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N. gonorrhoeae, the causative agent of gonorrhea, is a gram-negative, nonmotile, non-spore-forming organism that grows singly and in pairs (i.e., as diplococci).
The ∼450,000 cases reported in the United States in 2016 probably represent only half the true number of cases because of underreporting, self-treatment, and nonspecific treatment without a laboratory diagnosis.
- More than 70% of reported cases in the United States occur in 15- to 24-year-old women and 20- to 29-year-old men.
- Gonorrhea is transmitted from males to females more efficiently than in the opposite direction, with 50–70% of women acquiring gonorrhea during a single unprotected sexual encounter with an infected man. Roughly two-thirds of all infected men are asymptomatic.
- Drug-resistant strains are widespread. Penicillin, ampicillin, and tetracycline are no longer reliable therapeutic agents, and oral cephalosporins and fluoroquinolones are no longer routinely recommended. In addition, strains highly resistant to ceftriaxone and azithromycin have been isolated in several countries, and combined resistance may contribute to the failure of the currently recommended dual therapy (see below).
Except in disseminated disease, the sites of infection typically reflect areas involved in sexual contact.
- Urethritis and cervicitis have an incubation period of 2–7 days and ∼10 days, respectively. See above for details.
- Anorectal gonorrhea can cause acute proctitis in women (due to the spread of cervical exudate to the rectum) and MSM.
- Pharyngeal gonorrhea is usually mild or asymptomatic and results from oral–genital sexual exposure (typically fellatio). Pharyngeal infection almost always coexists with genital infection, resolves spontaneously, and is rarely transmitted to sexual contacts.
- Ocular gonorrhea is typically caused by autoinoculation and presents as a markedly swollen eyelid, hyperemia, chemosis, and profuse purulent discharge.
- Gonorrhea in pregnancy can have serious consequences for both the mother and the infant.
- Salpingitis and PID are associated with fetal loss.
- Third-trimester disease can cause prolonged rupture of membranes, premature delivery, chorioamnionitis, funisitis, and neonatal sepsis.
- Ophthalmia neonatorum, the most common form of gonorrhea among neonates, is preventable by prophylactic ophthalmic ointments (e.g., containing erythromycin or tetracycline), but treatment requires systemic antibiotics.
- Gonococcal arthritis results from dissemination of organisms due to gonococcal bacteremia. Pts present during a bacteremic phase (relatively uncommon) or with suppurative arthritis involving one or two joints (most commonly the knees, wrists, ankles, and elbows), with tenosynovitis and skin lesions. Menstruation and complement deficiencies of the membrane attack complex (C5–C9) are risk factors for disseminated disease.
NAATs, culture, and microscopic examination (for intracellular diplococci) of urogenital samples are used to diagnose gonorrhea; NAAT of urine samples is most sensitive. A single culture of endocervical discharge has a sensitivity of 80–90%.
See Table 86-2.
|DIAGNOSIS||TREATMENT OF CHOICEa|
|Uncomplicated gonococcal infection of the cervix, urethra, pharynxb, or rectum|
Ceftriaxone (250 mg IM, single dose)
Azithromycin (1 g PO, single dose)
Cefixime (400 mg PO, single dose) or ceftizoxime (500 mg IM, single dose) or cefotaxime (500 mg IM, single dose) or spectinomycin (2 g IM, single dose)d,e or cefotetan (1 g IM, single dose) plus probenecid (1 g PO, single dose)d or cefoxitin (2 g IM, single dose) plus probenecid (1 g PO, single dose)d
Azithromycin (1 g PO, single dose)
|Epididymitis||Ceftriaxone (250 mg IM once) followed by doxycycline (100 mg PO bid for 10 days)|
|Pelvic inflammatory disease||See text on specific syndrome|
|Gonococcal conjunctivitis in an adult||Ceftriaxone (1 g IM, single dose)f|
|Ophthalmia neonatorumg||Ceftriaxone (25–50 mg/kg IV, single dose, not to exceed 125 mg)|
|Disseminated gonococcal infectionh|
|Pt tolerant of β-lactam drugs||Ceftriaxone (1 g IM or IV q24h; recommended) or cefotaxime (1 g IV q8h) or ceftizoxime (1 g IV q8h)|
|Pts allergic to β-lactam drugs||Spectinomycin (2 g IM q12h)d|
|Continuation therapyi||Cefixime (400 mg PO bid)|
|Meningitis or endocarditis||See text for specific recommendationsj|