Neonatal Group B Streptococcus Sepsis Research Articles

Group B Streptococcus among Pregnant Women and Neonates in Saudi Arabia: A Systemic Review.

Sepsis caused by Group B Streptococcus (GBS) continues to cause mortality and morbidity in newborns, especially in developing countries. Bacterial sepsis in newborns varies nationally and even within countries. Developing countries have reported 34 deaths per 1000 live births compared to 5 in developed countries. This systemic review aimed to assess the prevalence of GBS colonization among pregnant women and the incidence of neonatal GBS sepsis in Saudi Arabia. A literature search of PubMed, MEDLINE Ovid, and Google Scholar was conducted. A total of 21 studies were found: 15 described maternal GBS colonization and 6 studies described neonatal GBS infections. The GBS colonization prevalence among pregnant women ranged from 2.1% to 32.8%. Inconsistencies in the reporting method for neonatal GBS infection rates were observed. Only two studies have the incidence of neonatal GBS as the primary outcome. No national multicenter studies exist on the GBS rates among neonates. Nationwide studies are warranted to assess the burden of GBS infections in neonates. These studies would guide appropriate GBS screening strategies during pregnancy for application in a national public health program.

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

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

Antibiotics at delivery: do the benefits outweigh the risks?

Antibiotics administered just before delivery or during the intrapartum period is common globally and recommendations for increased use continue to expand. Before the introduction of maternal screening and treatment for Group B Streptococcus (GBS) colonization to prevent neonatal GBS sepsis in the 1990's, maternal antibiotic treatment at delivery was used rarely, usually for confirmed maternal infections. With maternal screening for GBS, including a 20-25% positivity rate in the United States (US), antibiotic use at delivery increased substantially.(1) Antibiotics at delivery were subsequently recommended for women with prolonged membrane rupture and preterm labor. Recommendations expanded further with evidence that antibiotics reduced post-partum maternal infections associated with cesarean delivery.(2) And now, following a trial in The Gambia that suggested reduced maternal and neonatal infections, several large trials in low- and middle-income countries (LMICs) are evaluating whether widespread azithromycin treatment, not only for women undergoing cesarean delivery, but among all pregnant women, reduces maternal and neonatal morbidity and mortality.(3).

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

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

Intrapartum antibiotics for prolonged rupture of membranes at term to prevent Group B Streptococcal sepsis

The timely administration of intrapartum antibiotic prophylaxis (IAP) to eligible pregnant mothers reduces the risk of early onset Group B Streptococcus (GBS) neonatal sepsis. The incidence of neonatal GBS sepsis is increasing, in spite of national guidelines for its prevention. This retrospective cohort study was undertaken to assess the incidence of culture-proven GBS sepsis before and after a change of practice on intrapartum management of GBS sepsis in babies born at Sunderland Royal Hospital between January 1 2008 and December 31 2017. The data regarding the risk factors, the intrapartum antibiotic prophylaxis and the outcomes of the babies were collected. Twenty-nine cases were identified and presented in two epochs—before and after changing guidelines for intrapartum management. There was a statistically significant reduction in early onset sepsis rates and no difference in late-onset sepsis rates. The prolonged rupture of membranes is a significant risk factor at any gestation. Impact statement What is already known on this subject? Appropriate intrapartum administration of antibiotics in mothers reduces 80% of early-onset GBS infections. In the United Kingdom, IAP is given based on risk factors, which fail to accurately identify and treat the woman who harbours GBS in the birth canal in labour and the incidence of GBS neonatal sepsis is increasing. The national guideline on the prevention of GBS sepsis is not consistent and is open to interpretation. What do the results of this study add? This study highlights prolonged rupture of membranes as a significant risk factor at any gestation and there were missed opportunities to prevent GBS sepsis in term babies with the prolonged rupture of membranes. This study also highlights that it is possible to reduce the neonatal GBS sepsis burden by adhering to guidelines and administering timely intrapartum antibiotics. What are the implications of these findings for clinical practice and/or further research? The timely administration of IAP to all eligible women is possible if the national guidelines are consistent and interpreted correctly. Our national guideline on the prolonged rupture of membranes at term is not clear and is interpreted differently. If IAP is provided in all those with risk factors irrespective of gestation, this would involve additional costs to the NHS; but in the long term, it will benefit as it reduces morbidity.

While waiting for a vaccine: opportunities for optimization of neonatal group B streptococcal (GBS) disease prevention in Israel.

To quantify effects of different strategies for decreasing neonatal early onset GBS sepsis (EOGBS) in Israel. A risk allocation model for EOGBS among infants ≥ 35w was adapted to Israeli data. Effects of strategies for antepartum (APS) and intrapartum (IPS) screening, and intrapartum (IAP) and/or postpartum antibiotic prophylaxis (PAP) were calculated. Estimated EOGBS attack rates (AR) with APS in 90%, IAP in 90%, may reduce AR to 0.18/1000. A rapid intrapartum test would further decrease AR to 0.16/1000, while reducing IAP from 21.3 to 12.5% of women. For babies with risk factors and GBS+ who do not receive IAP, further risk reduction could be achieved by PAP. IAP remains the main intervention to decrease EOGBS. IAP and PAP together may reduce EOGBS present incidence by 40%. Combining rapid intrapartum screening with selective IAP and selective PAP for remaining gaps, would be the most efficient strategy.

Novel Approaches to the Study of Neonatal Infections.

The pathogenesis of neonatal infection is incompletely understood. Neonatal immune immaturity and the microbial factors of virulence only partially explain the interindividual differences in the protective responses to the most common neonatal pathogens. Stratification of infants into high- and low-risk groups through epidemiological studies has been invaluable in designing preventive strategies and reducing the burden of neonatal infection. The discovery of the role of maternal antibodies (Abs) as, for instance, anti-capsular polysaccharide group B streptococcal (GBS) Abs, in protecting newborn infants against neonatal GBS sepsis, has been a milestone in the unraveling of the molecular underpinnings of susceptibility to infection in the neonatal age. Future work should aim at defining the cellular and molecular differences in the neonatal immune responses that account for individual susceptibility and resistance to common neonatal pathogens. The interplay between the genetic and immune backgrounds of the infant, changes in the infant's microbiome, maternal factors, and the pathogen's characteristics needs to be accurately described through human studies. Precise phenotyping and dissection of the clinical heterogeneity of neonatal infection should identify cohorts that can be studied through different study methodologies. Term and preterm infants should be investigated according to the most likely underlying mechanism, single-gene disorders and multifactorial predisposition, respectively. Novel technologies, including genotyping studies, exome and genome sequencing, analysis of the microbiome, and the study of the metabolome, are nowadays established and available and can be integrated to gain a better insight into the unexplained bases of individual susceptibility to neonatal infections.

Clinical analysis of 30 cases of neonatal group B streptococcus sepsis

Objective To explore the clinical characteristics, treatment and prognosis of neonatal group B streptococcus (GBS) sepsis. Methods According to the onset time and clinical features of the patients, 30 cases of neonatal GBS sepsis in Department of Neonatology, Zhuhai People′s Hospital and ICU of Newborn of Maternity and Child Care Health Hospital of Guangxi from January 2013 to February 2015 were divided into the early-onset group (onset day of the patients ≤7 days) and late-onset group (onset day of the patients >7 days). The clinical manifestations, the examination results of laboratory, imaging examination, treatment and prognosis were retrospectively analyzed. Results Among the newborns diagnosed as neonatal GBS sepsis, there were 19 cases of early-onset sepsis and 11 cases of late-onset sepsis, including 17 males and 13 females, consisting of 24 term infants and 6 premature infants.The early-onset newborns were mainly diagnosed with respiratory symptoms like anhelation, groaning (73.7%, 14/19 cases), late-onset GBS sepsis with high fever (81.8%, 9/11 cases), high frequency of early-onset intraute-rine infection pneumonia (89.5%, 17/19 cases) and late-onset intracranial infection (63.6%, 7/11 cases). The differences between the 2 groups were statistically significant(all P<0.05). Laboratory tests of GBS sepsis showed that the early value of procalcitonin (PCT) increased, while the number of white blood cells, platelet decreased and C-reactive protein (CRP) increased relatively late.Chest X-ray examination showed 16 cases of pneumonia in children, 1 case of pulmonary hemorrhage, 1 case of bilateral pneumothorax. Head CT, B ultrasound, and magnetic resonance imaging discover 1 case of ventricular perivascular hemorrhage, 2 cases of intraventricular hemorrhage with ventricular dilatation and 1 case of subdural effusion.Drug sensitivity test showed that 30 cases of children were sensitive to Penicillin, Vancomycin among which 17 cases (56.66%) were cured, 4 cases (23.33%) were improved, 9 cases died, 6 cases died of abandoning treatment, and the total mortality was 30.00% (9/30 cases). The 6-month follow-up of 9 cases of purulent meningitis newborns showed that there were 2 cases of mild mental retardation and motor dysfunction, 1 case of mild ventricular dilatation with no progressive increase, and 6 cases with no significant sequelae. Conclusion The clinical manifestations of neonatal GBS sepsis are typical.Dynamically monitoring the changes of PCT, CRP, white blood cells and platelet helps to early identify GBS sepsis infection and use sensitive antibiotics to cure the newborns. Key words: Group B streptococcal; Infant, neonatal; Sepsis

Serotype distribution and antimicrobial susceptibility of group B streptococci in pregnant women: results from a Swiss tertiary centre

To evaluate the rates of penicillin, clindamycin and erythromycin resistance and the serotype distribution among isolates of group B streptococcus (GBS) obtained from pregnant women at the University Hospital of Bern in Switzerland. We prospectively collected screening samples for GBS colonisation at the University Women's Hospital Bern, Switzerland, between March 2009 and August 2010. We included 364 GBS isolates collected from vaginal, cervical or vaginal-perianal swabs at any gestation time. The minimal inhibitory concentrations for penicillin, clindamycin and erythromycin were established using Etest with 24 hours of incubation, and inducible clindamycin resistance was tested with double disk diffusion tests. Serotyping was done with a rapid latex agglutination test or, if not conclusive, with polymerase chain-reaction (PCR) testing. We looked for significant associations between resistance patterns, age groups, serotype and ethnicity. All isolates were susceptible to penicillin. Resistance rates were 14.5% for erythromycin and 8.2% for clindamycin. Of 364 isolates, 5.8% were susceptible to clindamycin but not to erythromycin, although demonstrating inducible clindamycin resistance. Hence, the final reported clindamycin resistance rate was 14%. Serotype III was the most frequent serotype (29%), followed by V (25%) and Ia (19%). Serotype V was associated with erythromycin resistance (p = 0.0007). In comparison with all other ethnicities, patients from Asia showed a higher proportion of erythromycin and clindamycin resistance (p = 0.018). No significant association between resistance patterns and age groups was found. In pregnant women with GBS colonisation, penicillin is the antibiotic of choice for intrapartum prophylaxis to prevent neonatal early-onset GBS sepsis. In women with penicillin allergy and at high risk for anaphylactic reaction, clindamycin may be an alternative. The resistance rate for clindamycin at our institution was 14%; therefore, susceptibility must be tested before administration.

Cervical Insufficiency: A New Issue for Guidelines on Prevention of Perinatal Group B Streptococcal Disease?

The updated Guidelines on Prevention of Perinatal Group B Streptococcal Disease, issued by the Centers for Disease Control and Prevention, actually represent the mainstay in the prevention of neonatal early-onset group B streptococcal (GBS) sepsis. According to these guidelines, patients with possible preterm delivery are screened for GBS colonization and offered intrapartum prophylaxis only if they enter preterm labor or experience preterm premature rupture of the membranes. Nonetheless, the fulfillment of these recommendations seems to be suboptimal in clinical practice, as it is heavily influenced by the knowledge of the colonization status. We report here 2 cases of blood culture-proven, early-onset neonatal GBS sepsis involving preterm infants delivered by mothers who had midtrimester cervical insufficiency and bulging membranes. Midtrimester acute cervical insufficiency strongly predicts preterm delivery. These women are liable to miss intrapartum antibiotic prophylaxis because they typically have shorter labor, and the test results for GBS status are unlikely to be available before delivery. We believe that women with midtrimester cervical insufficiency and bulging membranes should be screened for GBS infection soon after hospital admittance if the gestational age is close to the threshold of fetal viability. A timely diagnosis of GBS colonization may not only increase the number of patients receiving targeted intrapartum antibiotic prophylaxis but would also allow consideration of the administration of antepartum antibiotic prophylaxis. Indeed, as further outlined in this report, GBS intraamniotic infection may dramatically occur before the onset of preterm labor or preterm premature rupture of the membranes.

Intrapartum polymerase chain reaction for detection of group B streptococcus colonisation

Lower vaginal swabs were collected to compare the intrapartum polymerase chain reaction (PCR) test to the standard antepartum culture for detection of group B streptococcus (GBS) colonisation. Four hundred and forty-five pregnant women with documented antepartum GBS cultures, who did not receive either antepartum or intrapartum antibiotics, were included in this prospective study. At the time of delivery and before the intrapartum antibiotic prophylaxis (IAP), double swabs were collected, one of the swab was used in the GBS molecular-based (PCR) test and the other was processed for GBS culture in Ahmadi Hospital Clinical Laboratory. Neonates were examined after delivery to diagnose GBS sepsis, and using intrapartum GBS culture as gold standard test; the intrapartum PCR test was compared to the antepartum culture. The sensitivity and specificity of antepartum culture to diagnose GBS colonisation were 73 & 95.5%, respectively, compared with 98.3% sensitivity & 99% specificity for intrapartum PCR test (P>0.05). Although the intrapartum PCR test was more accurate (98.8%) for detection of GBS colonisation than antepartum culture (90%), its accuracy was significantly different. The neonatal GBS sepsis was significantly related to positive intrapartum cultures, and intrapartum PCR tests, but was not related to positive antepartum cultures (the IAP to the antepartum GBS-positive mothers reduces GBS sepsis of their neonates). The intrapartum PCR test is an accurate bedside test and it has the potential to be used as intrapartum screening for GBS colonisation allowing appropriate management of mothers and neonates.

High Incidence of Group B Streptococcal Infection in Infants Born to HIV-Infected Mothers

To the Editor: In their cross-sectional study comparing group B streptococcus (GBS) carriage among HIV-infected and HIV-uninfected women in Malawi, Gray et al. found no differences in GBS carriage between both groups but found a higher carriage rate for HIV-infected women with high CD4 cell counts (1). They proposed that a GBS-specific immune defect might exist in HIV-infected pregnant women and suggested that this defect could be blurred by competitive exclusion of GBS as a consequence of changes in microbial flora at lower CD4 counts. We recently reported an increased incidence of neonatal GBS sepsis in HIV-exposed uninfected (HEU) infants born in Belgium, compared with the general population (2). In our cohort, the risk for GBS infection was 20× higher in HEU infants than in infants born to HIV-uninfected mothers. Moreover, the episodes of GBS sepsis in HEU infants, compared with the general population, were more severe and mostly of late onset. We are currently looking prospectively at GBS carriage in HIV-infected and control uninfected pregnant women to learn whether our observation can be explained by a higher carriage rate in HIV-infected women or by increased susceptibility of HEU infants to this capsulated bacteria. The latter hypothesis would be in line with the higher susceptibility of HEU children to other types of severe infections, as has been described in several studies from sub-Saharan Africa and Latin America (3–5). The incidence of GBS sepsis in HIV-exposed infants born in Africa is unknown. In addition to the need for further investigation of anti-GBS immunity in HIV-infected pregnant women, we believe that studies comparing the incidence of neonatal GBS sepsis in HEU and HIV-unexposed infants are warranted. If the increased risk for GBS sepsis is confirmed, prophylaxis should be implemented in the population concerned.

Genetic Differences Between Invasive and Noninvasive Neonatal Group B Streptococcal Isolates

Streptococcus agalactiae, also known as group B streptococcus (GBS), is the most common cause of neonatal sepsis and meningitis. To improve our understanding of the pathogenesis of neonatal GBS sepsis, better knowledge of clonal relatedness and diversity among invasive and noninvasive GBS isolates is critical. In a Germany-based study, invasive neonatal GBS isolates were compared with noninvasive isolates from neonates in whom sepsis was suspected, but whose blood cultures were sterile. The comparison was conducted by means of pulsed-field gel electrophoresis and surface protein gene profiling. In addition, multilocus sequence typing was performed on invasive and noninvasive isolates of the most frequent invasive serotype III. Pulsed-field gel electrophoresis analysis of noninvasive GBS showed a remarkably more diverse fingerprinting pattern than that of invasive isolates. In contrast to invasive strains, noninvasive isolates did not show any clustering. Surface protein gene profiling also showed significantly different distribution patterns between the 2 panels of isolates. Multilocus sequence typing of invasive and noninvasive serotype III isolates revealed the same clonal complexes, but displayed different sequence types (ST); ST-17 was most common (68.6%) among invasive strains, whereas ST-389 (clonal complex-19) was predominant among noninvasive strains (47.8%). Our results illustrate a large molecular diversity among neonatal noninvasive GBS strains. Invasive strains, however, represent only a small proportion of the noninvasive GBS population. These findings suggest a selection process that prefers more virulent strains during invasion.

Evaluation of a rapid, real-time intrapartum group B streptococcus assay

We sought to evaluate an intrapartum nucleic acid amplification test (NAAT) for group B streptococcus (GBS). This was a prospective cohort study of 559 women comparing intrapartum GBS culture with antepartum culture and intrapartum NAAT. GBS prevalence was 19.5% by antepartum culture and 23.8% by intrapartum culture. Compared with intrapartum culture, antepartum culture had 69.2% sensitivity (60.6-76.9%) and 96.0% specificity (93.7-97.7%). The NAAT demonstrated sensitivity of 90.8% (84.6-95.2%), specificity of 97.6% (95.6-98.8%), and predictive values >92%. The incidence of discordant cultures was 10.4%. Of the women with negative antepartum and positive intrapartum cultures, only 1 (2.4%) received intrapartum antibiotics. Compared with white women, black (P = .02) and Hispanic (P = .02) women were more likely to have discordant cultures. This intrapartum NAAT has excellent characteristics. It may be superior to antepartum culture for detecting intrapartum GBS-allowing more accurate management of laboring mothers and reducing neonatal GBS sepsis.

Diagnosis of neonatal group B Streptococcus sepsis by nested-PCR of residual urine samples

Group B streptococcus (GBS) remains the most common cause of early-onset sepsis in newborns. Laboratory gold-standard, broth culture methods are highly specific, but lack sensitivity. The aim of this study was to validate a nested-PCR and to determine whether residue volumes of urine samples obtained by non invasive, non sterile methods could be used to confirm neonatal GBS sepsis. The nested-PCR was performed with primers of the major GBS surface antigen. Unavailability of biological samples to perform life supporting exams, as well as others to elucidate the etiology of infections is a frequent problem concerning newborn patients. Nevertheless, we decided to include cases according to strict criteria: newborns had to present with signs and symptoms compatible with GBS infection; at least one of the following biological samples had to be sent for culture: blood, urine, or cerebrospinal fluid; availability of residue volumes of the samples sent for cultures, or of others collected on the day of hospitalization, prior to antibiotic therapy prescription, to be analyzed by PCR; favorable outcome after GBS empiric treatment. In only one newborn GBS infection was confirmed by cultures, while infection was only presumptive in the other three patients (they fulfilled inclusion criteria but were GBS-culture negative). From a total of 12 biological samples (5 blood, 3 CSF and 4 urine specimen), eight were tested by culture methods (2/8 were positive), and 8 were tested by PCR (7/8 were positive), and only 4 samples were simultaneously tested by both methods (1 positive by culture and 3 by PCR). In conclusion, although based on a restricted number of neonates and samples, our results suggest that the proposed nested-PCR might be used to diagnose GBS sepsis as it has successfully amplified the three types of biological samples analyzed (blood, urine and cerebrospinal fluid), and was more sensitive than culture methods as PCR in urine confirmed diagnosis in all four patients. Moreover, PCR has enabled us to use residue volumes of urine samples collected by non invasive, non sterile methods, what is technically adequate as GBS is not part of the normal urine flora, thus avoiding invasive procedures such as suprapubic bladder punction or transurethral catheterization. At the same time, the use of urine instead of blood samples could help preventing newborns blood spoliation.

Efficacy of a strategy to prevent neonatal early-onset group B streptococcal (GBS) sepsis

Existing guidelines recommend different strategies to prevent early-onset neonatal GBS sepsis. In 1997, using our own data on incidence and risk factors, we established a new prevention strategy which includes GBS screening at 36 weeks' gestation and intrapartum antibiotic prophylaxis (IAP) in women with positive or unknown GBS colonization with at least one risk factor. The present study evaluates the efficacy of the new prevention strategy. Retrospective study of the incidence of early-onset GBS sepsis among all live births at the University Women's Hospital Basel between 1997 and 2002. Additional analysis of delivery and post partum period of all GBS sepsis cases, including GBS screening, risk factors during labor (prematurity, rupture of membranes (ROM) <12 h, intrapartum signs of infection), and IAP. Comparison of this group's characteristics G2 (9,385 live births, using the new strategy) with the previous group, G1 (1984-1993, 16,126 live births, without GBS screening or routine IAP) was performed. The incidence of early-onset GBS sepsis was reduced from 1/1000 (G1) to 0.53/1000 (G2). We observed a significant reduction of overall intrapartum risk factors in cases of GBS sepsis. This study suggests that our new prevention strategy is effective in reducing the incidence of early-onset GBS sepsis in neonates. In comparison, implementation of the CDC's prevention strategy might have prevented 2 additional cases in 9385 live births. However, this would have required treating a much larger number of pregnant women with IAP with consequential increasing costs, side effects and complications.

331 Choosing Strategy for Prevention of Neonatal Group B Streptococcal (GBS) Infection - Has Maternal Origin Country to be Consider?

Background: During the last two decades our maternal GBS carrier and neonatal sepsis rates has varied, 3.5%–11% and 0.2–0.9/1000 LB respectively. Thus, Israeli current policy is Risk Factor Approach with no routine GBS screening.Objective: 1. To update colonization & attack rate. 2. To determine whether our Risk factor Approach is still applicable.Design/Methods: In Jan.-June 2002 we randomly sampled women admitted for delivery. Vaginal & rectal cultures were obtained before 1st pelvic examination. GBS was isolated using a selective broth medium and identified by latex agglutination and antigen B assay. Neonatal sepsis/meningitis rate was defined as positive blood/CSF cultures in 2002. Chi2 and multivariate analysis were performed.Results: Of the 637 sampled women 94 were GBS positive (14.7%). Fifty (7.8%) of the mothers were from N. America origin and there colonization rate was 26% (13:50) as opposed to mothers of other origins which was 13.8% (81:587) p= 0.02. In multivariate analysis, including variables of maternal age, parity, blood type, duration of rupture of membranes, infant gender and birth weight, N. America Origin was found to be the single risk for GBS carrier (p= 0.0273). Neonatal sepsis (8:9995) rate was 0.8/1000 LB for the entire population. The percentage of the N. America Origin mothers in the sampled population was 7.8% (50/637) their component in the GBS infected group was 37.5% (3:8) p=0.016. No difference was noted in GBS serotypes between origin groups.Conclusions: We identified N America origin women as an increased risk factor for GBS colonization in the Israeli society. The high N American origin neonatal GBS sepsis rate was correlated with the higher colonization rate in these mothers. Given our high carrier & attack rate in N. America origin women & babies we now recommend routine prenatal screening in that ethnic subgroup.

Prevention of neonatal group B streptococcal disease: Progress, challenges and dilemmas

Significant advances in the prevention of neonatal group B streptococcal (GBS) disease have occurred in the last decade. In Australia, as well as in centres overseas, intrapartum penicillin given to carrier mothers has been shown to unequivocally decrease early onset neonatal GBS sepsis. In choosing which women should receive intrapartum chemoprophylaxis, recent data suggest that screening programmes for the detection of GBS carriage may be more effective than risk-based strategies to prevent early onset neonatal GBS sepsis. Combined vaginal and rectal swabs, collected between 35 and 37 weeks gestation, either by a health care worker or by the patient herself and inoculated onto selective media after enrichment provide the optimum conditions to detect carriage. Increasingly erythromycin and clindamycin resistance is being described overseas, which may influence the choice of antibiotics used in those allergic to penicillin. Widespread antibiotic use, particularly with broad-spectrum agents, may lead to increasing neonatal sepsis with ampicillin resistant organisms. Whilst rates of non-GBS neonatal sepsis are generally stable there is evidence suggesting that Escherichia coli sepsis in premature infants is increasing. Novel vaccination strategies for GBS are being developed that may ultimately provide broader protection for mothers and babies and eliminate the need for intrapartum antibiotics.

Neonatal Group B streptococcal infection at the Mount Hope Women's Hospital, Trinidad.

To determine the incidence of early onset Group B streptococcal (GBS) infection in neonates at the Mount Hope Women's Hospital, Trinidad over the period 1996-97. This retrospective study included all babies with a positive blood culture for GBS during the study period. There were 9866 live births (LB) of whom 29 were diagnosed as early onset GBS disease. The incidence was 2.9/1000 LB. 37.9% of babies were preterm and 65.5% were delivered to primiparous women. Rupture of amniotic membranes occurred within 12 h of delivery in 55% of infected babies. Four of the 29 infected babies died and all were preterm. The incidence of early onset neonatal GBS sepsis was five to six times higher in this series than that reported in the USA and UK. An intervention policy to control this preventable disease is urgently needed.

Prevalence and mechanisms of macrolide resistance in invasive and noninvasive group B streptococcus isolates from Ontario, Canada.

Macrolide resistance has been demonstrated in group B streptococcus (GBS), but there is limited information regarding mechanisms of resistance and their prevalence. We determined these in GBS obtained from neonatal blood cultures and vaginal swabs from pregnant women. Of 178 isolates from cases of neonatal GBS sepsis collected from 1995 to 1998, 8 and 4.5% were resistant to erythromycin and clindamycin, respectively, and one isolate showed intermediate penicillin resistance (MIC, 0.25 microg/ml). Of 101 consecutive vaginal or rectal/vaginal isolates collected in 1999, 18 and 8% were resistant to erythromycin and clindamycin, respectively. Tetracycline resistance was high (>80%) among both groups of isolates. Of 32 erythromycin-resistant isolates, 28 possessed the erm methylase gene (7 ermB and 21 ermTR/ermA) and 4 harbored the mefA gene; one isolate harbored both genes. One isolate which was susceptible to erythromycin but resistant to clindamycin (MIC, 4 microg/ml) was found to have the linB gene, previously identified only in Enterococcus faecium. The mreA gene was found in all the erythromycin-resistant strains as well as in 10 erythromycin-susceptible strains. The rate of erythromycin resistance increased from 5% in 1995-96 to 13% in 1998-99, which coincided with an increase in macrolide usage during that time.