The efficacy of a single dose of aqueous
penicillin G in preventing neonatal
group-B streptococcal infections was demonstrated in a randomised study conducted over 41 months. 16 082 infant received a single dose of
penicillin within one hour of delivery, and 15 976 infants who received
tetracycline ophthalmic
ointment served as the control group. Group-B streptococcal systemic
infections were significantly less common in the
penicillin-treated infants (0.6 vs 1.7 cases per 100 live birth, p = 0.004). The incidence of
infection caused by
penicillin-resistant pathogen was insignificantly increased in the
penicillin group (2.2 vs 1.6 cases per thousand live birth, p = 0.32). this difference was accounted for almost completely by the events of the first 12 months of the study period when, for unexplained reasons, there was a considerable increase in the number of
penicillin-resistant
infections in the
penicillin group (3.6 vs 1.4 cases per 1000 live births, p = 0.09). The mortality associated with
penicillin-susceptible pathogens was higher in the control group (0.1 vs 0.4 per 1000 live births, p = 0.18). However, the mortality associated with
penicillin-resistant pathogens was increased in the
penicillin (0.4 vs 1.0 per 1000 live births, p = 0.06). The combined mortality rates for all pathogens were not significantly different (1.1 vs 0.7 per 1000 liver births, p = 0.27, for the
penicillin and control groups, respectively) and were nearly equivalent when the excess number of deaths associated with
penicillin-resistant
infections in the
penicillin group during the first study year was excluded from analysis. The incidence of gonococcal
ophthalmia and
conjunctivitis was unaffected by the use of intramuscular
penicillin at birth.