Recent trends in sexually transmitted infections among adolescents, Catalonia, Spain, 2012-2017.

Monitoring sexually transmitted infections (STIs) in adolescents is essential to inform STI prevention strategies at primary and secondary levels in this key population. We aim to describe recent trends in STIs among adolescents and to analyse their socio-demographic and behavioural characteristics in Catalonia, Spain between 2012 and 2017. Data on Chlamydia trachomatis (CT) infection, gonorrhoea and syphilis cases aged from 13 to 19 years reported to the Catalan Mandatory Notifiable System from 2012 to 2017 were analysed. Diagnosis rates were calculated and a descriptive analysis was performed. Between 2012 and 2017, CT infection, gonorrhoea and syphilis cases reported among adolescents aged 13-19 years accounted for more than one-eleventh of all reported cases in Catalonia. The rate of the three nationally-notifiable STIs increased dramatically among adolescents. CT infection rates rose from 13 to 144.1 per 100,000 adolescents between 2012 and 2017, an increase of 1007%; gonorrhoea cases increased by 246% (from 13.4 to 45.4/100,000) and syphilis cases increased by 247% (from 1.7 to 5.9/100,000). Gonorrhoea and syphilis cases affected mainly males while CT infection cases were mostly in females (84%). Adolescents are being increasingly affected by CT infection, gonorrhoea and syphilis. A broader array of intervention strategies aimed at adolescents should be reinforced through strong prevention campaigns, improved sexual health information, as well as encouragement of regular offers of STI screening by healthcare providers.