Are We Playing It Fast and Loose With the Serofast?

Area of Science:

• Pediatrics
• Infectious Diseases
• Maternal-Fetal Medicine

Background:

• Congenital syphilis poses risks to newborns.
• Maternal treatment for syphilis is crucial but may not always prevent infant transmission.
• Current guidelines may underestimate infant risk in certain serological scenarios.

Purpose of the Study:

• To report cases of congenital syphilis in infants born to mothers with serofast syphilis despite adequate treatment.
• To highlight potential limitations in current diagnostic and classification guidelines for congenital syphilis.
• To emphasize the importance of thorough infant evaluation and follow-up.

Main Methods:

• Case series of four infants (one singleton, one set of triplets) born to mothers with serofast reactive plasma reagin titers (1:4-1:8).
• Maternal treatment with benzathine penicillin G was documented.
• Infant evaluation included physical examination, laboratory tests, and radiographic imaging.
• Infants received treatment according to Centers for Disease Control and Prevention (CDC) guidelines.

Main Results:

• All four infants were diagnosed with congenital syphilis.
• The singleton was asymptomatic but showed radiographic evidence.
• One of the triplets had laboratory abnormalities and a rash; all three triplets had radiographic findings.
• Despite maternal treatment and a four-fold decrease in maternal titers, infants presented with clinical and radiographic signs.

Conclusions:

• Infants can be at risk for congenital syphilis even when maternal treatment appears adequate and titers are serofast.
• Current classification guidelines (e.g., "congenital syphilis unlikely") may not sufficiently capture all at-risk infants.
• Comprehensive maternal history, neonatal physical assessment, and diligent follow-up with repeat nontreponemal titers are essential for all neonates born to mothers with treated syphilis.