Gonorrhoea is caused by the Gram-negative diplococcus Neisseria gonorrhoeae In the UK, the various conditions caused by the bacterium declined in incidence throughout the 1980s and into the early 1990s, but since 1994 it has become more common, In 2002 there were about 26000 cases diagnosed at Genitourinary Medicine clinics in the UK. An unknown number of people were diagnosed in other settings. The increase in cases is thought to be due to increased sexual activity, in particular more people having concurrent sexual partners.
The disease is most common in large cities and in areas of relative deprivation. Condoms are effective in preventing transmission of gonorrhoea, but they need to be used for fellatio as well as vaginal and anal sex since pharyngeal infection is not uncommon and is usually asymptomatic.
The bacteria can infect any mucosal surface, including the conjunctiva, cervix, urethra, pharynx and rectum.
The pathophysiology of Neisseria gonorrhoeae and the relative virulence of different subtypes depend on the antigenic characteristics of their respective surface proteins. Certain subtypes are able to evade serum immune responses and are more likely to lead to disseminated infection. Plasmid and non-plasmid genes are transmitted between different subtypes. It is the exchange of surface protein genes that results in high host susceptibility to reinfection.
Presentation of Gonorrhoea
The etymology of gonorrhoea is from the Greek gonos: semen and rhoia: flow. Anyone who has seen a man with the typical heavy urethral discharge of gonorrhoea will know how it got its name. But urethral discharge is not universal — 10% of men with urethral infection are asymptomatic at that site, although they may have signs of infection when examined.
Since Neisseria gonorrhoeae can infect so many sites, people with the condition can present to a variety of healthcare providers. Table Symptoms of gonorrhoea shows the possible modes of (symptomatic) presentation, with the more common presentations listed first.
Table Symptoms of gonorrhoea
|Men||Urethral infection||White/yellow/green often heavy urethral discharge Dysuria||90% of cases|
|Scrotal contents||Unilateral scrotal pain and swelling||If epididymo-orchitis. Do not confuse with testicular torsion!|
|Women (asymptomatic in 50% of cases)||Genital||Abnormal vaginal discharge Dysuria||Commonest single symptom Unusual, as is symptomatic urethral discharge|
|Intermenstrual bleeding/ post-coital bleeding||Less common a symptom than in Chlamydia|
|Abdomen||Pelvic pain||If pelvic inflammatory disease (pelvic inflammatory disease) or if chorioamnionitis|
|Right upper quadrant pain||If perihepatitis, aka Fitz-Hugh-Curtis syndrome|
|Both sexes||Pharynx||Sore throat, dysphagia||Almost always asymptomatic|
|Anus/rectum||Anorectal pain, rectal discharge||Usually asymptomatic. In women, rectal infection can occur by spread from the vagina as well as by anal sex|
|Eyes||Purulent eye in neonate or adult||Conjunctivitis is usually bilateral in neonates but unilateral in adults. Can lead to blindness if left untreated|
|Musculoskeletal||Single large joint arthritis (usually a knee) with severe pain, oedema, erythema and decreased range of movement||A common cause of septic arthritis in young people|
|Migratory polyarthralgia and polyarthritis with pain, tenderness, decreased range of motion, and erythema||Rare. A feature of disseminated gonococcal infection (DGI)|
|Tenosynovitis usually of the hands||Rare. A feature of disseminated gonococcal infection|
|Muscle abscess presenting as localized tenderness oedema and pain||Rare. A feature of disseminated gonococcal infection|
|Central nervous system||Meningism/meningitis||Rare. A feature of disseminated gonococcal infection. Progresses less rapidly than meningococcal meningitis|
|Cardiovascular system||Murmur, tachycardia and other symptoms/signs of endocarditis||Rare. A feature of disseminated gonococcal infection|
|Systemic||Fever usually <39°C||Rare. A feature of disseminated gonococcal infection and severe pelvic inflammatory disease|
|Skin||Maculopapular, vesico-pustular or necrotic rash. Usually occurring on the torso, limbs, palms and soles.||Rare. Seen in disseminated gonococcal infection. Usually spares the head. Lesions are usually at different stages of development at presentation|
Complications of Gonorrhoea
As with chlamydia, serious complications are more common in women than in men. Infection can ascend from the cervix leading to pelvic inflammatory disease (pelvic inflammatory disease). This can cause pelvic pain and in severe cases, peritonitis. Late complications include chronic abdominal pain, ectopic pregnancy and infertility (see pelvic inflammatory disease). Chorioamnionitis can lead to miscarriage and pre-term labour.
Spread from the urethra can cause epididymo-orchitis (see epididymo-orchitis) and occasionally prostatitis (see prostatitis). Urethral strictures can occur following inflammation and scarring of the periurethral glands. This can occasionally lead to urethral obstruction and infertility. The mythical ‘cocktail umbrella’ device feared by many first-time male GU clinic attendees probably has its origin in the devices used to treat urethral strictures.
In about 1% of cases, infection can spread haematogenously to distant sites leading to disseminated gonococcal infection (disseminated gonococcal infection). This has numerous manifestations, although the most common symptom is joint or tendon pain. Later complications include permanent neurologic sequelae from meningitis and destruction of heart valves by endocarditis.
disseminated gonococcal infection is more common in women and appears to be facilitated by menstruation. Untreated conjunctivitis can lead to corneal scarring, globe perforation and blindness. Gonococcal septic arthritis can cause joint destruction, although this is less common than in septic arthritis of other causes, e.g. staphylococcal.
Gonorrhoea increases the chance of acquiring or transmitting HIV from an episode of unprotected sex.
Fetus and neonate
Infections in pregnant women can lead to miscarriage and prematurity. Neonatal infection can cause symptoms at any site but most commonly conjunctivitis. Rarely generalized sepsis or disseminated gonococcal infection can occur.
Diagnosis of Gonorrhoea
• Specimens should be collected from all sites where the infection is suspected. In men, this usually means the urethra unless they have had sex with men, in which case it is customary to take rectal and pharyngeal specimens too, depending on the sexual history.
• In women, the main site to sample is the cervix, although the pharynx and rectum should be sampled if there are symptoms at those sites or as indicated by the sexual history, A urethral swab is useful if the woman is a contact of gonorrhoea or if you are working somewhere where gonorrhoea is relatively common.
• Which diagnostic method (s) you use will depend on where you are working.
• The mainstay of diagnosis remains culture, which has a sensitivity of around 95%. Swabs are plated onto selective, enriched media (e.g. chocolate agar) and growth of oxidase-positive, Gram-negative diplococci confirms the diagnosis, N. gonorrhoeae requires, a CGyenriched atmosphere.
• In most genitourinary medicine clinics, swabs are, plated in the consultation room, but sending a swab to the lab in transport medium gives acceptable results. If the interval between specimen collection and plating is greater than 12 hours, the sensitivity starts to fall,
• Gram-stained microscopy can speed diagnosis and this is a sensitive and specific test in male urethral specimens. In female urethral specimens and samples from other sites, it is much less useful because of the presence of other bacteria with similar morphology.
• If you suspect gonorrhoea, smear some of the specimen onto a slide, air dry it and send to the lab. If the organism fails to grow, the diagnosis might then be made from microscopy,
• Nucleic acid amplification tests (which can use urine as a specimen) are available but are not widely used in the UK, In low-prevalence populations they generate a lot of false positives. Culture is still necessary in positive cases to confirm the diagnosis and determine antibiotic sensitivity.
• In the absence of laboratory tests, a clinical diagnosis can usually be made in men with classic symptoms and signs, but this should always be confirmed if at all possible.
• If disseminated gonococcal infection is suspected, blood and joint effusions should be sent for Gram stain and culture, although negative stain results and sterile cultures do not rule out the condition.
• Cerebrospinal fluid should be stained and cultured if there are signs or symptoms of meningitis.
• Gram stains and cultures of genital, rectal, conjunctival and pharyngeal secretions also should be obtained when disseminated gonococcal infection is suspected, even if the patient has no localized symptoms at any of those sites.
Treatment of Gonorrhoea
Treatment is complicated by the high proportion of isolates that are resistant to antibiotics. Well-characterized plasmids commonly carry antibiotic-resistance genes, most notably penicillinase. The exchange of antibiotic resistance genes has led to extremely high levels of resistance to beta-lactam antibiotics over the last two decades. More recently, fluoroquinolone resistance also has been documented on multiple continents.
In the UK, ciprofloxacin and penicillin are now inappropriate for blind treatment of gonorrhoea due to high levels of resistance. Of course, if sensitivity results are available you can choose any agent on the list the microbiology lab give you.
• blind treatment of suspected/confirmed uncomplicated anogenital gonorrhoea:
– cefixime 400 mg p.o. once (first choice), or
– ceftriaxone 250 mg i.m. once, or
– cefotaxime 500 mg i.m. once.
• if sensitivities known:
– ciprofloxacin 500 mg p.o. once (not if pregnant, breast feeding or under 5), or
– ofloxacin 400 mg p.o. once (not if pregnant, breast feeding or under 5), or
– amoxicillin 3 g p.o. once plus probenecid 1 g p.o. once.
• spectinomycin 2 g i.m. once is useful for treating quinolone- and penicillin-resistant cases in people who are allergic to cephalosporins. Unfortunately it can be hard to obtain
• amoxicillin and spectinomycin are less effective at eradicating pharyngeal infection than other agents
• treatment of gonococcal pelvic inflammatory disease —see site
• treatment of gonococcal epididymo-orchitis — see site
• treatment of disseminated gonococcal infection — admit to hospital and exclude endocarditis and meningitis
– ceftriaxone 1 g i.v. o.d., or
– cefotaxime 1 g i.v. t.d.s. until symptoms improve for 24 hours, then
– cefixime 400 mg p.o. o.d. (or other agent if sensitivities known) to extend treatment to a total of 7 days
– plus repeated joint aspiration if large joint septic arthritis.
• endocarditis — ceftriaxone 2 g i.v. b.d. for 4 weeks
• meningitis — ceftriaxone 2 g i.v. b.d. for 4 weeks
• conjunctivitis (adult)
– ceftriaxone 1 g i.m. or i.v. once (and lavage with saline)
– if deep ophthalmic infection, use 2 g/day until improving.
• conjunctivitis (child)
– ceftriaxone 50 mg/kg (max 125 mg) i.m. once
– if deep ophthalmic infection use 50-100 mg/kg/day until improving.
• HIV-positive patients — no change to the above treatment.
In most cases, patients should be referred to GU medicine specialists for management. Health advisers will make arrangements to screen and treat sexual partners. Patients should be advised to avoid unprotected sexual intercourse until they and their partner(s) have completed treatment and follow-up.
Discuss ways of reducing the risk of acquiring STIs in the future, i.e. reducing the number of partners and using condoms.
Other management of Gonorrhoea
About one-fifth of people with gonorrhoea also have a genital Chlamydia trachomatis infection. Patients should therefore be tested for this and should be advised to take epidemiological treatment. Patients should be advised to have a check up for other STIs including HIV.
The need for a test of cure (TOC) is debatable. If symptoms have resolved from the affected areas and an antibiotic was used to which the organism was sensitive then a TOC is probably not needed.
If the patient was culture positive from a site at which they were asymptomatic then there is still value in doing a TOC. This is particularly true of pharyngeal infection where treatment failure is more common. A TOC is best done at around 10-14 days following treatment and gives an opportunity to review treatment of contacts. The specimens for the TOC should be taken from all sites where the infection was initially diagnosed. If the pharynx was not swabbed at initial presentation, it should be swabbed now because infection can be harder to eradicate from this site.
If gonorrhoea is diagnosed in a child, consider sexual abuse and discuss with a consultant community paediatrician.
Consider an ophthalmology referral for someone (adult or child) with gonococcal conjunctivitis, since corneal ulceration and further ocular damage can occur rapidly.