Genomic Epidemiology Of Neisseria Gonorrhoeae Isolates In Sweden-2016 National Study

Background The number of reported cases of gonorrhoea in Sweden continuously increased from an incidence of 7.8 per 100 000 inhabitants in 2009 to 31.4 in 2019. The largest increase in incidence was observed during 2016–2017. No national molecular epidemiological study investigating the population of N. gonorrhoeae circulating in Sweden has been performed in the last two decades. Our aim was to examine the antimicrobial resistance (AMR) and genome-based epidemiology, in conjunction to patient epidemiological data, of all gonococcal isolates (n=1279; one isolate per case) from gonorrhoea cases in Sweden during 2016. Methods AMR testing was performed using Etest, and MICs were interpreted using current clinical resistance breakpoints from EUCAST. All isolates were whole genome sequenced using Illumina HiSeq X platform. Patient epidemiological data was obtained from the Public Health Agency of Sweden. Results The gonorrhoea patients consisted of 252 (19.7%) women and 1027 men (80.3%). The medium age of the women was 27.4 years and of the men 32.1 years. Regarding sexual orientation, 619 (48.4%) reported homosexual, 605 (47.3%) heterosexual, 31 (2.4%) bisexual, and 24 (1.9%) did not report. Most prevalent countries of infection were Sweden (n=875, 68.4%), followed by Thailand (n=70, 5.5%) and Germany (n=32, 2.5%). Overall, the phenotypic AMR was as follows: ceftriaxone and spectinomycin (0%), cefixime (1.7%), azithromycin (1.3%) and ciprofloxacin (51.1%). A high concordance between phenotypic AMR and molecular AMR determinants was found. Results from the genome-based epidemiology are currently in final analysis. Conclusions AMR in N. gonorrhoeae in Sweden remains low, in particular to ceftriaxone and azithromycin that is recommended internationally for dual therapy. The incidence increases in Sweden appear to be driven by increased spread among men-who-have-sex-with-men but also younger heterosexuals of both genders. This is the first national genome-based epidemiological study for N. gonorrhoeae in Sweden and final genomic results are pending.