Abstract
Congenital syphilis is one of the most well-known congenital infections. Despite notable progress in early diagnosis of syphilis paired with the accessibility of cost-effective treatment and preventive strategies, a few cases continue to be diagnosed in the department of obstetrics. This paper presents a case study of an infant with low birth weight, delivered by an adolescent mother, part of a marginalized demographic group. Due to the mother's lack of routine prenatal care, the infant's management required a series of investigations to establish a comprehensive differential diagnosis. Maternal serological assessments for syphilis, including both non-treponemal antibody test (RPR) and treponemal antibody test (TPHA), yielded positive results following fetal extraction via cesarean section, specifically after diagnosis of syphilis in the infant. Within the first 24 hours of life, newborn serologic tests for syphilis (STS) (including RPR and TPHA assays) exhibited reactivity with titers equivalent to maternal samples. Furthermore, at three weeks of life, the neonatal STS titer exceeded that of the maternal titer, displaying a fourfold increase over the maternal STS level. This finding was concomitant with the detection of IgM antibodies against T. pallidum. Screening for other congenital infections yielded negative results. Subsequent to the high-risk infant follow-up, in accordance with the National Guidelines, the infant had a good outcome.