Neonatal Group B Streptococcus Disease Research Articles

Burden of Invasive Group B Streptococcus Infection Among Omani Infants Less Than 90 Days Old: A Multicenter Study.

Group B Streptococcus (GBS) infection is the leading cause of neonatal morbidity and mortality worldwide. This study aims to investigate the incidence of invasive GBS disease among infants less than 90 days old in Oman and to describe their risk factors, clinical presentations and clinical outcomes. We retrospectively collected the data of less than 90-day-old Omani infants with culture-positive GBS from sterile samples. This study was conducted in 3 tertiary hospitals in Oman from 2009 to 2018. Over 10 years, we identified 92 cases of culture-confirmed invasive GBS infection from 178,285 live births in the 3 hospitals, giving an overall incidence of 0.53 per 1000 live births [95% confidence interval (CI): 0.4-0.7)]. Of those, 59 (64.1%) had early-onset neonatal GBS disease and 33 (35.9%) had late-onset neonatal GBS disease. The incidence of invasive GBS disease was significantly higher in the last 5 years from 2014 to 2018 (0.69 per 1000 live births, 95% CI: 0.5-0.9) compared to the previous years from 2009 to 2013 (0.36 per 1000 live births, 95% CI: 0.2‒0.5), (P = 0.004). Infants with late-onset neonatal GBS disease had a higher risk of meningitis compared to infants with early-onset neonatal GBS disease (30.3% vs. 10.2%, P = 0.021). The mortality rate was 13.5%. The incidence of invasive GBS disease in Oman is similar to what was reported worldwide, however, the burden of the disease in terms of mortality is high. In addition, a significant increase in the annual incidence of invasive GBS disease in Omani infants was found over the study period.

Neonatal invasive disease caused by Streptococcus agalactiae in Europe: the DEVANI multi-center study.

Group B streptococcus (GBS) remains a leading cause of invasive disease, mainly sepsis and meningitis, in infants < 3months of age and of mortality among neonates. This study, a major component of the European DEVANI project (Design of a Vaccine Against Neonatal Infections) describes clinical and important microbiological characteristics of neonatal GBS diseases. It quantifies the rate of antenatal screening and intrapartum antibiotic prophylaxis among cases and identifies risk factors associated with an adverse outcome. Clinical and microbiological data from 153 invasive neonatal cases (82 early-onset [EOD], 71 late-onset disease [LOD] cases) were collected in eight European countries from mid-2008 to end-2010. Respiratory distress was the most frequent clinical sign at onset of EOD, while meningitis is found in > 30% of LOD. The study revealed that 59% of mothers of EOD cases had not received antenatal screening, whilst GBS was detected in 48.5% of screened cases. Meningitis was associated with an adverse outcome in LOD cases, while prematurity and the presence of cardiocirculatory symptoms were associated with an adverse outcome in EOD cases. Capsular-polysaccharide type III was the most frequent in both EOD and LOD cases with regional differences in the clonal complex distribution. Standardizing recommendations related to neonatal GBS disease and increasing compliance might improve clinical care and the prevention of GBS EOD. But even full adherence to antenatal screening would miss a relevant number of EOD cases, thus, the most promising prophylactic approach against GBS EOD and LOD would be a vaccine for maternal immunization.

Maternal Group B Streptococcal Rectovaginal Colonization after Intrapartum Antibiotic Prophylaxis.

Maternal rectovaginal colonization with Group B Streptococcus (GBS) during labor is a prerequisite for neonatal early-onset GBS disease. Intrapartum antibiotic prophylaxis (IAP) has been proven to prevent GBS perinatal infection, while there are few studies on the evaluation of the effectiveness of different antibiotic prophylaxis regimens. This study aimed to assess the maternal rectovaginal GBS colonization status after IAP, antimicrobial susceptibility and maternal and neonatal outcomes among women administered different antibiotic prophylaxis regimens. A prospective study was conducted between June 2018 and June 2022. GBS carriers identified at 35-37 weeks of gestation were provided IAP (penicillin, cefazolin or clindamycin) at delivery based on the local protocol for GBS prevention. Rectovaginal samples were obtained from participants again after delivery. Antimicrobial susceptibility testing in GBS isolates was performed using the broth microdilution method. A total of 295 cases were included in this study. In the postpartum re-examination for GBS, the overall negative rectovaginal culture rate was 90.8% (268/295). Women who received cefazolin prophylaxis had the highest negative culture rate (95.2%, 197/207), which was followed by those who received penicillin (80.7%, 67/83) and clindamycin (80.0%, 4/5) (p = 0.001). All GBS isolates achieved sensitivity to penicillin and cefazolin, whereas resistance to clindamycin was shown in 21.4% of the strains. There were no significant differences in maternal and neonatal outcomes among the IAP groups. The use of IAP is highly effective in reducing the maternal rectovaginal GBS colonization. Cefazolin may offer equivalent efficacy and safety compared to standard penicillin prophylaxis.

The Group B Streptococcal Adhesin BspC Interacts with Host Cytokeratin 19 To Promote Colonization of the Female Reproductive Tract.

ABSTRACTStreptococcus agalactiae, otherwise known as Group B Streptococcus (GBS), is an opportunistic pathogen that vaginally colonizes approximately one third of healthy women. During pregnancy, this can lead to in utero infection, resulting in premature rupture of membranes, chorioamnionitis, and stillbirths. Furthermore, GBS causes serious infection in newborns, including sepsis, pneumonia, and meningitis. Previous studies have indicated that GBS antigen (Ag) I/II family proteins promote interaction with vaginal epithelial cells; thus, we hypothesized that the Ag I/II Group B streptococcal surface protein C (BspC) contributes to GBS colonization of the female reproductive tract (FRT). Here, we show that a ΔbspC mutant has decreased bacterial adherence to vaginal, ecto-, and endocervical cells, as well as decreased auto-aggregation and biofilm-like formation on cell monolayers. Using a murine model of vaginal colonization, we observed that the ΔbspC mutant strain exhibited a significant fitness defect compared to wild-type (WT) GBS and was less able to ascend to the cervix and uterus in vivo, resulting in reduced neutrophil chemokine signaling. Furthermore, we determined that BspC interacts directly with the host intermediate filament protein cytokeratin 19 (K19). Surface localization of K19 was increased during GBS infection, and interaction was mediated by the BspC variable (V) domain. Finally, mice treated with a drug that targets the BspC V-domain exhibited reduced bacterial loads in the vaginal lumen and reproductive tissues. These results demonstrate the importance of BspC in promoting GBS colonization of the FRT and that it may be targeted therapeutically to reduce GBS vaginal persistence and ascending infection.

Population genomics of Group B Streptococcus reveals the genetics of neonatal disease onset and meningeal invasion

Group B Streptococcus (GBS), or Streptococcus agalactiae, is a pathogen that causes preterm births, stillbirths, and acute invasive neonatal disease burden and mortality. Here, we investigate bacterial genetic signatures associated with disease onset time and meningeal tissue infection in acute invasive neonatal GBS disease. We carry out a genome-wide association study (GWAS) of 1,338 GBS isolates from newborns with acute invasive disease; the isolates had been collected annually, for 30 years, through a national bacterial surveillance program in the Netherlands. After controlling for the population structure, we identify genetic variation within noncoding and coding regions, particularly the capsule biosynthesis locus, statistically associated with neonatal GBS disease onset time and meningeal invasion. Our findings highlight the impact of integrating microbial population genomics and clinical pathogen surveillance, and demonstrate the effect of GBS genetics on disease pathogenesis in neonates and infants.

Variation of invasive neonatal GBS disease across the regions

Group B streptococcus (GBS) emerged in the 1960s as the leading cause of neonatal disease in the USA,1 and yet the reason for its emergence is unknown. Possible reasons are past underdiagnosis or a change in the population structure of GBS.2 Intrapartum antibiotic prophylaxis (IAP) was recommended as the prevention strategy for early-onset invasive GBS (EOGBS),3 and was adopted by various high-income countries. As a result, a substantial decline in the incidence of neonatal disease was observed.

Outcomes in reported penicillin allergic mothers and neonates requiring Group B streptococcal prophylaxis: a retrospective observational cohort study

BackgroundInfectious morbidity and mortality in the first week of life is commonly caused by early-onset neonatal Group B streptococcus (GBS) disease. This infection is spread from GBS positive mothers to neonates by vertical transmission during delivery and results in serious illness for newborns. Intrapartum prophylactic antibiotics have decreased the incidence of early-onset neonatal GBS disease by 80%. Patients labeled with a penicillin allergy (PcnA) alternatively receive either vancomycin or clindamycin but effectiveness is controversial. We evaluated the influence of a reported PcnA label versus no PcnA label on inpatient maternal and neonatal outcomes.MethodsOur goal was to examine the relationship between a PcnA label, maternal and neonatal outcomes, and hospital costs. We collected retrospective data with institutional IRB approval from 2016 – 2018 for hospitalized patients who were GBS positive, pregnant at time of admission, ≥ 18 years of age, received antibiotic prophylaxis for GBS, were labeled as PcnA or non-PcnA, and completed a vaginal delivery. Patient characteristics and maternal/neonatal outcomes were examined. Statistical tests included calculations of means, medians, proportions, Mann–Whitney, two-sample t-tests, Chi-squared or Fisher’s Exact tests, and generalized linear and logistic regression models. Significance was set at p < 0.05.ResultsMost PcnA patients were white, older, had a higher median body mass index and mean heart rate, and a greater proportion used tobacco than non-PcnA patients. In regression analyses, PcnA hospitalized patients received a shorter duration of antibiotic treatment than non-PcnA patients [incidence rate ratio (IRR): 0.45, 95% CI: 0.38–0.53]. PcnA patients were also more likely to have their baby’s hospital LOS be > 48 h [adjusted odds ratio (AOR): 1.35, 95% CI: 1.07–1.69] even though the PcnA mothers’ LOS was not different from non-PcnA mothers. Cost of care, mortality, intensive care, median parity, mean gravidity, and miscarriage were similar between the groups.ConclusionsIn hospitalized obstetric patients, a PcnA label was associated with a shorter maternal course of antibiotic treatment and a longer neonatal LOS. Further prospective studies are needed to clarify the underlying reasons for these outcomes.

Cost-effectiveness of maternal immunization against neonatal invasive Group B Streptococcus in the Netherlands

BackgroundNeonatal invasive Group B Streptococcus (GBS) infection causes considerable disease burden in the Netherlands. Intrapartum antibiotic prophylaxis (IAP) prevents early-onset disease (EOD), but has no effect on late-onset disease (LOD). A potential maternal GBS vaccine could prevent both EOD and LOD by conferring immunity in neonates. ObjectiveExplore under which circumstances maternal vaccination against GBS would be cost-effective as an addition to, or replacement for the current risk factor-based IAP prevention strategy in the Netherlands. MethodsWe assessed the maximum cost-effective price per dose of a trivalent (serotypes Ia, Ib, and III) and hexavalent (additional serotypes II, IV, and V) GBS vaccine in addition to, or as a replacement for IAP. To project the prevented costs and disease burden, a decision tree model was developed to reflect neonatal GBS disease and long-term health outcomes among a cohort based on 169,836 live births in the Netherlands in 2017. ResultsUnder base-case conditions, maternal immunization with a trivalent vaccine would gain 186 QALYs and prevent more than €3.1 million in health care costs when implemented in addition to IAP. Immunization implemented as a replacement for IAP would gain 88 QALYs compared to the current prevention strategy, prevent €1.5 million in health care costs, and avoid potentially ~ 30,000 IAP administrations. The base-case results correspond to a maximum price of €58 per dose (vaccine + administration costs; using a threshold of €20,000/QALY). Expanding the serotype coverage to a hexavalent vaccine would only have a limited additional impact on the cost-effectiveness in the Netherlands. ConclusionsA maternal GBS vaccine could be cost-effective when implemented in addition to the current risk factor-based IAP prevention strategy in the Netherlands. Discontinuation of IAP would save costs and prevent antibiotic use, however, is projected to lead to a lower health gain compared to vaccination in addition to IAP.

Current status of group B Streptococcus infection in neonates: a multicenter prospective study.

To investigate the incidence of maternal group B Streptococcus (GBS) colonization and neonatal early-onset GBS disease (GBS-EOD), and to study the factors associated with the development of GBS-EOD in the offspring of pregnant women with GBS colonization. A total of 16 384 pregnant women and 16 634 neonates delivered by them were enrolled prospectively who had medical records in Xiamen Maternal and Child Care Hospital, Beijing Obstetrics and Gynecology Hospital of Capital Medical University, and Zhangzhou Zhengxing Hospital from May 1, 2019 to April 30, 2020. Unified GBS screening time, culture method, and indication for intrapartum antibiotic prophylaxis (IAP) were adopted in the three hospitals. The incidence rates of maternal GBS colonization and neonatal GBS-EOD were investigated. A multivariate logistic regression analysis was used to identify the factors associated with the development of GBS-EOD in the offspring of pregnant women with GBS colonization. In these three hospitals, the positive rate of GBS culture among the pregnant women in late pregnancy was 11.29% (1 850/16 384), and the incidence rate of neonatal GBS-EOD was 0.96‰ (16/16 634). The admission rate of live infants born to the GBS-positive pregnant women was higher than that of those born to the GBS-negative ones (P<0.05). The live infants born to the GBS-positive pregnant women had a higher incidence rate of GBS-EOD than those born to the GBS-negative ones [6.38‰ (12/1 881) vs 0.27‰ (4/14 725), P<0.05]. The multivariate logistic regression analysis showed that placental swabs positive for GBS and positive GBS in neonatal gastric juice at birth were independent predictive factors for the development of GBS-EOD (P<0.05), while adequate IAP was a protective factor (P<0.05) in the offspring of pregnant women with GBS colonization. GBS colonization of pregnant women in late pregnancy has adverse effects on their offspring. It is important to determine prenatal GBS colonization status of pregnant women and administer with adequate IAP based on the indications of IAP to reduce the incidence of neonatal GBS-EOD. Citation.

Disease burden due to Group B Streptococcus in the Indian population and the need for a vaccine - a narrative review.

Streptococcus agalactiae, a Gram-positive bacterium, causes invasive infection known as Group B streptococcal disease (GBS). It is a leading cause of neonatal death and complications prior to delivery. The burden of GBS is unknown in India despite the high incidence of preterm and stillbirths. In this study, we performed a narrative review of the available literature (published in the last 10 years) on the epidemiology of GBS, using PubMed and Google Scholar, to understand its impact in India and evaluate potential strategies to prevent the disease in the high-risk population, that is, neonates. The review showed that the incidence of early- and late-onset GBS in neonates (per 1000 live births) was in the ranges of 0.090–0.68 and 0.0–0.07 respectively. The overall case fatality rate reported in only one study was 0.63. In pregnant women, the prevalence of GBS colonization was 2–62% and its transmission to their newborns varied from 6.7% to 11.1%. The serotype distribution of GBS is unclear, but some studies reported the distribution of types Ia, Ib, II, III, V, VII among pregnant women in India. The associated risk factors for GBS colonization in pregnant women are unclear but a few studies suggest the role of age and multigravida, while the risk factors in neonates include preterm birth, prolonged rupture of membrane (⩾18 h), maternal fever, obstetric complications, and prolonged labor >18 h. Screening of GBS is not a routine practice in India and intrapartum antibiotics prophylaxis is limited to only in risk conditions to prevent neonatal disease transmission. A few studies also suggest that high birth rate, poor detection methods, and financial constraints limit routine GBS screening in a developing country such as India. Hence, maternal vaccination is the most promising strategy to prevent neonatal GBS and Pfizer’s hexavalent GBS conjugate vaccine (GBS6) is being developed for GBS neonatal disease.

Differences in maternal group B Streptococcus screening rates in Latin American countries

ObjectiveTo determine rates and results of maternal Group B streptococcus (GBS) screening during pregnancy and identify sociodemographic characteristics associated with GBS screening in Latin American countries. BackgroundGBS is a primary cause of morbidity and mortality in neonates and is prevented by screening pregnant women for GBS before delivery and intrapartum antibiotic treatment. Yet, data regarding national GBS screening practices and the epidemiology of maternal GBS colonization in Latin America are limited. MethodsWe conducted a retrospective observational study using de-identified records of pregnant women in six Latin American countries from a regional database. 460,328 collected from January 1, 2009 through December 31, 2012 met study criteria and were included. Maternal screening rates for GBS were determined, association of demographic variables (ethnicity, age, education level, and civil status) with maternal GBS screening was determined using logistic regression, odds ratios were calculated comparing incidence of adverse neonatal outcomes (sepsis, pneumonia, and meningitis) between countries with high and low rates of GBS screening, maternal GBS colonization prevalence was determined by year and association of demographic variables with maternal GBS colonization was determined using logistic regression. ResultsMaternal GBS screening was less than 15% in each country, except Uruguay which screened greater than 65% of women. The final regression model examining maternal screening rates and demographic variables included the covariates ethnicity, maternal age group, education level and civil status. Countries with lower rates of maternal GBS screening had increased odds of neonatal sepsis [OR 23.3; 95% CI (15.2–35.9)] and pneumonia [OR 19.9; 95% CI (12.1–32.6)]. In Uruguay, GBS prevalence over the study period was 18.5%. Black women, older women and women without a primary education had higher rates of GBS colonization (21.3%, 20.4% and 21.9% respectively). ConclusionsOur study highlights the need for national policy and investments to increase maternal GBS screening and better understand the prevalence of maternal GBS colonization in Latin America. Further research on the burden of neonatal GBS disease within Latin America is needed to inform the introduction of a maternal GBS vaccine, when available.

Identification of Group B Streptococcus Serotypes and Genotypes in Late Pregnant Women and Neonates That Are Associated With Neonatal Early-Onset Infection in a South China Population.

Background: Group B streptococcus (GBS) colonized in late pregnancies has been associated with neonatal early-onset GBS disease (GBS-EOD) in China.Objective: This study investigated if GBS serotype and genotype in late pregnancy is associated with GBS-EOD, providing a reference for GBS-EOD prevention and treatment.Methods: A total of 298 pregnant women with GBS colonization during their late pregnancy and 32 invasive GBS-EOD cases were included in this study for GBS serotyping and genotyping using commercial kits and DNA sequencing.Results: We identified 266 GBS strains from mothers whose newborns were not infected with GBS-EOD. Serotype III [54.9% (146/266)] was the most common serotype, followed by Ib [17.3% (46/266)] and V [10.1% (27/266)]. ST19 was the most prevalent genotype [19.9% (53/266)], followed by ST862 [9.4% (25/266)] and ST12 [7.9% (21/266)]. We found that 32 mothers and their neonates with GBS-EOD had the same GBS strains. In 32 cases of GBS-EOD, the top three serotypes were III, Ia, and Ib, while the top three genotypes were ST17, ST23, and ST19. ST17 was the dominant genotype of serotype III, which was the most common prevalent in GBS-EOD [72.2% (13/18)], and ST23 was the dominant genotype of serotype Ia, the second most prevalent in GBS-EOD [87.5% (6/8)]. There were statistically significant differences in serotypes (p = 0.046) and genotypes (p = 0.000) distribution between the 266 pregnant women without GBS-EOD neonates and 32 cases of GBS-EOD.Conclusion: This study revealed a statistically significant associations of GBS serotype Ia, and ST17 and ST23 between GBS colonization in women during late pregnancy and in neonatal GBS-EOD. The GBS ST23 of serotype Ia and ST17 of serotype III possessed a strong pathogenicity.

Duration of Intrapartum Antibiotic Prophylaxis for Group B Streptococcus [06A

INTRODUCTION: Intrapartum vertical transmission of group B streptococcus (GBS) occurs in approximately 50% of vaginal births without antibiotic prophylaxis. This prospective cohort study aimed to determine if &lt;4 hours duration of intrapartum antibiotic prophylaxis (IAP) before delivery reduces GBS vertical transmission rates. METHODS: 1354 GBS positive parturients presented to Yale New Haven Hospital between 10/1/2009 and 3/28/2012. Of eligible patients ≥37 weeks with singleton gestations in labor (n=1111), 316 were invited after IRB approval to participate and 240 completed the study. Maternal characteristics, labor course, delivery and neonatal outcomes were obtained. Of 240 maternal-infant dyads, 69 received &lt;4 hours of IAP and 158 received ≥4 hours. Nine did not receive IAP. Infant oropharyngeal and rectal swabs were collected after 24 hours to detect mucosal GBS colonization. RESULTS: Rates of GBS transmission were equivalent in those receiving less than and greater than 4 hours of prophylaxis before delivery, respectively (1.5 vs 1.2%; P=1.0). No significant differences in GBS transmission were observed between those with and without risk factors for early neonatal GBS disease. No cases of GBS vertical transmission occurred in those who received IAP prior to membrane rupture versus 3 (3.9%) cases of transmission (P=.036) among those who received IAP after membrane rupture. CONCLUSION: GBS vertical transmission rates among individuals who received IAP &lt;4 hours were equivalent to those receiving IAP ≥4 hours before delivery. Antibiotic prophylaxis duration may be less relevant than membrane rupture timing in vertical transmission and deserves further exploration to optimize newborn monitoring protocols after delivery in maternal GBS colonization.

A Vaccine Against Group B Streptococcus: Recent Advances.

Group B streptococcus (GBS) causes a high burden of neonatal and infant disease globally. Implementing a vaccine for pregnant women is a promising strategy to prevent neonatal and infant GBS disease and has been identified as a priority by the World Health Organisation (WHO). GBS serotype-specific polysaccharide – protein conjugate vaccines are at advanced stages of development, but a large number of participants would be required to undertake Phase III clinical efficacy trials. Efforts are therefore currently focused on establishing serocorrelates of protection in natural immunity studies as an alternative pathway for licensure of a GBS vaccine, followed by Phase IV studies to evaluate safety and effectiveness. Protein vaccines are in earlier stages of development but are highly promising as they might confer protection irrespective of serotype. Further epidemiological, immunological and health economic studies are required to enable the vaccine to reach its target population as soon as possible.

Neonatal Group B Streptococcal Infection in a Tertiary Care Hospital in Saudi Arabia: A 13-year Experience.

Group B streptococcus (GBS) is a leading cause of neonatal bacterial sepsis and meningitis globally. Studies concerning the incidence and burden of neonatal GBS disease in Saudi Arabia are lacking. This study determined the incidence and burden of GBS infection among neonates in association with maternal GBS screening. A retrospective cohort chart review study included all neonatal GBS disease cases identified through microbiology lab records within the first 90 days of life in the hospital from January 2004 to December 2016. Charts were reviewed to collect maternal and neonatal characteristics using a standardized form. Over 13 years, of 108,609 live births, 55 GBS disease cases were identified (overall incidence, 0.51/1000 live births), 69.1% (n = 38) of those had early onset disease (EOD). The annual incidence in 2015 and 2016 was significantly higher than in any previous year (P < 0.0001), coinciding with the discontinuation of routine universal maternal GBS screening. Median age at presentation was 1 day (range, 0-54 days). We found that 67.3% (n = 37) of mothers were not screened antenatally, 72.9% (n = 27) of whom had neonates present with EOD. Neonates of unscreened mothers were more likely to have GBS disease (P = 0.01) and to present with EOD (P = 0.005). Urinary tract infection was the most common manifestation (47.3%, n = 26), followed by sepsis (43.6%, n = 24). Mortality rate was 3.6% (n = 2). The incidence of neonatal GBS infection in Saudi Arabia is similar to the worldwide incidence. Universal antenatal screening discontinuation was significantly associated with an increase in EOD incidence.

Disease burden of neonatal invasive Group B Streptococcus infection in the Netherlands.

BackgroundGroup B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis worldwide. We aimed to estimate the current burden of neonatal invasive GBS disease in the Netherlands, as a first step in providing an evidence base for policy makers on the potential benefits of a future maternal GBS vaccine.MethodsSurveillance of neonatal invasive GBS occurs at the National Reference Laboratory for Bacterial Meningitis, where culture isolates from cerebrospinal fluid and blood are sent by diagnostic laboratories. From the number of cultures we estimated the incidence of neonatal (age 0–90 days) GBS meningitis and sepsis. We constructed a disease progression model informed by literature and expert consultation to estimate the disease burden of neonatal invasive GBS infection. As many neonates with a probable GBS sepsis are never confirmed by blood culture, we further estimated the disease burden of unconfirmed cases of probable GBS sepsis in sensitivity analyses.ResultsAn estimated 97 cases and 6.5 deaths occurred in the Netherlands in 2017 due to culture positive neonatal invasive GBS infection. This incidence comprised 15 cases of meningitis and 42 cases of sepsis per 100.000 births, with an estimated mortality of 3.8 per 100.000 live births. A disease burden of 780 disability-adjusted life years (DALY) (95% CI 650–910) or 460 DALY per 100.000 live births was attributed to neonatal invasive GBS infection. In the sensitivity analysis including probable neonatal GBS sepsis the disease burden increased to 71 cases and 550 DALY (95% CI 460–650) per 100.000 live births.ConclusionIn conclusion, neonatal invasive GBS infection currently causes a substantial disease burden in the Netherlands. However, important evidence gaps are yet to be filled. Furthermore, cases of GBS sepsis lacking a positive blood culture may contribute considerably to this burden potentially preventable by a future GBS vaccine.

Analysis of screening strategy of group B streptococcus in the third trimester and its influence on pregnancy outcome

Objective: To investigate the screening strategy of group B streptococcus (GBS) in the reproductive tract of women in the third trimester and analyze its impact on pregnancy outcome. Methods: A total of 85 461 pregnant women in 35-37 weeks of gestation from Bao'an Maternity and Child Health Hospital, Jinan University from January 2011 to June 2018 were enrolled. They were divided into 3 periods according to different GBS screening strategies, the unscreened period included 31 384 cases (36.72%), 33 267 cases (38.93%) were included in partial screening period, 20 810 cases (24.35%) were included in screening period. All GBS screening positive pregnant women were given intrapartum antibiotic prophylaxis (IAP). The impact on pregnancy outcomes, and the impact of different GBS collection transport and culture methods on the positive rate of GBS screening were analyzed. Results: (1) The incidence of neonatal early onset GBS disease (EOGBSD) in unscreened period was 0.03% (11/31 773), in partial screening period was 0.02%(6/33 887), and in screening period, the incidence of neonatal EOGBSD decreased to 0, the difference was statistically significant (χ(2)=7.86, P=0.02).(2) The incidence of hematogenous infection of GBS in pregnant women was 0.02%(6/33 887) in partial screening period, and there was none in screening period, there was no significant difference (adjusted χ(2)=3.75, P=0.05). (3) In the screening period, the positive rate of GBS was 14.08%(2 719/19 306), which was significantly higher than the positive rate of GBS in the partial screening period (11.48%, 2 058/17 920; χ(2)=56.12, P=0.00). (4) Antibiotic sensitivity tests of 4 777 GBS strains showed that the antibiotics with higher resistance rate were tetracycline (81.52%, 3 896/4 777), erythromycin (66.59%, 3 181/4 777), and clindamycin (64.31%, 3 072/4 777). The combination of erythromycin, clindamycin and tetracycline was the most common resistant pattern, accounting for 48.80% (2 331/4 777). No penicillin, ceftriaxone or vancomycin resistant strains was found. Conclusions: GBS screening strategy in different regions could combine the local neonatal EOGBSD incidence rate, maternal GBS colonization rate, and the socioeconomic factors to determine whether universal GBS screening or screening for high-risk maternal women. GBS screening positive rate is related to the population, scope of the investigation, the sample collection, delivery and culture methods. The multi-drug resistance rate of GBS is high.

Assessment of maternal GBS colonization and early-onset neonatal disease rate for term deliveries: a decade perspective.

Objective To assess the maternal group B streptococcal (GBS) colonization rate and neonatal early-onset GBS (EOGBS) disease in term deliveries, a decade apart. Methods This was a retrospective computerized study between 2005 and 2016. A universal GBS culture-based approach gradually replaced the GBS risk-oriented screening. A vaginal-rectal culture taken at 35-37 weeks was recorded at admission for delivery. Results We identified 149,910 term deliveries during the study period. GBS status was recorded in 53,879 (35.9%) cases. The GBS screening rate constantly increased from 20% in 2005 to 47.5% in 2016. GBS colonization rates significantly decreased, from 50.3% in 2005 to 31.7% in 2016, P<0.001. Overall, EOGBS disease was diagnosed in 37 term neonates (0.25 per 1000 live births.). The rate of EOGBS in neonates decreased dramatically from 0.361 per 1000 deliveries between 2005 and 2009 to 0.19 per 1000 deliveries between 2010 and 2016 (P<0.05). During the latter period, over 35% of the deliveries were screened for GBS. Remarkably, 64.9% of the EOGBS originated in the non-screened population. Conclusion The universal screening policy was associated with a significant decrease in neonatal EOGBS and therefore should be adopted. Further national surveillance studies should be performed in order to validate this approach.

Group B Streptococcus Colonization in Late Pregnancy and Invasive Infection in Neonates in China: A Population-Based 3-Year Study

Background: As no population-based studies of group B Streptococcus (GBS) colonization rates in late pregnancy (at 35–37 weeks of gestation) have been conducted in China, the incidence of and risk factors for neonatal early-onset GBS disease (GBS-EOD) in China remains poorly understood. Objectives: To determine the GBS colonization rate in late pregnancy and neonatal GBS infection in Xiamen, China, and to assess the effectiveness of intrapartum antibiotic prophylaxis (IAP) for the prevention of neonatal GBS-EOD. Methods: A total of 49,908 pregnant women were enrolled between April 1, 2014 and March 31, 2017. Bacterial culture was used to diagnose GBS infection in both pregnant women and neonates. Women with GBS colonization received IAP during parturition or rupture of fetal membranes. Results: The GBS colonization rate was 13.89% (6,933/49,908); 50,772 neonates were born to 49,908 pregnant women, of whom 75 (1.48 per 1,000) were diagnosed with GBS-EOD. The incidence of GBS-EOD among neonates born to GBS-positive mothers (8.77‰; 62/7,068) was 29 times higher than that of neonates born to GBS-negative mothers (0.30‰; 13/43,704). Logistic regression analysis indicated that gestational bacteriuria, GBS disease in infants from previous pregnancies, and chorioamnionitis were risk factors for GBS-EOD (p = 0.007, p = 0.000, and p = 0.018, respectively). IAP effectively protected against neonatal GBS-EOD (p = 0.011). Conclusions: GBS colonization was detected in nearly 14% of late pregnant women. The IAP for reducing GBS-EOD was effective. Therefore, universal screening of maternal GBS and subsequent IAP for those with GBS colonization should be implemented in China.

654: Vaginal ecology of the pathobiont Group B Streptococcus (S. agalactiae) in the perinatal period

It is fundamentally challenging to predict which bacteria will cause disease or function as harmless commensal organisms. One example is Group B Streptococcus (GBS), which fewer than 0.4/1000 will cause invasive early sepsis in neonates. A commensal in adults, GBS colonization of the vagina or rectum occurs in an estimated 10-30% of pregnant women. Given that thousands of women will be exposed to antibiotics to prevent a single case of newborn GBS sepsis, we aimed to determine if the co-occurrence of GBS with other species of the vaginal microbiome could help explain the disparity between maternal prevalence (10-30%) and early invasive newborn disease (<0.02% at baseline, currently <0.004%). Whole genome shotgun sequencing was performed on vaginal samples (n=201) collected from 60 gravidae during 3rd trimester, delivery, and 4-6 weeks postpartum. All subjects underwent culture-based GBS screening at 36 weeks. Metagenomic classification was performed using MetaPhlAn2 and Centrifuge. BWA was used to map sequence reads to the GBS reference genome 2603V/R. Metagenomics identified GBS in 4/5 and 50/55 subjects with a positive or negative clinical culture, respectively. There was no significant difference in the relative abundance of GBS based on clinical culture status (p>0.05). On average, GBS-classified samples had a two-fold increased genomic coverage compared to samples classified without (Fig.1A). Markov chain modeling of GBS status demonstrated that GBS positive subjects are likely to remain positive at subsequent timepoints (Fig.1B). Probabilistic modeling to examine species co-occurrence revealed numerous significant associations (Fig.1C). A majority represented positive co-occurrences, including with L. iners. Interestingly, a negative co-occurrence was identified with L. crispatus, including at delivery (Fig.1D). Our findings are of marked significance as they demonstrate that GBS is a more common commensal in the vagina than previously estimated. We further establish via Markov modeling a high probability of becoming/staying GBS positive and that keystone vaginal species negatively co-occur with GBS, including with L.crispatus, which has a known protective role in vaginal health. Although we had no cases of neonatal GBS disease in our cohort, future studies leveraging our novel observations may have implications for risk modification or tailoring of indications for GBS prophylaxis in labor.