coital debut appears to be associated with subsequent patterns of multiple sexual partners and sex with risky partners, such as bisexual, injecting-drug-using, or HIV-infected individuals (27). Furthermore, the hormonal microenvironment is age-dependent. Thus, for young adolescents, behavioral risk factors such as multiple, risky partners conspire with biological risk factors such as large zones of cervical ectopy to result in high STD rates.
Younger cohorts also report more sexual partners than older groups, and the proportion of young adults with multiple sexual partners appears to be increasing over time (24, 25, 28-31). In fact, between 1971 and 1988, the proportion of sexually active adolescent women reporting more than one sexual partner swelled from 39% to 62% (29). In part this may be due to the combined effect of trends toward younger age of coital debut and older age at first marriage. During the decade of the '80s, American women experienced an increase of approximately 30% in the median number of years that they spend in this relatively high risk stage of their reproductive lives (32). In addition, these increases were greatest for Black women and for women living in poverty.
Sonenstein and colleagues (33) have observed analogous trends among young men. Among 17- to 19-year-old American men, the average number of sexual partners in the previous year rose from 2.0 in 1988 to 2.6 in 1991, and the proportion reporting 5 or more partners increased from 6% to 11% over the same time period. Both this study and the 1991 National Survey of Men suggest that Black men report more sexual partners than White or Hispanic men; however, other national survey data indicate that these patterns vary substantially by gender and marital status (30-32, 34).
Both commercial sex (exchange of sex for money or drugs) and specific sexual practices such as anal intercourse, intercourse during menses, or ''dry sex"* have also been linked to increased risk of STDs or their sequelae (21, 35-37). However, few trend data are available on these sexual behaviors. Cross-sectional national survey data indicate that more White men than Black men reported anal intercourse (21% vs. 13.6%) or same-gender sexual activity during the past 10 years (2.4% vs. 1.3%) (30). In contrast, anecdotal information suggests that dry sex may be practiced more frequently by Black Americans than by Whites (31).
Sex during which efforts are made to minimize lubrication of the vagina by using intravaginal desiccants, by wiping out the vagina, or by other methods. The intent is usually to increase the pleasure of the male partner; however, this practice may increase STD or HIV transmission because it may result in vaginal inflammation, traumatic lesions, or more frequent condom breakage.