Rectovaginal Cultures Research Articles

Group B Streptococcus Infection and Obstetric Hemorrhage Risk.

To elucidate the association between GBS infection and maternal risk for obstetric hemorrhage (OBH) and OBH-related morbidities (OBH-M). This was a retrospective cohort study of all deliveries with a documented GBS status at a single large academic medical center from 2018 to 2019. GBS status was determined by either urine culture or rectovaginal culture collected during the antepartum period. The primary outcomes were quantitative blood loss (QBL), OBH, and a composite of OBH-M. Secondary outcomes were individual components of the OBH-M composite and frequency of hemorrhage-related interventions utilized intrapartum and postpartum. A stratified analysis was conducted examining only patients who were diagnosed intrapartum with an intrapartum intraamniotic infection (III). Of 4679 pregnant individuals who delivered a live infant between January 1, 2018 and January 1,2019 with a documented GBS status, 1,487 were identified as GBS positive (+) and 3192 were identified as GBS negative (-). The GBS + group did not have significantly higher QBL (p = 0.29) or rate of OBH (p = 0.35). There were no significant differences by GBS status in OBH morbidity (p = 0.79) or its individual components or frequency of individual pharmacologic or non-pharmacologic OBHrelated interventions. There were also no significant differences by GBS status among patients with an III. GBS infection at the time of delivery was not associated with increased risk for OBH or OBH-M. Further research is needed to further explore the relationship between peripartum infections and OBH risk.

Cervicovaginal Microbial-Immune State and Group B Streptococcus Colonization in Pregnancy.

Maternal colonization with Group B Streptococcus (GBS) is a significant risk factor for serious neonatal morbidity. There are limited data on how the cervicovaginal (CV) microbiota and host immune factor β-defensin-2 might influence GBS colonization in pregnant individuals. This study sought to determine if the CV microbiota is associated with GBS colonization in pregnant individuals, and if β-defensin-2 modifies this relationship. This was a secondary analysis of a prospective cohort study of pregnant individuals with singleton pregnancies who had CV microbiota specimens analyzed at 16 to 20, 20 to 24, and 24 to 28 weeks' gestation, along with a third trimester GBS rectovaginal (RV) culture (n = 492). Microbiota data were analyzed with 16S rRNA gene sequencing and classified into community state types (CSTs). Log-binomial multivariable regression was used to model associations between CST and GBS RV status and to calculate risk ratios. β-defensin-2, an immune factor known to modulate the relationship between CST and pregnancy outcomes, was examined as an effect modifier. Of 492 individuals, 34.3% were GBS RV + . Compared with individuals with CST I at 16 to 20 weeks, individuals with CST IV-A and CST II had a significantly elevated relative risk of subsequent GBS RV+ status. When stratified by high and low β-defensin-2 levels, β-defensin-2 was found to be an effect modifier of the association between CST IV-A and GBS RV+ status. In individuals with low β-defensin-2 levels, CST VI-A was associated with GBS RV+ status, but among individuals with high β-defensin-2 levels, there was no such association (interaction p-value = 0.03). Pregnant individuals with CV microbiota characterized by CST IV-A and CST II had significantly elevated risk of GBS RV colonization in the third trimester compared with those with CST I, and β-defensin-2 was an effect modifier of the association between CST IV-A and GBS RV+ status. Future research should investigate if manipulation of the CV microbiota can prevent GBS colonization, thereby reducing intrapartum antibiotic prophylaxis and the risks of neonatal GBS infection. · The relationship between the CV microbiota and GBS RV colonization is unknown.. · A Lactobacillus-deficient, anaerobic rich vaginal community, CST IV-A, is associated with increased risk of GBS RV colonization.. · β-defensin-2 is an effect modifier of the association between CST IV-A and GBS RV+ status..

Maternal Group B Streptococcal Rectovaginal Colonization after Intrapartum Antibiotic Prophylaxis.

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

Supplementation of Probiotics in Pregnant Women Targeting Group B Streptococcus Colonization: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed to determine if probiotic supplementation in pregnancy reduced maternal Group B streptococcus (GBS) recto-vaginal colonization in pregnant women at 35-37 weeks of gestation. Electronic databases (i.e., PubMed, MEDLINE, ClinicalTrials.gov, ScienceDirect, and the Cochrane Library) were searched from inception up to February 2022. We included RCTs assessing the effects of probiotic supplementation in pregnancy on GBS recto-vaginal colonization. The primary outcome was GBS-positive recto-vaginal cultures performed at 35-37 weeks of gestation. Secondarily, we evaluated obstetric and short-term neonatal outcomes. A total of 132 publications were identified; 9 full-length articles were reviewed to finally include 5 studies. Probiotic supplementation reduced vaginal GBS colonization: the GBS positive culture rate was estimated at 31.9% (96/301) in the intervention group compared to 38.6% (109/282) in the control group (OR = 0.62, 95% CI 0.40-0.94, I2 4.8%, p = 0.38). The treatment started after 30 weeks of gestation and was more effective in reducing GBS colonization (OR 0.41, 95% CI 0.21-0.78, I2 0%, p = 0.55). Probiotic administration during pregnancy, namely in the third trimester, was associated with a reduced GBS recto-vaginal colonization at 35-37 weeks and a safe perinatal profile. Whether this new strategy could reduce the exposition of pregnant women to significant doses of antibiotics in labor needs to be evaluated in other trials.

Prevention of neonatal group B streptococcal disease

Group B streptococcal (GBS) disease and its early onset continues to pose major economic and perinatal implications regarding maternal and neonatal morbidity and mortality rates and methods of treatment. Universal GBS screening via rectovaginal culture is now recommended between 36 and 37 weeks and 6 days of gestation for all pregnant women. Timely identification of groups of women suitable for intravenous intrapartum antibiotic prophylaxis of GBS early onset infection has also proven to be effective, although less so than the universal screening approach.

Evaluation of the relationship between preeclampsia and positive rectovaginal culture of group B Streptococcus and Helicobacter pylori positive serology

Introduction: Identifying the incidence of pathogen colonizations in pregnant women with preeclampsia can be effective in providing proper treatment and reducing complications. Objectives: We evaluated the frequency and association between positive rectovaginal culture of group B Streptococcus (GBS) and positive Helicobacter pylori serology with preeclampsia in two groups of pregnant women (with and without preeclampsia). Patients and Methods: The present case-control study included pregnant women with preeclampsia and healthy pregnant controls during 2019-2020. Blood and rectovaginal samples were obtained and the data were statistically analyzed using SPSS software. Results: Fifty-four people were included in the study. The mean gestational age was 36 ± 3.4 months in the preeclampsia group and 37 ± 2.9 months in the control group. There was no significant relationship between preeclampsia and H. pylori-positive serology (P=0.84). Additionally, the association between positive H. pylori serology and the severity of preeclampsia was not significant (P=0.15). However, there was a significant relationship between positive H. pylori tests with early- and late-onset preeclampsia (P=0.04). However, there was no statistically significant relationship between the positive rectovaginal culture of GBS and preeclampsia, the severity of preeclampsia, the onset time, or the weight of newborns. Conclusion: There was a significant relationship between H. pylori infection and late-onset preeclampsia in preeclamptic mothers. H. pylori screening and eradication therapy before pregnancy can prevent preeclampsia and its serious consequences in both the mother and the fetus.

Polymerase chain reaction for Group B Streptococci (GBS) at labor highly correlates with vaginal GBS load

Objective To explore factors associated with a high vaginal GBS load during labor considering (1) the recto-vaginal GBS load at 35–37 weeks’ gestation determined by culture and (2) the vaginal GBS colonization determined by a polymerase chain reaction (PCR) assay during labor. Methods From an unselected cohort of 902 pregnant women, we obtained (1) recto-vaginal swabs for culture of GBS at 35–37 weeks’ gestation (GBSrectovag-36), (2) vaginal swabs for GBS PCR detection at labor (PCRvag-labor), and (3) vaginal swabs for culture of GBS at labor (GBSvag-labor). The GBS load was classified semi quantitatively according to a culture protocol without prior broth enrichment of the swab samples: none (0), few (+), some (++), or many (+++) GBS colonies. Results Among 902 unselected pregnant women, 859 (95%) had a vaginal swab culture taken at labor, which was classified semi quantitatively. High load GBSvag-labor (+++) were found in 31 participants. GBSrectovag-36 showed a sensitivity of 90% (28/31) and a PPV of 23% (28/121), whereas PCRvag-labor had a sensitivity of 98% (30/31, non-significant difference) and a PPV of 42% (30/71, p < .01). PCR at labor had a lower sensitivity (78%) for detection of vaginal colonization with GBS at labor (any load) compared to recto/vaginal colonization with GBS at 36 weeks (92%). Vaginal colonization with GBS at 36 weeks seemed to have a lower sensitivity for detecting GBS in vagina at labor for high load (48%) and for any load (39%). Conclusion PCR at labor has higher detection rate (non-significant) and PPV in identification of laboring women with a high load of vaginal GBS compared with recto-vaginal culture at 36 weeks’ gestation.

The performance of GeneXpert® PCR assay in detecting group B streptococcus colonization at labor

Background: The aim of this study was to assess the performance of GeneXpert® group B streptococcus (GBS) PCR assays in a Danish setting, using rectovaginal GBS culture at labor as the gold standard. Methods: Three hundred and sixty-six (366) women with one or more of the following risk factors for GBS carriage—GBS during current pregnancy, prior infant with EOGBS, temperature &gt;38.0 ∘C during labor, preterm labor &lt;37 weeks of gestation, rupture of membranes ≥18 hours—were included in the study. Intrapartum rectovaginal swab samples were tested at the bedside by GeneXpert® GBS PCR assay, and cultured on agar plates (Granada) with and without prior use of growth-selective enrichment broth. Results: The GeneXpert® GBS PCR assay showed a sensitivity of 91.7%, a specificity of 97.2%, a PPV of 92.6 %, and a NPV of 96.8%. The turnaround time of the assay was 50 minutes. Conclusions: The GeneXpert® has a high performance, indicating that the assay can be used in a clinical setting.

Association of Obesity With Maternal and Cord Blood Penicillin Levels in Women With Group B Streptococcus Colonization.

To compare maternal and cord blood penicillin concentrations in women with and without obesity who are receiving intrapartum group B streptococcus (GBS) prophylaxis. 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. 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). 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.

Evaluation of Urine and Rectovaginal Culture Results in Pregnant Women with Threatened Preterm Labor

Amaç: Doğum eyleminin 20 0/7 ile 36 6/7 gebelik haftaları arasında başlamasına erken doğum tehdidi denir. En önemli sebeplerinden biri ürogenital enfeksiyonlardır. Bu çalışmada erken doğum tehdidi ile ürogenital enfeksiyonlar arasındaki ilişkinin araştırılması amaçlanmıştır. Araçlar ve Yöntem: Ekim 2018-Ekim 2019 tarihleri arasında erken doğum tehdidi sebebiyle Kadın Hastalıkları ve Doğum servisine yatırılan 49 adet gebe çalışmaya dahil edildi. Her hastaya jinekolojik muayene yapıldı ve mikrobiyolojik inceleme için idrar ve rektovajinal sürüntü örnekleri alındı. Elde edilen veriler bir veri tabanında toplandı ve analiz edildi. Bulgular: Hastaların %24.5’inde vajinal kültürde (n=12), %16.3’ünde idrar kültüründe (n=8), %6.1’inde rektal kültürde (n=3) üreme oldu. Vajen kültürü sonuçları; 5 adet vajinal kandidiyazis (Candida albicans), 3 adet Grup B streptokok, 2 adet bakteriyel vajinozis (Gardnerella vaginalis), 2 adet Trichomanas vaginalis, idrar kültürü sonuçları; 5 adet Escherichia coli, 2 adet Staphylococcus aureus, 1 adet Proteus mirabilis, rektal kültür sonuçları; 3 adet rektovajinal grup B streptokok idi. Kültürde üremesi olan ve uygun antibiyoterapi ile tedavi edilen 20 hastanın 1’inde erken doğum gözlendi. Sonuç: Erken doğum tehdidi olan hastalarda idrar ve rektovajinal kültür yapılıp belirlenen patojene göre uygun tedavi verilmesi doğum eyleminin ilerlemesini engellemek için atılacak en önemli adımdır.

Prevalence of rectovaginal colonization by group B Streptococcus in pregnant women seen at prenatal care program of a health organization.

ABSTRACTObjectiveTo evaluate the prevalence of group B Streptococci in pregnant women of a corporate health program, as well as the epidemiological correlations.MethodsThis retrospective study used medical records of patients who participated of the prenatal care program at a private hospital in the city of São Paulo (SP), Brazil, from 2015 to 2016. Those who abandoned the program or had incomplete data in their medical records were excluded. Quantitative variables were described by means, standard deviations, median, minimal and maximal values. Parity and socioeconomic status were described by absolute frequency and percentages. We used logistic regression models in the software (SPSS) to analyze correlations of variables according to vaginal-rectal culture, considering a 95%CI and p-values. Variables were age, number of pregnancies, weight gain in pregnancy and gestational age at delivery.ResultsA total of 347 medical records were included, and after applying the exclusion criteria, 287 medical records composed the final sample. Patients’ age ranged between 17 and 44 years. Mean age was 30.6 years, 67 patients had positive result for group B Streptococcus (prevalence of 23.3%; 95%CI: 18.7-28.5).ConclusionConsidering the high prevalence of group B Streptococcus in our service, the antibiotic prophylaxis strategy based on rectovaginal culture screening approach seems to be cost-effective.

The Accuracy of Group Beta Streptococcus Rectovaginal Cultures at 35 to 37 Weeks of Gestation in Predicting Colonization Intrapartum.

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.

Racial disparities in intrapartum group B Streptococcus colonization: a higher incidence of conversion in African American women.

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. 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. 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). 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.

647: The cost effectiveness of GBS screening vs. universal intrapartum antibiotic prophylaxis

Group B streptococcus (GBS) is the leading cause of neonatal sepsis in the US. As such, rectovaginal culture for all women between 35-37 weeks gestation is recommended to screen for those colonized with the pathogen. Early onset disease in neonates can be prevented by intrapartum antibiotic prophylaxis (IAP), but missed screening opportunities and false negative maternal cultures result in preventable neonatal disease. We sought to evaluate the cost-effectiveness of universal IAP in reducing neonatal morbidity and mortality related to GBS. A decision-analytic model was created using TreeAgePro; probabilities, costs, and utilities were derived from the literature. We compared universal screening with rectovaginal culture by 37 weeks gestation to no screening and IAP given to all women at delivery after 37 weeks. This model was applied to a theoretical cohort of 1,600,000 women with no documented penicillin allergy based on the estimated number of nulliparous, term-births annually in the United States. The cost-effectiveness threshold was set to $100,000 per quality adjusted life year (QALY). Univariate sensitivity analyses were used to evaluate the robustness of the results. In our theoretical cohort of 1.6 million women, we found that IAP given to all laboring women, no matter their GBS status, was cost effective when compared to IAP given to GBS positive women based on screening culture. Universal IAP results in 803 fewer cases of neonatal sepsis, 29 fewer cases of meningitis, 13 fewer cases of neurodevelopmental delay, and 24 fewer neonatal deaths, despite an increase in cases of maternal anaphylaxis, maternal death from anaphylaxis, and increased cost overall. The universal antibiotics strategy resulted in 1,134 additional QALYs and an incremental cost effectiveness ratio of $22,300/QALY. Univariate sensitivity analysis demonstrated that universal IAP was cost-effective when the cost of culture was between $16.75 and $48.25, and was cost-saving for culture cost above $48.25. Our findings suggest that the current standard of care for prenatal screening of GBS may not be cost-effective compared to prophylactically treating all women in pregnancy with penicillin. Further research is necessary to determine if a change in diagnostic test or screening strategy would improve maternal and neonatal outcomes.

Risk‐based approach versus culture‐based screening for identification of group B streptococci among women in labor

To compare a risk-based and culture-based screening approach for identification of group B streptococci (GBS) vaginal colonization using an intrapartum rectovaginal culture as the reference standard. Pregnant women attending the prenatal clinic at Lillebaelt Hospital, Kolding, Denmark, between April 1, 2013, and June 30, 2014, were invited to participate in a prospective observational study. For prepartum culture-based screening, vaginal and rectal culture samples were obtained and, for reference, standard, paired vaginal and rectal culture samples were collected during labor. Risk factors for risk-based screening were previous early-onset GBS, GBS bacteriuria during pregnancy, maternal temperature ≥38.0°C intrapartum, and rupture of membranes for more than 18hours. The intrapartum rectovaginal GBS colonization rate was 30% (32/108) among participants with risk factors and 15% (123/794) among participants without risk factors. Culture-based screening demonstrated a sensitivity, specificity, positive predictive value, negative predictive value, and positive likelihood ratio in predicting intrapartum GBS carriage of 78% (95% confidence interval [CI] 71-84), 95% (94-97), 78% (70-84), 95% (94-97), and 17 (12-23), respectively; for risk-based screening, these values were 21% (15-28), 90% (87-92), 30% (22-38), 85% (83-86), and 2(1-3),respectively. Culture-based screening performed considerably better than a risk-based approach in identifying intrapartum GBS colonization.

Prevalence and Clinical Significance of Streptococcus dysgalactiae subspecies equisimilis (Groups C or G Streptococci) Colonization in Pregnant Women: A Retrospective Cohort Study.

Objectives Little is known about the significance of Streptococcus G or C colonization in pregnant women. The objective of this study was to assess whether vaginal Streptococcus group G or C colonization detected in late pregnancy increases the infectious morbidity of the mother or newborn. Methods A total of 15,114 rectovaginal cultures taken at 35–37 weeks of pregnancy were analyzed at Tampere University Hospital, Finland, between 2012 and 2014. From this laboratory data, all Streptococcus G or C-positive cultures were included to study maternal and neonatal infectious morbidity after delivery. This study population was compared to women with a positive Streptococcus B culture and to women with a negative culture. Results The prevalence of Streptococcus G or C colonization was 2.9%. Significantly more postpartum endometritis was found in this study group. No association was found between colonization and neonatal bacteremia. Conclusions Streptococcus G or C colonization is associated with postpartum endometritis. More research is needed to clarify if antibiotic prophylaxis is reasonable for this group during delivery.

853: The cost effectiveness of multiple GBS screening intervals

Group B streptococcus (GBS) is the leading causative agent of neonatal sepsis in the United States. As such, the CDC recommends a single GBS screening in the form of rectovaginal culture at 35-37 weeks gestation to determine use of maternal intrapartum antibiotic prophylaxis (IAP) to prevent perinatal transmission. However, prediction of perinatal transmission is complicated by the conversion of some women to GBS-positive status prior to delivery, despite a negative initial test result. This study set out to evaluate the use of repeat screening at varying weekly intervals as a cost-effective strategy to decrease rates of GBS transmission to neonates and subsequent outcomes. A decision-analytic model was created using TreeAgePro and probabilities, costs, and utilities derived from the literature. The screening strategies compared included: the usual care of no repeat screening; one additional test at 39, 40, or 41 weeks gestation; every other week testing beginning at 38 weeks; or weekly testing beginning at 37 weeks. This model was then applied to a theoretical cohort of 1,800,000 women based on the estimated number of nulliparous, term-births annually in the United States. The cost-effectiveness threshold was set at $100,000 per quality-adjusted life year (QALY). Univariate sensitivity analyses were performed to evaluate the robustness of the results. In our model, at baseline assumptions of antepartum culture sensitivity of 97% when compared to intrapartum culture, a single repeat screen at 41 weeks was the cost-effective strategy. This persisted to culture sensitivity as low as 94.6% and culture cost ranging from $14 to $44. When compared to no retesting, a single retest at 41 weeks yielded 1.1 fewer neonatal deaths at a cost of $2.7 million. However, weekly testing resulted in 5 fewer neonatal deaths at a cost of $120 million when compared to no repeat testing (Table 1). Repeat antepartum GBS screening at 41 weeks compared to usual care is a cost-effective strategy. Rescreening at 41 weeks appears to be cost effective at a variety of hypothetical culture sensitivities and costs. Repeat antepartum screening should be considered in the management of women with initial GBS negative screening.

847: The accuracy of GBS rectovaginal cultures at 35-37 weeks of gestation in predicting gbs colonization intrapartum

Group B Streptococcus (GBS, Streptococcus agalactiae) is one the leading causes of serious neonatal infection, which may occur during fetal exposure to the vaginal microbiome at delivery. Standard preventative care is maternal screening via urine culture in the first trimester with antibiotic treatment as warranted, followed by rectovaginal culture at 35-37 weeks. Those who test positive at 35-37 weeks receive intrapartum treatment with antibiotics. The objective of this study was to investigate the accuracy of GBS rectovaginal cultures at 35-37 weeks (antepartum) in predicting GBS colonization intrapartum. An IRB-approved prospective cohort study of women admitted to the Labor and Delivery Unit was conducted from from October 2015 through April 2017. In addition to both standard-of-care screening tests for GBS, a rectovaginal culture was obtained intrapartum. The primary outcome was the accuracy of 35-37 week GBS status when compared to that at delivery via McNemar’s test. Secondarily, we compared demographic and delivery outcomes between groups with varying GBS status at third trimester and intrapartum, utilizing Chi-square and t-test as appropriate. First-trimester and third-trimester GBS statuses were also compared via McNemar’s test. A total of 300 patients were enrolled in the study. There was a statistically-significant disparity (p=0.001) between GBS status at 35-37 weeks and at intrapartum; 230 women were negative at both screenings, 25 were positive at both, 33 were positive and became negative, while 11 were newly positive at delivery. Thus, 44 (14.67%) of the women were not treated appropriately at delivery. The 11 women who were newly positive at delivery had a higher pregravid BMI (31.34±6.55 kg/m2) than that among the 230 women negative at both screenings (24.62±5.32 kg/m2; p<0.001). No other demographic or outcome differences were found between those groups. No neonatal GBS infections were reported. GBS culture at 35-37 weeks is a statistically poor predictor of GBS colonization at time of delivery, leaving 11(3.6%) of fetuses vulnerable to infection and 33(11%) overtreated. This may indicate the utility of a rapid intrapartum screen to prevent inappropriate chemoprophylaxis. However, clinical significance of this difference in terms of neonatal outcomes warrants further study.

The impact of prenatal group B streptococcus screening as a national health policy in Taiwan

ObjectiveThere was no national data on group B streptococcus (GBS) infections in Taiwan. Until 2012, when prenatal GBS screening was introduced to obstetric practices as a national health policy aimed at reducing neonatal GBS infections. The purpose of this study was to examine the impact of this national health policy on the incidence of maternal GBS colonization and neonatal GBS infection rate. Relatedly, the clinical characteristics of neonatal GBS infection were investigated to determine the correlations between the incidence of maternal GBS colonization and the neonatal GBS infection rate. Materials and methodsThis population-based nationwide study used data for 2012–2013 from the National Health Insurance Research Database of Taiwan. A total of 789 newly diagnosed pregnant women with genital GBS infection were recruited. ResultsThe maternal GBS screening rate was 93.2%. The maternal colonization rate of GBS was around 8.2%, and the incidence of neonatal GBS infection was 22.6%. The data indicate that no sepsis was developed in any of the cases, while fever was found in 3 cases (3/179, 1.7%) and UTI was found in 1 case (1/179, 0.6%). ConclusionsWe conclude that a policy calling for universal maternal rectovaginal cultures for GBS with intrapartum antibiotic prophylaxis is a good national policy for reducing morbidity due to GBS infections in neonates in Taiwan.

Effectiveness of a group B streptococcus protocol on screening and intrapartum antibiotic prophylaxis at Kenyatta National Hospital

Background: Intrapartum Antibiotic Prophylaxis (IAP) is highly effective in preventing early-onset Group B Streptococcus (GBS) disease among infants born to colonized women. The burden of GBS at Kenyatta National Hospital (KNH) is comparable to the global prevalence yet standardized IAP guidelines have neither been developed nor implemented. This is important in averting GBS associated mortality and morbidity. Objective: To determine if introduction of a GBS screening and IAP protocol is associated with changes in proportion of women receiving appropriate GBS screening and IAP at KNH. Materials and methods: This was a pre and post intervention quasi-experimental study. In the pre intervention phase, clinicians providing reproductive health services were first interviewed on GBS IAP practices and then trained on the proposed GBS IAP protocol. During the post intervention phase, the clinicians were re-interviewed on GBS IAP practices. During both phases, data was extracted from the patient files to assess GBS IAP practice. Intervention comprised Continuous Medical Education (CME), posters of protocol in clinical areas and an email of the proposed protocol sent. Descriptive statistics was conducted for categorical variables and reported as proportions while continuous variables were described using measures of central tendency and dispersion (mean, mode and median). The strength of the association’s was obtained from the effect estimate and p value &lt; 0.05 considered significant. Results: Between 1st May 2015 and 30th November 2015, we retrieved a total of 110 patient files. Nearly half of the files for the pre intervention and post intervention met the inclusion criteria. A total of 93 of the 103 clinicians approached were interviewed; 50 at pre intervention and 43 at post intervention. The prescription of appropriate antibiotics for GBS IAP by clinicians increased from none at pre intervention to 44% at post intervention. However, none of the patients had evidence of rectovaginal swab culture or antibiotic sensitivity pattern for GBS both at pre intervention and post intervention. Conclusion: Introduction of a GBS IAP protocol substantially and significantly increased GBS IAP but did not have effect on screening practices.