Chapter 48 Sexually Transmitted Infections: Gonorrhea
INTRODUCTION
Description: Infection with gonorrhea, a gram-negative intracellular diplococcus, remains common, accounting for 358,366 new cases of gonorrhea in the United States in 2006.
ETIOLOGY AND PATHOGENESIS
Risk Factors: It is estimated that the rate of infection with one act of intercourse with an infected partner is 20% for men but 60% to 80% for women. (For this reason, any patient exposed to gonorrhea within the preceding month should be cultured and treated presumptively.) This rate increases to 60% to 80% for both sexes with four or more exposures. The groups with the highest risk are adolescents, drug users, and sex workers.
CLINICAL CHARACTERISTICS
DIAGNOSTIC APPROACH
Workup and Evaluation
Laboratory: Culture on Thayer-Martin agar plates kept in a CO2-rich environment. Cervical cultures provide 80% to 95% diagnostic sensitivity. Cultures should also be obtained from the urethra and anus, although these additional cultures do not significantly increase the sensitivity of testing. A Gram stain of any cervical discharge for the presence of gram-negative intracellular diplococcus supports the presumptive diagnosis but does not establish it (sensitivity 50% to 70%, specificity 97%). A solid-phase enzyme immunoassay may also be used. Even when the diagnosis is established by other methods, all cases of gonorrhea should have cultures obtained to assess antibiotic susceptibility, although therapy should not be delayed pending the results.
