Group B streptococcal disease: from trials and tribulations to triumph and trepidation.

Group B streptococci garnered attention during the 1970s when they surpassed Escherichia coli and Staphylococcus aureus to become the principal causes of sepsis in early infancy. During the 1980s, several clinical trials demonstrated that administration of antimicrobial agents during labor could interrupt vertical transmission and prevent invasive disease in the first week of life (i.e., early-onset disease). However, prophylaxis was not widely used during the next 10 years. On the basis of efforts by clinician-researchers, professional organizations, community-based parent advocacy groups, and the public health community, consensus recommendations for group B streptococcal prophylaxis were finally issued in 1996. By the end of 1999, the incidence of early-onset disease in selected counties within the United States had decreased by 70%, and the gap between black and white persons with disease narrowed by 75%. This recent triumph leaves the professional community treading lightly, alert to the need to monitor for unintended consequences that may threaten recent progress.