日本性感染症学会誌 Journal of Japanese Society for Sexually Transmitted Infections

We encountered a case of congenital syphilis involving two siblings. The older child (male) showed no abnormalities before birth; however, congenital syphilis was suspected and diagnosed after birth based on clinical signs and laboratory test findings. The mother’s infection was also discovered concurrently, and we considered that she had contracted the infection after the initial prenatal infection screening. The younger child (female) was diagnosed with congenital syphilis postmortem at an estimated gestational age of 25 weeks, based on physical examination findings, placental pathology, and the mother’s laboratory test results. Although the mother and the male sibling underwent successful antibiotic treatment following the latter’s birth, it was presumed that the mother was reinfected, resulting in the female child’s in utero infection. Social issues were a crucial factor, as both the male sibling and mother discontinued medical follow-ups. Furthermore, the mother did not visit an obstetrician during the pregnancy with the female sibling. This case highlights the importance of addressing such situations from a social model perspective within the biopsychosocial framework.