Group B Streptococcal Infection

Group B streptococcal infection is the infectious disease caused by the bacterium Streptococcus agalactiae, the most common human pathogen in group B of the Lancefield classification of streptococci. Infection can cause serious illness and sometimes death, especially in newborns, the elderly and people with compromised immune systems, and the most severe form is neonatal meningitis in infants, which is frequently lethal and can cause permanent neuro-cognitive impairment. The organism was recognized as a pathogen in cattle in the late 1880s, its significance as a human pathogen was first described in 1938, and in the early 1960s it came to be recognized as a major cause of infections in newborns. In most people it is a harmless commensal, and up to 30 percent of healthy adults are asymptomatic carriers.