May 27, 2022

Clinician Alert

Syphilis Transmission Increasing: Updated Screening Guidelines & Prevention of Congenital Syphilis

Actions Requested 

• Recognize that syphilis transmission is increasing locally and that, although men who have sex with men are still the most frequently affected risk group, the recent increase has expanded beyond that group and led to a resurgence in congenital syphilis.
• Expand serologic screening for latent syphilis to all the groups and scenarios set forth in the attached guidelines from the Washington State Department of Health with a top priority on detecting untreated syphilis prior to or early in pregnancy in order to prevent congenital syphilis.
• Recall that serologic testing for syphilis during pregnancy is required by Washington State law (RCW 70.24.090, WAC 246-100-202). Testing should be repeated early in the 3^rd trimester for seronegative mothers with risk factors for acquisition.
• Report all suspected and confirmed syphilis cases of any stage to the Snohomish Health District’s STD/HIV Program (tel: 425-339-5261, fax: 425-339-8707).  Please also seek consultation on diagnosis and management of cases and their contacts so that we can work together to ensure that both personal health and disease control objectives are achieved.  
• Consider attending or delegating attendance to a statewide webinar on Maternal and Congenital Syphilis in Washington State that will take place June 1, 2022 at 12:00PM PDT (Zoom link: https://washington.zoom.us/j/91033203704). 

Background

Statewide Situation

• Syphilis transmission was nearly eliminated in Washington State in the mid-1990s following population-level behavioral changes elicited by the response to the human immunodeficiency virus.  Subsequent to reintroduction in the late 1990s, endemic transmission was re-established and has continued to increase, particularly (but not exclusively) among men who have sex with men (MSM).
• Rates of syphilis among cisgender women and among heterosexual men in Washington State have been rising since 2015, even more so during 2020-2021.

• The 2021 rate of total syphilis among cisgender women in Washington was nearly double that observed in 2020 and more than 8 times higher than in 2012. 
• A record 51 cases of congenital syphilis were reported in Washington state in 2021 (versus 3 cases in 2019 and 10 in 2020). 
• Congenital syphilis can result in stillbirth, neonatal death, prematurity, and permanent neurologic deficits. Of the 51 known cases of congenital syphilis in Washington during 2022, four resulted in fetal demise and at least 31 were born prematurely and/or required prolonged neonatal intensive care unit stays. Congenital syphilis is entirely preventable with timely testing and treatment. 
• Historically and continuing through 2019, the majority of syphilis in women has been staged as latent or unknown duration, implying that it was detected through serologic screening rather than through presentation with primary or secondary disease. Over the past two years, we have seen a reversal in that paradigm, with the majority of cases being reported with primary or secondary disease.  This suggests that there are more cases in women that are not being detected through screening and implies that we have a growing reservoir of undiagnosed latent syphilis in women. This reservoir has the potential to foster ongoing transmission, including transplacental transmission during pregnancy resulting in future cases of congenital syphilis.

Snohomish County Situation

• Primary-and-secondary syphilis cases have increased nearly 10-fold since 2010, with that increase accelerating over the past several years.

• Latent syphilis case reports continue to exceed primary-and-secondary cases among females, a finding in contrast to the recent statewide predominance of primary-and-secondary staging among reported cases.  This suggests that local screening efforts to detect subclinical infection among females may be going better locally than the statewide concern mentioned above implies. 
• While 43 (47%) of the 92 primary-and-secondary cases reported in 2021 were among men who have sex with men, 14 (15%) were among heterosexual women, and 16 (17%) were among heterosexual men.  For 19 (21%), partner gender was not reported.  
• The total number of syphilis cases (all stages) among women 15-44 years of age increased from 17 in 2017 to 42 in 2021. Primary-and-secondary cases increased from an average of 2.5 cases per year during 2017-2020 to 14 cases in 2021.  

• One case of congenital syphilis was reported in Snohomish County in March 2022, and two cases were reported in 2021.  During 1992-2020, no cases of congenital syphilis were reported.   

Adapted from: Barbee L, Golden M, Lindquist S.  Congenital Syphilis Letter to Providers (accessed May 19, 2022). 

Additional Resources

Ramchandani M.  General Clinical Syphilis Overview (45 minutes).  University of Washington STD Prevention & Training Center, 2018 (accessed May 19, 2022).

UW STD Prevention & Training Center (accessed May 19, 2022).

Centers for Disease Control and Prevention. Syphilis in Sexually Transmitted Infections Treatment Guidelines, 2021 (accessed May 19, 2022).

Washington State Department of Health.  STI Fast Facts, Washington State, 2021 (accessed May 19, 2022).