Other Sources of Surveillance Data

STD Surveillance Network

In 2005, CDC established the STD Surveillance Network (SSuN) as a collaborative network of state, county and/or city health departments following common protocols to conduct sentinel and enhanced STD surveillance activities. The purpose of SSuN is to improve the capacity of national, state, and local STD programs to detect, monitor, and respond to trends in STDs through enhanced data collection, reporting, analysis, visualization, and interpretation of disease information. More information about SSuN is available here: https://www.cdc.gov/std/ssun/default.htm  

Cycle 4 (2019–2024) of SSuN provides funding to 11 jurisdictions to conduct two core sentinel and enhanced STD surveillance activities. SSuN Cycle 4 sentinel surveillance activities include abstraction of clinical and demographic information on a full census of patients attending participating 16 STD clinics (Strategy A). SSuN Cycle 4 enhanced surveillance activities include provider and patient investigations on a probability sample of all persons diagnosed and reported with gonorrhea and case data for reported adult syphilis cases (Strategy B). All patient records from Strategy A and Strategy B activities are matched to the jurisdiction’s HIV surveillance registry.  Funded jurisdictions collaborating in SSuN Cycle 4 include Baltimore City (Maryland), California (excluding San Francisco County), City of Columbus (8-County metropolitan statistical area), Florida, Indiana, Multnomah County (Oregon), New York City (New York), Philadelphia City/County (Pennsylvania), San Francisco City/County (California), Utah, and Washington State.  

In both core Strategies of SSuN, unique persons (diagnosed and reported with gonorrhea or seeking care in participating clinical facilities) are longitudinally followed using unique, non-name-based coded IDs to provide information on repeat infections and/or care seeking behaviors. The primary unit of analysis for sentinel surveillance activities in clinical facilities is unique persons. These data are merged with multiple clinic visit, laboratory, diagnostic, and treatment observations to provide a comprehensive picture of services and diagnoses received for each individual patient. For enhanced, case-based surveillance activities in SSuN, the primary unit of analysis is a diagnosed and reported episode (case) of gonorrhea or adult syphilis from any provider type or setting within the funded jurisdiction. Case data also included a unique person identifier, which allowed merging with multiple laboratory observations, matching with other health department disease registries, querying provider-based clinical information systems, and unique patient demographic and behavioral data obtained through direct patient interviews. Gonorrhea cases in the probability sample were weighted to reflect study design and to adjust for non-response by demographic category of the patient. Weighted analysis provides estimates of case-level and person-level characteristics representative of all gonorrhea cases diagnosed and reported in the funded jurisdictions. 

Gay, bisexual, and other men who have sex with men (MSM) are defined in all SSuN data collection activities as men who: a) reported having sex with another man in the preceding 2–3 months, and/or, b) those who reported that they considered themselves gay/homosexual or bisexual. Men who have sex with women (MSW) are defined as men who reported having sex with women exclusively, or who did not report the sex of their sex partners but reported that they considered themselves to be straight/heterosexual. 

Data presented from Strategy A (sentinel surveillance in STD clinics) include data from STD clinics in eight of the 11 participating Cycle 4 jurisdictions (Baltimore City [Maryland], Miami, Leon, and Escambia County STD clinics [Florida], Multnomah County [Oregon], New York City [New York], Philadelphia [Pennsylvania], San Francisco [California], and Seattle [Washington]).

Data presented from Strategy B (enhanced surveillance of gonorrhea cases) of SSuN for 2021 include gonorrhea cases sampled, investigated and weighted for analysis from Baltimore City, Columbus (Ohio), Florida, Indiana, Multnomah County (Oregon), New York City, Philadelphia, San Francisco County, Utah, and Washington State.

Gonococcal Isolate Surveillance Project

Data on antimicrobial susceptibility in Neisseria gonorrhoeae were collected through the Gonococcal Isolate Surveillance Project (GISP), a sentinel system of selected STD clinics located at an average of 27 GISP sentinel sites and 4 regional laboratories in the United States. More details about GISP are available here: https://www.cdc.gov/std/GISP/.  

For 2021, the antimicrobial agents tested by GISP were ceftriaxone, cefixime, azithromycin, ciprofloxacin, penicillin, tetracycline, and gentamicin. Many of the antimicrobial susceptibility criteria used in GISP for 2021 are also recommended by the Clinical and Laboratory Standards Institute (CLSI).1As of the end of 2021, the CLSI criteria for resistance to ceftriaxone, cefixime, gentamicin, and azithromycin and for susceptibility to gentamicin have not been established for N. gonorrhoeae.  

The following criteria are used to display GISP data in this report based on minimum inhibitory concentrations (MICs): 

Ciprofloxacin: MIC ≥ 1.0 µg/mL
Penicillin: MIC ≥ 2.0 µg/mL or Beta-lactamase positive
Tetracycline: MIC ≥ 2.0 µg/mL 

Elevated MICs:
Azithromycin: MIC ≥ 1.0 µg/mL (2000–2004); ≥ 2.0 µg/mL (2005–2021)
Ceftriaxone: MIC ≥ 0.125 µg/mL
Cefixime: MIC ≥ 0.25 µg/mL 

Job Corps

Job Corps (formerly referred to as the National Job Training Program in STD Surveillance Reports) is the largest nationwide residential career training program in the country. The program helps opportunity youth ages 16 through 24, including youth with disabilities, young parents, victims of human trafficking, and youth experiencing homelessness complete their high school education, trains them for meaningful careers, and assists them with obtaining employment in fulfilling careers, including placement into a Registered Apprenticeship or the military. As part of the health and wellness program, Job Corps students are provided a medical examination at enrollment, including chlamydia and gonorrhea screening. De-identified chlamydia and gonorrhea test results are provided to CDC by the US Department of Labor. More information is available at: https://www.dol.gov/agencies/eta/jobcorps  

Due to the COVID-19 pandemic, there were no new on-campus enrollments into the Job Corps after mid-March 2020, resulting in a lower number of chlamydia and gonorrhea tests in 2020 compared to earlier years, and though enrollments resumed in 2021, the number of enrollments with valid chlamydia or gonorrhea test results did not meet established criteria for inclusion in this report (i.e., chlamydia or gonorrhea prevalence data are only presented when valid test results for 100 or more students per year are available for the population subgroup and state). For 2021, the number of chlamydia and gonorrhea tests did not meet these criteria in the majority of states, and hence data from the Job Corps are not included in the Sexually Transmitted Disease Surveillance 2021.


  1. Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 31st CLSI supplement M100 Clinical and Laboratory Standards Institute, USA, 2021