Congenital syphilis and fluorescent treponemal antibody test reactivity after the age of I year

Background: Many believe that a persistently reactive fluorescent treponema l antibody absorption (FTA-ABS) is manifested with congenital syphilis afte r the age of 1 year, that it is useful in the retrospective diagnosis of ch ildren with congenital syphilis, and that it can he used to confirm other t reponemal tests. Goal: To determine whether a reactive FTA-ABS after the age of 12 months is indicative of congenital syphilis, Study Design: Prospective outpatient follow-up evaluation until at least th e age of 12 months was conducted for 194 babies born to mothers with reacti ve syphilis serology at delivery, and for two additional children with cong enital syphilis diagnosed when they were younger than 1 year (total, 196 ch ildren). Results: In the study group, 511 children had reactive FTA-ABS (reactors) u ntil the age of at least 12 months or more, and 1 12 children had nonreacti ve FTA-ABS (nonreactors) at the age of 12 months or more. Of the 54 reactor s, 17 (31%) had evidence of congenital syphilis at birth, whereas evidence of congenital syphilis was seen in 14 of the 142 (10%) nonreactors (P = 0.0 002). At 15 months, nonreactive FTA-ABS de, eloped in six reactors, and eve ntually in 15 of 44 reactors (34%) tested, Conclusions: A reactive FTA-ABS may be seen at 12 months in children with a nd without evidence of congenital syphilis at birth. Not all children with congenital syphilis will manifest reactive FTA-ABS at 12 months, and FTA-AB S reactivity wanes with time.