Sexually Transmitted Infections

Abstract

The incidence of sexually transmitted infections (STIs) has been increasing in recent years, and the informed primary care provider is positioned to address this challenge. Prevention counseling, including through the use of videos accessed on the patient’s cell phone, serves as the first step in reducing the burden of STIs. Screening for chlamydia, gonorrhea, and human immunodeficiency virus (HIV) according to USPSTF guidelines will also have an impact. For patients presenting with potential exposure, providers need a working knowledge of chlamydia, gonorrhea, pelvic inflammatory disease (PID), HIV, syphilis, and viral hepatitis. Pre- and post-exposure prophylaxis are new measures that providers can employ to help prevent new HIV infection. Finally, Ebola and Zika virus are emerging infections that can be sexually transmitted.

Review Questions

• 1. A 24-year-old woman presents for routine cervical cancer screening. She and her boyfriend use latex condoms coated with nonoxynol-9, except when they occasionally use “lambskins” (natural membrane condoms). She is using injectable medroxyprogesterone acetate (Depo-Provera) for contraception as well. She is concerned about contracting HIV, since it is prevalent in her community.

  You counsel your patient that she can reduce her risk of acquiring HIV by:

  • A. Continuing to use condoms coated with nonoxynol-9 spermicide.

  • B. Switching to plain latex condoms.

  • C. Using a male latex condom together with a female condom.

  • D. Switching to natural membrane (“lambskin”) condoms.

  • E. Stopping the injectable contraceptive, medroxyprogesterone acetate.

  The correct answer is B. Latex condoms have been shown to be effective in preventing the spread of HIV. On the other hand, the use of nonoxynol-9 spermicide appears to increase the risk of HIV acquisition in users, likely by disrupting the genital epithelium [3]. The male and female condom should not be used together [2]. Natural membrane condoms have a large pore size that prevents the passage of sperm but not viruses [2]. Previous concern regarding the possibility that the injectable contraceptive medroxyprogesterone acetate might increase a women’s risk of HIV acquisition has been laid to rest by a large randomized trial [4].

• 2. An 18-year-old woman presents to your office stating that she read on the Internet that since she is now sexually active, she should undergo screening for herpes infection. She and her boyfriend are healthy college students who use condoms consistently and neither of them have any relevant symptoms.

  Which of the following STI screening tests do you recommend?

  • A. No STI testing is needed since she faithfully uses condoms

  • B. Chlamydia, gonorrhea, and HIV

  • C. Chlamydia, gonorrhea, syphilis, and HIV

  • D. Chlamydia, gonorrhea, and HSV

  The correct answer is B. The CDC and USPSTF recommend annual screening for both chlamydia and gonorrhea in all sexually active women and girls age 24 and younger, as well as in older women at increased risk [2, 5]. The CDC also recommends universal HIV screening in all Americans age 13–64, at least once. Although the incidence of syphilis in the U.S. has recently increased dramatically, universal screening is not advised since infection remains unlikely in persons lacking risk factors. The USPSTF specifically recommends against routine screening for herpes in asymptomatic hosts [7].

• 3. A 24-year-old woman presents for an acute appointment stating that her boyfriend informed her that he was diagnosed with chlamydia yesterday. What are the next steps in management?

  • A. Conduct a history; perform a pelvic exam; examine a wet mount of vaginal secretions; obtain specimens to test for gonorrhea, chlamydia, and Trichomonas; order syphilis and HIV serologies; and prescribe empiric treatment for chlamydia.

  • B. Order testing for chlamydia infection and treat the patient only if the result comes back positive.

  • C. Prescribe empiric treatment for chlamydia now.

  • D. Take a history, perform a pelvic exam, and prescribe treatment if the patient has clinical evidence of chlamydia infection.

  The correct answer is A. The patient will be empirically treated for chlamydia based on documented exposure; however, she is evaluated as well. In addition to chlamydia infection, this patient is at risk for other STIs, since coinfection is common. Clinical evaluation is also needed to exclude PID, a serious complication that would warrant more extensive antibiotic treatment and closer monitoring [2, 21]. Confirmatory testing for the reported infection is collected prior to empiric treatment to allow notification of her other recent (within 60 days) sexual contacts if the results are positive. Uncomplicated chlamydia and gonorrhea infections are most often asymptomatic and without clinical signs.

• 4. A 19-year-old woman who uses condoms most of the time presents with the complaint of lower abdominal pain for 3 days. Her office pregnancy test is negative and her urine dipstick is unremarkable. Her pelvic exam is notable for uterine tenderness and cervical motion tenderness. You are concerned that your patient might have PID.

  Which additional finding is needed before you initiate treatment?

  • A. Fever >101 °F orally

  • B. Mucoid discharge from the cervical os

  • C. Rebound tenderness on abdominal examination

  • D. No additional findings are necessary before initiating treatment

  • E. Positive chlamydia or gonorrhea test result

  The correct answer is D. PID is a clinical diagnosis. The CDC supports making the presumptive diagnosis and initiating treatment in a susceptible host if no other cause can be found to explain a patient’s lower abdominal pain if tenderness is noted on pelvic exam (either cervical motion tenderness, uterine tenderness or adnexal tenderness). Only half of patients with PID have a cervical discharge. (However, women with PID who lack this finding usually do have evidence of inflammation in the form of excess leukocytes on wet mount). Treatment of PID should be initiated as soon as the clinical diagnosis is made, without waiting for test results. It should also be noted that a negative chlamydia or gonorrhea test result in the presence of PID is common and does not exclude this infection in the upper tracts [2].

• 5. A 45-year-old woman presents for urgent evaluation because of a 2-day history of a new painful “sore” on her vulva. Pelvic examination reveals a 4 mm ulcer on her vulva. Her pelvic exam is otherwise unremarkable and the patient appears well overall. The patient agrees to undergo HIV testing. Appropriate steps to diagnose her genital ulcer include:

  • A. Herpes simplex virus PCR testing via ulcer swab

  • B. Herpes simplex virus PCR testing via ulcer swab and serologies for syphilis

  • C. PCR testing of the lesion for both herpes simplex virus and T. pallidum.

  • D. Serologies for both syphilis and herpes simplex virus

  The correct answer is B. In the U.S., infectious genital ulcers usually result from herpes or syphilis. Since the clinical features of the two infections can overlap and coinfection is possible, patients presenting with genital ulcers are always tested for both infections [2]. A swab specimen is used to obtain material from the base of the ulcer for type-specific HSV PCR testing, and serologies are ordered to diagnose syphilis. Since genital ulcers facilitate the spread of HIV, HIV testing is also recommended for all patients presenting with genital ulcers [2].

• 6. A 23-year-old patient recently diagnosed with genital herpes infection returns for 3-week follow-up. The PCR test of the ulcer isolated Herpes simplex virus type 2. Which of the following counseling points should be mentioned with respect to preventing future outbreaks?

  • A. Once suppressive therapy is begun it is usually continued indefinitely.

  • B. Chronic suppressive treatment with valacyclovir has been shown to reduce transmission of herpes to the uninfected partner in discordant couples.

  • C. A recurrent outbreak will be completely prevented when episodic treatment is begun at the first sign of tingling.

  • D. If PCR testing had revealed HSV type 1 then suppressive therapy would be indicated.

  The correct answer is B. Chronic suppressive antiviral treatment will reduce recurrence rates of herpes outbreaks and greatly reduce viral shedding (which occurs even in the absence of outbreaks). For this reason, suppressive therapy is the first-line treatment for an HSV-discordant couple [2, 37]. Outbreaks wane over time and each year immunocompetent patients suffering few recurrences should be offered a trial off of suppressive therapy [2]. Episodic treatment shortens the duration of symptoms and reduces the intensity of outbreaks but does not affect the recurrence rate. Persons with genital HSV-1 infection are generally less prone to recurrences and are initially managed with episodic treatment.

• 7. A 25-year-old woman presents complaining of two growths on her vulva. Examination reveals a cluster of dome-shaped gray papules that are classic for genital warts. Appropriate management entails:

  • A. Performing a Pap smear now and again in 1 year given her increased risk of cervical cancer

  • B. Biopsying the lesions to first confirm the diagnosis

  • C. Offering her several treatment strategies, including a trial of watchful waiting

  • D. Withholding the HPV vaccine, since she already has HPV infection

  • E. Performing in-office cryotherapy to destroy the wart and eliminate the HPV infection

  The correct answer is C. Warts can be treated using a number of modalities; however, the success rate is only fair and wart removal likely reduces but does not eliminate the underlying HPV infection. While the CDC recommends treating warts prior to initiating a sexual relationship with a new partner, in most other settings a reasonable option is to withhold treatment for a year and monitor for progress, as spontaneous resolution is common [2]. Genital warts typically result from infection with benign (“low-risk”) serotypes of HPV and thus the recommended frequency of cervical cancer screening remains unchanged for women with genital warts. Genital warts are diagnosed by visual inspection and biopsy is unnecessary and unhelpful unless there are atypical features or a complete lack of response to treatment--either of which raises concern for possible malignancy [81]. While it is likely that the HPV vaccine will not be therapeutic for this patient’s established HPV infection, the 9-valent vaccine will likely protect her from other HPV serotypes, and women age 26 and younger are eligible for vaccination. Dedicated training in the use of cryotherapy for the treatment genital warts is recommended [2].

• 8. A healthy 53-year-old woman calls you on Monday in the late afternoon to report that she had unprotected sex with a friend late on Friday night. She knows he is HIV-positive and is fairly confident that he is not getting medical care. She has been trying to reach him by phone and tearfully asks if there is anything she can do for this high-risk exposure. How do you manage this patient?

  • A. Prescribe a 28-day regimen of tenofovir/emtricitabine once daily and raltegravir 400 mg twice daily to begin today, and order HIV testing as well as routine chemistries and STD testing.

  • B. Refer to an infectious disease physician to consider nonoccupational post-exposure HIV prophylaxis.

  • C. Start once daily tenofovir/emtricitabine indefinitely

  • D. Advise her that she is presenting too late for post-exposure prophylaxis

  The correct answer is A. The patient should be prescribed nonoccupational post-exposure prophylaxis (nPEP) for HIV, which is effective when instituted within 72 hours of exposure [58]. Prompt initiation is critical, and thus waiting for HIV test results or referring to another clinician is inappropriate. The most common regimen in use is a 28-day course of a three-drug regimen consisting of tenofovir-emtricitabine 300 mg/200 mg (Truvada) once daily plus raltegravir (Isentress) 400 mg twice daily. Answer C is the two-drug regimen tenofovir-emtricitabine 300 mg/200 mg (Truvada), which is effective for preexposure prophylaxis [63] but inadequate for post-exposure prophylaxis.