The Emergence of Neisseria gonorrhoeae With Decreased Susceptibility to Azithromycin in Kansas City, Missouri, 1999 to 2000

Abstract

Background and Objectives We describe the first cluster of persons with Neisseria gonorrhoeae with decreased susceptibility to azithromycin (AziDS; minimum inhibitory concentration ≥1.0 μg/mL) in the United States. Goal The goal of this study was to identify risk factors for AziDS N. gonorrhoeae and to describe isolate microbiology. Study Design Persons with AziDS N. gonorrhoeae (cases) were identified in Kansas City, Missouri, through the Gonococcal Isolate Surveillance Project (GISP) in 1999 and expanded surveillance, January 2000 to June 2001. A case-control study using 1999 GISP participants was conducted; control subjects had azithromycin-susceptible N. gonorrhoeae. Results Thirty-three persons with AziDS N. gonorrhoeae were identified. Case patients were older than control patients (median age, 33 years vs. 23 years; P <0.001). Fifty percent of cases and 13% of control subjects had a history of sex with a female commercial sex worker (odds ratio, 7.0; 95% confidence interval, 1.3–36.0); 50% of cases and 4% of control subjects met sex partners on street A (P <0.01). AziDS N. gonorrhoeae isolates were phenotypically and genotypically similar and contained an mtrR gene mutation. Conclusions With few treatment options remaining, surveillance for antimicrobial-resistant N. gonorrhoeae is increasingly important, especially among persons at high risk.