160 likes | 306 Views
Successful prevention of syphilis infection with azithromycin in both HIV-negative and HIV-positive individuals, San Francisco, 1999-2003.
E N D
Successful prevention of syphilis infection with azithromycin in both HIV-negative and HIV-positive individuals, San Francisco, 1999-2003. J. D. Klausner,1,2 K. Steiner,1R. Kohn11San Francisco Dept Public Health, San Francisco, CA2University of California, San Francisco, San Francisco, CA.
Background:Previous studies on azithromycin and syphilis • Hook EW, Stephens J, Ennis DM, Ann Intern Med, 1999 • randomized trial of 1 gram azithromycin vs. 2.4 mu benzathine penicillin for incubating disease • no reactive FTA-ABS at 3 months in either group • Hook EW et al., Sex Trans Dis, 2001 • RCT of azithromycin vs. benzathine penicillin for syphilis cases • 2 grams of azithromycin as effective as benzathine penicillin for treating disease
Background:Syphilis treatment in San Francisco • Contacts: new cases versus “epi treatment” • 2.4 mu benzathine penicillin G I.M. (“bicillin”) • 100 mg doxycycline P.O. BID for 14 days • 1 gram azithromycin P.O. • Field-delivered therapy with Azithromycin began March, 1999
Objective • Compare observed success in treating incubating syphilis using azithromycin to success with other treatments in order to justify continued use of azithromycin
Methods:San Francisco STD Registry • STD clinic medical record data • Reported morbidity and reactive STS • Interview data and field activity • Screening data
Methods: Sample • Data from 1999 through 2003 • Non-reactive RPR or VDRL with any syphilis treatment (n=3812) • Follow-up titer between 30 and 90 days after initial titer (n=151)
Methods: Measurements • Outcome: any reactive titer defines treatment failure • Biological false positives excluded from analysis • HIV status measured from multiple sources, including self-reported status
Conclusions • Failure rate for azithromycin was not significantly greater than rate for bicillin • Since no resistance to bicillin has been documented, apparent treatment failures likely indicate re-exposure • Success in treatment did not vary between HIV-negative and HIV-positive clients
Limitations • No way to distinguish treatment failure from re-exposure • Not all exposed will develop disease • No randomization • penicillin allergies • field versus clinic • Small number of follow-up titers • Wide confidence limits for negative results
Limitations • No power to assess temporal trends • Azithromycin epi-treatment failures: • November 2002 • April 2003 • July 2003 • Bicillin epi-treatment failure: • April 1999
Further research • Another randomized trial of azithromycin vs. bicillin • HIV-positive clients only • San Francisco & Los Angeles • Five years later than 1999 study by Hook