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Meta-Analysis
. 2017 Nov 6;65(suppl_2):S100-S111.
doi: 10.1093/cid/cix658.

Maternal Colonization With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses

Neal J Russell  1   2 , Anna C Seale  1   3 , Megan O'Driscoll  4 , Catherine O'Sullivan  5 , Fiorella Bianchi-Jassir  1 , Juan Gonzalez-Guarin  6 , Joy E Lawn  1 , Carol J Baker  7 , Linda Bartlett  8 , Clare Cutland  9 , Michael G Gravett  10   11 , Paul T Heath  5 , Kirsty Le Doare  4   5 , Shabir A Madhi  12   13 , Craig E Rubens  10   14 , Stephanie Schrag  15 , Ajoke Sobanjo-Ter Meulen  16 , Johan Vekemans  17 , Samir K Saha  18 , Margaret Ip  19 ; GBS Maternal Colonization Investigator Group
Collaborators, Affiliations
Meta-Analysis

Maternal Colonization With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses

Neal J Russell et al. Clin Infect Dis. .

Abstract

Background: Maternal rectovaginal colonization with group B Streptococcus (GBS) is the most common pathway for GBS disease in mother, fetus, and newborn. This article, the second in a series estimating the burden of GBS, aims to determine the prevalence and serotype distribution of GBS colonizing pregnant women worldwide.

Methods: We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus), organized Chinese language searches, and sought unpublished data from investigator groups. We applied broad inclusion criteria to maximize data inputs, particularly from low- and middle-income contexts, and then applied new meta-analyses to adjust for studies with less-sensitive sampling and laboratory techniques. We undertook meta-analyses to derive pooled estimates of maternal GBS colonization prevalence at national and regional levels.

Results: The dataset regarding colonization included 390 articles, 85 countries, and a total of 299924 pregnant women. Our adjusted estimate for maternal GBS colonization worldwide was 18% (95% confidence interval [CI], 17%-19%), with regional variation (11%-35%), and lower prevalence in Southern Asia (12.5% [95% CI, 10%-15%]) and Eastern Asia (11% [95% CI, 10%-12%]). Bacterial serotypes I-V account for 98% of identified colonizing GBS isolates worldwide. Serotype III, associated with invasive disease, accounts for 25% (95% CI, 23%-28%), but is less frequent in some South American and Asian countries. Serotypes VI-IX are more common in Asia.

Conclusions: GBS colonizes pregnant women worldwide, but prevalence and serotype distribution vary, even after adjusting for laboratory methods. Lower GBS maternal colonization prevalence, with less serotype III, may help to explain lower GBS disease incidence in regions such as Asia. High prevalence worldwide, and more serotype data, are relevant to prevention efforts.

Keywords: colonization; group B Streptococcus; pregnancy; serotypes; vaginal.

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Figures

Figure 1.
Figure 1.
Maternal group B Streptococcus (GBS) colonization in GBS disease schema, as described by Lawn et al [1]. Abbreviations: GBS, group B Streptococcus; NE, neonatal encephalopathy.
Figure 2.
Figure 2.
Data search and included studies for maternal group B Streptococcus colonization. Abbreviations: LILACS, Latin American and Caribbean Health Sciences Literature; WHOLIS, World Health Organization Library Information System.
Figure 3.
Figure 3.
Geographic distribution of included data, showing the range of number of women tested per country. Data for Algeria, Libya, Portugal, and Qatar were excluded from final analyses due to inadequate description of culture methods. Borders of countries/territories in the map do not imply any political statement.
Figure 4.
Figure 4.
Maternal group B Streptococcus colonizing serotype distribution by United Nations subregion.
Figure 5.
Figure 5.
Prevalence of group B Streptococcus (GBS) colonization by country, adjusting for sampling site and laboratory culture method. Borders of countries/territories in map do not imply any political statement.
See this image and copyright information in PMC

References

    1. Lawn JE, Bianchi-Jassir F, Russell N et al. . Group B streptococcal disease worldwide for pregnant women, stillbirths, and children: why, what, and how to undertake estimates? Clin Infect Dis 2017; 65(suppl 2):S89–99. - PMC - PubMed
    1. Sørensen UBS, Poulsen K, Ghezzo C, Margarit I, Kilian M. Emergence and global dissemination of host-specific Streptococcus agalactiae clones. mBio 2010; 1 pii:e00178-10. - PMC - PubMed
    1. Melin P, Efstratiou A. Group B streptococcal epidemiology and vaccine needs in developed countries. Vaccine 2013; 31(suppl 4):D31–42. - PubMed
    1. Le Doare K, Heath PT. An overview of global GBS epidemiology. Vaccine 2013; 31(suppl 4):D7–12. - PubMed
    1. Kwatra G, Cunnington MC, Merrall E et al. . Prevalence of maternal colonisation with group B Streptococcus: a systematic review and meta-analysis. Lancet Infect Dis 2016; 16:1076–84. - PubMed

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