Congenital syphilis in the twenty-first century: an area-based study

The resurgence of syphilis and subsequent risk for newborns has been described worldwide; however, European data on this congenital infection is lacking. We report the activity of a multidisciplinary specialized unit assisting a large area in the Southern Italy. A retrospective cohort study has been conducted at the Perinatal and Pediatric Infectious Diseases Units of the Federico II University of Naples, enrolling all newborns and children referred from January 2010 to June 2022 exposed to Treponema pallidum in utero and/or congenitally infected. A total of 323 patients were included in the analysis. Twenty (6.2%) received a diagnosis of confirmed congenital syphilis (CS) and one died. Fifteen CS cases had typical clinical features. Since 2017, the number of referred neonates tripled while the rate of late maternal diagnoses did not significantly differ. When compared with mothers of exposed infants, mothers of CS cases were younger (25 ± 7.2 vs 29.9 ± 6 years, p = 0.041), had less previous pregnancies (0.64 vs 1.11, p = 0.044), and received a diagnosis of syphilis at a later stage of pregnancy (86% vs 20%, from third trimester or later on; p < 0.001). Appropriate maternal therapy was protective against vertical transmission (− 1.2; − 1.4, − 1 95% CI; p < 0.001). Paternal syphilis status was known in 36% of cases.