|
Gonorrhea is caused by the bacteria Neisseria gonorrhoeae. It typically infects epithelia of the urethra, cervix, rectum, pharynx, or eyes, 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.
N. gonorrhoeae 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 (see Infections in Neonates: Etiology), 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—see Vaginitis, Cervicitis, and Pelvic Inflammatory Disease (PID): Pelvic Inflammatory Disease (PID)). Chlamydiae or intestinal bacteria may also cause PID. Gonorrheal cervicitis is commonly accompanied by dysuria or inflammation of Skene's ducts and Bartholin's 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
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's and Littre's glands, periurethral abscesses, or infection of Cowper's 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's ducts or Bartholin's glands. Rarely, infections in sexually abused prepubertal girls cause dysuria, purulent vaginal discharge, and vulvar irritation, erythema, and edema.
PID 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, a closely related organism that is 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 disorders may cause genital symptoms (eg, reactive arthritis—see Joint Disorders: Reactive Arthritis).
Gonococcal septic arthritis is a more focal 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 used to have or still have 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
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 CO2-containing environment. Blood and joint fluid samples should be sent to the laboratory with notification that gonococcal infection is suspected.
Unamplified nucleic acid–based tests may be done on genital rectal or oral swabs. Most tests simultaneously detect gonorrhea and chlamydial infection and then differentiate between them in a subsequent specific test. Nucleic acid amplification tests (NAAT) further increase the sensitivity adequately to enable testing of urine samples in both sexes.
In the US, confirmed cases of gonorrhea, chlamydial infection, and syphilis must be reported to the public health system. A serologic test for syphilis (STS) and a screening test for chlamydial infection should be done.
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 nucleic acid–based testing. If a pelvic examination is not possible, NAAT of a urine sample 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 nucleic acid–based tests.
Arthritis, DGI, or both:
An affected joint should be aspirated, and fluid should be sent for culture and routine analysis (see Approach to the Patient With Joint Disease: 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 WBCs (typically > 20,000/μL).
Screening:
Asymptomatic patients considered at high risk of sexually transmitted diseases (STDs) can be screened by NAAT of urine samples, thus not requiring invasive procedures to collect samples from genital sites. Patients at risk include
(See also the US Preventive Services Task Force's summary of recommendations regarding screening for gonorrhea.)
Treatment
Uncomplicated gonococcal infection of the urethra, cervix, rectum, and pharynx can be treated with a single dose of ceftriaxone 125 mg IM or cefixime 400 mg po. Previous alternative regimens with quinolones (eg, ciprofloxacin, levofloxacin, ofloxacin) are no longer recommended because of increasing drug resistance. Routinely, patients are simultaneously given a single dose of azithromycin 1 g po to treat chlamydial infection (see Sexually Transmitted Diseases (STDs): Treatment) because it often coexists in patients with gonorrhea.
DGI with gonococcal arthritis is initially treated with IM or IV antibiotics (eg, ceftriaxone 1 g IM or IV q 24 h, ceftizoxime 1 g IV q 8 h, cefotaxime 1 g IV q 8 h) continued for 24 to 48 h once symptoms lessen, followed by 4 to 7 days of oral therapy. Antichlamydial therapy is also routinely given.
Gonococcal arthritis does not usually require joint drainage. 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 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, cultures are repeated, and antimicrobial sensitivity testing is done. Patients should abstain from sexual activity until treatment is completed to avoid infecting sex partners.
Sex partners:
All sex partners who have had sexual contact with the patient within 60 days should be tested for gonorrhea and other STDs and treated if results are positive. Sex partners with contact within 2 wk should be treated presumptively for gonorrhea (epidemiologic treatment).
Expedited partner therapy (EPT) involves giving patients a prescription or drugs to deliver to their partner. EPT may enhance partner adherence and reduce treatment failure due to reinfection. It may be most appropriate for partners of women with gonorrhea or chlamydial infection. However, a health care visit is preferable to ascertain histories of drug allergies and to screen for other STDs.
Last full review/revision November 2008 by J. Allen McCutchan, MD, MSc
Content last modified February 2012
|