The infection
Gonorrhoea is caused by Neisseria gonorrhoeae. It infects the urethra, cervix, rectum, throat and occasionally the eye. Cases have risen steeply over the past fifteen years in most countries. What makes it alarming is its capacity to evolve: the organism has in turn escaped sulphonamides, penicillin, tetracyclines and fluoroquinolones, and strains resistant to last-line cephalosporins have now been described.
Key facts
| Organism | Bacterium Neisseria gonorrhoeae |
|---|---|
| Incubation | Two to seven days in men; longer and quieter in women |
| Asymptomatic cases | About half of women; almost always for throat and rectum |
| Reliable testing from | One to two weeks |
| Sample | Urine or vaginal NAAT, plus throat and rectum; culture advised before treatment |
| Curable | Yes, with a single injection, but resistance is advancing |
| Test of cure | Recommended, unlike for chlamydia |
How it is transmitted
It passes through unprotected vaginal, anal and oral sex. Oral sex is a consistently underestimated route: throat infection is almost always symptomless and acts as a major reservoir, all the more so because it allows the organism to swap resistance genes with other bacteria in the throat. Transmission at birth can cause severe conjunctivitis in the newborn.
Symptoms
In men it is loud in around nine cases out of ten: heavy yellow or green urethral discharge and intense burning on passing urine, two to seven days after exposure. In women it is often mild or absent: altered discharge, burning, pelvic pain. Throat and rectal infections are almost always silent and are found only by targeted swabbing.
Testing
Diagnosis uses a nucleic acid amplification test, which is sensitive and fast. Because of resistance, a culture with sensitivity testing is strongly recommended before treatment: it is the only way to confirm the antibiotic will work and to monitor resistance trends. As with chlamydia, throat and rectal swabs must be requested according to your practices, because urine testing alone does not detect them.
Treatment
Treatment is a single intramuscular injection of ceftriaxone, at a dose that has been increased in most guidelines to counter resistance. A test of cure is recommended, particularly for throat infection, which is harder to clear. Partners should be treated at the same time and sex avoided for seven days after the injection.
If left untreated
Untreated, gonorrhoea causes pelvic inflammatory disease, ectopic pregnancy and infertility, as chlamydia does, and epididymitis in men. Less often it spreads through the bloodstream, producing fever, arthritis and skin lesions, which is a medical emergency. Gonococcal conjunctivitis in the newborn can cause blindness without immediate treatment.
Prevention
- Condoms remain the main protection, including for oral sex — the route most often neglected.
- Regular screening is advised with multiple partners, with swabs from all three sites.
- Never use antibiotics left over from a previous course: that is the principal engine of resistance.
- The meningococcal B vaccine gives partial cross-protection; some countries now use it for this purpose.
What has changed recently
The United Kingdom launched the world's first gonorrhoea vaccination programme in 2025, using a meningococcal B vaccine that offers partial cross-protection. Other countries are evaluating the same approach.
After a diagnosis
- Notify partners from the last two months, and the most recent partner beyond that.
- Attend the test of cure on the date given: it is a check on effectiveness, not a formality.
- Add tests for chlamydia, syphilis, HIV and hepatitis: co-infection is common.
- Report any apparent treatment failure; it feeds directly into resistance surveillance.
Worth remembering
Discharge that persists after treatment is not necessarily failure: it may be co-infection with chlamydia or mycoplasma. Go back rather than taking further antibiotics on your own.
A little history
Genital discharges are described from antiquity, and it was Galen, in the second century, who coined the word "gonorrhoea" — literally "flow of seed", because he believed that was what it was. For centuries gonorrhoea and syphilis were taken for one and the same disease; the surgeon John Hunter, in 1767, inoculated himself with pus from a patient who had both, which kept the confusion alive. It took Philippe Ricord, in Paris in 1838, to separate the two infections for good.
The gonococcus was identified in 1879 by the German dermatologist Albert Neisser, who gave it his name (Neisseria gonorrhoeae). In 1881 Carl Credé introduced silver nitrate drops in newborns' eyes, which all but eliminated gonococcal blindness in infants. Sulphonamides in the 1930s, then penicillin in the 1940s, made the disease easy to cure — for a while.
Since then the gonococcus has learned to resist every antibiotic thrown at it: penicillinase-producing strains in 1976, resistance to tetracyclines and to fluoroquinolones (abandoned in the United States in 2007), then reduced sensitivity to cephalosporins. Cases of "super-gonorrhoea" resistant to every usual treatment have been reported since 2018, and the WHO lists the gonococcus among the priority bacteria for which new antibiotics are urgently needed.
How this differs between countries
Gonorrhoea is the one infection here whose management is directly shaped by international resistance surveillance.
- Resistance surveillance. Countries with laboratory networks update protocols as the data change; elsewhere regimens sometimes remain those of a decade ago, using antibiotics that no longer work.
- Vaccination. The United Kingdom launched the world's first gonorrhoea vaccination programme in 2025, using a meningococcal B vaccine. Others are evaluating it; none has generalised it.
- Ceftriaxone dose. Increased in several countries to counter resistance; recommendations are not aligned everywhere.
- Test of cure. Routine in some countries, limited to throat infection in others, absent elsewhere.
- Syndromic management. Where laboratory diagnosis is unavailable, gonorrhoea is treated together with chlamydia as urethral discharge syndrome, without distinction or sensitivity testing.