EPIDEMIOLOGY OF GROUP B STREPTOCOCCI (GBS) IN MOTHERS AND INFANTS

Abstract

The incidence of neonatal GBS disease in Israel is strikingly low. As neonatal GBS colonization and disease directly relates to maternal GBS carriage, we sampled the maternal and infant Jerusalem population for GBS colonization and surveyed GBS neonatal disease to ascertain the epidemiologic relationships. As GBS serotypes vary in their virulence we also analyzed the prevalence of the different serotypes of GBS isolates. In 1984, GBS colonization of 254 Jewish women and 189 Arab women was 5.4% and 1.6% respectively. In 1987 the rate in 116 Jewish women was 3.5%. Colonization of infants from the same mothers was 1.8%, 1.3% and 1.1% respectively. Differences between these rates was not significant. GBS neonatal disease for the period 1982-1987 was 0.2/1000 live births. Serotype distribution from 150 isolates was Type I 45%, Type II 17%, Type III 13%, other 24%. Our data documenting the low prevalence of GBS colonization in mothers and infants and the low incidence of neonatal GBS disease supports the hypothesis that maternal GBS colonization is the major determinant of GBS neonatal disease. Furthermore the low prevalence of the virulent GBS serotype III may further explain the low attack rate.