Decreases in reported Sexually Transmitted Infections during the time of COVID-19 in King County, WA: Decreased transmission or screening?

BACKGROUND: In response to the COVID-19 pandemic, Washington State's Stay Home, Stay Healthy (SHSH) order was implemented on 3/24/2020. We hypothesized that pandemic mitigation measures might reduce sexually transmitted infection (STI) screening and/or transmission. METHODS: We used King County, WA STI surveillance and sexual health clinic (SHC) data from 1/1/2019-7/31/2020. We calculated mean weekly case counts for gonorrhea, primary and secondary (P&S) syphilis, male urethral gonorrhea, and early latent (EL) syphilis for three time periods in 2020: pre-SHSH (1/1-3/23), SHSH (3/24-6/5), and reopening (6/6-7/31). P&S syphilis and male urethral gonorrhea were used as proxies for sexual behavior and EL syphilis was used as a proxy for STI screening. We compared SHC visits (2019 vs. 2020) and SHC gonorrhea treatment practices (across 2020 time periods). RESULTS: Compared to January-July 2019, from January-July 2020, reported cases of gonorrhea, male urethral gonorrhea, P&S syphilis, and EL syphilis decreased by 9%, 5%, 16%, and 22%, respectively. Mean weekly case counts of gonorrhea, male urethral gonorrhea, and EL syphilis decreased pre-SHSH to SHSH, but all returned to pre-SHSH levels during reopening. SHC visits during SHSH were 55% lower in 2020 than 2019. In the SHC during SHSH, ceftriaxone treatment for gonorrhea decreased whereas cefixime/cefpodoxime treatment and gonorrhea treatment with no testing increased. CONCLUSIONS: Decreases in reported STIs concurrent with COVID-19 SHSH may reflect a true decline in STI transmission. However, the larger decreases in asymptomatic infections indicates much of the observed decrease was likely due to decreased screening.