Transmission of Chlamydia trachomatis and Neisseria gonorrhoeae among men with urethritis and their female sex partners

Transmission of Chlamydia trachomatis and Neisseria gonorrhoeae among infected men and their female sex partners was examined using a design enhancing the likelihood that spread was directed from men to women. Chlamydia culture-negative specimens were examined using DNA amplification tests. Infection rates in women exposed to male sex partners with Chlamydia only were 65% (20/31) and with gonorrhea only were 73% (33/45). Infection of women by either agent was not influenced by the number of sexual exposures to or coinfection in men. There was a 98% (40/41) concordance of N. gonorrhoeae isolates among partners by auxotype and serovar. Chlamydia isolates were serotyped using ELISA and immunofluorescence testing and confirmed by nested polymerase chain reaction: 50% (6/12) of men and 57% (8/14) of women yielded mixed serovars. Sixty-four percent of pairs (9/14) were infected with identical serovars and an additional 28% shared at least one serovar. Multiple serovars of C. trachomatis, but not of N. gonorrhoeae, were common in sex partners and exchanged frequently.