Background Currently, the combination of Ceftriaxone (CTX) and Azithromycin (AZM) is favoured over CTX and Doxycycline (DOXY) for treatment of uncomplicated Neisseria gonorrhoeae infections (GC) in both the UK and the USA.
Aims/Objectives To retrospectively compare retreatment rates between patients receiving CTX + AZM and those receiving CTX + DOXY.
Methods We analysed clinic records for all patients treated for GC at either of Baltimore's public STD clinics between January 2004 and June 2011 and measured time to retreatment from the date when the CTX regimen was administered. Patients were censored 2 years after treatment was received or on 30 September 2011, whichever came first. Kaplan–Meier curves and Cox Proportional Hazards models were used to compare retreatment rates.
Results Overall, 4134 patients were treated for GC with CTX + AZM (n=1185, 31.5%) or CTX + DOXY (2830, 68.5%), 406 (9.8%) of whom were retreated. Treatment regimen was not related to time to retreatment, even when controlling for risk factors associated with re-infection (adjusted HR 0.88, 95% CI 0.70 to 1.14); a sub analysis of patients who were retested for GC within 90 days of CTX treatment also found no difference in retreatment rates across treatment regimens. Other factors that independently increased the risk of retreatment included: being a man who has sex with men, aged <25 years, having a history of GC or chlamydia, and reporting >2 sex partners within the past 6 months at time of CTX treatment. Patients treated after Expedited Partner Therapy (EPT) became available were 30% less likely to be retreated regardless of whether the patient themselves received EPT.
Discussion/Conclusions Compared to CTX + DOXY, CTX + AZM did not provide enhanced efficacy in this population. EPT is associated with a reduction in retreatment rates in the population even among those who did not receive EPT themselves.