Efficacy of Doxycycline Prophylaxis to Reduce Syphilis in High-Risk, HIV-Positive MSM (DPMSM)

Doxycycline Prophylaxis or Incentive Payments to Reduce Incident Syphilis Among HIV- Infected Men Who Have Sex With Men Who Continue to Engage in High Risk Sex: A Randomized, Controlled Pilot Study

This pilot study will investigate the feasibility of conducting a large, randomized trial comparing a structural intervention to contingency management to reduce incident syphilis infections in an especially high risk group: HIV+ men who have sex with men (MSM) who have had syphilis twice or more since their HIV diagnosis. Subjects will be randomized to receive either QD doxycycline as syphilis prophylaxis or a financial incentive to remain STI free. The investigators will : 1) measure adherence to study visits in both arms; 2) measure adherence to the prophylaxis regimen; 3) measure any changes in risk behaviors among study participants and 4) to the extent possible in a small pilot study of short duration, compare effectiveness of doxycycline with that of a monetary incentive for remaining STI free.

Subjects in the incentive arm will receive escalating payments for remaining STI free at Weeks 12, 24 and 36.

Measure changes in the incidence of Syphilis, Gonorrhea and Chlamydia at 12 weeks, 24 weeks, 26 weeks and 48 weeks in the Doxycycline Arm and Contingency Management Arms

Measure adherence to study visits in the Doxycycline and Contingency Management Arms at Weeks 12, 24, 36 and 48

Measure adherence to daily Doxycycline Use using Blood Samples in the Doxycycline Arm at Weeks 12, 24 and 36

At Weeks 12, 24 and 36, blood samples were drawn from participants in the Doxycycline arm and sent to a lab to measure doxycyline levels in each participant in the Doxycyline Arm. The purpose of this outcome is to determine if individuals in the Doxycycline Arm are consistently adhering to the daily regimen of the drug.

Measure changes in self-report sexual risk behaviors (e.g., condom use, drug use and number of partners) in the Doxycycline and Contingency Management Arms at Weeks 12, 24 and 36

Prior to having labs drawn, participants in both the Doxycycline and Contingency Management Arms were asked about their risk behaviors in the past three months including: meth use, condom use with casual partners, condom use with regular partners, condom use with a main partner, number of casual sexual partners and number of regular sexual partners.

Inclusion Criteria: HIV-infected MSM or transgender women who have sex with men At least two documented and adequately treated episodes of syphilis since HIV diagnosis Exclusion Criteria: Had a known allergy or intolerance to doxycycline Abused alcohol or other substances which in the opinion of the investigators would jeopardize adherence to study procedures

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