Characteristics, management, and outcomes of early symptomatic congenital syphilis in infants at a tertiary specialist hospital in Beijing from 2008 to 2024

Abstract Background: The neonate and infant periods are critical time windows for diagnosing and treating congenital syphilis (CS) so as to prevent its adverse outcomes. In order to assist pediatricians in achieving early diagnoses and to standardize evaluations and treatments of early CS, this study described the clinical characteristics, management, outcomes of infants with early symptomatic CS in Beijing, China, and compared the characteristics of neonatal syphilis with those of post-neonatal syphilis, to enhance the prognosis for affected children. Methods: Clinical data, including demographics, clinical manifestations, laboratory test results, imaging reports, treatments, and follow-up outcomes, were collected from the electronic medical record system of Beijing Ditan Hospital, Capital Medical University (a tertiary-level general teaching hospital specializing in infectious diseases) in Beijing, China. The data pertained to patients admitted to the hospital from January 1, 2008, to December 31, 2024, who were diagnosed with early CS and met the inclusion criteria of this study. Nonparametric tests were used to compare the neonatal and post-neonatal group for non-normally distributed continuous data, and χ 2 tests were used for categorical data. Results: A total of 121 infants with early symptomatic CS were included in this study. Typical skin lesions ( n = 97, 80.2%), hepatomegaly ( n = 65, 53.7%), and fever ( n = 50, 41.3%) were the most common symptoms. Liver damage was the most prevalent abnormality ( n = 87, 71.9%), followed by hematological abnormalities, including anemia ( n = 68, 56.2%) and thrombocytopenia ( n = 30, 24.8%). In addition, 45 of the infants exhibited bone involvement, 29 had abnormal cerebrospinal fluid (CSF) analysis, and 28 had renal injury. Jaundice and elevated direct bilirubin levels occurred significantly more frequently in neonates (36 cases in total, with 50.0% [18 cases] and 63.9% [23 cases] respectively), whereas infants with post-neonatal CS (85 cases in total) were more prone to having hepatomegaly (63.5%, 54 cases), fever (50.6%, 43 cases), nasal congestion (32.9%, 28 cases), and cough (31.8%, 27 cases), as well as a higher incidence of elevated white blood cell count (72.9%, 62 cases) and a toluidine red unheated serum test (TRUST) titer ≥1∶128 (83.5%, 71 cases). There were a total of 120 infants who completed the anti-syphilis treatment. Of these, 96.7% (116 cases) were fully cured of syphilis-related damage. Moreover, 101 of the 120 infants who completed the treatment had serological follow-up, with 94.1% (95 cases) showing negative or ≥4 - fold reduced TRUST titers. Conclusion: Infants diagnosed with CS after the neonatal period exhibited more frequent and complex symptoms, a higher incidence of leukocytosis, and a greater likelihood of complications, underscoring the importance of early diagnosis.