STI Reference Guide
Common STIs: Symptoms, Testing, and Treatment
Gonorrhea Curable
Bacterial Infection (Neisseria gonorrhoeae)
Symptoms
- Often none (especially rectal and throat infections)
- Penile: discharge (yellow, green, white), burning urination
- Vaginal/cervical: increased discharge, pelvic pain, spotting
- Rectal: discharge, pain, bleeding
- Throat: usually asymptomatic, rarely sore throat
Testing
- Urine sample (urogenital)
- Swabs from throat, rectum, or urethra
- NAAT test (nucleic acid amplification) is most accurate
- Test all sites of sexual contact, not just urine
- Recommended every 3 months for sexually active MSM
Treatment
- Single dose ceftriaxone injection (IM) is first-line treatment
- Oral alternatives for uncomplicated cases: cefixime
- Sexual partners in the last 60 days should be notified and tested
- Drug-resistant gonorrhea is a growing public health concern
- Retest 1 to 2 weeks after treatment to confirm cure
LGBTQ+ note: Gonorrhea rates are disproportionately high among gay and bisexual men. Throat and rectal infections are almost always asymptomatic and will be missed if only urine is tested. Always specify all sites of sexual contact when requesting testing.
Chlamydia Curable
Bacterial Infection (Chlamydia trachomatis)
Symptoms
- Often none (up to 70% of cases)
- Penile: mild discharge, burning urination
- Vaginal/cervical: discharge, bleeding between periods, pelvic pain
- Rectal: discharge, pain, bleeding
- Untreated: can cause pelvic inflammatory disease (PID) and fertility issues in people with a uterus
Testing
- Urine NAAT test (most common)
- Swabs from urethra, cervix, rectum, or throat as appropriate
- At-home test kits widely available through mail-order programs
- CDC recommends annual testing for all sexually active women under 25
- Every 3 to 6 months for sexually active MSM and trans people at risk
Treatment
- Doxycycline (100mg twice daily for 7 days) is first-line treatment
- Single-dose azithromycin is an alternative (less effective per newer data)
- All partners in the last 60 days should be treated
- Avoid sex for 7 days after single-dose or during full course treatment
- Retest 3 months after treatment (reinfection is common)
LGBTQ+ note: LGV (Lymphogranuloma venereum) is a more aggressive chlamydia strain that is increasingly found in MSM communities, particularly among those who engage in receptive anal sex. It requires a longer doxycycline course (21 days) and testing for LGV specifically if you have rectal symptoms.
Syphilis Curable
Bacterial Infection (Treponema pallidum)
Symptoms by Stage
- Primary: painless sore (chancre) at infection site, often goes unnoticed
- Secondary: rash (often on palms and soles), flu-like symptoms, wart-like sores
- Latent: no symptoms (can last years)
- Tertiary: serious damage to heart, brain, and other organs (if untreated)
- Neurosyphilis: can occur at any stage, causes neurological symptoms
Testing
- Blood test (RPR or VDRL as initial screen; confirmed with treponemal test)
- Swab of any active sore
- CDC recommends annual syphilis testing for sexually active MSM
- More frequent if multiple partners
- Testing recommended during each prenatal visit
Treatment
- Penicillin G injection: highly effective at all stages
- Primary and secondary: single dose benzathine penicillin G IM
- Latent or tertiary: multiple weekly injections
- Doxycycline for penicillin-allergic patients
- Follow-up blood tests at 6 and 12 months to confirm treatment success
LGBTQ+ note: Syphilis rates have increased dramatically among MSM over the past decade, with a record high in 2022. Syphilis chancres are often painless and may be hidden inside the rectum or on the cervix where they cannot be seen. Annual (or more frequent) testing is essential even if you feel completely well.
Herpes (HSV-1 and HSV-2) Manageable
Viral Infection (Herpes Simplex Virus)
Symptoms
- Often none or very mild (most people don't know they have it)
- Outbreaks: clusters of blisters or sores on or around genitals, buttocks, or mouth
- First outbreak may include fever, body aches, swollen lymph nodes
- Outbreaks tend to decrease in frequency and severity over time
- Tingling or burning sensation before an outbreak (prodrome)
Testing
- Swab of active sore is most accurate
- Blood test (type-specific IgG) can detect infection without active sores
- HSV-2 blood testing has false positive rates: discuss with provider
- Standard STI panels often do not include herpes blood testing; ask specifically
- Testing during an outbreak is most reliable
Treatment
- No cure, but antiviral medications effectively control symptoms
- Acyclovir, valacyclovir (Valtrex), or famciclovir reduce outbreak severity and duration
- Daily suppressive therapy: reduces outbreaks by 70 to 80% and reduces asymptomatic shedding (reducing transmission risk)
- People on suppressive therapy with no active sores can still transmit herpes; condoms further reduce risk
Context: HSV-1 (commonly associated with cold sores) can be transmitted genitally through oral sex. An estimated 67% of people under 50 globally have HSV-1. An estimated 11% of Americans have HSV-2. Having herpes does not define you or make you "dirty." Millions of people in healthy, loving relationships have herpes. Open communication with partners and suppressive therapy are the tools for managing it with care.
HPV (Human Papillomavirus) Vaccine-Preventable
Viral Infection (over 100 strains)
Symptoms
- Most HPV infections: no symptoms and clear on their own
- Some low-risk strains: genital warts (soft, flesh-colored growths)
- High-risk strains (HPV-16, HPV-18): associated with cervical, anal, penile, oral, and throat cancers
- Anal HPV: particularly relevant for MSM and anyone who has receptive anal sex
- Cancer develops years to decades after initial infection
Testing and Screening
- No approved HPV test for people with a penis; diagnosis by visual inspection or biopsy of lesions
- Cervical HPV: tested during Pap smear (co-testing for people over 30)
- Anal Pap smear: recommended for MSM and HIV-positive individuals to screen for anal cancer precursors; ask your provider
- Anoscopy: visual exam of the anal canal; recommended if anal Pap is abnormal
Prevention and Treatment
- Gardasil 9 vaccine: protects against 9 HPV strains including the highest-risk cancer-causing types. Approved for ages 9 to 45
- CDC recommends vaccination for everyone through age 26. For ages 27 to 45, discuss with your provider
- Genital warts: treated with topical medications, cryotherapy, or laser removal
- No antiviral treatment for HPV itself; most infections clear within 1 to 2 years
LGBTQ+ note: MSM who have never been vaccinated have significantly higher rates of anal HPV infection and anal cancer. Anal cancer rates are rising in this population. If you are a gay or bisexual man and have not been vaccinated, talk to your provider about Gardasil 9 and whether anal Pap screening is appropriate for you.
Hepatitis A and B Vaccine-Preventable
Viral Liver Infections
Transmission
- Hep A: fecal-oral route; transmitted through rimming (oral-anal contact), contaminated food/water
- Hep B: blood, semen, vaginal fluids; transmitted through sex, needle sharing, and from parent to child at birth
- Hep C: primarily blood-to-blood; less efficiently through sex (more relevant with anal sex involving blood, HIV co-infection, or injection drug use)
Testing
- Blood tests for Hepatitis A antibodies, Hepatitis B surface antigen/antibody, and Hepatitis C antibody
- All sexually active adults should know their Hep B status
- Hep C test recommended at least once for all adults
- More frequent Hep C testing for people who inject drugs or have multiple partners
Prevention and Treatment
- Hepatitis A vaccine: 2-dose series, highly effective
- Hepatitis B vaccine: 3-dose series (or 2-dose Heplisav-B), highly effective
- Both vaccines recommended for all LGBTQ+ adults who are not immune
- Hepatitis C: curable with modern direct-acting antivirals (DAAs) taken for 8 to 12 weeks with very high cure rates
Note on Truvada/Descovy and Hepatitis B: Both medications used in PrEP treat Hepatitis B in addition to preventing HIV. If you have Hepatitis B and start or stop PrEP, this can significantly affect your Hepatitis B status. Always tell your provider if you have Hepatitis B before starting or stopping these medications.
Mpox (formerly Monkeypox) Vaccine Available
Viral Infection (Orthopoxvirus)
Symptoms
- Rash or sores that look like pimples or blisters, which may appear on genitals, rectum, hands, feet, chest, face, or mouth
- Flu-like symptoms: fever, swollen lymph nodes, fatigue, body aches
- Rectal pain or discharge if rectal lesions are present
- Symptoms appear 3 to 17 days after exposure
- Illness typically lasts 2 to 4 weeks
Transmission and Testing
- Close skin-to-skin contact with rash, sores, or scabs
- Contact with infected respiratory secretions during prolonged face-to-face contact
- Contact with contaminated materials (bedding, clothing)
- Testing: swab from active lesion, sent to lab; requires provider order
- Tell your provider if you have a new unexplained rash
Prevention and Treatment
- JYNNEOS vaccine: two-dose series, highly effective at preventing mpox
- Recommended for gay/bisexual men and trans people who are sexually active
- Vaccine available through health departments, LGBTQ+ health centers, and some providers
- Tecovirimat (TPOXX): antiviral treatment for severe cases
- Most cases resolve on their own; treatment focuses on symptom management
LGBTQ+ note: During the 2022 global mpox outbreak, gay and bisexual men and other MSM were disproportionately affected due to skin-to-skin sexual contact being a primary transmission route. If you are sexually active and have not been vaccinated, contact your local health department or LGBTQ+ health center about JYNNEOS vaccination.