Gonorrhea
What is
Gonorrhea?
Gonorrhea is caused by the bacteria Neisseria gonorrhoeae. It typically infects epithelia of the urethra, cervix, rectum, pharynx, or conjunctivae, causing irritation or pain and purulent discharge. Dissemination to skin and joints, which is uncommon, causes sores on the skin, fever, and migratory polyarthritis or pauciarticular septic arthritis. Diagnosis is by microscopy, culture, or nucleic acid amplification tests. Several oral or injectable antibiotics can be used, but drug resistance is an increasing problem.
(Seealso Overview of Sexually Transmitted Infections.)
N.
gonorrhoeae is a gram-negative diplococcus that occurs only in humans and is
almost always transmitted by sexual contact. Urethral and cervical infections
are most common, but infection in the pharynx or rectum can occur after oral or
anal intercourse, and conjunctivitis may follow contamination of the eye.
After an
episode of vaginal intercourse, likelihood of transmission from women to men is
about 20%, but from men to women, it may be higher.
Neonates
can acquire conjunctival infection during passage through the birth canal, and
children may acquire gonorrhea as a result of sexual abuse.
In 10 to
20% of women, cervical infection ascends via the endometrium to the fallopian
tubes (salpingitis) and pelvic peritoneum, causing pelvic inflammatory disease
(PID). Chlamydiae or intestinal bacteria may also cause PID. Gonorrheal
cervicitis is commonly accompanied by dysuria or inflammation of Skene ducts
and Bartholin glands. In a small fraction of men, ascending urethritis
progresses to epididymitis.
Disseminated
gonococcal infection (DGI) due to hematogenous spread occurs in < 1% of
cases, predominantly in women. DGI typically affects the skin, tendon sheaths,
and joints. Pericarditis, endocarditis, meningitis, and perihepatitis occur
rarely.
Coinfection
with Chlamydia trachomatis occurs in 15 to 25% of infected heterosexual men and
35 to 50% of women.
Symptoms and Signs of Gonorrhea
About 10
to 20% of infected women and very few infected men are asymptomatic. About 25%
of men have minimal symptoms.
Male urethritis has an incubation period from 2 to 14 days. Onset is usually marked by mild discomfort in the urethra, followed by more severe penile tenderness and pain, dysuria, and a purulent discharge. Urinary frequency and urgency may develop as the infection spreads to the posterior urethra. Examination detects a purulent, yellow-green urethral discharge, and the meatus may be inflamed.
Epididymitis usually causes unilateral scrotal pain, tenderness, and swelling. Rarely, men develop abscesses of Tyson and Littre glands, periurethral abscesses, or infection of Cowper glands, the prostate, or the seminal vesicles.
Cervicitis usually has an incubation period of > 10 days. Symptoms range from mild to severe and include dysuria and vaginal discharge. During pelvic examination, clinicians may note a mucopurulent or purulent cervical discharge, and the cervical os may be red and bleed easily when touched with the speculum. Urethritis may occur concurrently; pus may be expressed from the urethra when the symphysis pubis is pressed or from Skene ducts or Bartholin glands. Rarely, infections in sexually abused prepubertal girls cause dysuria, purulent vaginal discharge, and vulvar irritation, erythema, and edema.
Pelvic
inflammatory disease occurs in 10 to 20% of infected women. PID may include
salpingitis, pelvic peritonitis, and pelvic abscesses and may cause lower
abdominal discomfort (typically bilateral), dyspareunia, and marked tenderness
on palpation of the abdomen, adnexa, or cervix.
Fitz-Hugh-Curtis
syndrome is gonococcal (or chlamydial) perihepatitis that occurs predominantly
in women and causes right upper quadrant abdominal pain, fever, nausea, and
vomiting, often mimicking biliary or hepatic disease.
Rectal
gonorrhea is usually asymptomatic. It occurs predominantly in men practicing
receptive anal intercourse and can occur in women who participate in anal sex.
Symptoms include rectal itching, a cloudy rectal discharge, bleeding, and
constipation—all of varying severity. Examination with a proctoscope may detect
erythema or mucopurulent exudate on the rectal wall.
Gonococcal
pharyngitis is usually asymptomatic but may cause sore throat. N. gonorrhoeae
must be distinguished from N. meningitidis and other closely related organisms
that are often present in the throat without causing symptoms or harm.
Disseminated
gonococcal infection (DGI), also called the arthritis-dermatitis syndrome,
reflects bacteremia and typically manifests with fever, migratory pain or joint
swelling (polyarthritis), and pustular skin lesions. In some patients, pain
develops and tendons (eg, at the wrist or ankle) redden or swell. Skin lesions
occur typically on the arms or legs, have a red base, and are small, slightly
painful, and often pustular. Genital gonorrhea, the usual source of
disseminated infection, may be asymptomatic. DGI can mimic other disorders that
cause fever, skin lesions, and polyarthritis (eg, the prodrome of hepatitis B
infection or meningococcemia); some of these other disorders (eg, reactive
arthritis) also cause genital symptoms.
Gonococcal
septic arthritis is a more localized form of DGI that results in a painful
arthritis with effusion, usually of 1 or 2 large joints such as the knees,
ankles, wrists, or elbows. Some patients present with or have a history of skin
lesions of DGI. Onset is often acute, usually with fever, severe joint pain,
and limitation of movement. Infected joints are swollen, and the overlying skin
may be warm and red.
Diagnosis of Gonorrhea
- Gram staining and culture
- Nucleic acid–based testing
Gonorrhea is diagnosed when gonococci are detected via microscopic examination using Gram stain, culture, or a nucleic acid–based test of genital fluids, blood, or joint fluids (obtained by needle aspiration).
Gram stain is sensitive and specific for gonorrhea in men with urethral discharge; gram-negative intracellular diplococci typically are seen. Gram stain is much less accurate for infections of the cervix, pharynx, and rectum and is not recommended for diagnosis at these sites.
Culture
is sensitive and specific, but because gonococci are fragile and fastidious,
samples taken using a swab need to be rapidly plated on an appropriate medium
(eg, modified Thayer-Martin) and transported to the laboratory in a carbon
dioxide–containing environment. Blood and joint fluid samples should be sent to
the laboratory with notification that gonococcal infection is suspected.
Because nucleic acid amplification tests have replaced culture in most
laboratories, finding a laboratory that can provide culture and sensitivity
testing may be difficult and require consultation with a public health or
infectious disease specialist.
Nucleic
acid amplification tests (NAATs) may be done on genital, rectal, or oral swabs
and can detect both gonorrhea and chlamydial infection. NAATs further increase
the sensitivity adequately to enable testing of urine samples in both sexes.
Men with urethritis
Men with
obvious discharge may be treated presumptively if likelihood of follow-up is
questionable or if clinic-based diagnostic tools are not available.
Samples
for Gram staining can be obtained by touching a swab or slide to the end of the
penis to collect discharge. Gram stain does not identify chlamydiae, so urine
or swab samples for NAAT are obtained.
Women with genital symptoms or signs
A
cervical swab should be sent for culture or NAAT. If a pelvic examination is
not possible, NAAT of a urine sample or self-collected vaginal swab can detect
gonococcal (and chlamydial) infections rapidly and reliably.
Pharyngeal
or rectal exposures (either sex)
Swabs of
the affected area are sent for culture or NAAT.
Arthritis,
DGI, or both
An
affected joint should be aspirated, and fluid should be sent for culture and
routine analysis (see arthrocentesis). Patients with skin lesions, systemic
symptoms, or both should have blood, urethral, cervical, and rectal cultures or
NAAT. In about 30 to 40% of patients with DGI, blood cultures are positive
during the first week of illness. With gonococcal arthritis, blood cultures are
less often positive, but cultures of joint fluids are usually positive. Joint
fluid is usually cloudy to purulent because of large numbers of white blood
cells (typically > 20,000/microliter).
Screening
Asymptomatic
patients considered at high risk of sexually transmitted infections (STIs) can
be screened by NAAT of urine samples, thus not requiring invasive procedures to
collect samples from genital sites.
Nonpregnant
women (including women who have sex with women) are screened annually if they
- Are sexually active and ≤ 24 years
- Have a history of a prior STI
- Engage in high-risk sexual behavior (eg, have a new sex partner or multiple sex partners, engage in sex work, use condoms inconsistently)
- Have a partner who engages in high-risk behavior
Pregnant
women are screened during their initial prenatal visit and again during the 3rd
trimester if they are ≤ 24 years or have risk factors.
Treatment of Gonorrhea
For
uncomplicated infection, a single dose of ceftriaxone plus azithromycin
For DGI
with arthritis, a longer course of parenteral antibiotics
Concomitant treatment for chlamydial infection
Treatment
of sex partners
Uncomplicated
gonococcal infection of the urethra, cervix, rectum, and pharynx is treated
with the following:
Preferred:
A single dose of ceftriaxone 250 mg IM plus azithromycin 1 g orally
Alternative:
A single dose of cefixime 400 mg orally plus azithromycin 1 g orally
In
patients who have an azithromycin allergy or who immediately vomit the drug,
doxycycline 100 mg orally twice a day for 7 days is an alternative to
azithromycin as a second antimicrobial.
Patients
who are allergic to cephalosporins are treated with one of the following:
Gemifloxacin
320 mg orally plus azithromycin 2 g orally once
Gentamicin
240 mg IM plus azithromycin 2 g orally once
Monotherapy
and previous oral regimens of fluoroquinolones (eg, ciprofloxacin,
levofloxacin, ofloxacin) or cefixime are no longer recommended because of
increasing drug resistance. Test of cure is recommended only for patients
treated with an alternative regimen for pharyngeal infections.
DGI with
gonococcal arthritis is initially treated with IM or IV antibiotics (eg,
ceftriaxone 1 g IM or IV every 24 hours, ceftizoxime 1 g IV every 8 hours,
cefotaxime 1 g IV every 8 hours) continued for 24 to 48 hours once symptoms
lessen, followed by oral therapy guided by antimicrobial susceptibility
testing, for a total treatment course of at least 7 days. A single dose of
azithromycin 1 g is also always given for adjunctive therapy for the gonococcal
infection and for possible co-infection with C. trachomatis (1).
Gonococcal
purulent arthritis usually requires repeated synovial fluid drainage either
with repeated arthrocentesis or arthroscopically. Initially, the joint is
immobilized in a functional position. Passive range-of-motion exercises should
be started as soon as patients can tolerate them. Once pain subsides, more
active exercises, with stretching and muscle strengthening, should begin. Over 95%
of patients treated for gonococcal arthritis recover complete joint function.
Because sterile joint fluid accumulations (effusions) may develop and persist
for prolonged periods, an anti-inflammatory drug may be beneficial.
Posttreatment
cultures are unnecessary if symptomatic response is adequate. However, for
patients with symptoms for > 7 days, specimens should be obtained, cultured,
and tested for antimicrobial sensitivity.
Patients
should abstain from sexual activity until treatment is completed to avoid
infecting sex partners.