The acceptability and behavioral effects of antibiotic prophylaxis for syphilis prevention

Use of preexposure antibiotic prophylaxis for syphilis control has been limited by concerns about acceptability and adverse behavioral effects.

The goal was to determine whether persons at high risk for syphilis accept antibiotic prophylaxis and if so, whether they subsequently increase their risky behavior.

We gave a prospective cohort of persons either: 1) single doses of benzathine penicillin, azithromycin, and cefixime; or 2) a single dose of cefixime and 3 doses of azithromycin given biweekly.

Of 268 persons approached, 186 (69%) agreed to participate, 174 were treated, and 125 (72%) were located for follow up. Four weeks and 4 months after enrollment, participants reported reductions in the number of sex partners. At 4 months, 1% had acquired gonorrhea, 5% had acquired chlamydia, and none had acquired syphilis.

Antibiotic prophylaxis for syphilis was acceptable and not followed by increases in risky behavior. Larger trials of preexposure antibiotic prophylaxis of core group members to control syphilis outbreaks should be undertaken.