Sexually transmitted infections, the epidemic that persists after the COVID-19 pandemic: an analysis of the primary care electronic health records covering about 5 million people in Catalonia

The aim of our study is to analyse the trends in the diagnosis of sexually transmitted infections (STIs) during the COVID-19 pandemic. We conducted an observational retrospective population-based study using data from primary care electronic health records spanning from January 2016 to December 2022 (involving 5.1 million people older than 14 years). We described the daily number of new STI diagnoses from 2016 to 2022; as well as the monthly accumulation of new STI diagnoses for each year. We compared the monthly averages of new diagnoses in 2019, 2020, 2021 and 2022 using the T-test. Finally, we performed a segmented regression analysis of the daily number of STI diagnoses. We analysed 200,676 new STI diagnoses. The number of diagnoses abruptly decreased coinciding with the lockdown. Overall in 2020, we observed a reduction of 15%, with higher reductions for specific STIs such as gonorrhoea (-21%), chlamydia (-24%), and HIV (-31%) compared to 2019. Following this drastic drop, which was temporarily associated with the lockdown, we observed a rapid rebound. In 2021, the number of STI diagnoses was similar to that of 2019. Notably, we found a considerable increase in 2022, particularly for non-specific STI, which lack laboratory confirmation (67% increase). HIV was the only STI with a reduction of up to -38% in diagnoses at the end of 2022 compared to 2019. After a significant reduction in 2020, the number of STIs recorded in primary care rapidly rebounded, and the current trend is similar to that of 2019, except for HIV. These findings underscore the dynamic impact of the COVID-19 pandemic on STI diagnoses and highlight the importance of ongoing monitoring and public health interventions in the post-pandemic period.