Worldwide incidences of neonatal early- and late-onset invasive group B streptococcal disease (iGBS), estimated at 0.4 and 0.3 cases per 1000 live births, mask considerable heterogeneity even between countries with similar resources.1  Within-country differences in infant iGBS related to ethnicity are also evident. In the United States, the national picture indicates up to twofold higher iGBS rates in Black compared with White infants against a backdrop of declining early-onset but not late-onset disease.2  Black women in the United States are more likely to be identified as colonized with Streptococcus agalactiae during pregnancy and to have iGBS infection.3  In England, maternal iGBS rates were similarly higher in non-White groups, with some evidence of higher GBS colonization rates in Black women from a study in London.4,5  Here we report rates of infant iGBS by ethnicity using national data for England over a 5-year period.

Laboratory-confirmed iGBS cases with specimen dates between January 1, 2016, and December 31, 2020, were extracted from the United Kingdom Health Security Agency (UKHSA) national microbiology surveillance system.6  Infant iGBS was defined as isolation of Streptococcus agalactiae from a normally sterile site at 0 to 6 days of life for early-onset iGBS and 7 to 90 days for late-onset disease. Parent-reported infant ethnicity was obtained by linking iGBS cases to National Health Service [NHS] Digital Hospital Episode Statistics hospital admission records. Hospital records from the NHS in England use ethnic categories defined by the United Kingdom Office for National Statistics. Annual live births data from the Office for National Statistics by ethnic group were used to calculate iGBS rates and rate ratios. All data were collected within statutory approvals granted to UKHSA for infectious disease surveillance and control.

There were 2512 infant iGBS cases in England during 2016 to 2020, of which 1639 (65.3%) were early-onset and 873 (34.8%) late-onset (0.52 and 0.28 cases per 1000 live births). Linkage was successful for 92.3% (2318) of cases, of which 92.7% (2149) had ethnicity data. Compared with White infants (0.43 per 1000 live births), Black infants had 48% higher (0.63) and Asian infants 40% higher (0.60) rates of early-onset iGBS (Table 1), the latter driven by 87%, 38% and 55% higher rates in infants of Bangladeshi (0.81), Pakistani (0.59), and other Asian (0.67) descent. In contrast, Indian infants had a similar early-onset rate (0.47) to White infants. Black infants had 57% higher rates of late-onset iGBS (0.37) than White infants (0.24), accounted for by 74% higher rates among Black African infants (0.41), who represented 70% of live births among all infants of Black ethnicity.

This population-wide data analysis reveals marked differences in iGBS rates among Black and minority ethnic infants in England, excepting infants of Indian heritage. Differences in iGBS rates may reflect differential maternal GBS carriage, including for late-onset iGBS,7  with a hospital study in England reporting higher prevalence of GBS colonization in mothers from Black and some Asian ethnic groups, but lower prevalence in mothers from the Indian subcontinent (mainly from India).4  National data show higher rates of maternal iGBS in Black and minority ethnic groups, albeit without differentiating Indian mothers,5  whereas international data show higher early- and late-onset iGBS rates in Africa than in Europe, North America, and Australia, but lower or similar rates in Asia (again, without differentiating between countries).1 

Our findings echo differentials by ethnicity in maternal colonization and neonatal iGBS incidence in the United States.2,3  The factors to which these differences might be attributed may not be the same in both countries, given that race and ethnicity are social constructs. Studies in the United Kingdom and United States have shown that differences in pregnancy outcomes by ethnicity cannot simply be explained by socioeconomic inequalities.810  In the United Kingdom, intrapartum antibiotic prophylaxis is offered to mothers who present with specific risk factors for infection in the neonate, such as preterm labor or a previous infant with iGBS.11,12 

A strength of our study is that it uses whole population data because the NHS provides 98% of hospital care in England. However, whereas all NHS laboratories feed data automatically to the UKHSA national microbiology surveillance system, reporting of GBS is not mandatory. Observational data such as these do not allow elucidation of causality, such as whether higher preterm birth rates in minority ethnic groups (for reasons other than GBS carriage or infection) lead to increased iGBS risk in neonates or whether maternal GBS leads to higher preterm birth rates and subsequent neonatal iGBS. Future linkage of NHS maternal and infant data could support a more in-depth investigation of pregnancy duration, mode of delivery, and other factors that might account for some of the observed differences by ethnicity.

Understanding the factors underpinning differences in rates of early-onset iGBS within south Asian groups in England may lead to new opportunities for prevention such as prioritized antenatal screening. Strategies to prevent neonatal iGBS must be tailored from high-quality quantitative and qualitative data to reach all women and protect all infants, irrespective of racial or ethnic background.

Dr Lamagni conceptualized the study, drafted the initial manuscript, and reviewed and revised the manuscript; Dr Collin extracted and linked the data, conducted the analyses, drafted the initial manuscript, and reviewed and revised the manuscript; Drs Demirjian and Swann critically reviewed the manuscript for important intellectual content; and all authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

FUNDING: No external funding.

CONFLICT OF INTEREST DISCLAIMER: The authors have indicated they have no conflicts relevant to this article to disclose.

iGBS

invasive Group B Streptococcal

NHS

National Health Service

UKHSA

United Kingdom Health Security Agency

1
Madrid
L
,
Seale
AC
,
Kohli-Lynch
M
, et al.
Infant GBS Disease Investigator Group
.
Infant Group B Streptococcal disease incidence and serotypes worldwide: systematic review and meta-analyses
.
Clin Infect Dis
.
2017
;
65
(
suppl_2
):
S160
S172
2
Nanduri
SA
,
Petit
S
,
Smelser
C
, et al
.
Epidemiology of invasive early-onset and late-onset Group B Streptococcal Disease in the United States, 2006 to 2015: multistate laboratory and population-based surveillance
.
JAMA Pediatr
.
2019
;
173
(
3
):
224
233
3
Edwards
JM
,
Watson
N
,
Focht
C
, et al
.
Group B Streptococcus (GBS) colonization and disease among pregnant women: a historical cohort study
.
Infect Dis Obstet Gynecol
.
2019
;
2019
:
5430493
4
Gopal Rao
G
,
Hiles
S
,
Bassett
P
, %
Lamagni
T
.
Differential rates of Group B Streptococcus (GBS) colonization in pregnant women in a racially diverse area of London, UK: a cross-sectional study
.
BJOG
.
2019
;
126
(
11
):
1347
1353
5
Lamagni
T
,
Wloch
C
,
Broughton
K
, et al
.
Assessing the added value of Group B Streptococcus maternal immunization in preventing maternal infection and fetal harm: population surveillance study
.
BJOG
.
2022
;
129
(
2
):
233
240
6
Public Health England
.
Laboratory Surveillance of Pyogenic and Nonpyogenic Streptococcal Bacteraemia in England, Wales and Northern Ireland: 2019
.
London, UK
:
Public Health England
;
2020
7
Berardi
A
,
Spada
C
,
Creti
R
, et al
.
Maternal carriage in late-onset Group B Streptococcus disease, Italy
.
Emerg Infect Dis
.
2021
;
27
(
9
):
2279
2287
8
Jardine
J
,
Walker
K
,
Gurol-Urganci
I
, et al.
National Maternity and Perinatal Audit Project Team
.
Adverse pregnancy outcomes attributable to socioeconomic and ethnic inequalities in England: a national cohort study
.
Lancet
.
2021
;
398
(
10314
):
1905
1912
9
Manuck
TA
.
Racial and ethnic differences in preterm birth: a complex, multifactorial problem
.
Semin Perinatol
.
2017
;
41
(
8
):
511
518
10
Opondo
C
,
Gray
R
,
Hollowell
J
,
Li
Y
,
Kurinczuk
JJ
,
Quigley
MA
.
Joint contribution of socioeconomic circumstances and ethnic group to variations in preterm birth, neonatal mortality and infant mortality in England and Wales: a population-based retrospective cohort study using routine data from 2006 to 2012
.
BMJ Open
.
2019
;
9
(
7
):
e028227
11
Hughes
RG
,
Brocklehurst
P
,
Steer
PJ
,
Health
P
,
Stenson
BM
,
on behalf of the Royal College of Obstetricians and Gynaecologists
.
Prevention of early-onset neonatal Group B Streptococcal disease: Green-top Guideline No. 36
.
BJOG
.
2017
;
124
(
12
):
e280
e305
12
National Institute for Health and Care Excellence (NICE)
.
Neonatal infection: antibiotics for prevention and treatment
.