Gonorrhoea is a sexually transmitted infection (STI) is caused by the Neisseria gonnorhoeae, a gram-negative bacterium that is diplococcus in shape. It remains one of the most common bacterial STI in the world.
Its rates in the UK are on the rise, of which many patients have other infections concomitantly (most commonly chlamydia). It commonly affects men who have sex with men (MSM) as well as individuals under 25 years of age.
Pathophysiology
Gonorrhoea is spread through unprotected sexual contact. Most commonly via penile penetration of a mucosal orifice such as the oropharynx (i.e. oral sex), vagina or anus. Male-to-female transmission is more likely than female-to-male transmission. Vertical transmission to infants is also possible and poses severe risks to the child. Eye infections most commonly occur from autoinoculation too.
Neisseria gonorrhoeae has outer membrane proteins that bind to mucosal epithelial surfaces. These are known as type IV pili. There are also surface proteins that bind to immune cell receptors as well as mediate tight interactions between host cells. These are known as Opa proteins. These are two anigens of note s they have great antigenic variation as a result of DNA mutation and recombination. This is why there is the issue of antibiotic resistance and also why we are unable to immunise against neisseria gonorrhoeae.
Neisseria may also spread to other anatomical sites through systemic spread or even transluminal spread which can cause subsequent secondary infection at a different site.
⚠️ Risk factors
- 15-24 years old
- Multiple sexual partners
- Unprotected sexual practices
- MSM
- History of STI (such as chlamydia or HIV)
- History of sexual abuse
- Low socioeconomic status
😷 Presentation
Around 90% of men are symptomatic with discharge being the most common symptom.
- Purulent penile discharge - green/yellow in colour and is odourless.
- Dysuria
- Epididymo-orchitis - leading to testicular pain and swelling. This is due to transluminal spread.
- Prostatitis
Women tend to be less symptomatic but once again the predominant symptoms are dysuria and discharge.
- Purulent vaginal discharge - again can be odourless with a green/yellow colour.
- Dysuria
- Lower abdominal/pelvic pain
- Intermenstrual bleeding/menorrhagia - this is a rare manifestation, however.
- Dyspareunia
- Pelvic inflammatory disease
Other manifestations of gonorrhoea may include:
- Rectal symptoms:
- Asymptomatic
- Anal discharge
- Proctitis
- Anal pain
- Tenesmus
- Rectal bleeding
- Pharyngeal symptoms:
- Asymptomatic
- Sore throat
- Erythema
- Exudate
- Anterior cervical lymphadenopathy
- Red eye + purulent discharge- indicates conjunctival infection.
Serious infection that occurs due to bacteraemia and dissemination across the body leading to infection of the joints and skin (also known as arthritis-dermatitis syndrome), heart or even meninges:
- Migratory polyarthralgia, arthritis, tenosynovitis
- Dermatitis, petechiae and pustular skin lesions
- Endocarditis
- Meningitis
🔍 Investigations
If gonorrhoea is suspected they should be seen in a genito-urinary medicine (GUM) clinic.
🏆 The diagnosis is made using nucleic acid amplification tests (NAAT). The sample is obtained differently in men and women:
- Men - first pass urine specimen.
- Women - vulvovaginal swab.
💡 MSM patients (and patients with ceftriaxone-resistant strains) should also have pharyngeal samples and rectal samples taken. Pharyngeal and rectal samples may also be taken in patients who engage in anal and oral sex or are displaying symptoms in these areas too.
All samples should also be used for cultures for susceptibility testing (given how resistant gonococcal infections are becoming). In women this may be done with an endocervical swab (charcoal swab). The reason we have to do separate tests for cultures is that NAAT simply looks for the presence of the DNA/RNA of neisseria gonorrhoea, but doesn’t actually grow the bacteria.
🧰 Management
Antibiotics should be prescribed after cultures, ideally. If there is an uncomplicated gonorrhoea infection we can prescribe:
- 🥇 Ciprofloxacin (oral) - if sensitivity is known.
- 🥇 Ceftriaxone (intramuscular) - if sensitivities are not known or in the case of pregnant/breastfeeding women. It is also preferred in neonates born to women with untreated gonococcal infections.
If this is contraindicated (due to allergy, needle phobia or other contraindications), we may consider:
- 🥈 Gentamicin (intramuscular)+ azithromycin
- 🥈 Cefixime (oral) + azithromycin
⭐️ Patients should be seen after 1 week for test of cure (TOC) using NAAT (RNA NAAT specifically) and if this is positive they may be seen after 2 weeks for another test of cure using DNA NAAT. The time for a negative TOC is variable and so even though most should be negative after 7 days, we can try again at 14 days.
Additional advice should be provided to the patient, such as:
- Screening for other STIs and HIV
- Partner notification - encourage the patient to notify the partner themselves. Empirical treatment is only recommended after positive test is found.
- Abstinence from sex - for 7 days after completion of treatment.
Children and young people should also be highly suspicious for sexual abuse (unless there is clear evidence of maternal-to-child transmission during labour or blood contamination).
🚨 Complications
- Pelvic inflammatory disease in women - which can then lead to chronic pelvic pain, infertility ectopic pregnancy.
- Epididymo-orchitis and prostatitis in men
- Infertility
- Ophthalmia neonatorum in neonates which can subsequently lead to blindness
- Fitz-Hugh-Curtis syndrome - this is perihepatitis (inflammation of the hepatic capsule) presenting with RUQ pain that may refer to the right shoulder. It mimics acute cholecystitis.
- Disseminated gonococcal infection (DGI)