Sexually Transmitted Diseases Health Article

Causes and symptoms

The chance for adolescents of getting and transmitting STDs is affected by complex interrelationships between key factors (sociodemographic, biologic, psychosocial, and behavioral). For example, many STD-related risk markers (e.g. age, gender, race/ethnicity) correlate with more fundamental determinants of risk status (e.g., access to health care, living in communities with high prevalence of STDs) to influence adolescents' risk for STDs.

Developmental factors such as pubertal timing, self-esteem, and peer affiliation may also increase their risk of exposure to STDs. An assessment of these interrelationships is critical to preventing and controlling STDs in adolescents. Moreover, since behavior is the common means by which STDs occur, an important first step in fighting STDs is to understand the prevalence and patterns of risk behaviors as well as the psychosocial context in which these behaviors occur.

Behavioral factors

Although biologic factors play an important role in the transmission of STDs, it is also the health-risking behaviors of adolescents that place them at increased risk for exposure to STDs. Behavioral risk factors include the age of sexual activity, number of sexual partners, use of contraceptives, and use of alcohol and drugs.

SEXUAL ACTIVITY Early initiation of sexual intercourse has been associated with high-risk sexual activities, including ineffective use of contraceptives, multiple sex partners over a short period of time, high-risk sex partners, and acquisition of STDs and their consequences of cervical cancer and dysplasia. The average age of first sexual intercourse is between 16 and 17 years for adolescent men and between the age of 17 and 18 years for adolescent women, and has been found to be as young as age 12 in some high-risk populations. Research on adolescents' decision to initiate sexual intercourse indicates an interaction between biological and social factors. However, much remains unknown about the interactions between hormones, behavior, and social factors.

The Youth Risk Behavior Surveillance System (YRBSS), a self-reported survey of a national representative sample of high school students in grades nine to 12, indicated that in 2003, 46.7 percent of the students reported having had sex. By grade level, the rates were 32.8 percent for ninth grade, 44.1 percent for tenth grade, 53.2 percent for eleventh grade, and 61.6 percent for twelfth grade. Approximately 7.4 percent of students reported having sex for the first time before age 13. Prevalence rates of sexual experience differed by race/ethnicity and gender. African-American students were significantly more likely (73.8% of males and 60.9% of females) than Caucasian (40.5% of males and 43.0% of females) and Hispanic (56.8% of males and 46.4% of females) students to have engaged in sexual intercourse. Moreover, data from the National Survey of Family Growth (NSFG), a large-scale national survey of women ages 15 to 44 years, reveal that family income is associated with adolescents' protection against HIV and many other STDs; adolescents from poor and low-income families are more likely to report an earlier age of sexual experience than their counterparts from higher income families.

In addition to early sexual activity, many adolescents have multiple sex partners within a short period of time in a pattern of serial monogamy which also increases their risk of acquiring STD for two important reasons: it increases the likelihood of being exposed to a sexually transmitted pathogen, and it may reflect poor choices of sexual partners. Among the sexually experienced high school students responding to the YRBSS, 14.4 percent reported having four or more sex partners. Multiple sex partners were noted more frequently among African-American students (41.7% of males and 16.3% of females), compared to Hispanic (20.5% of males and 11.2% of females) and Caucasian (11.5% of males and 10.1% of females) students.

Involuntary sexual intercourse such as rape and sexual abuse may occur more commonly among adolescents, especially younger adolescent women, and often pose a potential risk for acquisition of STDs. A study on the effects of child abuse (i.e., incest, extra-familial sexual abuse, and physical abuse) on adolescent males showed a strong association between abuse and a number of risk-taking behaviors, such as forcing female sexual partners into having sexual intercourse and drinking alcohol prior to sexual intercourse. Moreover, when sexual intercourse is intermittent, as it is with most sexually experienced adolescents, the adolescents are less likely to take proper measures to safeguard against STDs.

CONTRACEPTIVE USE Sexually experienced adolescents are also at risk for STDs because of their patterns of contraceptive use, especially their use of barrier-method contraceptives. Some data indicate that adolescents do not use effective methods to reduce their risk of STDs or unintended pregnancies. Sexual abstinence is the only sure method of eliminating risk for STDs. When used consistently and correctly, however, condoms offer the best protection against acquisition of STDs, including HIV. Even when condoms are used improperly they reduce the risk of acquiring infections by 50 percent.

The overall reported use of contraceptives, particularly condoms, has increased among adolescents between 1994 and 2004. Data from the 2003 YRBSS reveal that 63.0 percent of the students who reported sexual activity in the three months prior to the survey also reported using condoms during their last sexual encounter; this behavior was more common among males of virtually all ages and racial/ethnic groups. In contrast, 20.6 percent of adolescent women ages 15 to 19 years reported use of birth control pills. It appears that while the use of oral contraceptives provides some protection against the development of gonococcal and nongonococcal forms of PID, it may increase the risk of chlamydial endocervical infections, and provides no protection against most STDs.

Differences in the types and patterns of contraceptive use by race/ethnicity, age, and socioeconomic status have also been noted. Also, adolescent women of higher income are more likely than young women of lower income to use oral contraceptives. These factors are related to access and use of medical services for reproductive health care. Thus, providing all sexually experienced adolescents with reproductive health counseling and education about the importance of consistently and correctly using barrier-method contraceptives such as condoms may play a crucial role in reducing their risk of acquiring and transmitting STDs.

ALCOHOL AND OTHER DRUG USE Use of alcohol and other drugs is prevalent among adolescents and thus poses a significant threat to their health. About 40 percent of high school youth responding to the YRBSS have used marijuana at least once with 22.4 percent of these students reporting use of this substance within 30 days before the survey. Cocaine was used at least once by 8.7 percent of the students and by 4.1 percent within 30 days of the survey. The substance of choice, however, is alcohol: 74.9 percent of students had at least one drink at some point in time and nearly half (44.9%) consumed alcohol in the 30 days prior to the survey. Among the current alcohol users, 28.3 percent had five or more drinks on at least one occasion, suggesting that a sizeable proportion of the students are periodic heavy drinkers. Grade, age, and gender differences were noted for lifetime and current use of alcohol and other illicit substances. In general, students in higher grade levels (grades 11 and 12) and males were more likely to use all substances. Racial/ethnic differences in use of substances were also found. Heavy use of alcohol was most prevalent among Caucasian and Hispanic males and females, while marijuana use was most common among African-American and Hispanic males.

Although these data strongly suggest that adolescents are at increased risk for social and physical morbidities, and even premature mortality because of their use of alcohol and other illicit substances, they underrepresent the actual prevalence of substance use among all adolescents. Teens who have dropped out or who are repeatedly absent from school and those who are homeless or otherwise disenfranchised are not represented by the reported data; many of these teens are potentially at higher risk for STDs because of their substance use behavior.

Substance use prior to sexual intercourse is likely to be related to a number of risk-taking behaviors: sexual intercourse with a casual acquaintance, lack of communication about use of condoms or previous sexual experiences, and no use of condoms. This association remained significant regardless of demographic factors, sexual experience, and dispositional factors such as adventure and thrill seeking. It appears that early intervention to prevent the use and abuse of alcohol and other substances may significantly decrease their risk of acquiring STDs.