Gonorrhea is a sexually transmitted infection (STI) of epithelium and commonly manifests as cervicitis, urethritis, proctitis, and conjunctivitis. If untreated, infections at these sites can lead to local complications such as endometritis, salpingitis, tuboovarian abscess, bartholinitis, peritonitis, and perihepatitis in female patients; periurethritis and epididymitis in male patients; and ophthalmia neonatorum in newborns. Disseminated gonococcemia is an uncommon event whose manifestations include skin lesions, tenosynovitis, arthritis, and (in rare cases) endocarditis or meningitis.
Neisseria gonorrhoeae is a gram-negative, nonmotile, non-spore-forming organism that grows singly and in pairs (i.e., as monococci and diplococci, respectively). Exclusively a human pathogen, the gonococcus contains, on average, three genome copies per coccal unit; this polyploidy permits a high level of antigenic variation and the survival of the organism in its host. Gonococci, like all other Neisseria species, are oxidase positive. They are distinguished from other neisseriae by their ability to grow on selective media and to use glucose but not maltose, sucrose, or lactose.
The incidence of gonorrhea had been declining steadily in the United States, but in 2016 there were ~450,000 newly reported cases—up 46% since 2011. With 80 million cases estimated by the World Health Organization to have occurred globally in 2014, gonorrhea remains a major public health problem worldwide, is a significant cause of morbidity in developing countries, and may play a role in enhancing transmission of HIV.
Gonorrhea predominantly affects young, nonwhite, unmarried, less educated members of urban populations. The number of reported cases probably represents half of the true number of cases—a discrepancy resulting from under-reporting, self-treatment, and nonspecific treatment without a laboratory-proven diagnosis. The number of reported new cases of gonorrhea in the United States rose from ~250,000 in the early 1960s to a high of 1.01 million in 1978. The recorded incidence of gonorrhea in modern times peaked in 1975, with 468 reported new cases per 100,000 population in the United States. This peak was attributable to the interaction of several variables, including improved accuracy of diagnosis, changes in patterns of contraceptive use, and changes in sexual behavior. A decline in the overall incidence of gonorrhea in the United States over the past quarter-century may reflect increased condom use resulting from public health efforts to curtail HIV transmission. Nevertheless, in 2016, 146 new cases per 100,000 population were reported in this country, representing a 1-year increase of 19%; this figure is the highest among industrialized countries. Simultaneously, antibiotic resistance is increasing in the United States and other countries, prompting the U.S. Centers for Disease Control and Prevention (CDC) to name antibiotic-resistant N. gonorrhoeae as one of the three most urgent threats of its kind. At present, the attack rate in the United States is highest among 15- to 24-year-old women and 20- to 29-year-old men; more than 70% of all reported cases occur in these two groups. From the standpoint of ...