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Department of Health Services

Dear Colleague Letter: Increasing Cases of Syphilis Among Females and of Congenital Syphilis

Published: April 28, 2023

Dear Colleague,

Sonoma County Public Health (PH) requests your assistance in responding to alarming increases in congenital syphilis in California and Sonoma County. Over the last several years, California has experienced a steep increase in syphilis among females and in congenital syphilis (CS). Many local health jurisdictions (LHJs) are seeing high CS morbidity defined as a threshold of more than 8.4 CS cases per 100,000 live births. In Sonoma County, even 1 CS case per year puts us above the high morbidity threshold. In addition, significant racial disparities have been observed, as rates of early syphilis and congenital syphilis are significantly higher among Black/African American and American Indian/Alaska Native infants than the statewide rate.

Congenital syphilis can be prevented with timely testing and treatment. A common risk factor, however, is receiving late or no prenatal care. Syphilis testing and treatment must expand beyond prenatal care clinics to other settings serving women at elevated risk for HIV and syphilis. PH requests your assistance to implement the following policies and best practices to Screen, Treat and Prevent, and Prepare for perinatal transmissions including, but are not limited to, the following:


  • Confirm syphilis status of all pregnant patients receiving care or services at emergency departments; urgent care clinics; jails; mental health, drug treatment, and syringe services programs; and street medicine or homeless outreach programs with documented lab results or by providing opt-out syphilis testing.
  • Screen all pregnant patients for syphilis three times during pregnancy: the first test should be as early as possible (during the first trimester), the second test should be during the third trimester (ideally between 28–32 weeks’ gestation), and the third test should be at delivery.

Treat and Prevent

  • Pregnant women with syphilis should be treated with the recommended penicillin regimen for their stage of infection as soon as possible.
  • Infants born to mothers with syphilis during pregnancy should be evaluated and treated for congenital syphilis per recommendations in CDC Sexually Transmitted Infection Treatment Guidelines


  • Refer and navigate all women diagnosed with bacterial STIs (syphilis or gonorrhea) for HIV Pre-Exposure Prophylaxis (PrEP) which can safely be provided during pregnancy.
  • Birthing hospitals should have expedited syphilis testing available 24 hours a day with results available within 1 hour during labor or delivery for women with undocumented syphilis status, including women who were not retested in the third trimester.
  • If syphilis results are positive, a protocol should be in place to provide immediate intrapartum penicillin G treatment (syphilis) to the mother.
  • Pregnant patients with syphilis may require intensive case management to ensure that they have access to treatment and care. Contact Sonoma County Public Health at 707-565-4567 to assist with navigation and support services. Preventing congenital syphilis is a critical priority for public health in California and Sonoma County.

Early diagnosis and treatment can prevent congenital syphilis but can only be achieved if testing and treatment are expanded beyond traditional settings. Thank you for your work to improve the sexual health of all Sonoma County residents. Together, we can end this epidemic and eliminate syphilis. Additional information and resources are appended below.

Kismet Baldwin-Santana, MD, MPH
Interim Public Health Officer

Syphilis/Congenital Syphilis/STDs

View letter as a PDF (196 kB) »