PC2104: Clinicodemographic Profile of Congenital Syphilis in a Tertiary-level Hospital

Background: Congenital syphilis remains a major public health problem, and its incidence is increasing worldwide. The purpose of this study was to describe the clinical, laboratory, and demographic characteristics of cases of congenital syphilis diagnosed at a tertiary-level hospital in Mexico.

Methods: This is an ambispective and observational study of cases with congenital syphilis diagnosed in a tertiary-level hospital of Mexico from October 2017 to July 2021. Medical records with structured collection of epidemiological, clinical, and laboratory data were analyzed. All cases were classified in the four scenarios proposed by the CDC guidelines: “proven”, “probable,” “less probable,” and “improbable.” This study was approved by our IRB with registration number PE21-0018.

Results: Of the 132 infants that were diagnosed with congenital syphilis, we identified 28 (21.21%) infants that were diagnosed as “proven” after the neonatal period. Among those ‘’proven’’ cases, 46.4% had a hematological, 50% liver, 10.7% eye, 3.6% hearing, 50% skin, 28.6% bone, 25% pulmonary, 28.6% neurological impairment. The ‘’proven’’ cases’ (median) laboratory findings at diagnosis were hemoglobin (16.2g/dl), leukocytes (16,4000u/L), platelets (252,000u/L), AST (69u/L), ALT (15u/L), total bilirubin (6mg/dL). 18 (13.6%) infants were admitted to the neonatal intensive care unit, 2 (1.8%) developed septic shock, 1 (0.8%) experienced neonatal respiratory distress syndrome, and 1 (0.8%) had a congenital malformation. Among mothers, 99 (75%) had a positive VDRL test, 12 (9.1%) were negative, and 21 (15.9%) had an unknown result. 72 (54.5%) mothers were diagnosed during pregnancy, 4 (3%) before pregnancy, 44 (33.3%) until after delivery, and 12 (9.1%) were unknown. According to the clinical stages of maternal syphilis, 110 (83.3%) were in the late latent phase, 16 (12.1%) in the early latent phase, and 6 (4.5%) in the secondary phase. No mothers with primary or tertiary syphilis were detected. 44 (33.3%) mothers were given 3 dosages of 2.5 million units of intramuscular benzathine penicillin G suspension, 28 (21.2%) were given a single dose of 2.5 million units of intramuscular benzathine penicillin G suspension, 13 (9.9%) were given a different treatment than penicillin, 26 (19.7%) did not receive treatment and 21 (16%) did not know if they received treatment.

Conclusion: Regardless of an antenatal negative screening, pediatricians should consider the diagnosis of congenital syphilis. Infants with congenital syphilis are still underdiagnosed at birth and only a small percentage of them exhibit symptoms. Because of its wide range of clinical manifestations, this preventable infection can be misdiagnosed as a variety of other diseases, causing delays in proper diagnosis and treatment that could have serious consequences.