multi class comparison
STI Comparison: Chlamydia vs Gonorrhea vs Syphilis — Presentation, Diagnosis, Treatment
All three are bacterial, all are reportable, and all get antibiotics — but the NCLEX expects you to match the right symptom to the right organism and pick the correct drug. Choosing azithromycin alone for gonorrhea misses ceftriaxone, and missing syphilis staging means missing neurosyphilis entirely.
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Side-by-side3 compared
Comparevs
Dimension
Chlamydia
Gonorrhea
Syphilis
Organism & risk
- Chlamydia trachomatis (intracellular)
- Most common bacterial STI
- incubation 1–3 wk
- Neisseria gonorrhoeae (gram-neg diplococcus)
- Incubation 2–5 days
- Treponema pallidum (spirochete)
- Incubation 10–90 days
Signs & symptoms
- Often asymptomatic — the "silent" STI
- Thin mucopurulent discharge or none
- ★Thick purulent yellow-green discharge
- Dysuria
- ★Primary: painless chancre
- Secondary: rash on palms and soles
Diagnostics & labs
- NAAT (urine or swab)
- NAAT
- culture for resistance testing
- Gram-neg intracellular diplococci on smear
- RPR/VDRL screen then FTA-ABS confirm
Nursing priorities
- Screen sexually active women ≤ 25
- Treat empirically
- test-of-cure in pregnancy
- Culture before treating (resistance)
- Co-treat for chlamydia
- Stage disease
- screen for HIV co-infection
- Watch Jarisch-Herxheimer after 1st dose
Treatment (first-line)
- Doxycycline 100 mg PO BID × 7 days
- ★Ceftriaxone 500 mg IM × 1
- Add doxycycline if chlamydia not excluded
- ★Benzathine penicillin G 2.4M units IM × 1
- 3 weekly doses for late latent
Partners & pregnancy
- Treat partners (60 days)
- abstain until both treated
- Neonatal conjunctivitis/pneumonia risk
- Treat partners (60 days)
- abstain until both treated
- Neonatal ophthalmia — eye prophylaxis at birth
- Evaluate/treat partners by exposure & stage
- Congenital syphilis — screen in pregnancy
Red flags — escalate
- PID then ectopic pregnancy, infertility
- Disseminated GC: septic arthritis
- Neurosyphilis
- cardiovascular syphilis
Complications & reporting
- Reactive arthritis
- infertility (reportable)
- PID, infertility, DGI (reportable)
- Gummas
- congenital syphilis (reportable)
Organism & risk
Chlamydia
- Chlamydia trachomatis (intracellular)
- Most common bacterial STI
- incubation 1–3 wk
Gonorrhea
- Neisseria gonorrhoeae (gram-neg diplococcus)
- Incubation 2–5 days
Signs & symptoms
Chlamydia
- Often asymptomatic — the "silent" STI
- Thin mucopurulent discharge or none
Gonorrhea
- ★Thick purulent yellow-green discharge
- Dysuria
Diagnostics & labs
Chlamydia
- NAAT (urine or swab)
Gonorrhea
- NAAT
- culture for resistance testing
- Gram-neg intracellular diplococci on smear
Nursing priorities
Chlamydia
- Screen sexually active women ≤ 25
- Treat empirically
- test-of-cure in pregnancy
Gonorrhea
- Culture before treating (resistance)
- Co-treat for chlamydia
Treatment (first-line)
Chlamydia
- Doxycycline 100 mg PO BID × 7 days
Gonorrhea
- ★Ceftriaxone 500 mg IM × 1
- Add doxycycline if chlamydia not excluded
Partners & pregnancy
Chlamydia
- Treat partners (60 days)
- abstain until both treated
- Neonatal conjunctivitis/pneumonia risk
Gonorrhea
- Treat partners (60 days)
- abstain until both treated
- Neonatal ophthalmia — eye prophylaxis at birth
Red flags — escalate
Chlamydia
- PID then ectopic pregnancy, infertility
Gonorrhea
- Disseminated GC: septic arthritis
Complications & reporting
Chlamydia
- Reactive arthritis
- infertility (reportable)
Gonorrhea
- PID, infertility, DGI (reportable)
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Clinical Pearl
Silent = chlamydia; purulent = gonorrhea + ceftriaxone; painless chancre + palm rash = syphilis + penicillin.
Component Topics
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Go further
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