In 2016, there were an estimated 127.2 million incident chlamydia infections worldwide.[3]Rowley J, Vander Hoorn S, Korenromp E, et al. Chlamydia, gonorrhoea, trichomoniasis and syphilis: global prevalence and incidence estimates, 2016. Bull World Health Organ. 2019 Aug 1;97(8):548-562P.
https://www.doi.org/10.2471/BLT.18.228486
http://www.ncbi.nlm.nih.gov/pubmed/31384073?tool=bestpractice.com
Genital chlamydia is the most common bacterial STI in resource-rich countries.[2]Nwokolo NC, Dragovic B, Patel S, et al. 2015 UK national guideline for the management of infection with Chlamydia trachomatis. Int J STD AIDS. 2016 Mar;27(4):251-67.
https://www.bashhguidelines.org/media/1192/ct-2015.pdf
http://www.ncbi.nlm.nih.gov/pubmed/26538553?tool=bestpractice.com
[4]Centers for Disease Control and Prevention. Sexually transmitted infections surveillance: national overview of STIs, 2022. Jan 2024 [internet publication].
https://www.cdc.gov/std/statistics/2022/overview.htm
[5]Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021. MMWR Recomm Rep. 2021 Jul 23;70(4):1-187.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8344968
http://www.ncbi.nlm.nih.gov/pubmed/34292926?tool=bestpractice.com
In the US, in 2022, there were 1,649,716 chlamydial infections reported to the Centers for Disease Control and Prevention. This is a rate of 495.0 cases per 100,000 population, which is similar to the rate of 495.5 cases per 100,000 population in 2021. Between 2021 and 2022, the rates of reported chlamydia increased 1.8% (from 357.4 to 363.7 per 100,000) among men and decreased 1.2% (from 628.8 to 621.2 per 100,000) among women. The overall reduction in the number of reported cases of chlamydia since 2019 (552.8 cases per 100,000 population) reflects a persistent disruption in chlamydia screening coverage because of the COVID-19 pandemic. Most reported infections in the US occur among 15-24 year olds (57.7% in 2022).[4]Centers for Disease Control and Prevention. Sexually transmitted infections surveillance: national overview of STIs, 2022. Jan 2024 [internet publication].
https://www.cdc.gov/std/statistics/2022/overview.htm
In 2019, in the UK there were 134,418 diagnoses of chlamydia in this age group, which is equivalent to a detection rate of 2043 cases per 100,000 population.[6]Public Health England. Sexually transmitted infections and screening for chlamydia in England, 2019. Dec 2019 [internet publication].
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/914184/STI_NCSP_report_2019.pdf