Abstract
Background
There is conflicting evidence on whether prior azithromycin (AZM) exposure is associated with reduced susceptibility to AZM (AZM
RS) among persons infected with
Neisseria gonorrhoeae (NG).
Methods
The study population included Public Health-Seattle & King County Sexual Health Clinic (SHC) patients with culture-positive NG infection at ≥1 anatomic site whose isolates were tested for AZM s usceptibility 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 AZM
RS NG (minimum inhibitory concentration [MIC] ≥2.0 µg/ml) and used linear regression to assess the association between number of AZM prescriptions in ≤12 months and AZM MIC level, controlling for demographic, behavioral, and clinical characteristics.
Results
A total of 2,155 unique patients had 2,828 incident NG infections, 156 (6%) of which were caused by AZM
RS NG. AZM
RS NG was strongly associated with receipt of AZM from the SHC in the prior 29 days (adjusted odds ratio [aOR] 6.76, 95% CI 1.76-25.90), 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 [aCor] 0.0004, 95% CI -0.04, 0.037), but was associated with number of prescrip tions with <30 days (adjusted coefficient [aCoef] 0.56, 95% CI 0.13-0.98)
Conclusion
Recent individual-level AZM treatment is associated with subsequent AZM
RS 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.
