Chart — Infection Control
STI Comparison Chart
Six infections carry most of the exam weight, and each has one giveaway: the painless chancre, the palms-and-soles rash, the painful vesicles, the frothy discharge. This chart puts the hallmarks, treatments, and teaching side by side.
Educational use only. Treatment regimens follow current CDC STI guidelines and provider orders — first-line agents and dosing change; verify against current protocol. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
The Major STIs Side by Side
| STI | Cause & Curability | Hallmark Findings | Treatment | Key Nursing / Teaching |
|---|---|---|---|---|
| Chlamydia | Bacterial (Chlamydia trachomatis) — curable | Usually ASYMPTOMATIC; discharge, dysuria, bleeding between periods; PID when it ascends | Doxycycline (or azithromycin in pregnancy); treat partners; retest ~3 months | Most commonly reported bacterial STI; screen sexually active women <25 annually; untreated → PID, ectopic pregnancy, infertility; reportable |
| Gonorrhea | Bacterial (Neisseria gonorrhoeae) — curable | Often silent in women; purulent discharge, dysuria; pharyngeal and rectal infection occur; can disseminate (joints) | IM ceftriaxone; treat partners; often co-treated with chlamydia | Travels with chlamydia; neonatal eye infection is why newborns get erythromycin ointment; reportable |
| Syphilis | Bacterial (Treponema pallidum) — curable | Primary: PAINLESS chancre. Secondary: rash on PALMS AND SOLES, fever, lymphadenopathy. Latent: silent. Tertiary: cardiac, gummas, neurosyphilis | Penicillin G (benzathine IM) — even in pregnancy (desensitize if allergic) | Stages are the exam favorite; screen all pregnancies (congenital syphilis); reportable |
| Genital herpes (HSV) | Viral — manageable, not curable | PAINFUL grouped vesicles → ulcers; flu-like first episode; recurrences with stress/illness; asymptomatic shedding transmits | Acyclovir/valacyclovir — shortens outbreaks, suppresses recurrence | Start antivirals at the first tingle; transmission occurs without lesions; active lesions at labor → cesarean |
| HPV | Viral — manageable; many infections clear on their own | Low-risk types: genital warts. High-risk types: usually invisible — found by Pap/HPV screening; cause cervical and other cancers | Warts: topical agents, cryotherapy. High-risk types: surveillance and treatment of precancerous changes | HPV vaccine is CANCER PREVENTION (routine 11–12, catch-up to 26); regular Pap/HPV screening still required |
| Trichomoniasis | Parasitic (Trichomonas vaginalis) — curable | FROTHY yellow-green malodorous discharge, vulvar irritation; often asymptomatic (especially men) | Metronidazole — BOTH partners | No alcohol with metronidazole (severe flushing/nausea reaction); reinfection from untreated partners is common |
Exam Traps
- ✦Painless ulcer = syphilis chancre; painful vesicles = herpes — the pain question is the discriminator.
- ✦Rash on the palms and soles = secondary syphilis until proven otherwise.
- ✦Treatment "failure" for chlamydia/gonorrhea is usually reinfection from an untreated partner — both partners, every time.
- ✦Metronidazole + alcohol = severe reaction; doxycycline = photosensitivity and avoided in pregnancy; penicillin treats syphilis even in pregnancy.
- ✦Bacterial/parasitic = curable (chlamydia, gonorrhea, syphilis, trich); viral = manageable (herpes, HPV, HIV, hep B) — and two have vaccines (HPV, hep B).
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with CDC / HICPAC · Infectious Diseases Society of America (IDSA) / SHEA. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →