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Diagnosis and Treatment

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Español: Diagnóstico y tratamiento


Group B strep disease is diagnosed by taking samples of a baby’s sterile body fluids, such as blood or spinal fluid. These samples are cultured (bacteria grown in the laboratory) to see if group B strep bacteria are present, which can take a few days.

If a mother who tested positive for group B strep bacteria received antibiotics during labor, doctors will check on the baby once he or she is born. The baby likely won’t need extra antibiotics or other medicine after birth, unless the doctor says they are needed. (See the secondary prevention of early-onset GBS among infants section of the CDC’s prevention guidelines to learn more.)

For both early-onset (occurs in babies younger than 1 week old) and late-onset (occurs in babies 1 week through 3 months old) disease, if a group B strep infection is suspected, doctors will take a sample of the baby’s blood and spinal fluids or take a chest x-ray to confirm the diagnosis.


Group B strep disease in newborns and older babies is treated with antibiotics (medicine used to kill bacteria in the body), such as penicillin or ampicillin, given through a vein (IV). For babies with severe illness, other procedures, in addition to antibiotics, may be needed.