Technical Notes
Sexually Transmitted Disease Surveillance 2021 presents trends in nationally notifiable sexually transmitted diseases (STDs) in the United States through 2021. This annual publication is intended as a reference document for policy makers, program managers, health planners, researchers, and others who are concerned with the public health implications of these diseases. The figures and tables in this report supersede those in earlier publications of these data. The surveillance data in this report are based on case notification data provided to the Centers for Disease Control and Prevention (CDC) through the National Notifiable Diseases Surveillance System (NNDSS) and data collected through projects and programs that monitor STDs in various settings, including the STD Surveillance Network (SSuN) and the Gonococcal Isolate Surveillance Project (GISP).
The majority of data included presents trends in diagnoses of three STDs: chlamydia, gonorrhea, and syphilis, including congenital syphilis. It is important to note that these data reflect only a portion of STDs occurring in the US population. Over 30 pathogens can be sexually transmitted, including common STDs, such as herpes simplex virus, which causes genital herpes, and human papillomavirus, which can lead to genital warts and cervical cancer. Additionally, STDs are often asymptomatic and may not be diagnosed. Published estimates of the burden of STDs in the United States, including estimated prevalence, incidence, and cost, can be found in the January 2021 special issue of the journal Sexually Transmitted Diseases, available here: https://journals.lww.com/stdjournal/pages/collectiondetails.aspx?TopicalCollectionId=4
Additionally, STD data collected during 2020 and 2021 should be interpreted with caution. The COVID-19 pandemic impacted trends in diagnosed and reported STDs, as well as in data collected through enhanced and sentinel STD surveillance activities. For more information, see Impact of COVID-19 on STDs.