Article

The accuracy of late antenatal screening cultures in predicting genital GBS colonization at delivery

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Abstract

To determine the accuracy of late antenatal anogenital cultures in predicting group B streptococcal colonization at delivery. Swabs of the vagina and rectum were obtained from 826 women during routine prenatal visits at approximately 35-36 weeks' estimated gestation. The same women were recultured at admission for delivery. Swabs were cultured in broth media. Test performance indices were calculated using culture status at the time of delivery as the reference. Based on the sensitivity and specificity of antenatal cultures derived from analysis of this study population, we estimated predictive values of late antenatal cultures for a range of group B streptococcal carriage rates. Group B streptococci were identified in specimens from 219 of 826 women (26.5%). The sensitivity of late antenatal cultures for identifying colonization status at delivery was 87% (95% confidence interval [95% CI] 83-92). Specificity was 96% (95% CI 95-98). Positive predictive value was 87% (95% CI 83-92), and negative predictive value was 96% (95% CI 95-98). Test performance was similar from 1-5 weeks before delivery, but declined when 6 or more weeks had elapsed between the antenatal culture and delivery. Among patients cultured 6 or more weeks before delivery, sensitivity was only 43%, specificity 85%, and positive and negative predictive values were 50 and 81%, respectively. We estimated positive and negative predictive values of 85 and 97% for a colonization rate of 20%, and 79 and 98% for a colonization rate of 15%. Anogenital cultures in broth media obtained during the late antenatal period are accurate in predicting group B streptococcal colonization status at delivery in term parturients, and they perform significantly (P < .01) better than cultures collected 6 or more weeks before delivery.

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... Although prior studies have compared antepartum and intrapartum cultures, their results have been varied. [10][11][12] Therefore, it was difficult to calculate a sample size based on a proportional difference between the 35 and 37 weeks of culture and the intrapartum culture. We therefore based our sample size calculation on data showing that the 35-to 37week GBS rectovaginal culture relative to rapid tests have a sensitivity of 42.3% (95% CI: 36-49%) and specificity of 100% (95% CI: 99-100%). ...
... A 1996 study of 826 women also screened pregnant women at their 35-to 36-week prenatal care visit, and again at admission for delivery, but demonstrated greater accuracy of the antepartum results compared with intrapartum, revealing a sensitivity of 87%, and specificity of 96%. 11 Additionally, a 2010 systematic review examined the predictive value of antenatal GBS cultures in 8,898 patients in nine prospective and retrospective studies. Their findings included positive predictive values for antenatal cultures ranging from 43 to 100% (mean 69%), and negative predictive values ranging from 80 to 100% (mean 94%). ...
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Objective This study aims to investigate accuracy of group beta Streptococcus (GBS) rectovaginal cultures at 35 to 37 weeks in predicting intrapartum colonization. Study Design Institutional review board (IRB) approved prospective cohort study of 302 women from October 2015 to May 2017. Patients had the following tests for GBS: first trimester urine culture, rectovaginal culture at 35 to 37 weeks, and intrapartum rectovaginal culture. Outcomes included accuracy of 35- to 37-week GBS rectovaginal culture in detecting results intrapartum, and accuracy of first trimester urine culture in comparison to intrapartum rectovaginal cultures. Results There was sufficient evidence of agreement between results at 35 to 37 weeks with intrapartum cultures (p = 0.001). However, agreement was weak, 11 patients (3.7%) were GBS positive intrapartum but negative at 35 to 37 weeks; and 33 patients (11%) were initially GBS positive but were negative intrapartum. Sensitivity and specificity of the 35- to 37-week culture was 69% (95% confidence interval [CI]:54–84%) and 87% (95% CI: 83–91%), respectively. There was also weak agreement between first trimester urine culture and intrapartum rectovaginal culture. Specificity for this assessment was 98% (95% CI: 97–100%) and was significantly different compared with antepartum GBS culture (p < 0.001). Accuracy between antepartum GBS rectovaginal culture and urine culture was similar (85 vs. 87%, p = 0.47). Conclusion The 35- to 37-week GBS rectovaginal culture might be a poor predictor for intrapartum colonization.
... The negative predictive value of an antenatal GBS culture declines if the interval between screening and birth is ≥ 5 weeks [10]. As a consequence, an estimated 12% -13.6% of women receive antibiotics in labour for GBS when they are GBS negative at the time they give birth [11]. While the Centres for Disease Control and Prevention [10] reports that 60% of babies who develop EOGBSD are born to mothers who tested GBS negative at 35 -37 weeks gestation. ...
... For comparing point-of-care Xpert GBS (Cepheid) with culture-based screening at 35 to 37 weeks gestational age we assumed a sensitivity of 90% for culture-based screening [11] and 95% for the point of care test. For a 20% rate of GBS colonisation, power of 80%, and alpha value of 5%, 1155 participants will be required [16]. ...
... Assuming that the universal culture-based screening was 96% specific for GBS colonization at delivery [15], that the percentage of newborns who would be colonized with GBS without administration of IAP was 50%, and that the incidence of EOGBSD was 5.1-10 per 1000 live births depending on absence or presence of risk factors [16], we estimated the anticipated number of EOGBSD who were born to women with negative results of prenatal GBS screening in the public hospitals and Maternal and Child Health Centers, and then compared with the observed numbers. ...
Article
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Objectives: To determine the prevalence of maternal colonization with group B streptococcus (GBS), and early onset GBS disease (EOGBSD) after implementation of universal screening. Methods: This was a three-year retrospective cohort study on universal antenatal rectovaginal culture-based screening and intrapartum antimicrobial prophylaxis (IAP) to colonized women in the public sector in Hong Kong. Routinely collected data including maternal colonization and EOGBSD were retrieved. Results: Of 113,989 GBS screening performed, 21.8% were positive. The colonization rate was higher in the public hospitals (higher risk) than in the Maternal and Child Health Centers (lower risk) (23.7% vs 18.1%, p < .001), while their false negative rates were not greater than expected. Majority of eligible women opted for screening, and colonized women received IAP. There were 29 cases of EOGBSD with clinical signs and a positive blood or cerebrospinal fluid culture. Compared to clinical risk-based screening, EOGBSD incidence decreased after universal screening (1 vs 0.24 per 1000 births, p < .001). Although EOGBSD occurred at a higher rate in preterm than term infants, 86.7% occurred in the latter, and were associated with a false negative screening result (41.3%), lack of screening (20.7%) or unavailability of a colonization result at labour (13.8%). Conclusions: Maternal GBS colonization rate was higher than previously reported, and varied with different risk populations. EOGBSD reduced after universal screening.
... In this case, a color change indicates GBS growth [7]. Unfortunately, this approach has variable sensitivity [8][9][10] and is associated with long turnaround times (18-72 h). A more rapid test that retains high sensitivity and specificity compared to conventional culture-based methods is real-time polymerase chain reaction (qPCR) [11]. ...
Article
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Background: Group B Streptococcus (GBS) is the leading cause of invasive neonatal infection. In this study, we aimed to evaluate the analytical validation of qualitative real-time polymerase chain reaction (qPCR) as a means to detect GBS. Methods: Genomic DNA (gDNA) was purified from 12 ATCC bacterial strains, two belonging to GBS and the remainder acting as negative controls. Additionally, gDNA was isolated from 21 strains of GBS from various serotypes (Ia, Ib and II-VIII). All gDNA was used to evaluate the analytical validation of the qPCR method employing a specific Taqman probe. Inclusivity, exclusivity, anticipated reportable range, the limit of detection and robustness were evaluated. The methods used are described in international guidelines and other existing reports. The performance of this qPCR method for detecting GBS was compared to other microbiological methods used with vaginal-rectal samples from pregnant women. Results: Our qPCR method for detecting GBS was analytically validated. It has a limit of detection of 0.7 GE/μL and 100% analytical specificity. It detects all strains of GBS with the same level of performance as microbiological methods. Conclusion: Data suggest that this qPCR method performs adequately as a means to detect GBS in vaginal-rectal swabs from pregnant women.
... Reportedly, the GBS colonization rate in the gastrointestinal or the genital tracts of pregnant women in the US was 18.6-26.5% [8][9][10], whereas this rate in pregnant Korean women was 2.0-11.5%, which was significantly lower than that in pregnant women in the US [11][12][13][14][15][16][17]. ...
Article
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Objective The purpose of this study was to evaluate the group B streptococcus (GBS) colonization rate in pregnant Korean women using selective culture media for GBS and to identify obstetrical complications and GBS-induced early-onset neonatal sepsis. Methods We evaluated 1,014 pregnant women who delivered at Busan Paik Hospital between January 2015 and December 2016. GBS colonization was assessed using chromID Strepto B agar. We evaluated GBS colonization in pregnant women, as well as the obstetrical complication and GBS-induced neonatal sepsis rates. Results The total GBS colonization rate was 11.6% (117/1,014). No significant increase was observed in the rate of pregnancy-related complications between the GBS-positive and the GBS-negative groups. Among the 134 neonates born to colonized mothers, early neonatal sepsis was reported in 2 neonates (1.5%); however, these were cases of non-GBS-induced sepsis. Conclusion The GBS colonization rate (using selective culture media) in this study involving pregnant Korean women showed a higher colonization rate than that previously reported in Korea. Therefore, based on this study, we recommend GBS screening and the administration of intrapartum antibiotic prophylaxis in pregnant Korean women.
... Although we cannot exclude the possibility of an inadequate antepartum sampling or laboratory error, as reported in prior analyses [7], these errors are unlikely to be disproportionate by race. Future investigations should evaluate the role of these factors in GBS conversion, as well as the differences in the vaginal microbiome that may contribute to a more frequent transient colonization [23,24]. ...
Article
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Objective: To compare the incidence of group B Streptococcus (GBS) conversion from a negative antepartum to a positive intrapartum culture among women who self-identify as non-Hispanic black, Hispanic, or non-Hispanic white. Study design: This was a prospective cohort study of women with a negative rectovaginal GBS culture obtained within 35 days of enrollment. An intrapartum rectovaginal swab was collected and cultured for GBS. Data were compared with chi-square, Fisher's exact, or Wilcoxon rank-sum test. Modified Poisson regression was used. Results: We enrolled 737 women; 75.4% were non-Hispanic white, 17.6% were non-Hispanic black, and 6.9% were Hispanic. Non-Hispanic black women were more likely to convert to GBS positive than non-Hispanic white women, 9.2% as compared to 5.3% (RR: 2.0; 95% CI: 1.02-3.8). Conclusion: The increased incidence of positive intrapartum GBS cultures among non-Hispanic black women suggests that non-Hispanic black race is a risk factor for GBS conversion in the late third trimester.
... Most previous studies on neonatal GBS colonization have not included detailed maternal data, which may have masked some risk factors [3]. Additionally, discordant results were reported and the effect sizes for the identified factors have varied considerably [4][5][6][7][8][9]. For example, the study in Beirut found that there was no significant association between preterm birth and GBS vertical transmission, but a significant association for preterm birth was observed in the France study [10,11]. ...
Article
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Background: The potential factors associated with group B streptococcus (GBS) vertical transmission have not been studied in detail. Study design: A prospective cohort study was conducted to recruit 1815 mother-neonate pairs for GBS analysis. Pearson's chi-squared tests and generalized linear models were used to explore the risk factors for neonatal GBS colonization. Results: The rate of GBS vertical transmission was 14.1%. GBS colonization in all neonates was significantly associated with maternal GBS colonization, mode of delivery, episiotomy, number of prenatal vaginal exams, parity, and hypertension. For neonates born to GBS-positive mothers, GBS vertical transmission was associated with the mode of delivery, episiotomy, and sexually transmitted diseases. For neonates born to GBS-negative mothers, neonatal GBS colonization was associated with the number of prenatal vaginal exams, parity, and hypertension. Conclusion: These findings suggest the need for prenatal GBS screening for pregnant women and intrapartum antimicrobial prophylaxis for GBS-colonized women.
... Actualmente la prueba de oro es el cultivo de muestra recto vaginal en un medio selectivo, la cual consiste en realizar un hisopado de la región perineal que incluya tejido rectal y vaginal y trasladarlo a un medio selectivo que permite el crecimiento del SGB en una muestra polimicrobiana. Este medio selectivo disminuye en un 50% los falsos negativos frente a los cultivos no selectivos, alcanzando a tener una sensibilidad del 87% y una especificidad del 96% (12,13). ...
Article
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Introducción: La infección neonatal por Streptococcus del Grupo B en mujeres gestantes es un problema creciente a nivel mundial y tiene múltiples consecuencias para el recién nacido, su prevención impacta directamente la morbi-mortalidad neonatal. Objetivo: Brindar al lector información relevante sobre la importancia clínica, nuevos métodos de tamizaje y formas de prevención de la infección por Streptococcus del Grupo B en gestantes, que será de utilidad para evitar complicaciones del binomio materno-fetal. Metodología: En esta revisión de la literatura, se estudiaron 53 artículos, abordando evidencia tanto en el ámbito local e internacional, utilizando las bases de datos PubMed, ScienceDirect y Google Scholar, dentro los criterios de búsqueda se tuvo en cuenta el año de publicación, incluyendo artículos que fueron publicados a partir del año 2011. Resultados: La comunidad internacional ha desarrollado guías y planes de prevención; en la actualidad, para una profilaxis y prevención adecuada se proponen diversos métodos, partiendo del tamizaje para las maternas, uso de antibióticos durante el embarazo y parto, además del desarrollo de vacunas maternas para prevenir infecciones. Conclusiones: La colonización por Streptococcus del Grupo B en gestantes y el riesgo que conlleva para el recién nacido y su madre, exige una constante actualización en técnicas de tamizaje, prevención y manejo. Numerosos avances en estos campos vienen llevándose a cabo en los últimos años y su fortalecimiento y desarrollo será clave para impactar positivamente la morbi-mortalidad materno-fetal.
... Additional factors that need to be evaluated include the timing of maternal colonization, and if the colonization density or specific strains of these organisms results in higher rates of neonatal colonization or invasive disease. For example, there can be transient or intermittent GBS colonization of the recto-vaginal tract but colonization assessed at 35e37 weeks is the best predictor of risk for early-onset neonatal infection; it is unclear if this finding would be similar in those mothers colonized with ESBL-Es [25]. Future studies are planned in this population to evaluate for maternal co-morbidities and ESBL-E status throughout pregnancy to help address these questions. ...
Article
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Objectives: The objective of this study was to assess the prevalence of maternal recto-vaginal extended-spectrum β-lactamase producing Enterobacteriacea (ESBL-E) colonization, identify risk factors for maternal and neonatal ESBL-E colonization, and subsequent impact on neonatal mortality. Methods: A prospective, cross-sectional study was conducted at the University of Abuja Teaching Hospital from April 2016 to May 2017. Maternal-neonatal pairs were screened for ESBL-E exposure at time of delivery. Neonatal mortality was assessed at 28 days. Results: A total of 1161 singleton deliveries were evaluated. In total, 9.7% (113/1161) of mothers and 4.3% (50/1161) of infants had ESBL-E-positive cultures at delivery. Maternal antibiotic exposure was associated with ESBL-E recto-vaginal colonization (18.6% (21/113) vs. 8.4% (88/1048), p < 0.001)). Maternal ESBL-E colonization (adjusted odds ratio (AOR) 14.85; 95% CI 7.83-28.15) and vaginal delivery (AOR 6.35; 95% CI 2.63-17.1) were identified as a risk factor for positive ESBL-E neonatal surface cultures. Neonatal positive ESBL-E surface cultures were a risk factor for neonatal mortality (stillbirths included, AOR 4.84; 95% CI 1.44-16.31). The finding that maternal ESBL-E recto-vaginal colonization appeared protective in regards to neonatal mortality (AOR 0.22; 95% CI .06-0.75) requires further evaluation. Conclusions: Maternal ESBL-E recto-vaginal colonization is an independent risk factor for neonatal ESBL-E colonization and neonates with positive ESBL-E surface cultures were identified as having increased risk of neonatal mortality.
... Determination of infection at the time of delivery is essential for neonatal vertical transmission prevention [7], because some women are intermittent carriers of GBS and the rate of GBS colonization may vary during pregnancy [8]. The predictive value of antenatal screening decreases if it is performed more than a few weeks before delivery [9]. Neonatal infections can be prevented in most cases by providing intrapartum antibiotic prophylaxis to the colonized mother [10]. ...
Article
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Background Streptococcus Group B (GBS) colonization in pregnant women is the most important risk factor for newborn disease due to vertical transmission during delivery. GBS colonization during pregnancy has been implicated as a leading cause of perinatal infections. Traditionally, pregnant women are screened for GBS between 35 and 37 weeks of gestation. However, antenatal culture-based screening yields no information on GBS colonization status and offers low predictive value for GBS colonization at delivery. Numerous assays have been evaluated for GBS screening in an attempt to validate a fast and efficient method. The aim of this study was to compare bacteria isolation by culture and two qPCR techniques, targeting sip and cfb genes, respectively, for detecting colonizing GBS. Methods Cultures – the gold-standard technique, a previous qPCR technique targeting the sip gene, and a new proposed qPCR assay targeting the cfb gene were evaluated as diagnostic tools on 320 samples. ResultsConsidering cultures as the gold standard, the evaluated qPCR method detected 75 out of 78 samples, representing a sensitivity of 93.58% (95% confidence interval (CI), 90.89–96.27) and specificity of 94.62% (95% CI, 91.78–97.46). However, an additional analysis was performed for true positives that included not only samples showing positives by culture but samples showing positive for both qPCR assays. The sensitivity and specificity were recalculated including these discrepant samples and a total of 89 samples were considered as positive, giving a prevalence of 27.81%. With this new analysis, the qPCR targeting the cfb gene showed a sensitivity of 95.5% (95% CI, 88.65–98.59) and specificity of 99.13% (95% CI, 96.69–99.97). Conclusions The new qPCR method is a sensitive and specific assay for detecting GBS colonization and represents a valuable tool for identifying candidates for intrapartum antibiotic prophylaxis. Cultures should be retained as the reference and the routine technique because of its specificity and cost analysis ratio, but it would be convenient to introduce PCR techniques to check negative culture samples or when an urgent detection is required to reduce risk of infection among infants.
... 12,13 Missed opportunities for EOGBS prevention exist in both protocols and lead to preventable infant morbidity, while overtreatment, undesirable in the light of rising antibiotic resistance and potential effects on the microbiome, occurs too. [14][15][16][17] Although technical developments such as vaccines or PCR quick tests are promising for EOGBS prevention, they have not been widely implemented. [18][19][20] Improving efficacy of IAP through either of the targeting protocols will help reduce the incidence of EOGBS disease, and may reduce overtreatment. ...
Article
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Background: Early-onset group B streptococcal (EOGBS) disease (including sepsis, meningitis, and pneumonia) causes significant morbidity and mortality in newborn infants worldwide. Antibiotic prophylaxis can prevent vertical streptococcal transmission, yet no uniform criteria to identify eligible women for prophylaxis exist. Some guidelines recommend universal GBS screening to pregnant women in their third trimester (screening-based protocol), while others employ risk-based protocols. Objectives: To compare the effectiveness of screening-based vs risk-based protocols in preventing EOGBS disease. Search strategy: Key words for the database searches included GBS, Streptococcus agalactiae, pregnancy, screening, culture-based, risk-based. Selection criteria: Studies were included if they investigated EOGBS disease incidence in newborn infants and compared screening or risk-based protocols with each other or with controls. Data collection and analysis: Risk ratios (RR) and 95% confidence intervals (CI) were determined using Mantel-Haenszel analyses with random effects. Main results: 17 eligible studies were included. In this meta-analysis , screening was associated with a reduced risk against EOGBS disease compared either with risk-based protocols (10 studies, RR 0.43, 95% CI 0.32-0.56), or with no policy (4 studies, RR 0.31 95% CI 0.11-0.84). Meta-analysis could not demonstrate a significant effect of risk-based protocols vs. no policy (7 studies, RR 0.86, 95% CI 0.61-1.20). In studies reporting on the use of antibiotics, screening was not associated with higher antibiotic administration rates (31% vs 29%). Conclusions: Screening-based protocols were associated with lower incidences of EOGBS disease compared to risk-based protocols, while not clearly overexposing women to antibiotics. This information is of relevance for future policymaking.
... The current gold standard for GBS detection is enrichment of the primary specimen, a vaginal-rectal swab, followed by subculture onto a blood agar plate with phenotypic characterization [1]. This gold standard method has a long turnaround time, and sensitivity is only 54-87% [8,9]. Furthermore, bacterial culture requires an experienced technician to further identify and test characteristics of GBS such as agglutination and beta hemolysis [1]. ...
Article
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Background: Group B Streptococcal (GBS) infections in the United States are a leading cause of meningitis and sepsis in newborns. The CDC therefore recommends GBS screening for all pregnant women at 35-37 weeks of gestation and administration of intrapartum prophylaxis (in those that tested positive) as an effective means of controlling disease transmission. Several FDA approved molecular diagnostic tests are available for rapid and accurate detection of GBS in antepartum women. Method: In this study, we report a clinical comparison of the Xpert GBS LB assay and a novel FDA-cleared test, Revogene GBS LB assay. A total of 250 vaginal-rectal swabs from women undergoing prenatal screening were submitted to the University of Wisconsin's clinical microbiology laboratory for GBS testing. Results: We found 96.8% of samples were concordant between the two tests, while 3.2% were discordant with a positive percent agreement of 98.0% and a negative percent agreement of 96.5% between the Revogene GBS LB assay and the GeneXpert GBS LB assay. Conclusion: Overall, we report that both assays perform well for the detection of GBS colonization in pregnant women.
... Vaginorectal samples are enriched in Todd-Hewitt broth with colistin and nalidixic acid (Lim broth) or other suitable media for 18 to 24 h, followed by inoculation on sheep's blood agar (SBA), identification of GBS-like colonies, and confirmation by agglutination testing for streptococcus grouping or by the CAMP test (4,5). The entire protocol has several limitations, including the time from enrichment to the subjective identification of colonies on SBA and the relatively low sensitivity of culture, which ranges from 54 to 90% (6)(7)(8)(9). Identification of GBS colonies is based on the presence of gray pigmentation or beta-hemolysis; however, approximately 5% of all GBS strains are nonhemolytic and/or nonpigmented (NHNP) and are still capable of causing invasive disease in neonates (10). Chromogenic agars have been developed to improve the culture-based identification of GBS; however, they also have poor sensitivity, and some of them can miss NHNP GBS colonies (11). ...
Article
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Vertical transmission of Group B streptococcus (GBS) causing neonatal sepsis is one of the leading reasons for neonatal mortality worldwide. The gold standard for GBS detection is enriched culture, with or without the aid of chromogenic agars. Given the high risk for morbidity and mortality in this population, high assay sensitivity is required to prevent the personal and economic costs of GBS disease. Nucleic acid amplification tests (NAATs) allow for objective determination of GBS colonization with higher sensitivity and specificity than traditional culture methods. In this study, we determined the analytical and clinical performance of the ARIES® GBS Assay, compared to enrichment culture and biochemical identification, and NAATs used at the study sites. Remnant Lim broth samples were used to perform the ARIES® assay and reference testing. Upon first testing using enriched culture as reference standard, the ARIES® GBS Assay identified GBS with 96.1% sensitivity (95% CI, 91.2-98.3) and 91.4% specificity (95%CI, 88.8-93.5%). The test performed with 100% positive agreement (83.2-100%) compared to the BD MAX™ GBS Assay and 98.0% (89.2-99.9%) compared to the Cepheid Xpert® GBS LB test. Repeatability and reproducibility was maintained in intra- and inter-laboratory testing, regardless of the instrument, module or user who performed the test. The ARIES® GBS Assay can be set up in less than five minutes, and produces results in two hours. The easy set-up, with minimal hands-on time, and high assay sensitivity and specificity make this a useful testing option for GBS screening in pre-partum women.
... In addition, some women may contract GBS after the initial third trimester screening. A study by Yancey et al. performed rectovaginal cultures on 826 women between 33 and 39 weeks' gestation and then again at delivery and found that four percent of the women with negative antenatal cultures were colonized at delivery [14]. It is possible that the mother in this case was a GBS carrier who had a false negative test or contracted GBS later in her pregnancy. ...
Article
Group B Streptococcus (Streptococcus agalactiae or GBS) infections are known as a leading cause of morbidity and mortality in the neonatal population. The role of water birth in colonizing and transmitting GBS between mother and infant is unclear. We present a case of an exclusively breastfed full-term infant, born via water birth, to a GBS-negative woman who developed GBS mastitis. The infant presented with severe, late-onset GBS meningitis/septic shock and subsequently developed fatal necrotizing enterocolitis. Literature regarding the potential role of water birth in GBS transmission is reviewed.
... This may be due to the fact that S. agalactiae colonization was intermittent (Hansen et al. 2004;Feuerschuette et al. 2018). When antenatal screening conducted more than a certain time before delivery could not effectively predict the risk of infection (Yancey et al. 1996). Therefore, rapid screening techniques at the time of delivery were needed to do to prevent the occurrence of serious early-onset disease. ...
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Streptococcus agalactiae (S. agalactiae) is an important pathogen that can lead to neonatus and mother infection. The current existing techniques for the identification of S. agalactiae are limited by accuracy, speed and high-cost. Therefore, a new multiple cross displacement amplification (MCDA) assay was developed for test of the target pathogen immediately from vaginal and rectal swabs. MCDA primers screening were conducted targeting S. agalactiae pcsB gene, and one set of MCDA primers with better rapidity and efficiency was selected for establishing the S. agalactiae-MCDA assay. As a result, the MCDA method could be completed at a constant temperature of 61 °C, without the requirement of special equipment. The detection limit is 250 fg (31.5 copies) per reaction, all S. agalactiae strains displayed positive results, but not for non-S. agalactiae strains. The visual MCDA assay detected 16 positive samples from 200 clinical specimen, which were also detected positive by enrichment/qPCR. While the CHROMagar culture detected 6 positive samples. Thus, the MCDA assay is prefer to enrichment/qPCR and culture for detecting S. agalactiae from clinical specimen. Particularly, the whole test of MCDA takes about 63.1 min, including sample collection (3 min), DNA preparation (15 min), MCDA reaction (45 min) and result reporting (6 s). In addition, the cost was very economic, with only US$ 4.9. These results indicated that our S. agalaciae-MCDA assay is a rapid, sensitive and cost-efficient technique for target pathogen detection, and is more suitable than conventional assays for an urgent detection, especially for 'on-site' laboratories and resource-constrained settings.
... pregnant women. 103,104 Finally, the authors caution that more studies are needed to demonstrate if the benefits are worth the potential risks and if parents do choose to perform vaginal seeding, they are advised to disclose this information to their healthcare providers. ...
Article
Microbial colonization of the gastrointestinal tract is an essential process that modulates host physiology and immunity. Recently, researchers have begun to understand how and when these microorganisms colonize the gut and the early-life factors that impact their natural ecological establishment. The vertical transmission of maternal microbes to the offspring is a critical factor for host immune and metabolic development. Increasing evidence also points to a role in the wiring of the gut-brain axis. This process may be altered by various factors such as mode of delivery, gestational age at birth, the use of antibiotics in early life, infant feeding, and hygiene practices. In fact, these early exposures that impact the intestinal microbiota have been associated with the development of diseases such as obesity, type 1 diabetes, asthma, allergies, and even neurodevelopmental disorders. The present review summarizes the impact of cesarean birth on the gut microbiome and the health status of the developing infant and discusses possible preventative and restorative strategies to compensate for early-life microbial perturbations.
... It is recognised that screening swabs taken before 6 weeks of birth fail to accurately predict GBS carriage at birth in >50% of women. 28 Following the introduction of screening-based IAP, the EOGBS rate our maternity service fell to a lower rate than 0.42/1000 live births reported by the Public Health England in 2014. 26 In this study, the number of women needed to screen to prevent one case of invasive EOGBS infection was 1459 (95% CI 831 to 5984). ...
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Background Against a background of failure to prevent neonatal invasive early-onset group B Streptococcus infections (GBS) in our maternity unit using risk-based approach for intrapartum antibiotic prophylaxis, we introduced an antenatal GBS carriage screening programme to identify additional women to target for prophylaxis. Objectives To describe the implementation and outcome of an antepartum screening programme for prevention of invasive early-onset GBS infection in a UK maternity unit. Design Observational study of outcome of screening programme (intervention) with comparison to historical controls (preintervention). Setting Hospital and community-based maternity services provided by Northwick Park and Central Middlesex Hospitals in North West London. Participants Women who gave birth between March 2014 and December 2015 at Northwick Park Hospital. Methods Women were screened for GBS at 35–37 weeks and carriers offered intrapartum antibiotic prophylaxis. Screening programme was first introduced in hospital (March 2014) and then in community (August 2014). Compliance was audited by review of randomly selected case records. Invasive early-onset GBS infections were defined through GBS being cultured from neonatal blood, cerebrospinal fluid or sterile fluids within 0–6 days of birth. Main outcome Incidence of early-onset GBS infections. Results 6309 (69%) of the 9098 eligible women were tested. Screening rate improved progressively from 42% in 2014 to 75% in 2015. Audit showed that 98% of women accepted the offer of screening. Recto-vaginal GBS carriage rate was 29.4% (1822/6193). All strains were susceptible to penicillin but 11.3% (206/1822) were resistant to clindamycin. Early onset GBS rate fell from 0.99/1000 live births (25/25276) in the prescreening period to 0.33/1000 in the screening period (Rate Ratio=0.33; p=0.08). In the subset of mothers actually screened, the rate was 0.16/1000 live births (1/6309), (Rate Ratio=0.16; p<0.05). Conclusions Our findings confirm that an antenatal screening programme for prevention of early-onset GBS infection can be implemented in a UK maternity setting and is associated with a fall in infection rates.
... With regard to the accuracy of prenatal cultures in predicting intrapartum GBS colonization, rectovaginal prepartum screening showed a PPV and a NPV (76.9 % and 95.4 %, respectively) that were equivalent to those communicated by other authors, ranging from 67 to 87 % for PPV and from 88 to 96 % for NPV [8,[26][27][28][29][30][31]. The PPV and NPV of GBS bacteriuria during the current pregnancy for our cohort were 59.3 and 89.5 %, respectively. ...
Article
Purpose: Current evidence is inconclusive regarding the intrapartum administration of chemoprophylaxis, merely based on the presence of group B streptococcal (GBS) bacteriuria of any colony count, in the prevention of early-onset neonatal GBS infection. The aim of this study was to assess whether GBS bacteriuria is a risk factor for intrapartum colonization (IPC) regardless of urinary concentration or the results of late third-trimester rectovaginal screening cultures (RVSCs). Methodology: Six hundred and eight pregnant women, with urine specimens cultured between May 2011 and May 2013, were enrolled in this prospective cohort study. RVSCs were available for 582 women and intrapartum rectovaginal cultures for 246. Results: The prevalence of GBS bacteriuria and positive RVSCs was 10.8 and 16.5 %, respectively. The frequency of IPC was 15.9 % (39/246). Sensitivity, specificity, positive and negative predictive values of urine culture and of RVSC in predicting GBS IPC were 41, 94.7, 59.3 and 89.5 %, and 76.9, 95.4, 76.9 and 95.4 %, respectively. GBS bacteriuria was significantly associated with IPC, overall [relative risk (RR) 5.6] and in women with negative RVSC (RR 8.5), with bacteriuria <104 c.f.u. ml-1 (RR 5.9) or when both circumstances coexisted (RR 8.9). The urinary colony count was <104 c.f.u. ml-1 in 13 of the 16 women with GBS bacteriuria and IPC. Conclusion: GBS bacteriuria is a risk factor for IPC, irrespective of urinary GBS concentration or of colonization status at late gestation. Therefore, microbiology laboratories should search, and report, GBS of any colony count in urine from pregnant women, and not only in the presence of ≥104 c.f.u. ml-1 as the 2010 CDC guidelines recommend.
... Afterwards, repeating a negative GBS test may be reasonable [19]. These recommendations come from a single study, which correlates test-to-delivery interval with test performance [33]. The study reports decline in positive and negative predictive values if test-delivery interval increases from 5 weeks to 6 or more weeks (88-43%, 95-80%, respectively). ...
Article
Rectovaginal colonization with group B streptococcus (GBS) is commonly encountered in pregnancy. GBS is the most common cause of early onset neonatal sepsis, which is associated with 12% case-fatality rate. Although screening protocols and prophylactic treatment are readily available worldwide, practice in low-resource countries is challenged by lack of awareness and limited implementation of these protocols. In addition, antibiotic susceptibility pattern may vary globally owing to different regulations of antibiotic prescription or prevalence of certain bacterial serotypes. This guideline appraises current evidence on screening and management of GBS colonization in pregnancy particularly in low-resource settings.
... Group B Streptococcus (GBS or S.agalactiae) is a major cause of life-threatening infections in susceptible hosts such as newborn infants, pregnant women and adults with underlying diseases such as diabetes mellitus, cancer, and heart disease (1,2). In USA, approximately 10-30% of pregnant women are colonized by GBS in the vagina and rectum (3)(4)(5). Recto-vaginal colonization of the mother at the time of birth is the primary risk factor for invasive disease in newborns (3,6). Neonatal infections are divided into early-onset disease (EOD) and late-onset disease (LOD) based on infants' age and disease manifestation (1,3,6). ...
Article
Full-text available
Background: Group B Streptococcus (GBS or S. agalactiae) is a major cause of severe disease in neonates. In perinatal infections or early-onset disease (EOD), GBS is transmitted vertically to the newborn from the birth canal during labor and delivery. Limited information is available on the prevalence of GBS recto-vaginal colonization among pregnant women in Iran. Methods: We performed a systematic search by using different electronic databases including: Medline (via Pubmed), Embase, Web of Science, and Iranian Database. Meta-analysis was performed by Comprehensive Meta-Analysis (Biostat V2.2) software. Results: Of 250 articles published from January 2000 to September 2016, 25 studies which reported incidence of GBS colonization in pregnant women were included in this review. The meta-analyses showed that the prevalence of GBS colonization among Iranian pregnant women was 9.8% (95% confidence interval [95% CI] 7.9-12). Conclusion: The results of this study indicates that GBS screening measures and chemoprophylaxis guidelines concerning GBS infections must be established for pregnant women in Iran and these guidelines must provide guidance for obstetricians, midwives and neonatologists on the prevention of GBS infections.
... Other limitations include differences across studies in the timing of swabs. Screening later in pregnancy is more predictive of GBS colonization during labor and therefore of the risk of neonatal invasive disease [44,51,60]. This review demonstrated a marginally higher prevalence in studies with sampling before 35 [39][40][41][42][43][44][45][46][47][48][49][50][51][52][61][62][63][64]. ...
Article
Full-text available
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.
... The current gold standard for GBS detection is enrichment of the primary specimen, a vaginal-rectal swab, followed by subculture onto a blood agar plate with phenotypic characterization (1). This gold standard method has a long turnaround time, and sensitivity is only 54-87% (8,9). Furthermore, bacterial culture requires an experienced technician to further identify and test characteristics of GBS such as agglutination and beta hemolysis (1). ...
Preprint
Full-text available
Background: Group B Streptococcal (GBS) infections in the United States are a leading cause of meningitis and sepsis in newborns. The CDC, therefore recommends GBS screening for all pregnant women at 35–37 weeks of gestation and administration of intrapartum prophylaxis (in those that tested positive) as an effective means of controlling disease transmission. Several FDA approved molecular diagnostic tests are available for rapid and accurate detection of GBS in antepartum women. Method: In this study, we report a clinical comparison of the Xpert GBS LB assay and a novel FDA-cleared test, Revogene GBS LB assay. A total of 250 vaginal-rectal swabs from women undergoing prenatal screening were submitted to the University of Wisconsin’s clinical microbiology laboratory for GBS testing. Results: We found 96.8% of samples were concordant between the two tests, while 3.2% were discordant with a positive percent agreement of 98.0% and a negative percent agreement of 96.5% between the Revogene GBS LB assay and the GeneXpert GBS LB assay. Conclusion: Overall, we report that both assays perform well for the detection of GBS colonization in pregnant women.
... In agreement with these statistics, sample collection from both rectal and vaginal sites has been shown to be the most reliable screening method for GBS colonization (Dillon et al., 1982). Sample collection and analysis at 1 to 5 weeks before delivery is fairly accurate for predicting colonization status at delivery (Yancey et al., 1996), and is generally recommended as prevention methods. ...
Thesis
Streptococcus agalactiae (also known as Group B Streptococcus, GBS) is an opportunistic Gram-positive pathogen responsible for severe invasive infections, especially in neonates. GBS strains belonging to the ST-17 sequence type are responsible for 80% of late-onset neonatal meningitis. Genomic comparison of ST-17 strains to non-ST-17 GBS isolates revealed a few surface proteins that are characteristic of ST-17 clone, such as HvgA and Srr2, which contribute to colonization and dissemination. Similarly, the PI-2b type pilus is conserved in ST-17 strains and the main goal of this PhD project was to decipher the role of this pilus in the physiopathology of ST-17 strains. In the first part of this work, we compared the expression of the PI-2b pilus in our ST-17 representative strain BM110, and a non-ST-17 human clinical isolate, A909. We showed that PI-2b expression, although variable, was lower in ST-17 isolates as compared to non ST17 isolates. In the representative strain BM110, we demonstrated that the lower expression was be due to the presence of a 43-base pair (bp) hairpin-like structure in the upstream region of PI-2b, preventing read-through transcription from upstream antigen B (AgB) operon. Furthermore, gene reporter assays to characterize the Ppi-2b promoter region revealed the requirement of an extended 5’ region and of GBS-specific regulatory factors to drive PI-2b transcription. PI-2b transcription was shown to be maximal at 37 °C. Collectively our results suggest a complex regulation of PI-2b expression in ST-17 clinical isolates, that may confer a selective advantage in the human host either by reducing host immune responses and/or increasing their dissemination potential.In the second part of this work, we sought to investigate the role of the putative adhesin AP1-2b, and the two accessory genes lep and orf in the biosynthesis of PI-2b pilus. We showed that both orf and lep are important for PI-2b expression. Our results suggest that Lep is a functional signal peptidase involved in the optimal processing of the major PI-2b pilin. The role of orf remains to be uncovered
Article
Objective: Chorioamnionitis is associated with an increased risk of cesarean delivery and uterine atony. We hypothesized that the onset of maternal fever is temporally associated with decreased uterine contractility. Study design: Retrospective cohort. Setting: Academic center. Patients: Term participants who developed a fever in the setting of an intrauterine pressure catheter. Main outcome measure: Montevideo units (MVUs) and oxytocin dose at time 0 (first oral temperature ≥38°C) and in the five 1--hour blocks preceding and following T0. Analysis: Montevideo units relative to the onset of fever. Results were adjusted for oxytocin dose and parity in a mixed-effects model. Results: One hundred participants were included. Uterine contractility was maintained for 2 hours after the onset of maternal fever but thereafter significantly and steadily declined by an average of 6.9 ± 3.2 MVU/h ( P = .03), despite the absence of a parallel decline in oxytocin exposure. Multiparas and nulliparas showed a similar pattern of waning uterine contractility. Patients who delivered vaginally maintained contractility, while those who delivered via cesarean had diminishing contractility ( P = .01). The postpartum hemorrhage (PPH) rate (postpartum bleeding requiring treatment) was 32%. Conclusions: A decline in myometrial contractility occurs 2 hours following the onset of maternal fever. Increased risk of cesarean delivery appears to be directly associated with waning uterine contractility and decreased uterine responsiveness to oxytocin. Clinically, close attention should be given to maintaining adequate uterine contractions following a diagnosis of suspected chorioamnionitis. The likelihood of successful vaginal delivery may decrease over time, and the risk of PPH is clinically significant.
Article
Background, presentation and outcomes GBS is a naturally occurring bacterium, carried in the vagina and lower intestine of approximately 20-25% of women in the UK (Daniels et al, 2011), without causing symptoms or harm to the carrier. Two-thirds of infected babies present with early-onset GBS (EOGBS) at 0-6 days and the rest present with late-onset GBS (LOGBS) at 7-90 days (Heath, 2016). EOGBS is more likely to present as sepsis and pneumonia, typically in the first day of life, caused by materno-fetal transmission around birth. The risk of EOGBS is considerably reduced by intrapartum antimicrobial prophylaxis (IAP) in labour (Lin et al, 2001). Worldwide, an estimated 205 000 babies developed EOGBS in 2015 (Seale et al, 2017). LOGBS is more likely to present as meningitis and sepsis, and the source of the bacteria causing disease may be the mother, the environment or other sources. LOGBS is not preventable by IAP (Jordan et al, 2008). LOGBS is uncommon after 4 weeks of age and almost unknown after 12 weeks. Worldwide, an estimated 114 000 babies developed LOGBS in 2015 (Jordan et al, 2008) Other GBS infections are a recognised cause of invasive disease in peripartum women, fetal infections, stillbirth and preterm labour. While most babies recover from their GBS infection, in 2015, an estimated 90 000 died and 10 000 survived with disability worldwide (Seale et al, 2017).
Article
Full-text available
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.
Article
Objective: To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes. Outcomes: Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use. Neonatal outcomes of rates of early-onset group B streptococcal infections are evaluated. Evidence: Published literature was retrieved through searches of MEDLINE, CINAHL, and The Cochrane Library from January 1980 to July 2012 using appropriate controlled vocabulary and key words (group B streptococcus, antibiotic therapy, infection, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to May 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values: The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Benefits, harms, and costs: The recommendations in this guideline are designed to help clinicians identify and manage pregnancies at risk for neonatal group B streptococcal disease to optimize maternal and perinatal outcomes. No cost-benefit analysis is provided. Summary statement: There is good evidence based on randomized control trial data that in women with pre-labour rupture of membranes at term who are colonized with group B streptococcus, rates of neonatal infection are reduced with induction of labour (I). There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation. Recommendations:
Article
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Хронічна попереково-крижова радикулопатія професійного генезу є однією з основних причин стійкої втрати працездатності в усьому світі. Наведено сучасні уявлення про термінологію, епідеміологію, механізми розвитку, клінічних особливостей, методів діагностики та формулювання діагнозу, що грунтуються на принципах доказової медицини.
Article
Résumé Objectif Analyser les données issues de la littérature et formuler des recommandations sur la prise en charge des parturientes en vue de prévenir l'infection néonatale à streptocoques du groupe B d'apparition précoce. Parmi les révisions clés que renferme la présente directive clinique mise à jour, on trouve des modifications quant aux recommandations en ce qui concerne les schémas posologiques d'antibioprophylaxie, les épreuves de sensibilité et la prise en charge des femmes présentant une rupture prématurée des membranes. Issues Parmi les issues maternelles évaluées, on trouvait l'exposition aux antibiotiques au cours de la grossesse et du travail, ainsi que les complications associées à l'administration d'antibiotiques. Les issues néonatales associées aux taux d'infection néonatale à streptocoques du groupe B d'apparition précoce ont été évaluées. Résultats La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, CINAHL et The Cochrane Library entre janvier 1980 et juillet 2012, au moyen d'un vocabulaire contrôlé et de mots clés appropriés (« group B streptococcus », « antibiotic therapy », « infection », « prevention »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en mai 2013. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. Valeurs La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs ( Tableau 1 ). Avantages, désavantages et coûts Les recommandations que renferme la présente directive clinique sont conçues de façon à aider les cliniciens à identifier et à assurer la prise en charge des grossesses exposées à un risque d'infection néonatale à streptocoques du groupe B, en vue d'optimiser les issues maternelles et périnatales. Aucune analyse de rentabilité n'est fournie. Déclaration sommaire Nous disposons de bonnes données (issues d'essais comparatifs randomisés) indiquant que, chez les femmes présentant une rupture prématurée des membranes à terme qui sont colonisées par des streptocoques du groupe B, le déclenchement du travail entraîne une baisse des taux d'infection néonatale (I). Aucune donnée ne permet de soutenir que, dans une telle situation clinique, la prise en charge non interventionniste permet l'obtention de bonnes issues néonatales. Recommandations • 1.Offrir, à toutes les femmes, un dépistage de la colonisation par des streptocoques du groupe B à 35 - 37 semaines de gestation au moyen d'une mise en culture effectuée à partir d'un écouvillonnage du vagin, en premier lieu, et du rectum par la suite (au-delà du sphincter anal). (II-1A) Cette approche s'applique également aux femmes chez qui une césarienne est planifiée, et ce, en raison de leur risque de connaître un travail ou une rupture des membranes avant la date prévue de la césarienne (II-2B). • 2.En raison de l'association entre une forte colonisation et l'infection néonatale d'apparition précoce, administrer une antibioprophylaxie intraveineuse visant les streptocoques du groupe B dans les cas suivants, au moment de l'apparition du travail ou de la rupture des membranes: • •toutes les femmes ayant obtenu des résultats positifs (indiquant la présence de streptocoques du groupe B) dans le cadre du dépi- stage par mise en culture d'un écouvillonnage vaginal / rectal mené à 35 - 37 semaines de gestation (II-2B); • •toute femme ayant déjà accouché d'un enfant présentant une infection à streptocoques du groupe B (II-3B); • •toute femme ayant présenté une bactériurie à streptocoques du groupe B documentée (peu importe le taux d'unités formatrices de colonies) dans le cadre de la grossesse en cours (II-2A). • 3.Administrer une antibioprophylaxie intraveineuse visant les strep- tocoques du groupe B pendant un minimum de 48 heures à toutes les femmes se trouvant à < 37 semaines de gestation et con- naissant un travail ou une rupture des membranes, sauf lorsqu'un résultat négatif a été obtenu au cours des cinq semaines précé- dentes dans le cadre d'un test rapide fondé sur les acides nucléi- ques ou d'un dépistage par mise en culture d'un écouvillonnage vaginal / rectal (II-3A). • 4.Administrer (par voie intraveineuse) des antibiotiques à large spectre ciblant la chorioamnionite et les streptocoques du groupe B à toutes les femmes qui présentent une fièvre intra- partum et des symptômes de chorioamnionite (sans égard à l'âge gestationnel ni à l'état quant aux streptocoques du groupe B) (II-2A). • 5.Demander la tenue d'une épreuve de sensibilité aux antibiotiques chez les femmes qui ont obtenu des résultats positifs en ce qui concerne la présence de streptocoques du groupe B, à la suite d'un dépistage urinaire et de la mise en culture d'un écouvillonnage vaginal/rectal, et que l'on soupçonne être exposées à un risque considérable d'anaphylaxie attribuable à la pénicilline (II-1A). • 6.Lorsqu'une femme présentant une rupture prématurée des mem- branes ≥ 37 semaines de gestation obtient des résultats positifs (au dépistage par mise en culture d'un écouvillonnage vaginal / rectal) indiquant la présence de streptocoques du groupe B, qu'elle a connu une bactériurie à streptocoques du groupe B pendant la grossesse en cours ou qu'elle a déjà accouché d'un enfant atteint d'une infection à streptocoques du groupe B, administrer une anti- bioprophylaxie intraveineuse visant les streptocoques du groupe B. La tenue immédiate d'un accouchement obstétrical (tel que le déclenchement du travail) s'avère indiquée, comme le décrit la directive clinique intitulée « Déclenchement du travail » qui a été publiée par la Société des obstétriciens et gynécologues du Canada en septembre 2013 (II-2B). • 7.À 2 37 semaines de gestation, lorsque le statut quant à la coloni- sation par des streptocoques du groupe B est inconnu, qu'une mise en culture n'a pas été menée à 35 - 37 semaines de gestation (ou que les résultats d'une telle mise en culture ne sont pas disponibles) et que les membranes sont rompues depuis plus de 18 heures, administrer une antibioprophylaxie intraveineuse visant les strepto- coques du groupe B (II-2B). • 8.Lorsque, chez une femme présentant une rupture prématurée des membranes à < 37 semaines de gestation, les résultats du dépi- stage des streptocoques du groupe B par mise en culture sont inconnus ou positifs, administrer une antibioprophylaxie intra- veineuse visant les streptocoques du groupe B pendant 48 heures, ainsi que d'autres antibiotiques lorsque cela s'avère indiqué, en attendant la mise en œuvre spontanée ou obstétricalement indiquée du travail (II-3B).
Article
Background: How best to target intrapartum antibiotic prophylaxis (IAP) to minimise both Early-Onset Group B Streptococcus (EOGBS) neonatal infection and maternal/fetal antibiotic exposure is uncertain, with both routine-screening and risk-factor approaches available. Aims: This retrospective cohort study was undertaken to examine the outcomes of a hybrid risk-and-screen approach to EOGBS prevention using GBS polymerase chain reaction (PCR). The target population was women with term prelabour rupture of membranes (TermPROM) having the risk factor of prolonged rupture of membranes (ROM) ≥18 h. Materials and methods: Non-labouring TermPROM women had rapid GBS PCR testing at presentation. GBS screen-positive women proceeded to induction of labour and received IAP. GBS screen-negative women were allowed home to await spontaneous labour and not given IAP regardless of duration of ROM, unless other risk factors developed. For all other women, the risk-factor approach was followed. Results: From 2009 to 2018, there were 20 cases of culture-positive EOGBS, a rate of 0.36/1000 live births (95% CI 0.22-0.56/1000), comparable to other recent reports. Over 2010-2018 when laboratory data were available, 1120 TermPROM women with ROM ≥18 h avoided antibiotics because they were GBS PCR-negative (2.3% of all births, 3.6% of vaginal births) while 338 TermPROM women with ROM <18 h received targeted antibiotics for being GBS-positive. No cases of EOGBS occurred in TermPROM women, those with ROM ≥18 h, or due to protocol-compliance failure. Conclusions: A hybrid approach involving risk-factor-based IAP and intrapartum GBS PCR screening of non-labouring TermPROM women delivers acceptably low rates of EOGBS while minimising and better targeting antibiotic exposure.
Article
Introduction Streptococcus agalactiae, a species of β-haemolytic streptococcus belonging to Lancefield’s group B (GBS), is known as a common infecting agent transmitted to infants during childbirth, causing sepsis, meningitis, or both, with a high incidence of mortality. Following the observation of a great variability between regional laboratories both in the methodology and in the results of tests for the detection of GBS in pregnancy, with high percentages of false negative results, in 2010 the Department for Health Policies of Piedmont, Italian region, issued specific recommendations for adhere to international guidelines. Our aim was to assess whether the impact of the publication of the recommendations has been lasting over time. Methods We analyzed the regional birth certificate register from 2006 to 2018, to evaluate the annual number of deliveries, the number of Streptococcus agalactiae tests in pregnancy and the percentage of positive culture results. We also evaluated the consistency of the percentage of positive tests with the expectations based on the guidelines and compared the two time periods before and after introduction of regional recommendations using a multivariate regression model. Results The mean proportion of women tested for GBS vaginal-rectal swabs during pregnancy increased from 83.5% in 2006 to 90.7% in 2018 with the biggest rise in 2010, the t-test for the comparison of the two means was statistically significant (p < .001). The mean positivity rate increased from 12.7% to 19.2%, with a rise in 2010, with a significant t-test (p < .001). Conclusion The results suggested a significant impact of the recommendations on the compliance and results regarding the carrying out and culture of vagino-rectal swabs for GBS, with better appropriateness of peripartum antibiotic therapy and possible reduction of GBS related neonatal sepsis.
Article
Streptococcus agalactiae, also known as group B Streptococcus, is a species of bacteria occasionally detected in the vagina and/or rectum of pregnant women. This report describes the case of a 33‐year‐old woman who developed infective endocarditis on puerperal day 17, owing to group B Streptococcus, and required lifesaving surgery. The patient was rushed to our hospital with chief complaints of fever and fatigue. After hospitalization, antibiotics were administered; however, the symptoms did not improve. Following a detailed examination, vegetation was found in the heart, suggestive of infective endocarditis. Surgical removal of the vegetation improved the patient's condition. The development of group B Streptococcus infection and infective endocarditis in a pregnant woman with no risk factors is rare. This case confirms that this patient's life was saved by a timely diagnosis and appropriate therapeutic intervention.
Article
Objective To compare various screening tests used in obstetrics and gynecology based upon their prevalence thresholds. We define the prevalence threshold as the prevalence level below which a test’s positive predictive value (PPV) declines most sharply relative to disease prevalence – and thus the rate of false positive results/false discovery rate increases most rapidly. Methods We searched Medline, EMBASE, Google Scholar, Scopus, ISI Web of Science, Cochrane database, and PubMed to obtain the sensitivity and specificity estimates for the following screening tests: 50 g-oral glucose tolerance test (GDM-50 g), non-invasive prenatal testing (NIPT), combined first trimester screening (FTS), vagino-rectal swab for group B streptococcus (GBS) in pregnancy, cervical cytology (Pap) and HPV testing, mammography and manual breast exam, urinary PCR and cervical-vaginal swab testing for gonorrhoea and chlamydia. We used these estimates to calculate disease-specific prevalence thresholds, comparing them to the actual estimates of disease prevalence. Results The prevalence thresholds and average estimates of disease prevalence (shown in brackets) are as follows: GDM-50 g 31% (6%), NIPT 7% (0.2%), combined FTS 19.5% (0.2%), GBS swab 18% (15-45%), Pap 21% (0.2%), HPV 27% (0.2%), mammography 25% (12.5%), breast exam 25% (12.5%), gonorrhea-chlamydia 6-13% (4.2-4.7%). Conclusion The prevalence thresholds of various screening tests used in obstetrics and gynecology are well above the estimated disease prevalence. This implies that when undertaking population-level screening a significant proportion of positive screening tests obtained are likely false-positives. Attempts at individualizing pre-test probability when undertaking population-level screening are needed in order to minimize the false positive rates of screening tests.
Article
Objective: To compare maternal and cord blood penicillin concentrations in women with and without obesity who are receiving intrapartum group B streptococcus (GBS) prophylaxis. Methods: We performed a prospective cohort study of term women receiving intrapartum penicillin prophylaxis for GBS colonization (determined by antenatal rectovaginal culture). The following outcomes were compared between obese (body mass index [BMI] 35 or higher at delivery) and nonobese (BMI less than 30 at delivery) groups: penicillin concentration in maternal blood (after two penicillin doses) and umbilical cord blood, GBS rectovaginal colonization status on admission and after two completed doses, and neonatal GBS colonization (using a postnatal ear swab). Fifty-five women were needed to detect a 0.75 SD difference in cord blood penicillin concentrations. Results: Fifty-five women were enrolled and had all specimens collected; 49 had complete data for analysis (obese n=25, nonobese n=24). There was no difference in the median maternal penicillin concentration between groups (obese 4.2 micrograms/mL vs nonobese 4.0 micrograms/mL, P=.58). There was, however, a 60% lower median cord blood penicillin concentration in the obese compared with the nonobese group (2.7 micrograms/mL vs 6.7 micrograms/mL, respectively, P<.01), with no significant difference in time from last penicillin dose to delivery (obese 2.9 hours vs nonobese 1.7 hours, P=.07). The difference in cord blood concentrations remained significant after adjustment for nulliparity, hypertensive disorders, and time from last penicillin dose to delivery. Only 59.6% of women tested positive for GBS by rectovaginal culture on admission (obese 60.9% vs nonobese 58.3%, P=.86). Conclusion: The median cord blood penicillin concentration was 60% lower in neonates born to women with obesity compared with those born to women without obesity. However, all concentrations exceeded the minimum inhibitory concentration. Maternal penicillin levels were not significantly different between groups. More than 40% of women who previously tested positive for GBS by antenatal culture tested negative for GBS on admission for delivery.
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Group B Streptococcus, a common commensal in the gut of humans and in the lower genital tract in women, remains an important cause of neonatal mortality and morbidity. The incidence of early onset disease has fallen markedly in countries that test women for carriage at 35-37 weeks of pregnancy and then offer intrapartum prophylaxis with penicillin during labour. Countries that do not test, but instead employ a risk factor approach, have not seen a similar fall. There are concerns about the effect on the neonatal microbiome of widespread use of antibiotic prophylaxis during labour, but so far the effects seem minor and temporary. Vaccination against GBS would be acceptable to most women and GBS vaccines are in the early stages of development. Tweetable abstract: Group B Strep is a key cause of infection, death and disability in young babies. Antibiotics given in labour remain the mainstay of prevention, until a vaccine is available.
Article
Objective: To evaluate whether group B streptococci (GBS) screening using the 2010 guideline (screening at 35 0/7-37 6/7 weeks of gestation) compared with the 2019 guideline (screening at 36 0/7-37 6/7 weeks of gestation with re-screening of women with GBS-negative results 5 weeks later) was more cost effective. Methods: We constructed a decision-analysis model to compare the outcome of GBS early-onset disease in a hypothetical cohort of 3,614,049 women at 35 0/7 weeks of gestation or greater (the number of live births in 2017 excluding births based on population frequency from 23 to 34 weeks of gestation, women with GBS bacteriuria during the current pregnancy, and those with a history of a previous neonate with GBS disease). We took both a health care and societal perspective and all costs were expressed in 2017 U.S. dollars. Effectiveness was based on neonatal quality-adjusted life years (QALYs) gained. An incremental cost-effectiveness ratio was estimated with a willingness to pay threshold set at $100,000/QALY. All model inputs were derived from the literature. One-way probability and cost sensitivity analysis were performed to investigate model assumptions. Results: Screening at 36 0/7-37 6/7 weeks of gestation with re-screening of women with GBS-negative results if 5 weeks passed from culture to delivery resulted in a 6% increase in neonatal QALYs gained (2,162 vs 2,037), 12% fewer cases of neonatal death (30 vs 34), and a 10% estimated reduction in total societal health care expenditures related to GBS early-onset disease ($639 million vs $707 million) when compared with the 2010 strategy of only screening at 35 0/7-37 6/7 weeks of gestation. The 2019 approach was cost effective, with an incremental cost-effectiveness ratio of $43,205 per neonatal QALY gained. Conclusion: Screening at 36 0/7-37 6/7 weeks of gestation with a 5-week re-screening for women with GBS-negative results is more cost effective than past strategies used in the United States.
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Introduction: The aim of this study was to evaluate the effect of increasing screening-to-labor interval on the performance of group B streptococcus (GBS) screening by late-pregnancy enriched culture compared with intrapartum real-time polymerase chain reaction (RT-PCR). Material and methods: Group B streptococcus colonization was determined in 2624 women with singleton pregnancies by culture at 35-37 weeks of gestation and at the beginning of labor by culture and RT-PCR from recto-vaginal swab samples. Results: Group B streptococcus colonization rates were 29.0% in late-pregnancy culture, 29.7% in intrapartum culture and 28.2% in intrapartum PCR. Intrapartum culture was used as a reference, the late-pregnancy culture had an overall sensitivity of 89.2% (95% CI 88.0%-90.4%) and specificity of 96.5% (95% CI 95.8%-97.2%), and intrapartum PCR had sensitivity of 91.5% (95% CI 90.4%-92.6%) and specificity of 98.5% (95% CI 98.0%-99.0%). However, up to 4 weeks after screening, the sensitivity of late-pregnancy culture was equivalent to or higher than that of RT-PCR. The RT-PCR was invalid in 0.9% of the women. Between late-pregnancy screening and labor, GBS colonization changed from negative to positive in 3.2% and from positive to negative in 2.5% of the women. Conclusions: The late-pregnancy enriched culture and intrapartum RT-PCR have comparable sensitivities in the detection of GBS when culture screening is conducted no more than 4 weeks before labor. Late-pregnancy culture sampling should be postponed to at least 37 weeks of gestation.
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Objective: The study objective was to determine the role and applicability of the culture-based approach to Group B Streptococcus(GBS) screening and the effect on pregnancy outcome.Materials and Methods: This is a prospective cross-sectional study involving 166 consenting antenatal clinic attendees at 35–37 weeks' gestation using purposive sampling. All participants had vaginal and rectal swabs collected and cultured with the availability of culture results at the time of presentation in labor. All GBS-colonized mothers received intrapartum prophylaxis with parenteral antibiotics based on antibiotic sensitivity from the onset of labor or the rupture of membrane until delivery. Statistical analysis was conducted using SPSS software version 21.0, while P < 0.05 was considered statistically significant. Results: The GBS maternal prevalence was 7.8%, and culture-positive women had both vaginal and rectal colonization. Marital status (P = 0.002), multiple sexual partners (P =0.001), previous sexually transmitted infections (P = 0.013), and low socioeconomic status (P = 0.012) were significantly associated with GBS colonization. GBS isolates were 100% sensitive to ampicillin, all participants had a minimum of two doses of intrapartum prophylaxis with parenteral ampicillin, there was no maternal morbidity, and the vertical transmission of GBS was 0%. Conclusions: The culture-based approach and the culture-based maternal intrapartum prophylaxis prevented both maternal and neonatal complications from GBS. Establishing regional- and national-level preventive protocols will be a central strategy for the prevention.
Article
Background: Universal screening of pregnant women at 35-37 weeks gestation is recommended for detection of anogenital group B streptococcus carriage. Intrapartum chemoprophylaxis is prescribed to carriers to prevent transmission to babies, reducing early-onset neonatal group B streptococcal sepsis. Aims: To review compliance with, and the effects of education on group B streptococcus screening and intrapartum chemoprophylaxis practices at The Royal Women's Hospital, Melbourne, Australia. Materials and methods: A retrospective audit of women delivering in February 2016 and February-March 2017 was conducted. In February 2017, updated early-onset group B streptococcal disease prevention guidelines were released and promoted with targeted education of clinical staff. Compliance was considered appropriate if practices followed up-to-date local protocols. Results: Screening rate for group B streptococcus was 84.4% (599/710) and carriage rate 19.5% (109/558), while intrapartum antibiotic prophylaxis was optimal in 83% of those labouring greater than four hours (39/47). There was no significant difference in compliance between 2016 and 2017. Of 113 women with unknown group B streptococcal status at delivery, only five of 33 (15%) with clinical risk factors for early-onset neonatal disease received intrapartum prophylaxis. Conclusions: Compliance remained stable, with no change during or after implementation of new protocols. Compliance with protocols was low for cases with unknown group B streptococcal status at delivery but with the presence of one or more clinical risk factors for early-onset group B streptococcal sepsis.
Article
Purpose: Streptococcus agalactiae, or group B streptococcus (GBS), is a leading neonatal pathogen that causes sepsis, meningitis and pneumonia. Globally, strategies have been implemented to address vertical transmission, and in Western Australia (WA), culture-based screening at 35-37 weeks' gestation is part of routine care and guides antibiotic administration. Previous Australian studies have focused on other regions or included low sample-size representatives; we aimed to describe antenatal GBS colonization in WA. Methodology: A cohort of 814 pregnant women attending antenatal clinics (2015-2017) self-collected vaginal and rectal swabs at ≤22 weeks (n=814) and ≥33 weeks' (n=567) gestation. These were assessed for GBS presence using culture and PCR, and serotyping was conducted using molecular methods. Lifestyle questionnaires and medical data were collected. Results: We observed an overall GBS colonization rate of 24%, with 10.6 % of positive participants transiently colonized. Ethnicity (Aboriginal, Torres Strait Islander and African), maternal age ≥25 years, vitamin use, frequent sexual intercourse (≥5 times/week) and use of sex toys were associated with GBS colonization. The dominant serotypes identified were Ia (27.9%), III (20.9%), II (16.3%), V (15.8%), Ib (8.4%), VI (5.1%), IV (2.8%), NT (1.9), VIII (0.5%) and IX (0.5%) at visit one, with V (18.9%) preceding serotype II (18.2%) at visit two. Serotype VII was not detected. Conclusion: This is the first cohort study to assess GBS colonization in Western Australian pregnant women and will be highly beneficial for guiding clinical practice and future therapeutic options, in particular, the selection of suitable vaccine candidates.
Article
The aim of the study was to test if maternal obesity and being overweight are independent risk factors for rectovaginal Group B Streptococcus (GBS) colonisation in pregnancy and for early onset GBS disease in the neonate. A case-control study of 9877 deliveries was conducted. The obese gravidas were significantly more likely to be colonised by GBS when compared with non-obese gravidas (22.7% versus 17.5%, P < .001). Obese gravidas were still 33% more likely than non-obese women to test positive for GBS after adjusting for the perinatal factors (adjusted OR 1.33 [95% CI 1.12–1.56]). The risk of early onset GBS disease was not calculated due to its very low incidence. The conclusion is that maternal obesity is a significant risk factor for GBS colonisation at term. • Impact statement • What is already known on this subject? Group B Streptococcus (GBS) is as an important cause of perinatal mortality and morbidity if prophylaxis is not performed. Intrapartum antibiotics are given if the carrier status is positive or unknown, provided that the risk factors are present. • What do the results of this study add? Maternal obesity is a significant and independent risk factor for GBS colonisation at term. • What are the implications of these findings for clinical practice and/or further research? Maternal obesity may be considered as a risk factor that should be taken into account in strategies for reducing GBS disease in neonates.
Article
Vertical transmission of group B Streptococcus (GBS) is among the leading causes of neonatal illness and death. Colonization with GBS usually is screened weeks before delivery during pregnancy, on the basis of which preventive measures, such as antibiotic prophylaxis, were taken. However, the accuracy of such an antenatal screening strategy has been questionable because of the intermittent nature of GBS carriage. We developed a simple-to-use, rapid, CRISPR-based assay for GBS detection. We conducted studies in a prospective cohort of 412 pregnant women and a retrospective validation cohort to evaluate its diagnostic performance. We demonstrated that CRISPR-GBS is highly sensitive and offered shorter turnaround times and lower instrument demands than PCR-based assays. This novel GBS test exhibited an overall improved diagnostic performance over culture and PCR-based assays and represents a novel diagnostic for potential rapid, point-of-care GBS screening.
Article
Background The widespread use of antepartum and intrapartum antibiotics has raised concerns about the possible disruption of the child’s gut microbiota and effects on the maturation from the infant to the adult microbiome. The Fetal Antibiotic EXposure (FAX) study provides a cohort to examine the association between in-utero exposure to antibiotics and adverse childhood outcomes including body weight, atopic diseases, and autism spectrum disorders and to investigate the role of other potential factors mitigating or moderating the risk for adverse outcomes. Objective The aim of this paper was to describe the methods, cohort characteristics, and retention of infants included in the study cohort. Methods For this retrospective cohort study, we included children born in Kaiser Permanente Southern California (KPSC) hospitals between January 1, 2007, and December 31, 2015, within 22 to 44 completed weeks of gestation with KPSC insurance coverage during the first year of life. Follow-up data collection was performed through electronic medical records. Results The study cohort was comprised 223,431 children of which 65.7% (146,720/223,431) were exposed to antibiotics in-utero: 19.0% (42,511/223,431) were exposed during the antepartum period, 30.0% (66,896/223,431) during the intrapartum period, and 16.7% (37,313/223,431) exposed during both the antepartum and intrapartum periods. Conclusions This cohort of children will provide a unique opportunity to address key questions regarding the long-term sequelae of in-utero exposure to antibiotics using real-world data. The high retention and multiple medical visits over time allow us to model the trajectories of body mass index over time. International Registered Report Identifier (IRRID) DERR1-10.2196/12065
Article
Objective: The Centers for Disease Control and Prevention 2010 guidelines recommend group B streptococcus (GBS) screening at 35–37-week gestation to identify women with positive cultures who should receive intrapartum antibiotics and notes that the predictive value of a negative culture declines after 5 weeks. However, despite the lack of evidence, current guidelines do not recommend rescreening for those screened between 35 and 37 weeks. Our objectives were to investigate the rate of conversion from negative to positive results in women rescreened after appropriate screening at 35–37-week gestation and to examine the impact of rescreening on the use of intrapartum antibiotics. Additionally, we examined cases of early-onset group B streptococcal sepsis (early-onset GBS) in term neonates. Methods: We performed a retrospective cohort study of women delivering liveborn infants 1 January, 2010–31 December, 2014 in Kaiser Permanente Northern California. Data were obtained from database extraction and chart review. Results: We identified 135,585 women with GBS screening at 35–37-week gestation; 4511 (3.3%) women were rescreened. Of the 3860 (85.6%) initially screened negative, 218 (5.6%) converted to positive. Fewer women in the discordant negative to positive group received GBS prophylaxis prior to delivery compared with women with a single positive culture (65.9 versus 92.3%, p < .001). In the discordant negative to positive group, results were available at the time of delivery in 133 of 217 subjects (61.3%). There were 18 cases of early-onset GBS at term (0.10 per 1000 livebirths); the majority of cases occurred among women with negative screening. Conclusion: Our results provide support for the current CDC recommendation against rescreening near term for those women already screened at 35–37-week gestation given the low rate of conversion from negative to positive, and the extremely low rate of early-onset GBS in the screened population.
Article
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Three bacteriological techniques for the isolation of group B streptococci in vaginal cultures were compared. A selective broth medium (SBM) containing gentamicin and nalidixic acid was more sensitive for the detection of vaginal isolates (28/76, 36.8%) from 76 women enrolled in a venereal disease clinic than was an identical selective plate medium (SPM) (17/76, 25%). Similarly, SBM allowed identification of positive cultures from college women (82/459, 17.9%) significantly more often than direct inoculation of swabs onto nonselective blood agar medium (43/460, 9.4%; chi2 = 42.2, P = less than 0.001). Failure to isolate group B streptococci detected in SBM occurred in 32.1% cultures by SPM and 49.4% of cultures by nonselective agar medium. Multiple serotypes were detected in a single vaginal culture from approximately 5% of the patients studied. These data support the routine use of SBM for the most accurate identification of women vaginally colonized with group B Streptococcus.
Article
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An increased awareness of the impact of group B streptococcus (GBS) infection on neonatal outcome has prompted several seemingly discordant committee recommendations. Intrapartum antibiotics are effective in reducing the risk of neonatal morbidity when administered to a colonized woman who has a clinical condition that places her neonate at high risk for early-onset sepsis. However, less is known about the efficacy of prophylactic antibiotics in the colonized woman who does not have obvious risk factors. Some authorities have suggested that providers refrain from administering intrapartum antibiotics to colonized women who do not have any of these risk factors, primarily due to concerns about potential adverse reactions, selection of resistant pathogens, and cost-effectiveness. These recommendations may conflict with the desires of an informed woman who weighs the real, albeit low, risk for serious neonatal disease against the lower perceived risk of adverse maternal sequelae from allergic reactions to the antimicrobial agents. Selective prophylaxis for GBS disease that is limited to the colonized parturient with risk factors has the potential for creating conflict because maternal beneficence-based obligations of the physician may be at odds with maternal autonomy-based obligations. We believe that, given all currently available information, providers have a moral obligation to discuss GBS screening and treatment issues with patients. The potential for conflict between patient and physician at the time of delivery can be minimized through the use of preventive ethics, allowing patients to develop advance directives regarding intrapartum management within the confines of reasonable and cost-effective care. Until a consensus is reached among experts, the most prudent approach would be to address such issues proactively and individualize care based upon the overall estimation and anticipation of risk as well as the patient's specific desires.
Article
OBJECTIVE: Our purpose was to study the association of cervicovaginal colonization with group B streptococci with pregnancy and neonatal outcome. STUDY DESIGN: A prospective study was conducted at seven medical centers between 1984 and 1989. Genital tract cultures were obtained at 23 to 26 weeks' gestation and at delivery. Prematurity and neonatal sepsis rates were compared between group B streptococci positive and negative women. RESULTS: Group B streptococci was recovered from 2877 (21%) of 13,646 women at enrollment. Heavy colonization was associated with a significant risk of delivering a preterm infant who had a low birth weight (odds ratio = 1.5, 95% confidence interval 1.1 to 1.9). Heavily colonized women given antibiotics effective against group B streptococci had little increased risk of a preterm, low-birth-weight birth. Women with light colonization were at the same risk of adverse outcome as the uncolonized women. Neonatal group B streptococci sepsis occurred in 2.6 of 1000 live births in women with and 1.6 of 1000 live births in women without group B streptococci at 23 to 26 weeks' gestation ( p = 0.11). However, sepsis occurred in 16 of 1000 live births to women with and 0.4 of 1000 live births to women without group B streptococci at delivery ( p < 0.001). CONCLUSIONS: Heavy group B streptococci colonization at 23 to 26 weeks' gestation was associated with an increased risk of delivering a preterm, low-birth-weight infant. Cervicovaginal colonization with group B streptococci at 23 to 26 weeks' gestation was not a reliable predictor of neonatal group B streptococci sepsis. Colonization at delivery was associated with sepsis. (AM J OBSTET GYNECOL 1996;174:1354-60.)
Article
EDITORIAL COMMENT: This paper presents important information concerning improvement in neonatal mortality and morbidity rates of infants born to mothers who are carriers of Group B streptococci by use of intrapartum penicillin treatment of these colonized women. These data indicate that to be effective chemotherapy must be given to the mother before delivery to minimize the risk of significant infection in the infant. Implementation of the protocol described in this paper could achieve significant improvement of neonatal results, but would not prevent stillbirths due to this infection. We still require introduction of a rapid sensitive antigen test for detection of GBS carrier status in early labour to identify those at risk patients who merit chemoprophylaxis -such a test could also be used to quickly identify GBS carrier status in patients with premature rupture of membranes where intrauterine infection may become established before the onset of labour. Summary: : At the Royal Women's Hospital, Melbourne over an 8-year period (1981–1988) all public antenatal patients were screened at 32 weeks' gestation for group B streptococcus (GBS). In a total of 30,197 livebirths there were no early onset neonatal GBS infections in infants of treated asymptomatic carrier mothers. By contrast there were 27 infections with 8 deaths in an unscreened control group of private patients (total livebirths 26,915). It is recommended that GBS screening occur antenatally at 28 weeks and that intrapartum chemoprophylaxis be offered at least to those carriers with obstetric risk factors.
Article
Early-onset group B streptococcus (GBS) disease in the infant is acquired by vertical transmission from the mother colonized with GBS. Thirty-four women colonized with GBS were treated with intravenous ampicillin sodium during labor. None of their infants were colonized with GBS at birth or within 48 hours. Twenty-four women colonized with GBS received no antibiotic therapy; 14 (58%) of their infants were colonized with GBS at birth or by 48 hours. This difference was highly significant. Mechanisms by which this may have occurred were temporary suppression of GBS vaginal and rectal colonization, high concentration of ampicillin in the amniotic fluid, and transplacental transport of the antibiotic to the infant. In areas where GBS disease is prevalent, we recommend screening pregnant women (34 to 36 weeks' gestation) and treating those colonized with GBS (with no history of penicillin hypersensitivity) with intravenous ampicillin during labor.
Article
An investigation to determine the throat and vaginal colonization rates of group B streptococci among second- and third-trimester pregnant women was performed. Group B streptococci were recovered from 25.4 per cent of third-trimester and 14.8 per cent of second-trimester parturient (p = less than 0.025). Serotype distribution of isolates was similar among these two study groups. No significant differences in colonization rates were noted on the basis of age, race, parity, or complications of pregnancy.However, postpartum fever occurred in 22 per cent of colonized and only 4 per cent of noncolonized second-trimester parturients. The reason for this significant increase in group B streptococcal colonization rates with advancing gestation remains speculative.
Article
Maternal screening--either selective or universal--is an accepted component of a number of strategies for prevention of congenital and perinatal infections. Using the results of maternal screening at prenatal visits and the presence of perinatal risk factors during labour, neonatal group B streptococcal (GBS) early-onset disease can be prevented by selective intrapartum chemoprophylaxis. Possible variations on this strategy may employ semiquantitative tests for GBS colonization at prenatal visits or, possibly, rapid bacterial diagnosis intrapartum. Based on the incidence and economic impact of GBS disease, selective intrapartum chemoprophylaxis appears cost-effective in United States populations, but may not be so in countries with lower incidence rates.
Article
Most cases of neonatal group B streptococcal disease with early onset have an intrapartum pathogenesis. Attack rates are increased substantially in infants born to mothers with prenatal group B streptococcal colonization and various perinatal risk factors (premature labor, prolonged membrane rupture, or intrapartum fever). In a randomized controlled trial, we studied the effect of selective intrapartum prophylaxis with ampicillin in 160 such high-risk women. In infants born to mothers who received intravenous ampicillin during labor, as compared with controls who received no treatment, neonatal colonization with group B streptococci was present in 8 of 85 (9 percent) versus 40 of 79 (51 percent; P less than 0.001), colonization at multiple (greater than or equal to 3) sites was observed in 3 of 85 (4 percent) versus 24 of 79 (30 percent; P less than 0.001), and bacteremia occurred in none of 85 versus 5 of 79 (6 percent; P = 0.024). The side effects of ampicillin were limited to a single episode of urticaria in a mother who had no history of penicillin allergy. We conclude that intrapartum ampicillin prophylaxis in women with positive prenatal cultures for group B streptococci who have certain perinatal risk factors can prevent early-onset neonatal group B streptococcal disease.
Article
Selective antepartum culturing was performed in pregnant women at high risk for low-birth-weight delivery and neonatal infection, in order to identify the presence of the group B streptococcus (GBS). Intrapartum culturing was performed in an additional group of gravid women when they presented either in premature labor or with prematurely ruptured membranes. Antepartum screening for GBS offered no additional advantage over intrapartum culturing in predicting pregnancies that resulted in neonatal infection. Therefore, an intrapartum approach is recommended.
Article
To improve culture methods for the detection of group B streptococcus colonization. This study prospectively compared the standard culture medium, a blood agar plate, to a selective culture medium, Todd Hewitt broth with antibiotics, and compared vaginal culture with rectal culture at the first prenatal exam. Of the 383 vaginal swabs received for evaluation of the two culture media, 78 (20.4%) were positive for group B streptococcus. The detection rates of the blood agar plate method and the Todd Hewitt broth with antibiotics were 64.1 and 97.4%, respectively. Using the Todd Hewitt broth with antibiotics, an additional 94 patients were cultured vaginally and rectally. Twenty-nine (30.9%) had positive cultures. The rate of detection was 58.6% for the vaginal culture, 89.7% for the rectal culture, and 100% for both culture sites combined. These data indicate that culture detection of group B streptococcus can be improved by using both a selective broth medium and a dual vaginal and rectal culture.