Summary

Comprehensive CDC update of the 2015 STD treatment guidelines covering screening, diagnosis, and treatment of STIs across populations. Key updates include single-dose ceftriaxone 500 mg for gonorrhea, doxycycline preferred over azithromycin for chlamydia, addition of metronidazole to PID regimens, multidose metronidazole for trichomoniasis in women, resistance-guided two-stage therapy for M. genitalium, expanded syphilis screening in pregnancy, universal one-time HCV screening, and two-step HSV serologic testing.

Key Recommendations

Treat uncomplicated gonorrhea (cervix, urethra, rectum, pharynx) with ceftriaxone 500 mg IM single dose (1 g if ≥150 kg); add doxycycline 100 mg BID × 7 days if chlamydia not excluded.
Treat chlamydia with doxycycline 100 mg orally twice daily for 7 days as first-line; azithromycin 1 g single dose is alternative (preferred in pregnancy).
Treat women with trichomoniasis using metronidazole 500 mg orally twice daily for 7 days (no longer single 2 g dose); men receive metronidazole 2 g single dose.
Treat bacterial vaginosis with metronidazole 500 mg orally BID × 7 days, 0.75% metronidazole gel intravaginally × 5 days, or 2% clindamycin cream × 7 days.
Treat PID with ceftriaxone 500 mg IM + doxycycline 100 mg BID × 14 days PLUS metronidazole 500 mg BID × 14 days (metronidazole now routinely added).
Treat primary, secondary, or early latent syphilis with benzathine penicillin G 2.4 million units IM single dose; late latent or unknown duration requires 3 weekly doses; pregnant women with penicillin allergy must be desensitized.
Use resistance-guided two-stage therapy for M. genitalium: doxycycline 100 mg BID × 7 days followed by azithromycin (macrolide-sensitive) or moxifloxacin 400 mg daily × 7 days (macrolide-resistant).
Screen all sexually active women aged <25 years annually for chlamydia and gonorrhea; screen MSM at least annually at all exposed anatomic sites, every 3–6 months if higher risk or on PrEP.
Screen all pregnant women for HIV, syphilis, HBsAg, and chlamydia at first prenatal visit; retest in third trimester if at increased risk; universal HCV screening each pregnancy.
Offer HIV PrEP to all sexually active adolescents and adults at substantial risk, including persons diagnosed with gonorrhea or syphilis in the prior 6 months.
Vaccinate all adolescents against HPV starting at age 11–12 years (can start at 9); catch-up through age 26; shared clinical decision-making ages 27–45.
Use two-step type-specific serologic testing (confirmatory Biokit or Western blot) for HSV-2 diagnosis due to poor specificity of HerpeSelect EIA at low index values.

Thresholds & Doses

Gonorrhea (uncomplicated, <150 kg): ceftriaxone 500 mg IM × 1; ≥150 kg use 1 g IM.
Gonococcal pharyngitis test of cure: 7–14 days after treatment.
Chlamydia: doxycycline 100 mg PO BID × 7 days; alternative azithromycin 1 g PO × 1 or levofloxacin 500 mg daily × 7 days.
Chlamydia in pregnancy: azithromycin 1 g PO × 1; test of cure at 4 weeks; rescreen at 3 months.
Trichomoniasis (women): metronidazole 500 mg PO BID × 7 days; (men): metronidazole 2 g PO × 1; retest women at 3 months.
Bacterial vaginosis: metronidazole 500 mg PO BID × 7 days OR metronidazole gel 0.75% × 5 days OR clindamycin 2% cream × 7 days; recurrent BV suppression: metronidazole gel twice weekly × ≥3 months.
Primary/secondary/early latent syphilis: benzathine penicillin G 2.4 million units IM × 1.
Late latent or unknown duration syphilis: benzathine penicillin G 2.4 million units IM weekly × 3 weeks (7.2 million units total).
Neurosyphilis/ocular/otosyphilis: aqueous crystalline penicillin G 18–24 million units/day IV (3–4 million units q4h) × 10–14 days.
Congenital syphilis (proven/highly probable): aqueous crystalline penicillin G 50,000 units/kg IV q12h × 7 days then q8h to complete 10 days.
Genital herpes first episode: acyclovir 400 mg TID, valacyclovir 1 g BID, or famciclovir 250 mg TID × 7–10 days.
HSV-2 suppression: acyclovir 400 mg BID, valacyclovir 500 mg–1 g daily, or famciclovir 250 mg BID.
PID outpatient: ceftriaxone 500 mg IM × 1 + doxycycline 100 mg BID × 14 days + metronidazole 500 mg BID × 14 days.
Epididymitis (STI cause): ceftriaxone 500 mg IM × 1 + doxycycline 100 mg BID × 10 days; enteric cause: levofloxacin 500 mg daily × 10 days.
M. genitalium: doxycycline 100 mg BID × 7 days then azithromycin 1 g × 1 then 500 mg daily × 3 days (sensitive) OR moxifloxacin 400 mg daily × 7 days (resistant).
Vulvovaginal candidiasis (uncomplicated): fluconazole 150 mg PO × 1 or topical azoles × 1–7 days; recurrent VVC: fluconazole 150 mg weekly × 6 months.
LGV: doxycycline 100 mg PO BID × 21 days.
Chancroid: azithromycin 1 g PO × 1 or ceftriaxone 250 mg IM × 1.
Cervical cancer screening: start at 21 years; cytology every 3 years ages 21–29; ages 30–65 cytology every 3 years OR HPV testing every 5 years OR cotest every 5 years; stop at 65 if criteria met.
HPV vaccination: 2-dose schedule (0, 6–12 months) if initiated <15 years; 3-dose if ≥15 years or immunocompromised.
Hepatitis B vaccine: 3-dose series (0, 1, 6 months) Engerix-B/Recombivax or 2-dose Heplisav-B (0, 1 month) for adults ≥18.
Hepatitis A postexposure prophylaxis: single-dose vaccine within 2 weeks; IG 0.1 mL/kg if age <12 months, immunocompromised, or chronic liver disease.
HIV PEP: initiate within 72 hours of exposure; 28-day course.
Emergency contraception: levonorgestrel 1.5 mg ≤72 hours; ulipristal 30 mg ≤120 hours; copper IUD ≤5 days.
Retest chlamydia, gonorrhea, trichomoniasis 3 months after treatment.
Pediculosis pubis: permethrin 1% rinse 10 minutes or pyrethrin with piperonyl butoxide; alternative ivermectin 250 µg/kg repeated in 7–14 days.
Scabies: permethrin 5% cream × 8–14 hours or ivermectin 200 µg/kg repeated in 14 days.

Citations

Treatment of Gonococcal Infections — ceftriaxone 500 mg IM regimen and dose-by-weight recommendation
Chlamydial Infections, Recommended Regimens — doxycycline as first-line over azithromycin
Pelvic Inflammatory Disease, Recommended Regimens — addition of metronidazole to all PID regimens
Syphilis sections (Primary/Secondary, Latent, Neurosyphilis, Congenital) — penicillin G regimens by stage
Mycoplasma genitalium, Treatment — resistance-guided two-stage therapy
Trichomoniasis, Recommended Regimens — 7-day metronidazole for women based on Kissinger RCT
STI Detection Among Special Populations, Pregnant Women — expanded syphilis testing and universal HCV screening
Human Papillomavirus Infections, Prevention — ACIP HPV vaccine recommendations
Diseases Characterized by Genital Ulcers, Genital Herpes — two-step HSV-2 serologic confirmation
Management of Persons Who Have a History of Penicillin Allergy — skin testing and direct ceftriaxone use guidance