Group B streptococcal disease in infants: a case control study.
OBJECTIVE
To describe and quantify the maternal and neonatal factors associated with Group B streptococcus (GBS) disease in infants <90 days of age.


METHODS
Neonatal Units in London, Oxford, Portsmouth and Bristol.


METHODS
Cases were infants <90 days of age with invasive GBS disease diagnosed between 2000 and 2003, and controls were healthy infants born in the same hospital and in the same birth weight category.


METHODS
Demographic and clinical data on the mother, baby, birth and neonatal stay.


RESULTS
138 cases and 305 controls were recruited. The majority of cases (74%) presented in the first week of life (early onset, EO); most on day 1 (89%). 65% of EO cases had one or more clinical risk factors (prematurity, prolonged rupture of membranes (PROM), known maternal GBS carriage, fever during labour). A multivariable logistic regression analysis found that the strongest independent associations with GBS disease were known maternal carriage of GBS (odds ratio (OR) 6.9), maternal infection in the peripartum period (OR 4.2) and maximum temperature in labour (OR 2.2 per degrees C). GBS disease was associated with twice the likelihood of PROM and fetal tachycardia (p = 0.05 and 0.07 respectively). EO cases had lower Apgar scores and were more likely to have respiratory distress and convulsions, and to require tube feeding than controls. They spent longer in hospital than controls, requiring longer stays at all levels of care.


CONCLUSIONS
Independent of birth weight, a number of maternal, birth and neonatal factors are significantly associated with GBS disease. The management of babies with GBS disease results in an appreciable use of hospital resources.
Heath
P T
PT
Child Health and Vaccine Institute, St George's, University of London, UK. pheath@sgul.ac.uk
Balfour
G F
GF
Tighe
H
H
Verlander
N Q
NQ
Lamagni
T L
TL
Efstratiou
A
A
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D015360:Analgesia, Epidural; D019072:Antibiotic Prophylaxis; D001724:Birth Weight; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005322:Premature Rupture of Fetal Membranes; D005334:Fever; D006340:Heart Rate, Fetal; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control / Q000706:statistics & numerical data*; D016015:Logistic Models; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D013292:Streptococcus agalactiae; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult