Group B Streptococcus Infection Sources and Risk Factors

Primary Sources of GBS Infection

Urinary tract infections caused by GBS complicate 2%-4% of pregnancies, but can also occur in non-pregnant adults, according to the CDC guidelines 1, 2
GBS in urine is considered a surrogate for heavy colonization and is associated with higher risk for invasive disease, as reported by the CDC 3, 4
The gastrointestinal tract serves as the natural reservoir for GBS and is the likely source of colonization at other body sites, according to the CDC guidelines 1, 2
Colonization can be transient, chronic, or intermittent, with approximately 10%-30% of adults colonized with GBS in the gastrointestinal tract, as reported by the CDC 3, 4

Intravascular devices can be sources of GBS bloodstream infections, according to the CDC guidelines and Clinical Infectious Diseases 5, 6, 7
Catheter-related bloodstream infections can be caused by GBS, though they are more commonly caused by other organisms like coagulase-negative staphylococci, as stated by the CDC guidelines and Journal of the American College of Radiology 5, 7

A single positive blood culture for GBS may represent true infection or contamination, according to the CDC guidelines 5
A recognized pathogen cultured from one or more blood cultures meets the definition of laboratory-confirmed bloodstream infection, as defined by the CDC guidelines 5

For non-pregnant adults with GBS in urine, treatment is recommended only if they are symptomatic or have underlying urinary tract abnormalities, as suggested by the Infectious Diseases Society of America, but the provided reference is from Praxis Medical Insights, an alternative reference is not available 8