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Vaccine Oct 202021 million pregnant women worldwide (18%) are estimated to carry Group B Streptococcus (GBS), which is a risk for invasive disease in newborns, pregnant women, and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
21 million pregnant women worldwide (18%) are estimated to carry Group B Streptococcus (GBS), which is a risk for invasive disease in newborns, pregnant women, and stillbirths. Adults ≥ 60 years or with underlying health conditions are also vulnerable to invasive GBS disease. We undertook systematic reviews on GBS organism characteristics including: capsular polysaccharide (serotype), sequence type (multi-locus sequence types (MLST)), and virulence proteins. We synthesised data by at-risk populations, to inform vaccine development.
METHODS
We conducted systematic reviews and meta-analyses to estimate proportions of GBS serotypes for at risk populations: maternal colonisation, invasive disease in pregnant women, stillbirths, infants 0-90 days age, and older adults (≥60 years). We considered regional variation and time trends (2001-2018). For these at-risk population groups, we summarised reported MLST and surface proteins.
RESULTS
Based on 198 studies (29247isolates), 93-99% of GBS isolates were serotypes Ia, Ib, II, III, IV and V. Regional variation is likely, but data gaps are apparent, even for maternal colonisation which has most data. Serotype III dominates for infant invasive disease (60%) and GBS-associated stillbirths (41%). ST17 accounted for a high proportion of infant invasive disease (41%; 95%CI: 35-47) and was found almost exclusively in serotype III strains, less present in maternal colonisation (9%; 95%CI:6-13),(4%; 95%CI:0-11) infant colonisation, and adult invasive disease (4%, 95%CI:2-6). Percentages of strains with at least one of alp 1, alp2/3, alpha C or Rib surface protein targets were 87% of maternal colonisation, 97% infant colonisation, 93% infant disease and 99% adult invasive disease. At least one of three pilus islands proteins were reported in all strains.
DISCUSSION
A hexavalent vaccine (serotypes Ia, Ib, II, III, IV and V) might provide comprehensive cover for all at-risk populations. Surveillance of circulating, disease-causing target proteins is useful to inform vaccines not targeting capsular polysaccharide. Addressing data gaps especially by world region and some at-risk populations (notably stillbirths) is fundamental to evidence-based decision-making during vaccine design.
Topics: Aged; Female; Humans; Infant; Infant, Newborn; Membrane Proteins; Multilocus Sequence Typing; Pregnancy; Streptococcal Infections; Streptococcus agalactiae; Vaccines
PubMed: 32888741
DOI: 10.1016/j.vaccine.2020.08.052 -
Vaccine Aug 2011Vaccine development for enterotoxigenic Escherichia coli (ETEC) is dependent on in-depth understanding of toxin and colonization factor (CF) distribution. We sought to... (Review)
Review
INTRODUCTION
Vaccine development for enterotoxigenic Escherichia coli (ETEC) is dependent on in-depth understanding of toxin and colonization factor (CF) distribution. We sought to describe ETEC epidemiology across regions and populations, focusing on CF and toxin prevalence.
METHODS
We conducted a systematic review of the published literature, including studies reporting data on ETEC CF and toxin distributions among those with ETEC infection. Point estimates and confidence intervals were calculated using random effects models.
RESULTS
Data on 17,205 ETEC isolates were abstracted from 136 included studies. Approximately half of the studies (49%) involved endemic populations, and an additional 17% involved only travel populations. Globally, 60% of isolates expressed LT either alone (27%) or in combination with ST (33%). CFA/I-expressing strains were common in all regions (17%), as were ETEC expressing CFA/II (9%) and IV (18%). Marked variation in toxins and CFs across regions and populations was observed.
DISCUSSION/CONCLUSIONS
These results demonstrate the relative importance of specific CFs in achieving target product profiles for a future ETEC vaccine. However, heterogeneity across time, population, and region, confounded by variability in CF and toxin detection methodologies, obfuscates rational estimates for valency requirements.
Topics: Bacterial Toxins; Enterotoxigenic Escherichia coli; Enterotoxins; Escherichia coli Infections; Escherichia coli Proteins; Escherichia coli Vaccines; Fimbriae Proteins; Humans
PubMed: 21723899
DOI: 10.1016/j.vaccine.2011.06.084 -
Microbial Genomics Nov 2023(group B , GBS) has recently emerged as an important pathogen among adults. However, it is overlooked in this population, with all global efforts being directed towards...
(group B , GBS) has recently emerged as an important pathogen among adults. However, it is overlooked in this population, with all global efforts being directed towards its containment among pregnant women and neonates. This systematic review assessed the molecular epidemiology and compared how the lineages circulating among non-pregnant populations relate to those of pregnant and neonatal populations worldwide. A systematic search was performed across nine databases from 1 January 2000 up to and including 20 September 2021, with no language restrictions. The Joanna Briggs Institute (JBI) Prevalence Critical Appraisal Tool (PCAT) was used to assess the quality of included studies. The global population structure of GBS from the non-pregnant population was analysed using typing and phylogenetic reconstruction tools. Twenty-four articles out of 13 509 retrieved across 9 databases were eligible. Most studies were conducted in the World Health Organization European region (12/24, 50 %), followed by the Western Pacific region (6/24, 25 %) and the Americas region (6/24, 25 %). Serotype V (23%, 2310/10240) and clonal complex (CC) 1 (29 %, 2157/7470) were the most frequent serotype and CC, respectively. The pilus island PI1 : PI2A combination (29 %, 3931/13751) was the most prevalent surface protein gene, while the tetracycline resistance M (55 %, 5892/10624) was the leading antibiotic resistance gene. This study highlights that, given the common serotype distribution identified among non-pregnant populations (V, III, Ia, Ib, II and IV), vaccines including these six serotypes will provide broad coverage. The study indicates advanced molecular epidemiology studies, especially in resource-constrained settings for evidence-based decisions. Finally, the study shows that considering all at-risk populations in an inclusive approach is essential to ensure the sustainable containment of GBS.
Topics: Pregnancy; Adult; Infant, Newborn; Humans; Female; Streptococcus agalactiae; Molecular Epidemiology; Phylogeny; Anti-Bacterial Agents; Databases, Factual
PubMed: 38019122
DOI: 10.1099/mgen.0.001140