Condoms have been shown consistently to prevent STDs, especially gonococcal and chlamydial infections, and assist in preventing HIV infection as well. Inadequate contraceptive use by adolescents is reflected in the high pregnancy and STD rates in this age group. Only one-third of female and one-half of male adolescents reported using condoms at last intercourse.

In addition to condoms, spermicides have also been shown to inhibit some STD agents. Nonoxynol-9, a major component of many spermicides, acts as a surfactant to destroy the STD agent’s cell walls and has been shown to inhibit N. gonorrhoeae, Treponema pallidum, T. vaginalis, Candida, and herpes simplex virus I and II in studies in vitro. Nonoxynol-9 has also been shown to kill HIV. Although a combination of a barrier method of contraception (condoms, diaphragms) and a spermicide seems to be the most effective protection against STDs for adolescents, fewer than 10% of adolescents use spermicides and fewer than a third use condoms.

Oral contraceptives have been linked to some STD infections. For example, candidal infections have long been associated with oral contraceptive use. Controversy surrounds the role of oral contraceptives and the establishment of endocervical infection and development of PID with N. gonorrhoeae and C. trachomatis. It appears that oral contraceptive users have fewer gonococcal endocervical infections, and when gonococcal PID occurs, it is less severe. The impact of oral contraceptives on the establishment of chlamydial endocervical infections is less clear, but most authors show an increased risk for chlamydial infection among oral contraceptive users. Oral contraceptive users, however, appear to have less chlamydial PID.

Clinical Aspects of Sexually Transmitted Diseases
An overview of STDs by agents, pathogenesis, common clinical syndromes, diagnosis, and treatment is outlined in

Table 3-16 for common bacterial, fungal, and viral infections.