Current research update on group B streptococcal infection related to obstetrics and gynecology.

Group B streptococcal (GBS) is a Gram-positive bacterium that is commonly found in the gastrointestinal tract and urogenital tract. GBS infestation during pregnancy is a significant contributor to maternal and neonatal morbidity and mortality globally. This article aims to discuss the infectious diseases caused by GBS in the field of obstetrics and gynecology, as well as the challenges associated with the detection, treatment, and prevention of GBS.

Changes in serum inflammatory factors in group B streptococcal infection and their predictive value for premature rupture of membranes complicated by chorioamnionitis.

Objective: The aim of this study as to unveil changes in serum inflammatory factors in pregnant women with genital tract group B Streptococcus (GBS) infection and their predictive value for premature rupture of membranes (PROM) complicated by chorioamnionitis (CS) and adverse pregnancy outcomes. Methods: The value of serum inflammatory factor levels in predicting PROM complicating CS and adverse pregnancy outcomes in GBS-infected pregnant women was evaluated by ELISA. Results: Serum IL-6, TNF-α, PCT and hs-CRP levels were higher in pregnant women with GBS infection. The combined diagnosis of these factors had excellent diagnostic value in PROM complicating CS and adverse pregnancy outcomes. Conclusion: Joint prediction of IL-6, TNF-α, PCT and hs-CRP has the best predictive value for PROM complicating CS and adverse pregnancy outcomes.

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Self-collection of samples for group B streptococcus testing during pregnancy: a systematic review and meta-analysis.

BACKGROUND: Sample self-collection for reproductive tract infection diagnosis has been found to offer greater convenience, privacy, autonomy, and expanded access to testing in non-pregnant adults. This review aimed to determine whether sample self-collection is as accurate as provider-collection for detection of group B streptococcus colonisation in pregnancy and whether a strategy of self-collection compared to provider-collection might improve maternal and neonatal health outcomes. METHODS: We searched CINAHL Plus, Medline, EMBASE, Maternity and Infant Care Database, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews in June 2022. Eligible studies compared self-collected and provider-collected samples taken from the same participants or participants randomised to either self-collection or provider-collection for reproductive tract infection testing using the same test and testing method in pregnant individuals. We included trials and observational studies. Reviewers assessed risk of bias using the QUADAS-2 checklist and independently extracted data. Sensitivity and specificity for group B streptococcus colonisation of self-collected compared to provider-collected samples were pooled using a bivariate, random-effects, meta-analytic model. This review was registered with PROSPERO (CRD42023396573). RESULTS: The search identified 5909 references, of which eleven diagnostic accuracy group B streptococcus studies were included (n = 3269 participants). No studies assessed the effects of self-collection in pregnancy on health outcomes. All studies had high or unclear risk of bias. Pooled sensitivities of self-collected samples for group B streptococcus detection were 82% (95% CI: 66-91%; I2 = 68.85%) in four trials (n = 1226) and 91% (95% CI: 83-96%; I2 = 37.38%) in seven non-randomised studies (n = 2043). Pooled specificities were 99% (95% CI: 98-99%; I2 = 12.08%) and 97% (95% CI: 94-99%; I2 = 72.50%), respectively. CONCLUSIONS: Self-collected samples for group B streptococcus detection in pregnancy had high specificity compared to provider-collection, but lower sensitivity, particularly for included trials. Studies investigating the effect of self-collection on health outcomes, and further higher quality trials comparing accuracy of self-collection to provider-collection, are required.

Higher body mass index after intrapartum antibiotic exposure in children persists over 10-years.

Exposure to intrapartum antibiotic prophylaxis to reduce perinatal group B streptococcal disease was associated with increased childhood body mass index (BMI) persisting to age 10 years compared to no exposure (Δ BMI at 10 years: vaginal delivery 0.14 kg/m2 , caesarean 0.40 kg/m2 ).

Not Just an Intrapartum Problem: Late-Onset Group B Streptococcus Disease.

Group B streptococcal (GBS) infection is a leading cause of neonatal morbidity and mortality globally. While prevention strategies for early onset GBS disease are well established, methods to prevent late-onset GBS disease do not eliminate disease burden, leaving potential for infection, and devastating consequences for affected neonates. Furthermore, the incidence of late-onset GBS has risen in recent years, with preterm infants at the highest risk of infection and death. Meningitis remains the most common and serious complication associated with late onset disease, occurring in 30 percent of cases. The assessment of risk for neonatal GBS infection should not be limited to the birth process or maternal screening results and intrapartum antibiotic prophylaxis treatment status. Horizontal transmission after birth from mothers, caregivers, and community sources has been observed. Late-onset GBS disease and its sequelae remain a significant risk to neonates, and clinicians should be able to recognize the signs and symptoms to provide timely antibiotic therapy. This article discusses of the pathogenesis, risk factors, clinical manifestations, diagnostics, and treatment of neonatal late-onset GBS infection and identifies implications for practicing clinicians.

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

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

Improving Intrapartum Group B Streptococcus Prophylaxis in Patients with a Reported Penicillin or Cephalosporin Allergy: A Quality Improvement Project.

OBJECTIVE: To evaluate the impact of a standardized allergy-guided approach to Group B Streptococcus (GBS) prophylaxis in pregnant women with reported penicillin or cephalosporin allergy. METHODS: This interrupted time-series analysis included obstetric patients requiring GBS prophylaxis who reported penicillin or cephalosporin allergies. Patients were divided into baseline (April 1, 2019 to July 21, 2020) and intervention (July 22, 2020 to July 31, 2021) groups. The primary outcome was prophylaxis appropriateness, based on antibiotic type, nature of reaction, and cross-reactivity risk. Secondary outcomes included type of prophylaxis received and antibiotic-related adverse events. RESULTS: The study included 88 patients in the baseline period and 52 patients in the intervention period. Appropriate prophylaxis increased from 47% (41/88) to 85% (44/52), with the segmented regression model confirming a statistically significant increase over time (incidence rate ratio 1.57; 95% CI 1.02-2.43, P = 0.04, slope coefficient 1.06/month; 95% CI 1.01-1.10, P = 0.01). Penicillin and cefazolin use increased from 61% (54/88) to 87% (45/52) in the intervention period (P = 0.002), and no hypersensitivity reactions occurred during this period. CONCLUSIONS: Implementation of standardized allergy-guided prophylaxis safely improved appropriate ß-lactam antibiotic use in obstetric patients requiring GBS prophylaxis who reported penicillin and cephalosporin allergies.

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

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

Re-evaluating Perinatal Group B Streptococcal screening in Israel - Is it time for a change in policy?

Group B streptococcal early-onset disease (EOGBSD) is a significant cause of morbidity and fatality in newborns. Current policy in Israel is risk-based management. Our aim was to re-evaluate the current screening policy for Group B Streptococcus (GBS), considering colonization and prevalence rates and costs estimates. This was a retrospective cohort study including term pregnancies between 2015 and 2016 insured by Maccabi Healthcare Services (MHS). A costs estimation model was performed comparing three approaches: universal culture-based screening, current policy in Israel and the current clinical scenario. Out of 54,759 pregnancies, 46.3% women undergo GBS culture-based screening. Overall GBS colonization rates in screened women were 21%. Six EOGBSD cases were identified, all offspring of mothers who were not screened. EOGBSD prevalence rate was 11 per 100,000. Universal culture-based screening was found to be 50% less costly than the current risk-based policy, and would have prevented 20.29 per 100,000 cases. Universal GBS culture-based screening was found to be more cost-effective, compared to the current policy and screening behaviors. Due to the clinical and economic benefits, we recommend that a change in policy should be considered.

Preventing early-onset group B streptococcal sepsis: clinical risk factor-based screening or culture-based screening?

INTRODUCTION: Two strategies are available for prevention of early-onset group B streptococcal (GBS) sepsis - clinical risk factor-based screening and routine culture-based screening of pregnant women for GBS colonisation. In our hospital, we switched from the former to the latter approach in 2014. METHODS: We compared the incidence of early-onset GBS sepsis during 2001-2015 between infants born to pregnant women who were screened for GBS colonisation and those born to women who were not screened. RESULTS: Among 41,143 live births, there were nine cases of early-onset GBS sepsis. All infants with GBS sepsis were born to pregnant women who were not screened for GBS colonisation. The incidence of early-onset GBS sepsis among infants of women who were not screened was 0.41 per 1,000 live births (95% confidence interval [CI] 0.19-0.77) when compared to infants of women who were screened, for whom the sepsis incidence was zero per 1,000 live births (95% CI 0-0.19; p = 0.005). CONCLUSION: Our data suggests that routine culture-based screening of pregnant women for GBS colonisation is a better preventive strategy for early-onset GBS sepsis in neonates when compared to clinical risk factor-based screening.

Uncovering Infant Group B Streptococcal (GBS) Disease Clusters in the United Kingdom and Ireland Through Genomic Analysis: A Population-based Epidemiological Study.

BACKGROUND: The true frequency of hospital outbreaks of invasive group B streptococcal (iGBS; Streptococcus agalactiae) disease in infants is unknown. We used whole genome sequencing (WGS) of iGBS isolates collected during a period of enhanced surveillance of infant iGBS disease in the UK and Ireland to determine the number of clustered cases. METHODS: Potentially linked iGBS cases from infants with early (<7 days of life) or late-onset (7-89 days) disease were identified from WGS data (HiSeq 2500 platform, Illumina) from clinical sterile site isolates collected between 04/2014 and 04/2015. We assessed time and place of cases to determine a single-nucleotide polymorphism (SNP) difference threshold for clustered cases. Case details were augmented through linkage to national hospital admission data and hospital record review by local microbiologists. RESULTS: Analysis of sequences indicated a cutoff of ≤5 SNP differences to define iGBS clusters. Among 410 infant iGBS isolates, we identified 7 clusters (4 genetically identical pairs with 0 SNP differences, 1 pair with 3 SNP differences, 1 cluster of 4 cases with ≤1 SNP differences) of which 4 clusters were uncovered for the first time. The clusters comprised 16 cases, of which 15 were late-onset (of 192 late-onset cases with sequenced isolates) and 1 an early-onset index case. Serial intervals between cases ranged from 0 to 59 (median 12) days. CONCLUSIONS: Approximately 1 in 12 late-onset infant iGBS cases were part of a hospital cluster. Over half of the clusters were previously undetected, emphasizing the importance of routine submission of iGBS isolates to reference laboratories for cluster identification and genomic confirmation.

Preventing early-onset group B streptococcal sepsis: clinical risk factor-based screening or culture-based screening?

INTRODUCTION@#Two strategies are available for prevention of early-onset group B streptococcal (GBS) sepsis - clinical risk factor-based screening and routine culture-based screening of pregnant women for GBS colonisation. In our hospital, we switched from the former to the latter approach in 2014.@*METHODS@#We compared the incidence of early-onset GBS sepsis during 2001-2015 between infants born to pregnant women who were screened for GBS colonisation and those born to women who were not screened.@*RESULTS@#Among 41,143 live births, there were nine cases of early-onset GBS sepsis. All infants with GBS sepsis were born to pregnant women who were not screened for GBS colonisation. The incidence of early-onset GBS sepsis among infants of women who were not screened was 0.41 per 1,000 live births (95% confidence interval [CI] 0.19-0.77) when compared to infants of women who were screened, for whom the sepsis incidence was zero per 1,000 live births (95% CI 0-0.19; p = 0.005).@*CONCLUSION@#Our data suggests that routine culture-based screening of pregnant women for GBS colonisation is a better preventive strategy for early-onset GBS sepsis in neonates when compared to clinical risk factor-based screening.

Preventing Early-Onset Group B Streptococcus neonatal infection and reducing antibiotic exposure using a rapid PCR test in term prelabour rupture of membranes.

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.

Hospital clusters of invasive Group B Streptococcal disease: A systematic review.

OBJECTIVES: To characterize outbreaks of invasive Group B Streptococcal (iGBS) disease in hospitals. METHODS: Systematic review using electronic databases to identify studies describing iGBS outbreaks/clusters or cross-infection/acquisition in healthcare settings where 'cluster' was defined as ≥2 linked cases. PROSPERO CRD42018096297. RESULTS: Twenty-five references were included describing 30 hospital clusters (26 neonatal, 4 adult) in 11 countries from 1966 to 2019. Cross-infection between unrelated neonates was reported in 19 clusters involving an early-onset (<7 days of life; n = 3), late-onset (7-90 days; n = 13) index case or colonized infant (n = 3) followed by one or more late-onset cases (median serial interval 9 days (IQR 3-17, range 0-50 days, n = 45)); linkage was determined by phage typing in 3 clusters, PFGE/MLST/PCR in 8, WGS in 4, non-molecular methods in 4. Postulated routes of transmission in neonatal clusters were via clinical personnel and equipment, particularly during periods of crowding and high patient-to-nurse ratio. Of 4 adult clusters, one was attributed to droplet spread between respiratory cases, one to handling of haemodialysis catheters and two unspecified. CONCLUSIONS: Long intervals between cases were identified in most of the clusters, a characteristic which potentially hinders detection of GBS hospital outbreaks without enhanced surveillance supported by genomics.

The Role of Laboratory Medicine for Health During Pregnancy.

Pregnancy produces profound physiological changes that increase in significance as it progresses. These changes include hormonal changes, metabolic changes, increases of plasma volume up to 50%, alterations to the balance of the coagulation system in favour of clotting, and GFR increases to a peak 50% above prepregnancy levels. Since healthy physiological changes occur during pregnancy, different reference intervals may be needed. First antenatal screens usually include Complete blood count, Blood group and antibody screen, rubella antibody status, syphilis serology, Hepatitis B serology and HIV abs testing. Additional testing in early pregnancy may be added to the first antenatal screen such as varicella, Chlamydia and vitamin D tests. The most important test in the second antenatal testing screen is gestational diabetes screening and protein detection in urine to rule out preeclampsia. Screening for Down syndrome, other chromosomal abnormalities and neural tube defects is recommended for all pregnant women above the age of 35 years. Additionally, 37 weeks into pregnancy, a swab to detect Group B streptococcal (GBS) infection is recommended.

The usefulness of determination of the procalcitonin (PCT) concentration in GBS piositive pregnant womens blood serum for anticipations of infections in newborns

Group-B streptococci (GBS) are commensal bacteria of the human body. They may, however, pose a serious life hazard to pregnant women. During labour, newborns of GBS-positive mothers run the risk of infections that may eventually lead to severe complications, sepsis or even death. For this reason, it is very important to find new diagnostic markers that will enable fast and effective diagnostics and control of the disease process. The level of procalcitonin emerges as a promising diagnostic parameter. AIM. Analysis of the impact of the procalcitonin (PCT) level in GBS-positive pregnant women on the possibility of complications and infections in mothers and newborns MATERIAL AND METHODS. The study group consisted of 115 GBS-positive pregnant women. For each mother-to-be, the CRP and the PCT concentration levels were determined. The clinical state of 117 newborns (2 twin pregnancies) was also assessed. After delivery, the CRP concentration level was determined in the newborns. The examinations had a retrospective character. RESULTS. 30 women showed a raised concentration of CRP and 13 ­ of PCT. No correlation was found between the two diagnostic markers. Similarly, no relation was found between a raised concentration of PCT and the occurrence of a bacterial infection or other complications in the parturient. A raised concentration of procalcitonin in the mother did not translate into the development of an infection in the newborn, either. CONCLUSIONS. The results of the study indicate that there is no correlation between a raised concentration of PCT in GBS-positive pregnant women and a raised CRP level. Abnormal PCT levels in the women covered by the study did not involve a higher frequency of the occurrence of complications or bacterial infections either in the mothers or in the newborns.

The strong correlation between neonatal early-onset Group B Streptococcal disease and necrotizing enterocolitis.

BACKGROUND: Necrotizing enterocolitis (NEC) is a leading cause of newborn gastrointestinal emergencies, affecting 1-3 per 1000 live births. Although NEC has been linked to a microbial etiology, associations with maternal intrapartum and resultant newborn early-onset invasive Group B streptococcus (EO-GBS) have been weakly defined. OBJECTIVE: The study aim was to determine the relationship between EO-GBS and NEC. STUDY DESIGN: Data from 2008 to 2015 were collected from pediatric records with ICD diagnosis codes consistent with all stages of NEC, with the exception of neonatal EO-GBS data (only available 2011-2015). RESULTS: For the 131 newborns meeting inclusion criteria, the mean gestational age (GA) and birthweight at delivery was 30.2 weeks and 1449 g. Maternal comorbidities were not associated with a more advanced stage of NEC, however male gender (OR 3.2, p < .001), lower mean 1 (OR = 0.89, p = .045) and 5 min Apgar scores (OR = 0.84, p = .009) were significantly associated with higher NEC stage, after controlling for GA. Infectious morbidities including chorioamnionitis (OR = 1.5, p = .553) and intrapartum antibiotic administration (OR = 1.3, p = .524) were not significantly associated with higher NEC stage. Neither neonatal sepsis workup (OR = 0.27, p = .060) nor positive blood culture (OR = 0.97, p = .942) prior to NEC diagnosis were statistically significant. Type of feed prior to diagnosis (p = .530) was not significantly associated with NEC stage, however, expressed breast milk tended to be protective against higher stage of NEC (OR = 0.49, p = .055). Type of feed included total parenteral nutrition, mother's or donor expressed breast milk, trophic, full and high calorie feeds. Of the 579 newborns admitted from 2011 to 2015, 13 (2%) were diagnosed with EO-GBS and 64 met diagnostic criteria for NEC. GBS positive newborns had significantly higher odds of NEC (OR = 5.37, p = .009). NEC stage was not significantly different for patients with GBS positive vs. GBS negative mothers (p = .732), nor was there a significant difference in GA (p = .161). CONCLUSION: Our study is the first to describe a strong correlation between neonatal EO- GBS disease and NEC, with more than a five-fold increase in the odds of developing NEC in newborns of GBS positive mothers. PURPOSE: To investigate a possible relationship between EO-GBS disease and the neonatal diagnosis of NEC. Secondary analysis will determine if maternal antepartum and intrapartum factors along with neonatal variables contribute to a more advanced stage of NEC by retrospective chart review of patient data collected at Children's Hospital: New Orleans.