Group B Streptococcal Disease, neonatal

Reporting Obligations

Individuals with suspect or confirmed cases must be reported to the Thunder Bay District Health Unit by the next working day by fax, phone or mail.

  • Fax: (807) 625-4822
  • Phone: 625-8318 or toll-free at 1-888-294—6630, ext. 8318
  • Mail: 999 Balmoral Street, Thunder Bay, ON P7B 6E7


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.


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 & 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, osteomyelitis or septic arthritis or late onset disease (7 days to 1 month), characterized by sepsis and meningitis.

Testing Information & Requisition


Treatment & Case Management

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

Patient Information

Patient Fact Sheet


  1. Ministry of Health and Long Term Care, Infectious Diseases Protocol - Appendix 1 (2022) Group B Streptococcal Disease, neonatal.
  2. SOGC. "The Society of Obstetricians and Gynaecologists of Canada- Group B Streptococcal Infection in Pregnancy."

Additional Resources

SOGC. "Clinical Practice Guideline for the prevention of early-onset neonatal group B streptococcal disease."

SOGC. "Clinical Practice Guideline, Management of Group B Streptococcal Bacteriuria in Pregnancy, May 2012."

CDC. "GBS: Prevention in Newborns."



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