Background: In 2013 the Centers for Disease Control and Prevention declared the emergence of multi-drug-resistant Neisseria gonorrhoeae (NG) infections to be one of the top three urgent threats to public health. In response, we developed a rapid molecular assay to detect alterations in the gyrase A (gyrA) genotype of NG species conferring fluoroquinolone-resistance. In November 2015, UCLA Health launched a laboratory-developed test, and began routine gyrA genotype testing NG positive specimens from the Cobas CT/NG assay (Roche Molecular Systems, Pleasant, CA).
Methods: We reviewed patient records for all laboratory confirmed NG cases between January 1st 2015 and February 29th 2016 to determine time-to-treatment and gyrA genotype results by anatomic site. NG infections diagnosed on the same date were considered unique cases. Infections in different anatomic locations were considered unique infections.
Results: Among 117 patients (85% men), there were 162 unique cases and 176 unique anatomic NG infections. Of cases, 57 (35.2%) were treated empirically. The average time to treatment among non-empirically treated cases (N=104) was 5.3 days (SD 5.0 days). After November 2015, 19 (51%) of 37 infections were successfully genotyped: 14 (74%) were wild-type gyrA and 5 (26%) were mutant gyrA. Among the remaining 18 infections, 15 could not be genotyped (11 pharyngeal, 3 urethral, 1 rectal) and 3 were not attempted. Among cases, 153 (94%) were treated with ceftriaxone: 121 (95%) of 127 before assay introduction versus 32 (91%) of 35 after assay introduction. Among 10 cases with wild-type gyrA genotype infection treated at least 2 days after specimen collection, only one was treated with Ciprofloxicin.
Conclusions: A large health system successfully implemented routine NG gyrA genotyping on NG positive specimens. Successful genotyping may depend on the anatomic site of infection. Physician education and further monitoring are necessary to determine if assay results impact treatment selection.