Outbreak of non-groupable Neisseria meningitidis-associated urethritis. Neisseria meningitidis

Backgound: Neisseria meningitidis (Nm), a Gram-negative diplococci that normally colonizes the nasopharynx, can rarely infect the urogenital tract. Oral sex is the presumptive mode of transmission. On urethral Gram stain, Nm can be confused with the more common sexually-transmitted pathogen Neisseria gonorrhoeae.Methods: In response to an outbreak of Nm urethritis among men at an STD clinic in Columbus, OH, there was an investigation into the epidemiologic, molecular and phylogenetic characteristics of cases identified between January 1 and November 18, 2015. Because the outbreak was identified through the CDC’s Gonococcal Isolate Surveillance Project, only men are included.Results: Seventy-two Nm urethritis cases were confirmed by biochemical and PCR testing. Men with Nm urethritis had a median age of 30.5 years (interquartile range (IQR): 24-38) and a median of 2 sex partners in the last 3 months (IQR: 1-3). Nm cases were overwhelmingly heterosexual (99%) and Black (82%). Nearly all cases had urethral discharge (90%), reported oral sex with a female in last 12 months (96%), and were treated with a regimen appropriate for Ng (94%). Only a minority had urethral chlamydia co-infection (15%). All urethral Nm isolates were non-groupable, part of the ST-11/CC-11 clonal complex, and phylogenetically clustered together.Conclusions: Between January-November 2015, there were 72 urethritis cases due to a clonal strain of Nm among men in Columbus, OH. Since Nm frequently colonizes the nasopharynx, oral sex may be a risk factor for transmission. Further study of this clonal Nm isolate, including short and long-term health consequences, is warranted.