(P421) Repeat Primary and Secondary Syphilis Infections in 10 U.S. Jurisdictions, STD Surveillance Network, 2020 – 2021

Background:



Recent increases in syphilis infections in the U.S. highlight the importance of evidence-based prevention and control efforts. Repeat syphilis infections indicate there may be undiagnosed cases within sexual networks, and previous work has identified HIV co-infection as a risk for repeat infections. Persons with HIV and syphilis may be at higher risk of severe syphilitic sequelae and for transmitting HIV. Because patient identifiers are not routinely available in national case reporting, repeat syphilis infections across multiple jurisdictions is unknown. We evaluated data with unique identifiers from a multi-site sentinel surveillance project to characterize repeat infections among an appropriately treated cohort of primary and secondary (P&S) syphilis cases.



Methods:

Using STD Surveillance Network (SSuN) data, we identified and determined treatment status for P&S syphilis cases reported during January–June 2020 from all reported syphilis cases in 10 U.S. jurisdictions. We then evaluated SSuN data over the period of January 2020–June 2021 to assess for evidence of repeat P&S syphilis infections among those with documentation of stage-appropriate treatment and compared patient demographics, HIV status, and behaviors among those with and without repeat infections.

Results:

During January–June 2020, there were 7,200 P&S syphilis cases reported. Stage-appropriate treatment was documented for 5,648 (78%) and 197 (3.5%) of these had a subsequent diagnosis of P&S syphilis reported. Time elapsed between original and repeat diagnosis ranged 117–697 days (median=386). The majority (67%) of all repeat infections were among men who have sex with men (MSM). Persons living with HIV and Non-Hispanic Blacks (NHB) were significantly more likely to have a repeat P&S syphilis infection (P< 0.0001). Number of reported sex partners, anonymous partners, age at diagnosis, and substance use were not significantly associated with repeat infection.

Conclusions:

While the proportion of cases with repeat P&S syphilis was relatively low, repeat infections contribute to the overall burden of syphilis in the community and potentially increase the risk of HIV transmission. Given the higher risk of repeat infections in MSM, NHB, and persons living with HIV, prompt syphilis treatment and engagement in HIV prevention and treatment services should be prioritized for these populations.