# Sexually Transmitted Infections

Use exposure-site testing, syndrome-directed empiric treatment when indicated, pregnancy-specific screening, partner management, and targeted prevention to interrupt transmission while preventing pelvic inflammatory disease, adverse pregnancy outcomes, and neonatal infection.

**Clinical question:** How should clinicians test, triage, treat, and prevent common sexually transmitted infections across exposure sites and risk groups?

Updated: 2026-08-24T16:17:30.852398+00:00

## What matters in practice
- Obtain nucleic acid amplification testing from every anatomic site of sexual exposure; molecular assays have reported sensitivity and specificity of approximately 95% to 99%. [9]
- Treat symptomatic urethritis, cervicitis, proctitis, pharyngitis, vaginitis, or genital ulcer disease according to the syndrome and likely pathogens while confirming organism-specific diagnoses when laboratory testing is available. [11][24]
- Screen and retest pregnant patients according to age and risk; untreated gonorrhea, chlamydia, and syphilis can cause serious maternal, fetal, and neonatal outcomes. [15][18]
- Offer doxycycline postexposure prophylaxis through shared decision-making to gay, bisexual, and other men who have sex with men and transgender women with a bacterial STI diagnosed within the prior 12 months; use 200 mg within 72 hours after sex and reassess every 3 to 6 months. [4][12]
- At any symptomatic STI encounter, test for HIV and other locally prevalent STIs, address sex partners, and use vaccination and barrier prevention as indicated. [17][24]

## Triage urgent syndromes and test the exposed sites

Use symptoms and anatomy to select immediate testing and empiric coverage.

Prioritize same-day evaluation for pelvic or lower-abdominal pain with concern for pelvic inflammatory disease, pregnancy with suspected or confirmed STI, acute proctitis, genital ulceration, ocular symptoms after sexual exposure, sexual assault, and possible disseminated infection. Untreated STIs in women are associated with pelvic inflammatory disease, infertility, chronic pelvic pain, ectopic pregnancy, pregnancy loss, stillbirth, and neonatal transmission. [15][17]

Take a site-specific sexual exposure history rather than inferring exposure from identity: urethral/penile, vaginal/cervical, rectal, pharyngeal, ocular, and skin-to-skin exposure. Obtain NAAT specimens from each exposed mucosal site for gonorrhea and chlamydia when testing is indicated; NAATs are the diagnostic standard and have reported sensitivity and specificity of 95% to 99%. Extragenital infection is frequently asymptomatic, so urine-only testing can miss rectal or pharyngeal infection. [9][11]

For symptomatic patients, add HIV testing and testing for other prevalent STIs at the same encounter. In patients with urethritis, cervicitis, proctitis, pharyngitis, vaginitis, or genital lesions, interpret a positive organism-specific test in an anatomic and syndromic context because concurrent infection with more than one pathogen is common. [11][17]
- Urethritis: test for gonorrhea and chlamydia; consider other sexually transmitted causes when symptoms persist despite initial management. [11][15]
- Cervicitis or vaginal symptoms: distinguish cervicitis from vaginitis and test for gonorrhea and chlamydia; include trichomoniasis and other causes when indicated by the clinical syndrome. [11][15]
- Proctitis: obtain rectal gonorrhea and chlamydia testing and assess for syphilis, herpes simplex virus, and lymphogranuloma venereum when the clinical pattern suggests these diagnoses. [11]
- Pharyngitis after oral exposure: obtain pharyngeal gonorrhea and chlamydia testing when exposure history supports testing; many extragenital infections are asymptomatic. [11]
- Genital ulcer disease: evaluate for syphilis and herpes simplex virus rather than assigning a diagnosis by lesion morphology alone. [15]

*Exposure-directed diagnostic framework for common sexually transmitted syndromes. [9][11][15]*

| Clinical pattern | Immediate tests | Interpretation and next action |
| --- | --- | --- |
| Urethral discharge or dysuria | Urethral or urine gonorrhea/chlamydia NAAT; HIV and other prevalent STI testing. [11][17] | Manage as urethritis while test results identify gonorrhea, chlamydia, or another cause. [11] |
| Cervical inflammation, postcoital bleeding, or mucopurulent discharge | Vaginal/cervical gonorrhea/chlamydia NAAT; assess for trichomoniasis and other causes based on syndrome. [11][15] | Do not rely on discharge alone to exclude infection; chlamydial and gonococcal infections are commonly asymptomatic. [21] |
| Rectal pain, discharge, or tenesmus | Rectal gonorrhea/chlamydia NAAT; assess for syphilis, herpes simplex virus, and lymphogranuloma venereum. [11] | Use results and severity to direct therapy; evaluate promptly when severe symptoms or systemic illness are present. [11] |
| Pharyngeal exposure or symptoms | Pharyngeal gonorrhea/chlamydia NAAT when indicated by exposure. [11] | A negative urine test does not exclude pharyngeal infection. [11] |
| Genital ulcer | Syphilis and herpes simplex virus evaluation; HIV testing. [15][17] | Treat based on confirmed or strongly suspected cause and arrange follow-up for serologic and lesion-response assessment. [15] |

## Match treatment to the organism and syndrome

Avoid a single empiric regimen for all mucosal complaints.

Gonorrhea, chlamydia, syphilis, trichomoniasis, Mycoplasma genitalium, herpes simplex virus, lymphogranuloma venereum, and noninfectious conditions can produce overlapping urethral, cervical, rectal, pharyngeal, and genital symptoms. When quality-assured molecular testing is available, use laboratory-supported diagnosis to select current evidence-based treatment rather than relying on syndromic management alone. [11][24]

Use the current CDC STI treatment guideline or its current updates to select organism-specific regimen, dose, route, and follow-up because resistance patterns and recommendations change. This is particularly important for gonorrhea, where antimicrobial susceptibility is a continuing clinical and public-health concern, and for persistent Mycoplasma genitalium infection. [1][2][15][18]

For patients with genital herpes, routine serologic screening is not recommended, including during pregnancy. Evaluate clinically apparent lesions and use the CDC STI treatment guidance for antiviral treatment and counseling. [15]

Persistent or recurrent symptoms after treatment should trigger reassessment of adherence, re-exposure from an untreated partner, infection at an untested anatomic site, coinfection, and an alternative infectious or noninfectious diagnosis. Do not assume microbiologic failure solely from ongoing symptoms. [11][15]
- Use organism-directed treatment after NAAT or serologic confirmation whenever the patient is clinically stable and follow-up is reliable. [24]
- Use empiric syndromic treatment when clinical severity, likelihood of loss to follow-up, or a high-probability syndrome makes delayed treatment unsafe; obtain diagnostic specimens before treatment whenever feasible. [11][20]
- At treatment visits, identify and manage sex partners to reduce reinfection and onward transmission. Partner counseling and treatment are core components of STI case management. [16][21]
- Document all exposed sites and ensure testing and treatment have addressed those sites; asymptomatic extragenital infection is common. [11]

### Sexual assault

After sexual assault, use a trauma-informed examination and minimize retraumatization while obtaining indicated baseline testing. Because follow-up adherence is often low, CDC-based guidance recommends presumptive antimicrobial treatment for chlamydia, gonorrhea, and trichomoniasis, plus emergency contraception, hepatitis B and HPV vaccination assessment, and HIV exposure evaluation. [20]
- Offer HIV postexposure evaluation promptly when the exposure could confer HIV risk. [20]
- Address hepatitis B and HPV immunization status at the initial visit rather than deferring prevention to follow-up. [20]

*Clinical branches that should change diagnostic and management actions. [11][15][20]*

| Branch | What changes the plan | Action |
| --- | --- | --- |
| Symptomatic mucosal syndrome | Site-specific inflammation or discharge with relevant exposure. [11] | Collect site-specific NAATs and treat empirically only when syndrome severity or follow-up limitations justify it. [11][20] |
| Genital ulcer syndrome | Ulcerative lesion rather than isolated discharge syndrome. [15] | Test for syphilis and herpes simplex virus and include HIV testing. [15][17] |
| Persistent symptoms | Symptoms after treatment or after renewed sexual exposure. [11][15] | Check reinfection, untreated partners, untested sites, coinfection, adherence, and alternative diagnoses before changing therapy. [11][15] |
| Sexual assault | High probability of missed follow-up. [20] | Provide indicated presumptive antimicrobial prophylaxis, emergency contraception, immunization assessment, and HIV evaluation at the initial encounter. [20] |

## Screen by pregnancy status, age, risk, and exposure anatomy

Screening finds infection that symptom-based care routinely misses.

Routine laboratory screening is indicated for sexually active adolescents, and screening strategies should account for age, pregnancy, sexual practices, community prevalence, and disease-specific sequelae. An opt-out approach can reduce dependence on sexual-history disclosure and may improve case detection among adolescents and young adults. [18][16]

During pregnancy, screen at the first prenatal visit according to CDC recommendations. For gonorrhea, screen pregnant patients at risk, including those younger than 25 years and those 25 years or older with a new sex partner, multiple partners, a partner with concurrent partners, a partner with an STI, or residence in a community with high gonorrhea rates. Treat identified infection during pregnancy and retest in 3 months, in the third trimester, or at delivery as indicated. [18]

Do not use routine serologic screening for genital herpes in pregnancy. CDC-based pregnancy screening guidance does not recommend routine testing for bacterial vaginosis, herpes, HPV, or trichomoniasis in pregnancy. [15][17]

For persons with ongoing exposure risk, align repeat STI screening with the risk pattern and anatomic exposure sites. In people using doxycycline postexposure prophylaxis, perform syphilis and gonorrhea/chlamydia screening at all sites of exposure every 3 to 6 months. [12]
- At prenatal intake, identify age-based and behavioral risk factors that require gonorrhea screening. [18]
- When infection is diagnosed in pregnancy, ensure partner testing and treatment to reduce reinfection before delivery. [18]
- Use opt-out screening as a workflow strategy where sexual-history-based testing leaves a substantial testing gap. [16]

*Pregnancy-focused STI screening and follow-up decisions. [15][17][18]*

| Situation | Action | Follow-up |
| --- | --- | --- |
| Pregnant patient younger than 25 years | Screen for gonorrhea at the first prenatal visit. [18] | Treat infection during pregnancy; retest in 3 months, in the third trimester, or at delivery as indicated. [18] |
| Pregnant patient 25 years or older with gonorrhea risk factors | Screen for gonorrhea at the first prenatal visit. [18] | Treat infection and test/treat sex partners; repeat testing as indicated. [18] |
| Pregnant patient without symptoms requesting herpes screening | Do not perform routine genital herpes serologic screening. [15] | Evaluate and manage clinically suspected herpes according to current STI guidance. [15] |
| Pregnant patient without symptoms requesting routine BV, HPV, or trichomonas testing | Routine testing is not recommended. [17] | Test when symptoms or another clinical indication is present. [17] |

## Build prevention around barriers, vaccination, HIV prevention, and partner treatment

Pair each STI diagnosis with a prevention and reinfection plan.

Recommend condoms for vaginal, oral, and anal sex; consistent correct use provides effective protection against STIs, including HIV, but does not fully protect against infections transmitted from uncovered ulcerated skin, including syphilis and genital herpes. [24]

Review hepatitis B and HPV immunization status. Safe and effective vaccines are available for hepatitis B and HPV, and vaccination should be incorporated into STI prevention visits rather than reserved for primary care follow-up. [24]

Use each bacterial STI diagnosis as a prompt to assess HIV testing needs and HIV prevention, including preexposure prophylaxis when risk warrants. All patients presenting with STI symptoms should be screened for HIV and other prevalent STIs. [17]

Address sex partners at the same visit: identify recent partners, facilitate notification, arrange testing and treatment, and counsel patients that untreated partners are a major driver of reinfection. Partner notification and partner treatment are established elements of STI case management. [16][21]
- Document a prevention plan that includes barrier use, vaccine status, HIV testing or prevention assessment, and partner management. [17][24]
- For recurrent bacterial STIs, reassess exposure sites and prevention tools rather than limiting the response to repeat antimicrobial treatment. [12][16]
- Use nonjudgmental, inclusive sexual-history questions to identify exposures that determine site-specific testing and prevention needs. [11][16]

*Prevention interventions selected by clinical scenario. [12][17][24]*

| Scenario | Intervention | Key limitation or monitoring step |
| --- | --- | --- |
| Any patient at risk for STI acquisition | Recommend condoms for vaginal, oral, and anal sex. [24] | Condoms do not fully prevent syphilis or genital herpes when lesions occur outside the covered area. [24] |
| Eligible or incompletely immunized patient | Assess and provide hepatitis B and HPV vaccination as indicated. [20][24] | Address vaccination during the STI encounter to avoid missed prevention opportunities. [20] |
| Symptomatic STI presentation | Test for HIV and other prevalent STIs. [17] | Link HIV prevention needs to the exposure pattern and test results. [17] |
| Confirmed bacterial STI | Initiate partner notification, testing, and treatment processes. [16][21] | Partner management reduces reinfection risk and should not be deferred. [16] |

## Use doxycycline PEP selectively and monitor for benefit and resistance concerns

Doxycycline PEP is an exposure-linked intervention, not universal prophylaxis.

CDC guidance released in 2024 recommends counseling gay, bisexual, and other men who have sex with men and transgender women with a bacterial STI diagnosed during the past 12 months about doxycycline postexposure prophylaxis and offering it through shared decision-making. The regimen evaluated in trials is doxycycline 200 mg orally within 72 hours after sex. [4]

Doxycycline PEP has reduced chlamydia and syphilis incidence in trials among persons assigned male sex at birth who were living with HIV or using HIV PrEP; gonorrhea benefit has been less consistent, plausibly reflecting tetracycline resistance in Neisseria gonorrhoeae. [4][5]

At initiation and every 3 to 6 months, reassess ongoing use, perform syphilis serology and gonorrhea/chlamydia testing at every exposed anatomic site, and test for HIV in persons without HIV according to current recommendations. Prescribe the number of doses through individualized shared decision-making. [12]

Discuss antimicrobial-resistance uncertainty explicitly. Wider doxycycline PEP use may increase resistance selection, including concern about co-transmission of gonococcal cephalosporin resistance with tetracycline resistance; this risk must be balanced against prevention of syphilis and chlamydia. [3]
- Eligibility emphasized by CDC: gay, bisexual, and other men who have sex with men and transgender women with a bacterial STI in the preceding 12 months. [4]
- Dose: doxycycline 200 mg orally as soon as possible and within 72 hours after sex. [4][5]
- Monitoring: reassess continuation and complete multisite STI screening every 3 to 6 months. [12]
- Do not present doxycycline PEP as a substitute for condoms, HIV prevention assessment, vaccination, or partner management. [12][17][24]

*Doxycycline PEP implementation framework. [3][4][12]*

| Decision point | Operational action | Follow-up |
| --- | --- | --- |
| Candidate selection | Counsel gay, bisexual, and other MSM and transgender women with a bacterial STI in the last 12 months; offer through shared decision-making. [4] | Reassess whether benefit continues to justify use every 3 to 6 months. [12] |
| Dose instruction | Doxycycline 200 mg orally within 72 hours after sex. [4][5] | Prescribe doses based on individualized patient-provider assessment. [12] |
| Laboratory surveillance | Screen for syphilis and gonorrhea/chlamydia at all sites of exposure. [12] | Repeat every 3 to 6 months; perform HIV testing in persons without HIV according to current guidance. [12] |
| Resistance discussion | Explain that gonorrhea prevention is less consistent and resistance selection is a concern. [3][5] | Revisit risks, benefits, incident STIs, and continued preference at follow-up. [3][12] |

## References
1. Diagnosis and Treatment of Sexually Transmitted Infections — jamanetwork.com — https://jamanetwork.com/journals/jama/fullarticle/2787903
2. Sexually Transmitted Infections — jamanetwork.com — https://jamanetwork.com/collections/5904/sexually-transmitted-infections
3. Doxycycline Postexposure Prophylaxis Could Accelerate the Emergence of Gonococcal Ceftriaxone Resistance—Reply — jamanetwork.com — https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2835081
4. Doxycycline Postexposure Prophylaxis and Bacterial Sexually Transmitted Infections Among Individuals Using HIV — jamanetwork.com — https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2828994
5. Does Meningococcal Group B Vaccination in the Setting of DoxyPEP Reduce Incidence of Gonorrhea? | NEJM Clinician — clinician.nejm.org — https://clinician.nejm.org/does-meningococcal-group-b-vaccination-setting-doxypep-reduce-incidence-gonorrhea-nejm-jw.NA57639
6. Sexually Transmitted Infection Treatment Guidelines for Adolescent Health Providers: What's New in 2021? — www.sciencedirect.com — https://www.sciencedirect.com/science/article/abs/pii/S1083318822000213
7. A Scoping Review of Approaches to Extragenital ... — www.sciencedirect.com — https://www.sciencedirect.com/science/article/pii/S1751485125001515
8. Addressing HIV/Sexually Transmitted Diseases and Pregnancy Prevention Through Schools: An Approach for Strengthening Education, Health Services, and School Environments That Promote Adolescent Sexual Health and Well-Being — www.sciencedirect.com — https://www.sciencedirect.com/science/article/pii/S1054139X21002779
9. Diagnosing sexually transmitted infections in resource — onlinelibrary.wiley.com — https://onlinelibrary.wiley.com/doi/pdf/10.1002/jia2.25343
10. Sexually Transmitted Infection Prevalence and ... — onlinelibrary.wiley.com — https://onlinelibrary.wiley.com/doi/10.1111/ijd.70344?af=
11. Sexually transmitted causes of urethritis, proctitis, pharyngitis, vaginitis and cervicitis - ScienceDirect — www.sciencedirect.com — https://www.sciencedirect.com/science/article/abs/pii/S1357303922000457#!
12. Utilization of Doxycycline Postexposure Prophylaxis at a Midwestern United States HIV/PrEP Clinic | Open Forum Infectious Diseases | Oxford Academic — academic.oup.com — https://academic.oup.com/ofid/article/12/2/ofaf062/7990430
13. January 2026 - Volume 53 - Issue 1  : Sexually Transmitted Diseases — journals.lww.com — https://journals.lww.com/stdjournal/toc/2026/01000
14. Filling in the Gaps: Updates on Doxycycline Prophylaxis for Bacterial Sexually Transmitted Infections | Clinical Infectious Diseases | Oxford Academic — academic.oup.com — https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciae062/7601780
15. Clinical Updates in Sexually Transmitted Infections, 2024 — pmc.ncbi.nlm.nih.gov — https://pmc.ncbi.nlm.nih.gov/articles/PMC11270754
16. Updates on Testing, Treatment, and Prevention of Sexually Transmitted Infections in the United States, 2025 — pmc.ncbi.nlm.nih.gov — https://pmc.ncbi.nlm.nih.gov/articles/PMC12755409
17. Sexually Transmitted Infections - StatPearls - NCBI Bookshelf — www.ncbi.nlm.nih.gov — https://www.ncbi.nlm.nih.gov/books/NBK560808
18. Sexually Transmitted Infections Treatment Guidelines, 2021 — pmc.ncbi.nlm.nih.gov — https://pmc.ncbi.nlm.nih.gov/articles/PMC8344968
19. WHO expands guidance on sexually transmitted infections and reviews country progress on policy implementation — www.who.int — https://www.who.int/news/item/26-07-2025-who-expands-guidance-on-sexually-transmitted-infections-and-reviews-country-progress-on-policy-implementation
20. Sexual Assault Infectious Disease Prophylaxis - StatPearls - NCBI Bookshelf — www.ncbi.nlm.nih.gov — https://www.ncbi.nlm.nih.gov/books/NBK482239
21. Sexually Transmitted Infections - IRIS — iris.who.int — https://iris.who.int/server/api/core/bitstreams/159eddb4-1021-4455-8990-85f6d9564ddc/content
22. STIs guidelines — www.who.int — https://www.who.int/teams/global-hiv-hepatitis-and-stis-programmes/guidelines/stis-guidelines
23. SEXUALLY TRANSMITTED INFECTIONS AMONG ... - IRIS — iris.who.int — https://iris.who.int/server/api/core/bitstreams/6c6a4c56-feeb-4214-b1ed-42c5d014404d/content
24. Sexually transmitted infections (STIs) — www.who.int — https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)

## Editorial note

Prepared from cited clinical literature using Astra's research workflow. Verify recommendations against current guidance and patient-specific factors.