National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine research support non-u.s. gov't u.s. gov't female male Child Infant newborn P.H.S. preschool risk factors leukocyte count streptococcal infections / complications streptococcal infections / epidemiology* shabir a madhi south africa / epidemiology shock streptococcal infections / mortality age of onset premature septic / complications low birth weight respiratory insufficiency / complications streptococcus agalactiae* pmid:12648320 doi:10.1179/000349803125002814 kholeka radebe alan kimura meningitis / complications