Article Text
Abstract
Background In British Columbia (BC), Canada, enhanced gonorrhea surveillance to monitor sequence types (STs) is based on cultures which are typically performed on symptomatic individuals, at extra-genital sites, and at clinics in the Greater Vancouver Area (GVA), leaving certain subpopulations under-represented. We sought to describe Neisseria gonorrhoeae multi-antigen sequence types (NG-MASTs) in a provincially representative sample using remnant nucleic acid amplification tests (NAATs).
Methods A sample of gonorrhea positive NAATs diagnosed at the BC Centre for Disease Control Public Health Laboratory from March 1 to September 31, 2018 were sent to the National Microbiology Laboratory for sequence typing using the NG-MAST method. Samples were selected to be representative of the distribution of gonorrhea in BC by sex and geography. NG-MAST was linked to case information from the provincial sexually transmitted infections surveillance database. Associations were tested using Chi-square or Fisher’s exact test.
Results There were 261 NAAT-positive gonorrhea specimens selected: 129 (49%) from urine, 71 (27%) from rectal, 35 (13%) from vaginal, 19 from cervical (7.3%) and 7 (2.7%) from urethral sites. Males represented 60% of the sample (156/261) and 21% (55/261) were from outside GVA. Mean age was higher in males than females (33 vs 28 years, p<0.01). Co-infection with chlamydia was more common among females than males (16% vs 5%, p<0.01). To date, results were available for 186 (71%) of the sample. The most common NG-MASTs were ST-7638 (11/186, 5.9%), ST-4207 (10/186, 5.4%), ST-12302 (9/186, 4.8%), ST-15246 (9/186, 4.8%) and ST-5985 (9/186, 4.8%). ST-12302 and ST-5985 were more common outside GVA (p<0.01 and p=0.03, respectively).
Conclusion We were able to use remnant NAAT specimens from a provincially representative sample to identify STs not routinely found using culture-based surveillance (e.g. ST7638, ST-4207). Moreover, some STs were more common outside GVA supporting the need for molecular methods to improve representativeness for gonorrhea surveillance.
Disclosure No significant relationships.