CDC conducts active surveillance for invasive group B strep (GBS) disease in certain geographic areas and publishes annual reports.

Overall trends

Group B Streptococcus (group B strep, GBS) emerged in the 1970s as the most common cause of sepsis in newborns. Early-onset disease (occurs in babies younger than 1 week old) declined by 80% since increased use of intrapartum prophylaxis. However, in the United States, these bacteria remain a leading cause of meningitis and bloodstream infections in a newborn’s first three months of life.

More recently, experts recognized the increasing impact invasive GBS disease has on adults. Invasive disease is when bacteria invade a site where there usually are no bacteria, like the blood.

Active surveillance

GBS disease is not reportable in most states.

CDC conducts active surveillance for invasive GBS disease through Active Bacterial Core surveillance (ABCs). ABCs covers a multistate population of approximately 38 million, including approximately 478,000 live births annually.

magnifying glass with bacteria symbol
Bact Facts Interactive

Analyze and visualize ABCs group B strep data using Bact Facts Interactive.

ABCs case definition

Cases for this active surveillance system have to meet the following case definition:

  • GBS bacteria must be isolated from a normally sterile site, such as:
    • Blood
    • Cerebrospinal fluid (CSF)
    • Pleural fluid
    • Peritoneal fluid
    • Pericardial fluid
    • Bone
    • Joint/synovial fluid
    • Internal body site (e.g., lymph node, brain)
  • Alternatively, GBS-specific nucleic acid must be detected in a specimen obtained from a normally sterile body site, using a validated molecular test
  • Case patient must be a resident of one of the defined surveillance areas