What is the recommended workup and treatment for a female patient with a suspected sexually transmitted infection (STI)?

STI Workup in Women

All sexually active women under 25 years should receive annual screening for chlamydia, gonorrhea, HIV, and syphilis, with testing performed using nucleic acid amplification tests (NAATs) from cervical or vaginal specimens. 1

Risk Assessment and Sexual History

Before initiating testing, conduct a structured sexual history using the "Five P's" framework (partners, practices, prevention of pregnancy, protection from STIs, and past history of STIs), supplemented with specific questions about injection drug use and sex work to identify HIV and viral hepatitis risk 2:

• Partners: Ask "In the past 2 months, how many partners have you had sex with?" and "Do you have sex with men, women, or both?" 2
• Practices: State "To understand your risks for STDs, I need to understand the kind of sex you have had recently" and inquire about vaginal, anal, and oral sex 2
• Protection: Ask about condom use frequency and, if never used, follow up with "Why don't you use condoms?" 2
• High-risk behaviors: Specifically ask "Have you or any of your partners ever injected drugs?" and "Have you or any of your partners exchanged money or drugs for sex?" 2

Screening Recommendations by Population

All Sexually Active Women Under 25 Years

• Annual screening for chlamydia and gonorrhea using cervical or vaginal NAATs 1
• Annual screening for HIV and syphilis 1
• Consider extragenital testing (pharyngeal and rectal) if history includes oral or anal sex 3

Women 25 Years and Older with Risk Factors

Screen annually if any of the following apply 1:

• New or multiple sex partners
• Inconsistent condom use
• Sex while using drugs or alcohol
• Partner with high-risk behaviors

Pregnant Women

First prenatal visit 4, 1:

• Serologic test for syphilis
• Hepatitis B surface antigen (HBsAg)
• Test for Neisseria gonorrhoeae
• Test for Chlamydia trachomatis if under 25 years or at increased risk
• HIV testing (offer to all, mandatory for high-risk)

Third trimester 4, 3:

• Repeat syphilis testing for high-risk women
• Repeat chlamydia and gonorrhea testing if under 25 years or at increased risk

At delivery 4, 3:

• Syphilis testing (no infant should be discharged without maternal syphilis status determined at least once during pregnancy)

Diagnostic Testing Methods

Chlamydia and Gonorrhea

• NAATs are preferred with sensitivities of 86.1%-100% and specificities of 97.1%-100% 5
• Collect cervical or vaginal specimens 1
• Consider pharyngeal and rectal specimens if sexual history indicates exposure at these sites 3

Syphilis

• Sequential serologic testing using both treponemal and nontreponemal (antiphospholipid) antibodies 5
• Screen at first prenatal visit, third trimester, and delivery for pregnant women 3
• Screen annually for all sexually active women in communities with primary/secondary syphilis rates >4.6 per 100,000 population 3

HIV

• Offer testing to all pregnant women and those with risk factors 4
• Annual screening for all sexually active women under 25 years 1

Trichomoniasis

• Wet mount and culture of vaginal swab specimen 4
• NAATs available with high sensitivity and specificity 5

Herpes Simplex Virus

• Serology not recommended for asymptomatic screening 3
• NAATs for symptomatic lesions have high sensitivity and specificity 5

Presumptive Treatment Approach

For women with cervicitis when follow-up is uncertain or in high-prevalence settings (>5% gonorrhea prevalence), initiate presumptive treatment before test results 4:

Recommended Regimens

• Azithromycin 1 g orally single dose 4, 6 OR
• Doxycycline 100 mg orally twice daily for 7 days 4, 7

Add concurrent gonorrhea treatment if local prevalence >5% or patient has risk factors (age <25 years, new or multiple partners, unprotected sex) 4

Special Considerations

Pregnant Women

• Only topical azole therapy for 7 days for vulvovaginal candidiasis; avoid oral fluconazole 8
• Doxycycline is contraindicated in pregnancy (Category D) 7
• Use azithromycin or amoxicillin for chlamydia treatment 4

HIV-Infected Women

• Same treatment regimens as HIV-negative women 4
• Treatment of cervicitis is vital as it reduces cervical HIV shedding and may reduce transmission 4

Persistent or Recurrent Cervicitis

• Reevaluate for reexposure to STDs 4
• Reassess vaginal flora for bacterial vaginosis 4
• Ensure sex partners have been evaluated and treated 4
• If all specific STDs excluded and symptoms persist, consider gynecologic specialist referral for possible ablative therapy 4

Partner Management

All sex partners from the past 60 days should be notified, examined, and treated 1:

• Partners should receive treatment for the same STDs as the index patient 4
• Patients and partners must abstain from sexual intercourse for 7 days after single-dose therapy or until completion of 7-day regimen 4
• Consider expedited partner therapy where legally permitted 9

Follow-Up and Retesting

• Retest 3 months after treatment for chlamydia or gonorrhea to detect reinfection 1, 5
• Return for reevaluation if symptoms persist after completing treatment 4
• For pregnant women, repeat testing in third trimester prevents maternal postnatal complications and neonatal infection 4

Common Pitfalls to Avoid

• Do not discharge infants without determining maternal syphilis status at least once during pregnancy 1
• Do not rely on cervicitis alone as a predictor of chlamydia or gonorrhea; most infected women do not have cervicitis 4
• Do not use lindane in pregnant or lactating women 4
• Do not assume negative initial testing after sexual assault; repeat testing at 2 weeks as infectious agents may not have produced sufficient concentrations for detection 4
• Do not forget extragenital sites when sexual history indicates oral or anal exposure 3

Reporting Requirements

• Syphilis, gonorrhea, and AIDS are reportable in every state 4, 1
• Chlamydia is reportable in most states 1
• Familiarize yourself with local reporting requirements and report in a timely manner 4, 1
• Reports are held in strictest confidence and protected by statute in many jurisdictions 4