We aimed to provide the first comprehensive estimates of the burden of group B Streptococcus (GBS), including invasive disease in pregnant and postpartum women, fetal infection/stillbirth, and ...infants. Intrapartum antibiotic prophylaxis is the current mainstay of prevention, reducing early-onset infant disease in high-income contexts. Maternal GBS vaccines are in development.
For 2015 live births, we used a compartmental model to estimate (1) exposure to maternal GBS colonization, (2) cases of infant invasive GBS disease, (3) deaths, and (4) disabilities. We applied incidence or prevalence data to estimate cases of maternal and fetal infection/stillbirth, and infants with invasive GBS disease presenting with neonatal encephalopathy. We applied risk ratios to estimate numbers of preterm births attributable to GBS. Uncertainty was also estimated.
Worldwide in 2015, we estimated 205000 (uncertainty range UR, 101000-327000) infants with early-onset disease and 114000 (UR, 44000-326000) with late-onset disease, of whom a minimum of 7000 (UR, 0-19000) presented with neonatal encephalopathy. There were 90000 (UR, 36000-169000) deaths in infants <3 months age, and, at least 10000 (UR, 3000-27000) children with disability each year. There were 33000 (UR, 13000-52000) cases of invasive GBS disease in pregnant or postpartum women, and 57000 (UR, 12000-104000) fetal infections/stillbirths. Up to 3.5 million preterm births may be attributable to GBS. Africa accounted for 54% of estimated cases and 65% of all fetal/infant deaths. A maternal vaccine with 80% efficacy and 90% coverage could prevent 107000 (UR, 20000-198000) stillbirths and infant deaths.
Our conservative estimates suggest that GBS is a leading contributor to adverse maternal and newborn outcomes, with at least 409000 (UR, 144000-573000) maternal/fetal/infant cases and 147000 (UR, 47000-273000) stillbirths and infant deaths annually. An effective GBS vaccine could reduce disease in the mother, the fetus, and the infant.
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The volume-outcomes relationship has led many to advocate centralization of cancer procedures at high volume hospitals (HVH). We hypothesized that in response cancer surgery has become increasingly ...centralized and that this centralization has resulted in increased travel burden for patients.
Using 1996 to 2006 discharge data from NY, NJ, PA, all patients > or = 18 years old treated with extirpative surgery for colorectal, esophageal, or pancreatic cancer were examined. Patients and hospitals were geocoded. Annual hospital procedure volume for each tumor site was examined, and multiple quantile and logistic regressions were used to compare changes in centralization and distance traveled.
Five thousand two hundred seventy-three esophageal, 13,472 pancreatic, 202,879 colon, and 51,262 rectal procedures were included. A shift to HVH occurred to varying degrees for all tumor types. The odds of surgery at a low volume hospital decreased for esophagus, pancreas and colon: per year odds ratios (ORs) were 0.87 (95% CI, 0.85 to 0.90), 0.85 (95% CI, 0.84 to 0.87), and 0.97 (95% CI, 0.97 to 0.98). Median travel distance increased for all sites: esophagus 72%, pancreas 40%, colon 17%, and rectum 28% (P < .0001). Travel distance was proportional to procedure volume (P < .0001). The majority of the increase in distance was attributable to centralization.
There has been extensive centralization of complex cancer surgery over the past decade. While this process should result in population-level improvements in cancer outcomes, centralization is increasing patient travel. For some subsets of the population, increasing travel requirements may pose a significant barrier to access to quality cancer care.
Altered fire regimes resulting from climate change and human activity threaten many terrestrial ecosystems. However, we lack a holistic and detailed understanding of the effects of altering one key ...fire regime component – season of fire. Altered fire seasonality can strongly affect post-fire recovery of plant populations through interactions with plant phenology. We identify seven key mechanisms of fire seasonality effects under a conceptual demographic framework and review evidence for these. We reveal negative impacts of altered fire seasonality and identify research gaps for mechanisms and climate types for future analyses of fire seasonality effects within the identified demographic framework. This framework and these mechanisms can inform critical decisions for conservation, land management, and fire management policy development globally.
Seasonality of fire is changing globally due to increasing human ignitions and climate change.There is concern that season of fire can strongly affect the persistence of plant populations and composition of plant communities, but our understanding of fire seasonality effects lags behind that for some of the other fire regime components, largely because such effects are often confounded with covarying fire intensity effects.By focusing on the causes of post-fire demographic change in plant populations, mechanisms of fire seasonality effects can be identified and studied.Improved understanding of fire seasonality effects is essential for policy development for fire management in fire-prone ecosystems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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.
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.
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.
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.
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Survivors of infant group B streptococcal (GBS) disease are at risk of neurodevelopmental impairment (NDI), a burden not previously systematically quantified. This is the 10th of 11 articles ...estimating the burden of GBS disease. Here we aimed to estimate NDI in survivors of infant GBS disease.
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) and sought unpublished data on the risk of NDI after invasive GBS disease in infants <90 days of age. We did meta-analyses to derive pooled estimates of the percentage of infants with NDI following GBS meningitis.
We identified 6127 studies, of which 18 met eligibility criteria, all from middle- or high-income contexts. All 18 studies followed up survivors of GBS meningitis; only 5 of these studies also followed up survivors of GBS sepsis and were too few to pool in a meta-analysis. Of meningitis survivors, 32% (95% CI, 25%-38%) had NDI at 18 months of follow-up, including 18% (95% CI, 13%-22%) with moderate to severe NDI.
GBS meningitis is an important risk factor for moderate to severe NDI, affecting around 1 in 5 survivors. However, data are limited, and we were unable to estimate NDI after GBS sepsis. Comparability of studies is difficult due to methodological differences including variability in timing of clinical reviews and assessment tools. Follow-up of clinical cases and standardization of methods are essential to fully quantify the total burden of NDI associated with GBS disease, and inform program priorities.
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Early-onset group B streptococcal disease (EOGBS) occurs in neonates (days 0-6) born to pregnant women who are rectovaginally colonized with group B Streptococcus (GBS), but the risk of EOGBS from ...vertical transmission has not been systematically reviewed. This article, the seventh in a series on the burden of GBS disease, aims to estimate this risk and how it varies with coverage of intrapartum antibiotic prophylaxis (IAP), used to reduce the incidence of EOGBS.
We conducted systematic reviews (Pubmed/Medline, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), World Health Organization Library Information System WHOLIS, and Scopus) and sought unpublished data from investigator groups on maternal GBS colonization and neonatal outcomes. We included articles with ≥200 GBS colonized pregnant women that reported IAP coverage. We did meta-analyses to determine pooled estimates of risk of EOGBS, and examined the association in risk of EOGBS with IAP coverage.
We identified 30 articles including 20328 GBS-colonized pregnant women for inclusion. The risk of EOGBS in settings without an IAP policy was 1.1% (95% confidence interval CI, .6%-1.5%). As IAP increased, the risk of EOGBS decreased, with a linear association. Based on linear regression, the risk of EOGBS in settings with 80% IAP coverage was predicted to be 0.3% (95% CI, 0-.9).
The risk of EOGBS among GBS-colonized pregnant women, from this first systematic review, is consistent with previous estimates from single studies (1%-2%). Increasing IAP coverage was linearly associated with decreased risk of EOGBS disease.
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•Most comprehensive review of Group B Streptococcal serotypes through 2018.•First systematic review of Group B Streptococcal strain type and protein data.•Theoretically candidate vaccines may protect ...against 93-99% disease-causing strains.•More studies on GBS strains in low- and middle-income countries are needed.
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.
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.
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.
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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Intrapartum antibiotic chemoprophylaxis (IAP) prevents most early-onset group B streptococcal (GBS) disease. However, there is no description of how IAP is used around the world. This article is the ...sixth in a series estimating the burden of GBS disease. Here we aimed to review GBS screening policies and IAP implementation worldwide.
We identified data through (1) systematic literature reviews (PubMed/Medline, Embase, Literature in the Health Sciences in Latin America and the Caribbean LILACS, World Health Organization library database WHOLIS, and Scopus) and unpublished data from professional societies and (2) an online survey and searches of policies from medical societies and professionals. We included data on whether an IAP policy was in use, and if so whether it was based on microbiological or clinical risk factors and how these were applied, as well as the estimated coverage (percentage of women receiving IAP where indicated).
We received policy information from 95 of 195 (49%) countries. Of these, 60 of 95 (63%) had an IAP policy; 35 of 60 (58%) used microbiological screening, 25 of 60 (42%) used clinical risk factors. Two of 15 (13%) low-income, 4 of 16 (25%) lower-middle-income, 14 of 20 (70%) upper-middle-income, and 40 of 44 (91%) high-income countries had any IAP policy. The remaining 35 of 95 (37%) had no national policy (25/33 from low-income and lower-middle-income countries). Coverage varied considerably; for microbiological screening, median coverage was 80% (range, 20%-95%); for clinical risk factor-based screening, coverage was 29% (range, 10%-50%). Although there were differences in the microbiological screening methods employed, the individual clinical risk factors used were similar.
There is considerable heterogeneity in IAP screening policies and coverage worldwide. Alternative global strategies, such as maternal vaccination, are needed to enhance the scope of global prevention of GBS disease.
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