Single-dose benzathine penicillin in infants at risk of congenital syphilis--results of a randomised study.

OBJECTIVE To determine the efficacy of single-dose benzathine penicillin G in infants at high risk of congenital syphilis. DESIGN Randomised study comparing benzathine penicillin with no therapy. SETTING Peninsula Maternal and Neonatal Service, Cape Town. SUBJECTS Asymptomatic infants born to mothers with untreated syphilis whose VDRL titre was 32 or more. OUTCOME MEASURES The number of cases of congenital syphilis was determined by results of IgM Western blots and follow-up VDRL titres. RESULTS AND CONCLUSIONS Of 8 patients followed up in the non-treatment group, 4 had congenital syphilis while 0/11 had the disease (P = 0.035) in the group receiving benzathine penicillin. Although the exact failure rate is unknown, benzathine penicillin is effective in preventing symptomatic congenital syphilis when administered to high-risk newborns.