Health United States 2020-2021

Sexually Transmitted Disease (STD) Surveillance

National Center for HIV, Viral Hepatitis, STD, and TB Prevention


Surveillance information on the burden of STDs is used to inform public and private health efforts to control these diseases. Case data are available for nationally notifiable STDs, including chancroid, chlamydia, gonorrhea, and syphilis. Enhanced surveillance of these conditions and surveillance of other STDs and STD-related sequelae, such as genital herpes simplex virus, genital warts, and trichomoniasis, use data collected from other sources, including data from sentinel surveillance and national surveys.


Case notifications of nationally notifiable STDs are provided to CDC through the National Notifiable Diseases Surveillance System (NNDSS) and reflect diagnosed cases from the 50 states, the District of Columbia (D.C.), and outlying areas (for example, U.S. territories). Data on STDs reported from the 50 states and D.C. are presented in Health, United States. Data from outlying areas are not included.


STD control programs in state, local, and territorial health departments collect case reports of nationally notifiable STDs using case definitions developed by the Council of State and Territorial Epidemiologists and voluntarily provide data to CDC for national surveillance efforts. National data collection for gonorrhea, syphilis, and chancroid began in 1941; however, gonorrhea, syphilis, and chancroid became nationally notifiable in 1944. Data collection for chlamydia began in 1984, and chlamydia was made nationally notifiable in 1995; however, chlamydia was not reported from all 50 states and D.C. until 2000. Since 2003, STD case notifications have been sent to CDC electronically via the National Electronic Telecommunications System for Surveillance and increasingly via Health level 7 messaging using National Electronic Disease Surveillance System standards. Select jurisdictions provide congenital syphilis cases via REDCap and a few territories provide data using standardized hard-copy reporting forms.

Issues Affecting Interpretation

Most STDs are asymptomatic. Because of incomplete diagnosis and reporting, the number of STD cases reported to CDC undercounts the actual number of infections occurring in the U.S. population.



For more information, see the NNDSS website at:, the surveillance case definitions at:, and the CDC website on STD data and statistics at: