89 Sexually Transmitted Infections
Sexually transmitted infections (STIs) present a significant source of morbidity among adolescents, especially young women. According to 2007 surveillance data, adolescents represent 25% of the sexually active population but account for 50% of new STIs. The high incidence of STIs is associated with greater susceptibility of the adolescent female reproductive tract, poor access to STI prevention services, inconsistent use of barrier prophylaxis, and high prevalence among sexual partners.
STIs present with a wide range of symptoms and physical findings. Moreover, many infections are asymptomatic. Thus, regular screening among sexually active adolescents is highly recommended.
This chapter focuses on the most common clinical syndromes among adolescents: vaginitis, urethritis, cervicitis, human papillomavirus (HPV) infection, herpes genitalis, chlamydia, gonorrhea, and syphilis.
Vaginitis
Vaginitis is one of the most common symptoms among adolescent females. It typically presents as increased or malodorous vaginal discharge and vulvovaginal erythema or edema. Although this can be caused by chemical or physical irritation, infectious causes include Trichomonas vaginalis, bacterial vaginosis (caused by Gardnerella vaginalis, genital Mycoplasmas, anaerobic bacteria) and Candida spp. In postpubertal women, normal vaginal flora is dominated by lactobacilli, which decrease the pH within the vaginal canal and prevent colonization by pathogens. However, any change to the genital environment can alter this balance and result in infection. Except T. vaginalis vaginitis, infectious vaginitis is not an STI. However, vaginitis is frequently diagnosed as part of the evaluation for STIs. The signs, symptoms, diagnostic criteria, and treatments for each infection are shown in Table 89-1.
Urethritis and Cervicitis
Epidemiology and Pathophysiology
Urethritis and cervicitis are most often caused by Neisseria gonorrhoeae and Chlamydia trachomatis. Gonorrhea and chlamydia are the most common reportable diseases in the United States, with approximately 360,000 cases of gonorrhea and 1.1 million cases of chlamydia reported in 2007. Adolescents are overrepresented: 50% of gonorrhea cases occur in individuals 15 to 24 years of age, and chlamydia infection among 15- to 19-year-old young women is 10 times the national average (3004 cases vs. 370 cases per 100,000 population). The transmission rate for each pathogen is much higher from males to females. Transmission occurs by oral, vaginal, or anal sexual contact. Each organism may be transmitted vertically to a newborn via passage through an infected birth canal.
N. gonorrhoeae is a gram-negative, oxidase-positive diplococcus, with 70 different strains. Its virulence is associated with the presence of pili and an outer membrane protein that increase adhesion of gonococci to tissues. C. trachomatis circulates as an elementary body. At epithelial cell attachment, it is ingested and then transforms into a reticulate body. It then reproduces within the infected cell, producing several elementary bodies, which are released. C. trachomatis also has a predilection for columnar epithelial cells, which are prevalent in the adolescent ectocervix.
Clinical Presentation
The clinical presentations of urethritis and cervicitis and their associated infections are detailed in Table 89-2 and Figure 89-1.
Pelvic Inflammatory Disease
Pelvic inflammatory disease (PID) is an important complication of cervicitis, most commonly caused by N. gonorrhoeae and C. trachomatis. Other vaginal and enteric pathogens may be involved, including Bacteroides spp., Ureaplasma urealyticum, and Mycoplasma hominis. Gonococcus, C. trachomatis, and other organisms may ascend into the uterus and fallopian tubes. Infected material in the fallopian tubes may result in tubo-ovarian abscess, and overflow may lead to peritonitis or perihepatitis. The risk of PID is associated with young age at first intercourse, multiple partners, vaginal douching, and use of intrauterine devices.
The presenting symptoms of patients with PID are described in Table 89-2. Some patients may have subclinical infection that is not diagnosed until evaluation for infertility reveals fallopian tube scarring. On examination, patients usually have lower abdominal tenderness. Pelvic examination may reveal cervical discharge; an inflamed cervix; cervical, adnexal, or uterine tenderness; or an adnexal mass. Timely diagnosis of PID is important to prevent infertility. Because the signs and symptoms of infection are not specific, the Centers for Disease Control and Prevention developed criteria to guide diagnosis and empiric treatment (Table 89-3). Fulfillment of minimal criteria indicates presumptive treatment.
Table 89-2 Signs and Symptoms of Urethritis, Cervicitis, and Associated Syndromes in Men and Women
| Men | Women | |
|---|---|---|
PID, pelvic inflammatory disease; RUQ, right upper quadrant.
Table 89-3 Signs and Symptoms of Pelvic Inflammatory Disease
| Minimal Criteria | Additional Criteria | Definitive Criteria |
|---|---|---|
|
Transvaginal sonography showing thickened fluid-filled tubes, free pelvic fluid, or tubo-ovarian complex
|
CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; WBC, white blood cell.
Other Manifestations of Gonococcal and Chlamydial Infection
Nongenitourinary manifestations of gonococcal and chlamydial infection include pharyngitis, conjunctivitis, and disseminated infection. Gonococcal pharyngitis should be considered for exudative pharyngitis in a sexually active adolescent. Disseminated gonococcal infection often manifests as arthritis, tenosynovitis, and dermatitis. Chlamydia is associated with Reiter’s syndrome (urethritis, spondylitis, uveitis). Both chlamydia and gonorrhea can also cause neonatal infection (see Chapter 105).
Evaluation and Management
Gonorrhea can be diagnosed by gram stain and culture from urethral and endocervical swabs. Chlamydia, as an intracellular organism, is difficult to grow in culture and has therefore been more difficult to diagnose. Newer and more rapid diagnostic methods include nucleic acid amplification techniques that have greatly increased the ease and sensitivity of testing. They can be performed on urine samples in addition to urethral or endocervical swabs. The other bacterial causes of urethritis—cervicitis and PID—are not generally isolated from cultures.
Patients with gonorrhea or chlamydia are at risk for co-infection. Therefore, treatment guidelines recommend covering for both pathogens when treating urethritis, cervicitis, or PID (Table 89-4). This is critical in PID, in which cervical culture results are often negative. Recommendations for PID also include anaerobic coverage because of the polymicrobial nature of the infection.
Table 89-4 Treatment Recommendations for Urethritis, Cervicitis, and Pelvic Inflammatory Disease*
| Treatment | Special Considerations | |
|---|---|---|
| Nongonococcal urethritis or cervicitis |
