Gonorrhoea, Chlamydia + Syphilis

Key bacterial GU pathogens of concern

Gonorrhoea (Neisseria gonorrhoeae), Chlamydia (Chlamydia trachomatis), Syphilis (Treponema pallidum); Bacterial vaginosis as flora imbalance, not true infection.

Gonorrhoea causative organism and characteristics

Neisseria gonorrhoeae, Gram-negative diplococcus; infects cervix, urethra, rectum, throat, or eyes; requires history of sexual activities as multi-site infections common.

Transmission routes of Gonorrhoea

Unprotected sexual intercourse; horizontal transfer from mother to baby (purulent conjunctivitis if birth canal infected).

Gonorrhoea asymptomatic rates

1 in 10 men (10%) asymptomatic; ~50% women asymptomatic; creates unaware transmission pool.

Syphilis causative organism and characteristics

Treponema pallidum, spirochete requiring living cells to survive; three stages (primary, secondary, late/tertiary).

Transmission routes of Syphilis

Unprotected sexual intercourse; mother-to-baby; sharing needles.

Key complications of Syphilis

5x higher HIV risk due to sores accessing circulation; severe pregnancy risks (discussed later); rising case numbers.

Chlamydia causative organism and characteristics

Chlamydia trachomatis, intracellular organism; common STI; frequent co-infection with Gonorrhoea (detected the same sample).

Chlamydia asymptomatic rates and demographics

50% men asymptomatic; 70-80% women asymptomatic; 64% cases in ≤25 years, but occurs all ages.

Bacterial vaginosis nature and symptoms

Vaginal flora imbalance (pH ~4.5 disrupted, anaerobic overgrowth); ~50% asymptomatic; fishy discharge, thin white homogeneous discharge on vagina/vestibule walls.

Treatments for Chlamydia + Gonorrhoea (select two)

Azithromycin (oral for Chlamydia); Ceftriaxone (IM for Gonorrhoea).

Administration routes for Azithromycin and Ceftriaxone

Azithromycin - Orally; Ceftriaxone - Intramuscular injection.

Gonorrhoea complications in women

Spread to uterus/fallopian tubes → pelvic inflammatory disease (PID); abdominal pain, fever, tubal damage, infertility, ectopic pregnancy risk (life-threatening).

Gonorrhoea complications in men

Epididymitis (painful tubes attached to testicles); rare infertility.

Chlamydia asymptomatic rates and complications

85% women, 40% men asymptomatic; untreated → PID (20-40% women), chronic pelvic pain, scarring, 15% female infertility, ectopic pregnancy.

Chlamydia screening program aims (under 25s)

Early detection/treatment; reduce transmission; prevent complications; inform/educate; offered at colleges, universities, home kits, pharmacies; targets 15-24 year olds.

Treatments for Syphilis (select two)

Benzathine benzylpenicillin; Doxycycline.

Primary Syphilis symptoms, treatment, outcome

Painless chancre (penile/anal/oral/vaginal), asymptomatic possible; Penicillin/Doxy/Erythromycin; resolves with/without tx, but untreated → secondary.

Secondary Syphilis symptoms, treatment, outcome

Generalised rash (hands/feet/chest), lymph enlargement, alopecia; Penicillin/Doxy; resolves with/without tx, untreated → tertiary.

Late (Tertiary) Syphilis symptoms, treatment, outcome

Organ effects (neurosyphilis, CNS syphilis, late benign); Penicillin/Doxy; disabling/death even with tx.

Contact tracing considerations (patient had 3 partners/3 months)

Partners at risk of infection (source or asymptomatic transmitters to others).

Jarisch-Herxheimer reaction in Syphilis treatment

Systemic inflammatory response to microbial products released by antibiotics; can be life-threatening.

Pregnancy risks from untreated Gonorrhoea/Chlamydia

Baby infection via birth canal → conjunctivitis; prompt treatment essential.

Syphilis in pregnancy (screening and risks if untreated)

Included in 16-week screening; risks: spontaneous abortion, stillbirth, non-immune hydrops, intrauterine growth restriction; counselling on termination possible.

Overlapping GU symptoms challenge

Many symptoms overlap (e.g., discharge, pain); definitive diagnosis requires lab results (NAAT, culture, serology).

Syphilis (early: primary/secondary/early latent)

Benzathine benzylpenicillin 2.4 million units IM, single dose.

Syphilis (late latent/unknown/tertiary)

Benzathine benzylpenicillin 2.4 million units IM weekly for 3 weeks.

Gonorrhoea (uncomplicated anogenital/pharyngeal)

Ceftriaxone 1 g IM, single dose.

Chlamydia (uncomplicated genital) – option 1

Doxycycline 100 mg orally twice daily for 7 days.

Chlamydia (uncomplicated genital) – option 2

Azithromycin 1 g orally, single dose.

Gonorrhoea/Chlamydia co-infection note

Ceftriaxone 1 g IM single + Doxycycline 100 mg BD oral 7 days (if chlamydia not excluded).