Prior Exposure to Azithromycin and Azithromycin Resistance Among Persons Diagnosed With Neisseria gonorrhoeae Infection at a Sexual Health Clinic: 2012-2019.

ABSTRACT

BACKGROUND: There is conflicting evidence on whether prior azithromycin (AZM) exposure is associated with reduced susceptibility to AZM (AZMRS) among persons infected with Neisseria gonorrhoeae (NG). METHODS: The study population included Public Health-Seattle and King County Sexual Health Clinic (SHC) patients with culture-positive NG infection at ≥1 anatomic site whose isolates were tested for AZM susceptibility in 2012-2019. We used multivariate logistic regression to examine the association of time since last AZM prescription from the SHC in ≤12 months with subsequent diagnosis with AZMRS NG (minimum inhibitory concentration [MIC], ≥2.0 µg/mL) and used linear regression to assess the association between the number of AZM prescriptions in ≤12 months and AZM MIC level, controlling for demographic, behavioral, and clinical characteristics. RESULTS: A total of 2155 unique patients had 2828 incident NG infections, 156 (6%) of which were caused by AZMRS NG. AZMRS NG was strongly associated with receipt of AZM from the SHC in the prior 29 days (adjusted odds ratio, 6.76; 95% confidence interval [CI], 1.76 to 25.90) but not with receipt of AZM in the prior 30-365 days. Log AZM MIC level was not associated with the number of AZM prescriptions within ≤12 months (adjusted correlation, 0.0004; 95% CI, -.04 to .037) but was associated with number of prescriptions within <30 days (adjusted coefficient, 0.56; 95% CI, .13 to .98). CONCLUSIONS: Recent individual-level AZM treatment is associated with subsequent AZMRS gonococcal infections. The long half-life and persistence of subtherapeutic levels of AZM may result in selection of resistant NG strains in persons with recent AZM use.