Background: Gonorrhea (GC) morbidity is persistently high and increasing in Baltimore, Maryland. Between 2014 and 2015, reported GC diagnoses increased by 26% from 2,006 to 2,525 cases. To inform local GC control programs, we sought to determine factors associated with this increase.
Methods: We characterized GC cases from 2014 and 2015 using routine public health surveillance data including: sex, age(young: <24 years; older: >24 years), sexual orientation, anatomic site of infection, history of GC in the past 12 months, and HIV and chlamydia co-infection. We aggregated cases by month of diagnosis to create epidemic curves and used chi squared tests to compared characteristics of GC cases diagnosed in 2015 vs. 2014. We stratified all analyses by sex and age.
Results: We observed substantial increases in GC(47%) between April-December 2015. During this period, cases among older men increased by 110%. Increases in diagnoses were observed among both older and younger women(79%, and 33%, respectively); diagnoses among younger men declined slightly(-4%). Overall, 2015 cases were more likely than cases from 2014 to be chlamydia co-infected(27% vs. 20%, p<0.0001), but were otherwise similar. Women and younger men diagnosed in 2015 also were more likely to be chlamydia co-infected. While older men diagnosed in 2015 were similar to those diagnosed in 2014, a substantial proportion of GC-infected older men were men who have sex with men(2014:25%; 2015:23%), and HIV-infected(2014:24; 2015:23%).
Conclusions: The observed increase in GC in 2015 occurred in women and older men. Chlamydia co-infection was significantly higher in cases diagnosed in 2015 vs. 2014. Since GC and chlamydia screening are conducted simultaneously, this may suggest an increase in screening practices. Cases among older men more than doubled throughout 2015; this increase, coupled with the high proportion of MSM and HIV-positive cases in this group is alarming and warrants further investigation.