all new HIV infections in Canada are linked to immigrants, even though they make up only 1.5% of the population.¹² In one HIV clinic in Minnesota, 12% of all clients were African-born.¹³ This issue of immigrant-related HIV infection also goes both ways: the University of California’s Health Initiative of the Americas recently reported that one-quarter of Mexico’s AIDS cases are among persons who spent prolonged periods in the United States.¹⁴

Some things related to STIs cannot be targeted. In a large study from Michigan, no behavioral characteristics in either sexually active or virginal adolescents were predictive of future human papillomavirus (HPV) infection.¹⁵ Targeting particular groups for HPV vaccination would have precluded many at-risk women from being protected. But other measures need to be better targeted, and better funded, including intensive STI and HIV counseling and prevention.

References:

References1. Health Guru News. Internets largest sex health survey gets one millionth response. http://news.healthguru.com/story/article/id/4033/Internets_Largest_Sex_Health_Survey_Gets_One_Millionth_Response. Accessed November 12, 2008.
2. U.S. Preventive Services Task Force. Behavioral counseling to prevent sexually transmitted infections: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2008;149:491-496.
3. Lin JS, Whitlock E, O’Connor E, Bauer V. Behavioral counseling to prevent sexually transmitted infections: a systematic review for the U.S. Preventive Services Task Force. Ann Intern Med. 2008;149:497-508.
4. Laurence J. Women and HIV. AIDS Reader. 2007;17:574, 580.
5. Ebrahim SH, McKenna MT, Marks JS. Sexual behaviour: related adverse health burden in the United States. Sex Transm Infect. 2005;81:38-40.
6. Centers for Disease Control and Prevention. HIV/AIDS surveillance in women: estimated number and proportion of AIDS cases among female adults and adolescents 1985-2005-United States and dependent areas. www.cdc.gov/hiv/topics/surveillance/resources/slides/women/index.htm. Accessed November 12, 2008.
7. Briggs JE. In inner city, risk is reality of sex. Chicago Tribune. July 20, 2008.
8. Pinkerton SD. Probability of HIV transmission during acute infection in Rakai, Uganda. AIDS Behav. 2008;12:667-684.
9. Chu A. State shuns sex education grants. Pittsburgh Post-Gazette. July 9, 2008.
10. Weed SE, Ericksen IH, Lewis A, et al. An abstinence program’s impact on cognitive mediators and sexual initiation. Am J Health Behav. 2008;32:60-73.
11. Lindberg LD, Jones R, Santelli JS. Noncoital sexual activities among adolescents. J Adolesc Health. 2008;43:231-238.
12. Theodore T. Government mulls changes after report on HIV-positive immigrants. Canadian Press. July 17, 2008.
13. Akinsete OO, Sides T, Hirigoyen D, et al. Demographic, clinical, and virologic characteristics of African-born persons with HIV/AIDS in a Minnesota hospital. AIDS Patient Care STDS. 2007;21:356-365.
14. Ferriss S. AIDS cases disproportionately hit ethnic group. Sacramento Bee. October 17, 2008.
15. Dempsey AF, Gebremariam A, Koutsky L, Manhart L. Behavior in early adolescence and risk of human papillomavirus infection as a young adult: results from a population-based study. Pediatrics. 2008;122:1-7.