Serotypes and clinical manifestations of group B streptococcal infections in western Sweden

Objectives To study the serotype distributions of group B streptococci (GBS ) isolated from blood and cerebrospinal fluid and from the genital tract of pregnant women and to investigate any possible relation between serotype, age and clinical manifestation. Methods Invasive strains were collected from 1988 to 1997 and genital strai ns from 1995 to 1996. Strains of GBS were serotyped with coagglutination. C linical data were obtained from hospital notes. Results A total of 144 invasive strains, 78 from neonates and infants and 6 6 fi om adults, were: serotyped. The most common isolates from neonates and infants were types III (62%), Ia (18%), and V (9%). The most common isolat es from adults were types III (29%), Ib (23%), V (21%) and II (15%). A majo rity of the adults (94%) had an underlying medical condition. The most comm on serotypes of the 114 strains isolated from the genital tract of pregnant women were types III (32%), V (22%), Ia (13%), Ib (13%) and II (11%). Conclusions Serotype III was the single most frequent GBS isolate from infa nts and adults. Serotype V, which appeared first in 1992, was the third mos t frequent isolate. A vaccine containing live GBS capsular polysaccharides appears to be appropriate for the Swedish population.