Serologic response to VDRL in infants with congenital syphilis: ceftriaxone vs. penicillin

OBJECTIVE: Penicillin remains the only safe and effective drug recommended for treating syphilis in pregnant women and congenital syphilis (CS). Nevertheless, alternative therapies are needed when penicillin is contraindicated, such as in allergic reactions, or unavailable due to supply limitations. This study aimed to compare the serological response to the Venereal Disease Research Laboratory (VDRL) test in infants reported with CS and treated with either ceftriaxone or penicillin. METHOD: A non-competitive cohort study was conducted in three public maternity hospitals in Fortaleza, Ceará, Northeast Brazil. Data were extracted from notification forms in the Notifiable Diseases Information System (SINAN), medical records from maternity hospitals and outpatient clinics, and electronic records from primary care units. The serological response of infants treated with ceftriaxone and penicillin was assessed. An adequate response was defined as two consecutive negative VDRL tests performed at the intervals recommended by the Brazilian Ministry of Health. Survival curves were estimated using the Kaplan-Meier method. RESULTS: Among 383 infants reported with CS, 56 (14.6 %) underwent VDRL testing in accordance with Ministry of Health guidelines. Of these, 19 (33.9 %) received ceftriaxone and 37 (66.1 %) penicillin. No statistically significant difference in time to VDRL negativity was observed between the groups (log-rank p = 0.73). The median time to negativity was 3 months in both cohorts. CONCLUSIONS: Serological response to VDRL was comparable between infants treated with ceftriaxone and those treated with penicillin. No cases of kernicterus or other CS-related complications occurred among ceftriaxone-treated infants.