AT IDWEEK 2017
SAN DIEGO (FRONTLINE MEDICAL NEWS) – Ciprofloxacin cured 100% of gyrase A wild-type Neisseria gonorrhoeae infections, and physicians prescribed it significantly more frequently when they received electronic reminders of test results and recommendations, in a single-center study.
“Recent reports of untreatable gonorrhea have caused great concern. Treatment with ceftriaxone may be a major driver of resistance, and reducing its use may curb the emergence of resistant infections,” Lao-Tzu Allan-Blitz, a medical student at the David Geffen School of Medicine at the University of California, Los Angeles, said at an annual scientific meeting on infectious diseases.
The Centers for Disease Control and Prevention ranks multidrug-resistant N. gonorrhoeae third among all drug-resistant threats in the United States, Mr. Allan-Blitz noted during an oral presentation at the meeting. Beginning in the late 1990s, strains of N. gonorrhoeae developed resistance to sulfanilamides, penicillin, tetracycline, and fluoroquinolones, leaving only the extended-spectrum cephalosporins for empiric treatment. Recent reports of cephalosporin-resistant N. gonorrhoeae in other countries have raised the specter of untreatable gonorrhea.
Because antimicrobial resistance can shift in response to selective pressure, experts are exploring the use of antibiotics once considered ineffective for treating N. gonorrhoeae infections. At UCLA, researchers developed a real-time reverse transcription polymerase chain reaction test for a mutation of codon 91 in the gyrase A (gyrA) gene in N. gonorrhoeae that reliably predicts resistance to ciprofloxacin.
Test results take 24-48 hours. The test is not Food and Drug Administration approved but has been validated in accordance with Clinical Laboratory Improvement Amendments, Mr. Allan-Blitz said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
In November 2015, UCLA Health began gyrA genotyping all N. gonorrhoeae positive specimens, and in May 2016, it began sending providers electronic reminders of genotype results and treatment recommendations. For gyrA wild-type infections, UCLA Health recommends 500 mg oral ciprofloxacin, Mr. Allan-Blitz said.
Genotyping of 582 cases tested between January 2015 and November 2016 showed that 43% were wild-type. Another 27% cases were mutant (resistant) and 30% had an indeterminate genotype. Before UCLA Health implemented its electronic reminder system, physicians treated only 3% of cases with ciprofloxacin. After the reminder system went into effect, this proportion rose to 18% (P = .002).
Initial test-of-cure data are promising. All 25 patients with wild-type infections who received ciprofloxacin and returned 7-90 days later tested negative for N. gonorrhoeae. Culture sites included the urethra (seven cases), pharynx (seven cases), rectum (seven cases), and genitals (four cases), Mr. Allan-Blitz said. “Prior studies have demonstrated that reminder notifications improve uptake of antimicrobial stewardship,” he said. “Other health centers should consider implementing the gyrA assay, and using reminder notifications may improve uptake by providers.”
The National Institutes of Health provided funding. The investigators reported having no conflicts of interest.