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Group B Streptococcal Disease, neonatal

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Reporting Obligations

Individuals who have or may have Group B Streptococcal disease, neonatal shall be reported to the local Health Unit.

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Aetiologic Agent

Group B streptococci (GBS) (S. agalactiae) are gram-positive cocci which are the most common cause of sepsis and meningitis in “at risk” newborns.

Clinical Presentation

Two distinct forms of illness can occur:

  1. Early onset disease (1–7 days after birth) presents with sepsis, respiratory disease, apnea, shock, pneumonia and meningitis;
  2. Late onset disease (≥ 7 days to several months after birth) presents with sepsis and meningitis, however note that only illness up to 28 days after birth is reportable.

Modes of Transmission

Early onset transmission occurs via the infected birth canal as well as in utero. Late onset transmission can also be through person to person contact.

Incubation Period

For early onset disease, the incubation period is from 1–7 days, presenting most frequently within the first 24 hours of life. The incubation period for late onset GBS disease in infants is unknown, as it can occur from ≥ 7 days to several months, but typically within 3–4 weeks.

Period of Communicability

Group B streptococci are transmissible to infants during labour if the mother is colonized; however, a negative vaginal culture at the time of labour does not guarantee absence of colonization.

The period of communicability is unknown but can extend throughout the duration of colonization or disease. Infants can remain colonized for several months after birth and after treatment for systemic infections.

Risk Factors/Susceptibility

Risk is greater among premature babies; delivery at less than 37 weeks.

Intrapartum temperature greater than 38 degrees Celsius.

Rupture of membranes for 18 hours or longer.

Having had a previous newborn with group B streptococcus infection.

Diagnosis and Laboratory Testing

Laboratory confirmation of Group B Streptococcus (Streptococcus agalactiae) from a normally sterile site (e.g.,cerebrospinal fluid), with clinically compatible signs and symptoms of invasive disease in a newborn up to 28 days after birth. Clinically compatible signs and symptoms are characterized by the following: early onset disease (1–7 days), characterized by sepsis, pneumonia, and less frequently meningitis, osteomyelitits or septic arthritis or late onset disease (7 days–1 month), characterized by sepsis and meningitis.

Primary cultures must be processed by the originating lab. Streptococcus agalactiae isolates are identified by conventional biochemicals and by serological methods at the Public Health Lab. Typing is performed upon request only. Specimens are forwarded to the Public Health Agency of Canada in Winnipeg for typing.

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Treatment and Case Management

Treatment is under the direction of the attending health care provider.

Patient Information

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Additional Resources

JOGC. “No. 298-The Prevention of Early-Onset Neonatal Group B Streptococcal Disease”.

Centers for Disease Control and Prevention. “Group B Strep (GBS) Prevention in Newborns, Preventing Early-Onset GBS.”


Heymann, D.L. Control of Communicable Disease Manual (Nineteenth Edition). Washington, American Public Health Association, 2008

Ministry of Health and Long-Term Care, Infectious Diseases Protocol, 2022.