Descriptive Analysis of Patients with N. Meningitidis Vs. N. Gonorrhoeae Urethritis

Background: N. meningitidis (NM) can colonize the anogenital tract, causing urethritis, however these reports are sporadic. Philadelphia’s STD clinic (HC1) and Public Health Lab (PHL) have been participating in GISP for years and few, if any of the cultures before August 2015, were identified as NM.

Methods: HC1 policy is to culture males with urethral discharge which are plated directly on MTM media and placed in a candle-jar and incubator until transported to the PHL. Neisseria isolates were tested using RapID NH system to differentiate N. gonorrhoeae (NG) and NM.  Demographic, symptom and laboratory data were obtained from clinic records for months when NM cases were detected. Characteristics of males with urethritis caused by NM and those of males with urethritis caused by NG were compared.

Results: Among urethral cultures sent to PHL over 4 months (August, September, December 2015, & January 2016), 118 were positive, 105 for NG and 13 for NM. The mean age for males with NG was 30.5 years versus 29.0 for those with NM, 76% of NG and NM patients were black. All patients with NM were MSW while 32% of the patients with NG were MSM. Most patients in both groups had discharge and urethral gramstains demonstrating gram negative intracellular diplococci and were treated on the day of testing. Twelve NM patients were tested for HIV the day of visit and all tested negative, while 76/105 NG patients were tested and 2 were found to be positive. Additional testing of 8/13 NM found the molecular profile similar to NM urethritis from other jurisdictions.

Conclusions: Male patients with NM urethritis were similar in age and race to patients with NG, however they were less likely to be MSM. Since NM transmission may not be solely sexual the social implications of NM urethritis are great.