Grant: Cat. Gr.: STBBI Res.: Beyond HIV/AIDS/Hep. C- STBBI other than HIV/hep. C (gen.)

Congenital syphilis is increasing rapidly across Canada. This is when babies are born with syphilis infections because their mothers were infected during pregnancy, Early diagnosis and treatment in pregnant women can stop them from passing syphilis to their babies. That's why it's recommended for all pregnant women to get tested for syphilis during their first trimester or at their first prenatal check-up. Additional testing during pregnancy is also suggested if the mother is thought to be at higher risk for syphilis. However, it's not certain whether it's better to test all pregnant women for syphilis multiple times during pregnancy or only those perceived to be at higher risk. In December 2022, a public health unit that serves the Kingston, Frontenac and Lennox & Addington regions in Ontario declared a syphilis outbreak because the rate of syphilis infections was twice as high as Ontario's average, and five babies were born with syphilis. They recommended testing all pregnant women for syphilis three times during pregnancy. Another public health unit in Ontario followed their lead soon after. Our study will investigate how well prenatal syphilis screening is followed across all public health units in Ontario. Next, we'll use the differences in recommendations between these units to see if increasing testing for all women is better at reaching those at the highest risk of syphilis compared to only testing based on risk factors. We will do this by using health administrative data and forming a new team with experts in public health, infectious diseases, and maternal and perinatal health. Our existing collaborations with public health units across Ontario will facilitate the timely completion of our research and allow our work to be implemented into practice. Overall, our research has the potential to evaluate equitable access to prenatal screening, which can ultimately reduce congenital syphilis and lay the groundwork for future syphilis research in Canada.