CDC's STI Surveillance Network (SSuN): Tracking Gonorrhea and Syphilis in Depth

The STI Surveillance Network (SSuN) helps CDC and state and local health departments understand the epidemiology of sexually transmitted infections (STIs), nationally and locally, to guide prevention.

What it is for

• Deeper behavioral, demographic and clinical information on gonorrhea and early adult syphilis cases reported to health departments.
• Information on patients seen in specialty STI clinics.
• New strategies to improve STI surveillance nationwide.

SSuN is a collaboration of competitively selected state, county and city health departments, funded for this work. Established in 2005, it is in its fifth cycle; the current cooperative agreement, CDC-RFA-PS-24-0082, funds activities through 2025.

Strategies

Cycle 5 has three strategies — two core and one optional — and each funded site takes on Strategy A, Strategy B or both.

Strategy A — sentinel surveillance in specialty STI clinics. Sites record each patient visit: the STI and HIV tests done, results, diagnoses, and patients' demographics and selected behaviors. This shows:

• who seeks sexual health care;
• how providers test and treat;
• changes in the number and share of patients diagnosed with STIs and HIV co-infection;
• uptake of prevention such as HIV pre-exposure prophylaxis (PrEP) and doxycycline post-exposure prophylaxis for STIs (doxy PEP).

Strategy B — enhanced case surveillance. Sites collect more information on every reported case of gonorrhea and syphilis — lab results, treatment, and outcomes of routine partner service interviews. Each site also randomly samples reported cases for enhanced clinical, treatment and behavioral investigation, giving a probability sample weighted to represent all reported cases in the participating sites. These investigations shed light on sex partners and on use of PrEP and doxy PEP.

Strategy C — no projects were funded in Cycle 5.

Matching with HIV registries. Every patient at the participating Strategy A clinics, and every reported Strategy B case, is matched against the site's HIV surveillance registry — so HIV prevalence can be measured among people diagnosed with these infections and among those seeking care at specialty STI clinics.

Why it matters

Together these activities add to routine national case reporting, giving CDC and its partner health departments trends in STI-related health care and incidence that no other source provides. CDC's SSuN page also lists data collection protocols, participating jurisdictions, publications and contacts.

Sources

Based on "STI Surveillance Network (SSuN)," Centers for Disease Control and Prevention; a work of the United States government in the public domain. The source's decorative stock image is not reproduced.