Hearing assessment of infants with congenital syphilis.

Only 23 of the 65 infants were assessed at 3 months. The other two thirds were never examined, so a hearing problem in those children would not have been picked up. Follow-up stopped at about 3 months. Congenital syphilis can cause hearing loss that appears later, so this study could not have detected it. Every baby in the study was asymptomatic for congenital syphilis at birth. Nothing here tells you about babies who are symptomatic, and the authors found no studies of hearing in that group. Middle ear function was not measured objectively because the equipment was unavailable; the ear drum was checked by eye with an otoscope, so a middle ear problem could have been missed. There was no comparison group. The study describes what was found in these infants rather than how they compare with infants without congenital syphilis. One centre, small numbers, and the authors themselves call for larger studies with longer follow-up.

The paper declares no financial support and nothing to declare for conflicts of interest. No other funding, sponsor involvement or author disclosure is reported.

Do not read this as proof that congenital syphilis leaves hearing intact. Only 23 of the 65 infants were assessed at 3 months and no child was followed beyond that, while the paper itself notes that hearing loss can appear later, around two years of age.