Surveillance for invasive neonatal sepsis and retrospective
analysis of risk factors for neonatal and pediatric GBS disease
» Background
Group B streptococci (GBS) are the major cause of bacterial sepsis
in neonates, occuring in 1-2 per 1000 live births. The source
of infection is the birth canal, with transmission occurring before
or during delivery. The high rates of morbidity and mortality
associated with neonatal GBS infection have led to numerous proposed
strategies to prevent infection in the newborn. Recent evidence
supports the use of maternal screening for GBS colonization late
during pregnancy, and intrapartum chemoprophylaxis for colonized
women. This is associated with a significantly reduced rate of
GBS sepsis in neonates; however, there is concern that it will
also be associated with an increased risk of infection due to
bacteria normally resistant to the penicillin/ampicillin used
for intrapartum chemoprophylaxis). Incidence and risk factors
for late onset GBS disease (in infants >3 months) and pediatric
disease are not well described. We propose to conduct a retrospective
analysis of all cases of GBS disease in neonates and children
up to 15 to look at risk factors in the various age groups.
The proposal comprises the following components:
- Active, population-based surveillance for invasive pneumococcal
disease (that associated with a sterile site culture)
- Active population-based surveillance for pneumococcal pneumonia
confirmed by culture of sputum or specimen obtained at bronchoscopy
- Case-control study of socio-economic and other risk factors
for pneumococcal disease comparing cases identified by population-based
surveillance with population-based, age-matched controls
- Active surveillance for cases of severe invasive group A streptococcal
disease
- Active surveillance for invasive Salmonella infections with
collection of relevant clinical data by chart review
- Active population-based surveillance for cases of invasive
meningococcal disease
- Active surveillance for cases of laboratory confirmed cases
of influenza requiring hospitalization
- Active population-based surveillance for neonatal sepsis
- Active population-based surveillance for invasive GBS disease
- Retrospective case review of cases of streptococcal toxic
shock from 1995-2003
- Retrospective case review of neonatal and pediatric GBS disease
from 1995-2004
» Methods
The microbiology laboratories serving hospitals in Toronto and
Peel and the three largest private laboratories will continue
to report cases of neonatal sepsis and invasive group B streptococcal
isolates to the study office and forward the bacterial isolate
to the study laboratory. The postal code of residence of the patient
will be screened to determine eligibility: Cases will be eligible
if the postal code of their home address is within the defined
population areas. Annual audits of cultures from all laboratories
will be performed to evaluate reporting accuracy.
Initial demographic data (date of birth of infant and mother,
postal code of residence of mother, organism and susceptibility
testing results, gestational age of infant, discharge date of
infant, and outcome (survived or not)) will be collected for all
case of neonatal sepsis.
When a microbiology laboratory telephones the central study office
and the case is identified as eligible, a "tracking record"
is initiated on which is recorded the date, reporting lab, patient
initials, study code number, hospital, physician name and telephone
number. For cases of neonatal and pediatric GBS, a retrospective
chart review will be conducted to determine specific demographic,
medical and treatment outcome information (see attached data forms).
All isolates from surveillance are shipped to the central study
lab.
