Gonorrhea, caused by Neisseria gonorrhoeae, is second only to chlamydial infections in the number of cases reported to the Centers for Disease Control and Prevention (CDC); 361,705 cases were reported to CDC in 2001 (2001 Sexually Transmitted Diseases Surveillance Report). The number of reported cases of gonorrhea increased steadily from 1964 to 1977, fluctuated through the early 1980s, increased until 1987, and since 1987 has decreased annually. The incidence of gonorrhea is highest in high-density urban areas among persons under 24 year of age who have multiple sex partners and engage in unprotected sexual intercourse. Increases in gonorrhea prevalence have been noted recently among men who have sex with men.
Antimicrobial resistance in N. gonorrhoeae contributed to the increase in cases of gonorrhea in the United States during the 1970s and 1980s. Antimicrobial resistance in N. gonorrhoeae occurs as plasmid-mediated resistance to penicillin and tetracycline, and chromosomally mediated resistance to penicillins, tetracyclines, spectinomycin, and recently to fluoroquinolones. The decline in gonorrhea prevalence may be attributed to recommendations by CDC (2002 Sexually Transmitted Diseases Treatment Guidelines) that only highly effective antimicrobial agents be used to treat gonorrhea.