Sexually transmitted infections and sexual risk behaviors: Comparing teenagers and adults in a probability sample of residents of Baltimore, MD, USA

Background. Surveillance data indicate that adolescents are at higher risk for acquiring sexually transmitted infections than their adult counterparts. Previous research has associated STI prevalence with sexual risk behaviors that may be more prevalent among teenagers.

Methods. The Monitoring STIs Survey Program (MSSP) monitors the prevalence of STIs in Baltimore, MD using automated telephone self-interviewing (T-ACASI) and urine collection kits sent out and returned by U.S. mail.

We report findings from the first two years of the MSSP on the prevalence of undetected STIs and sexual risk behaviors among Baltimore residents, comparing teenagers aged 15-19 to adults aged 20-35.

Results. Chlamydia trachomatis (CT) rates were significantly higher among teens than among 20-35-year-olds, 7.4% v. 3.3% (p=0.01), but age group differences in T. vaginalis (TV) prevalence were not statistically significant. Teens were significantly more likely than adults to have had more than one sexual partner in the previous year. However, teens were also more likely to have used a condom during most recent sexual intercourse and less likely to have had sex while under the influence of drugs or alcohol. In multivariable logistic regression, age group was not associated with the odds of having CT. Moreover, when analyses were run separately for teens and adults, factors associated with a higher odds of CT infection were the same for both age groups; only nonwhite race and having more than four sexual partners were predictive of CT infection, suggesting the possible role of network and/or biological factors in teens' CT infection risk.