Early-onset Group B Streptococcus Research Articles

Early-onset group B Streptococcus (EOGBS) infection subsequent to cessation of screening-based intrapartum prophylaxis: findings of an observational study in West London, UK

ObjectivesTo describe the impact on early-onset group B Streptococcus (EOGBS) infection rates following reversion from screening-based to risk-based intrapartum antimicrobial prophylaxis (IAP) for prevention.SettingMaternity services provided by secondary healthcare organisation...

Serotype distribution and clinical correlation of Streptococcus agalactiae causing invasive disease in infants and children in Taiwan.

Streptococcus agalactiae, or group B Streptococcus (GBS), remains to be one of the leading pathogens causing invasive infections in infants. The clinical GBS isolates from sterile sites of patients younger than 18 years old were collected from October 1998 to December 2014 in two hospitals in Taiwan. Medical records were retrospectively reviewed. Every isolate was serotyped with a multiplex PCR assay. Multilocus sequence typing (MLST) was performed in representative isolates of different serotypes. A total of 205 GBS isolates were collected from 181 patients with 182 infection episodes. Serotype Ia was the most common in patients less than 72h old, whereas III the most common in patients older than 72h. In early-onset disease (0-6 days), Ia and III each caused 27.5% of the infection, followed by Ib (14.5%). In late-onset disease (7-89 days), serotype III predominated (75.3%), followed by Ia (10.1%) and Ib (6.8%). Thirty-one episodes (17%) were complicated with culture-confirmed meningitis. We compared serotype Ia and III patients, and found that serotype Ia patients were significantly younger (median age, 3 days), had more perinatal maternal fever and higher mortality. ST17 and ST19 were exclusively found in serotype III, while ST23 and ST24 comprised of 85% of serotype Ia. In Taiwan, serotypes Ia and III are the most common cause for early-onset and late-onset neonatal GBS infections, respectively. Some differences in the clinical features of invasive GBS infections caused by serotype Ia and III were observed.

Clinical and Laboratory Features of Group B Streptococcus Meningitis in Infants and Newborns: Study of 848 Cases in France, 2001-2014.

Group B Streptococcus (GBS) disease is the leading cause of neonatal bacterial meningitis despite women receiving an intravenous antibiotic prophylaxis during labor. We aimed to describe GBS meningitis in children <1 year old in France. Clinical and biological data of GBS meningitis gathered by the Association Clinique et Thérapeutique Infantile du Val de Marne (ACTIV) were analyzed. The cases were classified by age: 0-6 days old (early-onset disease [EOD]), newborns and infants 7-89 days old (late-onset disease [LOD]: LOD1, 7-26 days; LOD2, 27-89 days), and infants aged 3 months to 1 year (infant disease). Among 848 GBS meningitis cases from 2001 to 2014, the incidence of EOD decreased by 63.3% (95% confidence interval [CI], 43.9%-80.1%]; P < .001) and that of LOD increased by 58.1% (95% CI, 39.1%-75.5%); P < .001) (52.9% and 64.3% for LOD1 and LOD2, respectively). The mean gestational age (GA) decreased significantly for EOD, LOD1, LOD2, and infant disease cases (38.7, 38.6, 37.3, and 34 weeks, respectively). Serotype III accounted for 83.9% of cases, with no significant difference among the 4 groups or by GA. The frequency of GBS belonging to the clonal complex 17 did not differ among the 4 groups. Case mortality was 11.4%. In the era of intravenous antibiotic prophylaxis, we found decreased incidence of early-onset GBS meningitis but, unexpectedly, increased incidence of LOD. These data underline the interest in the development of effective GBS vaccines for pregnant women.

Perinatal Risk Factors for Neonatal Early-onset Group B Streptococcal Sepsis after Initiation of Risk-based Maternal Intrapartum Antibiotic Prophylaxis-A Case Control Study.

To identify the perinatal risk factors for early-onset Group B Streptococcus (EOGBS) sepsis in neonates after inception of a risk-based maternal intrapartum antibiotic prophylaxis strategy in 2004. Case control study. All newborn with early onset GBS sepsis (born between 2004 and 2013) were deemed to be "cases" and controls were selected in a 1:4 ratio. More than three per vaginal (PV) examinations [odds ratio (OR) 8.57, 95% confidence interval (CI) 3.10-23.6] was a significant risk factors. Peripartum fever (OR 3.54, 95% CI 1.3-9.67), urinary tract infection (OR 2.88, 95% CI 1.08-7.63), meconium-stained amniotic fluid (MSAF) (OR 2.52, 95% CI 1.18-5.37) and caesarean section (OR 1.99, 95% CI 1.16-3.43) were also found to be associated with EOGBS sepsis. Multiple vaginal examinations are the strongest risk factors for peripartum Group B Streptococcal (GBS) sepsis. The association of MSAF and caesarean section indicates that foetal distress is an early symptom of perinatal GBS infection.

Reduced incidence of neonatal early-onset group B streptococcal infection after promulgation of guidelines for risk-based intrapartum antibiotic prophylaxis in Sweden: analysis of a national population-based cohort.

This study aimed to investigate the incidence of neonatal early-onset group B streptococcal (GBS) infection in Sweden after promulgation of guidelines (2008) for risk factor-based intrapartum antibiotic prophylaxis, and evaluate the presence of risk factors and obstetric management in mothers. National registers were searched for infants with early-onset GBS infection during 2006-2011. Medical records of cases and case mothers were abstracted. Verified cases of sepsis/meningitis and cases with clinical sepsis/pneumonia were documented, as well as risk factors in case mothers and timeliness of intrapartum antibiotic prophylaxis administration. There were 227 cases with verified infection, with an incidence of 0.34‰ of live births during the whole period. There was a significant decrease after promulgation of guidelines, from 0.40 to 0.30‰ [odds ratio (OR) 0.75, 95% confidence interval (CI) 0.57-0.99]. A significant decrease in the number of cases with clinical GBS sepsis/pneumonia was also observed. In parturients with one or more risk factors, the incidence of any GBS infection was reduced by approximately 50% (OR 0.47, 95% CI 0.35-0.64), although there were many cases where the opportunity for timely administration of intrapartum antibiotic prophylaxis was missed. In infants of mothers without risk factor(s) there was no reduction in early-onset GBS morbidity. The mortality in verified cases was 4.8% (95% CI 2.1-7.6). The introduction of national guidelines for risk-based intrapartum antibiotic prophylaxis coincided with a significant 50% risk reduction of neonatal early-onset GBS infection in infants of parturients presenting with one or more risk factors. A stricter adherence to guidelines could probably have reduced the infant morbidity further.

Screening for group B Streptococcus (GBS) at labour onset using PCR: accuracy and potential impact – a pilot study

This pilot study assessed the diagnostic accuracy and potential impact of a rapid PCR-based screening test for the detection of group B Streptococcus (GBS) at the onset of labour for the purpose of optimising intrapartum antibiotic prophylaxis (IAP). Vaginal and rectal swabs from a convenience sample of 158 women were analysed by conventional broth-enriched culture and a rapid PCR test. Overall, GBS carriage was 18.98% by culture and 19.62% by PCR. PCR for the detection of GBS had a sensitivity of 93.1%, specificity of 96.67% and area under the curve (AUC) of 0.95. Only 19.3% GBS-positive women received IAP. Three-fourths of babies born to GBS-positive mothers did not receive surveillance for early-onset GBS disease. Of the women who received IAP, only 32.5% were GBS carriers. Seventy-four percent of the GBS-positive mothers delivered more than 5 h after recruitment, which gives adequate swab to delivery interval for appropriate antibiotic prophylaxis in labour.Impact statementWhat is already known about this subject: Appropriate intra-partum treatment of colonized mothers reduces the risk of GBS transmission to neonates. Universal ante partum screening of pregnant women or IAP based on risk factors in labour for GBS prevention fail to accurately identify and treat the woman who actually harbors GBS in the birth canal in labour. A PCR based rapid test, allows for real-time assessment of GBS carriage in labour.What this study adds: This study highlights the fact that a large number of GBS carriers in labour, who could potentially infect their babies, do not receive IAP, and most of their babies do not receive added surveillance in the neonatal period for EOGBS disease. It also confirms that PCR testing at onset of labour is a highly sensitive and reliable test that identifies the women who are GBS carriers in labour and hence need IAP.What the implications are of these findings for clinical practice and/or further research: Timely provision of IAP for the appropriate woman is possible by adopting universal GBS screening at the onset of labor using GBS-PCR. This would involve additional costs to health care facilities and added work to laboratory personnel.

Group B streptococcal bacteriuria during pregnancy as a risk factor for maternal intrapartum colonization: a prospective cohort study.

Current evidence is inconclusive regarding the intrapartum administration of chemoprophylaxis, merely based on the presence of group B streptococcal (GBS) bacteriuria of any colony count, in the prevention of early-onset neonatal GBS infection. The aim of this study was to assess whether GBS bacteriuria is a risk factor for intrapartum colonization (IPC) regardless of urinary concentration or the results of late third-trimester rectovaginal screening cultures (RVSCs). Six hundred and eight pregnant women, with urine specimens cultured between May 2011 and May 2013, were enrolled in this prospective cohort study. RVSCs were available for 582 women and intrapartum rectovaginal cultures for 246. The prevalence of GBS bacteriuria and positive RVSCs was 10.8 and 16.5 %, respectively. The frequency of IPC was 15.9 % (39/246). Sensitivity, specificity, positive and negative predictive values of urine culture and of RVSC in predicting GBS IPC were 41, 94.7, 59.3 and 89.5 %, and 76.9, 95.4, 76.9 and 95.4 %, respectively. GBS bacteriuria was significantly associated with IPC, overall [relative risk (RR) 5.6] and in women with negative RVSC (RR 8.5), with bacteriuria <104 c.f.u. ml-1 (RR 5.9) or when both circumstances coexisted (RR 8.9). The urinary colony count was <104 c.f.u. ml-1 in 13 of the 16 women with GBS bacteriuria and IPC. GBS bacteriuria is a risk factor for IPC, irrespective of urinary GBS concentration or of colonization status at late gestation. Therefore, microbiology laboratories should search, and report, GBS of any colony count in urine from pregnant women, and not only in the presence of ≥104 c.f.u. ml-1 as the 2010 CDC guidelines recommend.

Prevention of early onset group B streptococcal disease by universal antenatal culture-based screening in all public hospitals in Hong Kong

Objectives: To determine the prevalence of maternal colonization with group B streptococcus (GBS), and early onset GBS disease (EOGBSD) after implementation of universal screening.Methods: This was a three-year retrospective cohort study on universal antenatal rectovaginal culture-based screening and intrapartum antimicrobial prophylaxis (IAP) to colonized women in the public sector in Hong Kong. Routinely collected data including maternal colonization and EOGBSD were retrieved.Results: Of 113,989 GBS screening performed, 21.8% were positive. The colonization rate was higher in the public hospitals (higher risk) than in the Maternal and Child Health Centers (lower risk) (23.7% vs 18.1%, p < .001), while their false negative rates were not greater than expected. Majority of eligible women opted for screening, and colonized women received IAP. There were 29 cases of EOGBSD with clinical signs and a positive blood or cerebrospinal fluid culture. Compared to clinical risk-based screening, EOGBSD incidence decreased after universal screening (1 vs 0.24 per 1000 births, p < .001). Although EOGBSD occurred at a higher rate in preterm than term infants, 86.7% occurred in the latter, and were associated with a false negative screening result (41.3%), lack of screening (20.7%) or unavailability of a colonization result at labour (13.8%).Conclusions: Maternal GBS colonization rate was higher than previously reported, and varied with different risk populations. EOGBSD reduced after universal screening.

Antibiotic Prevention for Maternal Group B Streptococcal Colonization on Neonatal GBS-Related Adverse Outcomes: A Meta-Analysis.

Maternal colonization with group B Streptococcus (GBS) during pregnancy increases the risk of neonatal infection by vertical transmission. However, it remains unclear whether treating all colonized women during labor exposes a large number of their neonates to possible adverse effects without benefit. We performed a meta-analysis to assess the effect of intrapartum antibiotic prophylaxis on neonatal adverse outcomes. We identified studies by searching several English and Chinese electronic databases and reviewing relevant articles. Data were pooled using fixed-effects or random-effects meta-analysis, and for each outcome both risk ratio (RR) and 95% confidence intervals (95% CIs) were calculated. Fourteen studies (2,051 pregnant women and 2,063 neonates) were included, comprising 13 randomized clinical trials and 1 cohort study. Antibiotic prophylaxis is associated with a significant reduced risk of all cause infections (RR = 0.28, 95% CI = 0.18–0.42), GBS infection (RR = 0.24, 95% CI = 0.13–0.44), early-onset GBS infection (RR = 0.24, 95% CI = 0.13–0.45), non-GBS infections (RR = 0.34, 95% CI = 0.20–0.59), and GBS colonization (RR = 0.10, 95% CI = 0.06–0.16). But no significant reduction was observed in late-onset GBS infection, mortality from early-onset GBS infection or from non-GBS infections. Notably, no significant differences were found between ampicillin and penicillin prevention for neonatal adverse outcomes. Our findings suggest that antibiotic prophylaxis is effective in reducing neonatal GBS colonization and infection.

Group B Streptococcus detection in pregnant women via culture and PCR methods.

Group B Streptococcus (GBS), a source of neonatal infection, colonizes the gastrointestinal and genitourinary tracts of pregnant women. Routine screening for maternal GBS in late pregnancy and consequent intrapartum antibiotic prophylaxis have reduced the incidence of early-onset GBS neonatal infection. The aim of this study was to evaluate the performance of PCR, compared to culture (gold standard), in GBS colonization screening of pregnant women, and to establish the prevalence of GBS colonization among this population. Vaginal introitus and perianal samples were collected from 204 pregnant women, between the 35th and 37th weeks of pregnancy, at the Obstetrics and Gynecology Unit of the University of Caxias do Sul General Hospital between June 2008 and September 2009. All samples were cultured after enrichment in a selective medium and then assayed by culture and PCR methods. The culture and PCR methods yielded detection rates of vaginal/perianal GBS colonization of 22.5% and 26%, respectively (sensitivity 100%; specificity 95.6%; positive and negative predictive values 86.8% and 100%, respectively). A higher prevalence of GBS colonization was detected in the combined vaginal and perianal samples by both culture and PCR assay analyses. PCR is a faster and more efficient method for GBS screening, allowing for optimal identification of women who should receive intrapartum antibiotic prophylaxis to prevent newborn infection.

Late Onset Streptococcus agalactiae Meningitis following Early Onset Septicemia: A Preventable Disease?

We report a neonate who presented with early onset Streptococcus agalactiae or group B streptococcus (GBS) septicemia within 24 hours of birth. After discharge at day 14, she went on to develop late onset GBS meningitis at 36 days of age. The infant was treated with intravenous antibiotics on both occasions and eventually discharged home with no apparent sequelae. We address issues associated with GBS infection in infancy including the demographics, risk factors, and the risk of late onset GBS meningitis following an early onset GBS infection. The major source of GBS in early onset GBS disease is maternal birth canal GBS colonization. On the other hand, nosocomial cross-infection is an important source of GBS in late onset disease. Penicillin remains the current treatment of choice for GBS infection. Given the rapid onset and progression within hours of birth and lack of an effective solution for preventing late onset GBS, administration of an effective GBS vaccine in pregnancy could provide a sensible and cost-effective solution in all settings.

Epidemiology of Late and Very Late Onset Group B Streptococcal Disease: Fifteen-Year Experience From Two Australian Tertiary Pediatric Facilities.

Group B Streptococcus (GBS) is a recognized cause of sepsis and meningitis, particularly in infants. Early onset (<7 days) GBS disease has been well characterized, whereas the epidemiology of late onset disease (LOD, 7-89 days) and very late onset disease (VLOD, ≥90 days) is less well understood. The aims of this study were to assess risk factors, presentation, management and outcome for GBS LOD and VLOD. Microbiology laboratory databases and hospital diagnostic coding for Sydney Children's Hospital and the Children's Hospital at Westmead were investigated for patients ≥7 days of age diagnosed with GBS bloodstream infection or meningitis from January 1, 2000 to December 31, 2014 (15 years). Subjects' medical records were reviewed to confirm diagnosis and analyze risk factors, presentation, management and outcome. Eighty-seven cases of LOD and 28 cases of VLOD were identified, including 49 cases of bloodstream infection and 66 cases of meningitis. No significant differences in risk factors or presentation were identified between LOD and VLOD. Patients with LOD were more likely to develop sequelae compared with VLOD [odds ratio (OR): 3, 95% confidence interval (CI): 1.03-8.77]. Female sex was the only significant risk factor identified for GBS meningitis (OR: 3.5, 95% CI: 1.5-8.1). GBS meningitis was significantly associated with neurodevelopmental impairment or death compared with bloodstream infection (OR: 30, 95% CI: 6.4-140.6). GBS LOD and VLOD are encountered in similar at-risk populations, with LOD associated with higher morbidity. Infants presenting with meningitis are at significantly higher risk of sequelae compared with bloodstream infection.

Recurrent late-onset group B streptococcus sepsis in a neonate from breast milk

Group B streptococcus (GBS) or Streptococcus agalactiae is a cause of considerable neonatal morbidity and mortality. Intrapartum antibiotic prophylaxis for mothers colonized with GBS has markedly reduced the rates of early-onset neonatal GBS bacteremia. Recurrent late-onset GBS bacteremia is a rare occurrence. Mucosal colonization and breast milk contamination have been implicated as causes of the recurrence. We report a case of recurrent late-onset neonatal GBS bacteremia from the United Arab Emirates, in a term baby whose mother was GBS negative on antenatal screens, with breast milk culture positivity for GBS. To our knowledge, this is the first report from the Middle East region.

Group B Streptococci Screening Before Repeat Cesarean Delivery: A Cost-Effectiveness Analysis.

To estimate the cost-effectiveness of universal group B streptococci (GBS) screening in women with a singleton pregnancy planning a repeat cesarean delivery. We conducted a decision analysis from a health care perspective to compare the cost-effectiveness of GBS screening for women planning a repeat cesarean delivery. With universal screening, all GBS-positive women who labored before a scheduled cesarean delivery received antibiotic prophylaxis. With no screening, women who presented in labor received antibiotics based on risk-based criteria. Neonates born to women colonized with GBS were at risk for early-onset GBS disease, disability, and death. We assumed a GBS prevalence of 25%, that 26.6% of women labored between 35 weeks of gestation and their scheduled time for cesarean delivery, and that 3.3% who planned a repeat cesarean delivery instead delivered vaginally. The primary outcome was cost per neonatal quality-adjusted life-year gained, with a cost-effectiveness threshold of $100,000 per quality-adjusted life-year. Neonatal quality of life was assessed using five health states (healthy, mild, moderate, or severe disability, and death) with a life expectancy of 79 years for healthy neonates. One-way sensitivity and Monte Carlo analyses were used to evaluate the results. In the base case, universal GBS screening in women planning a repeat cesarean delivery was not cost-effective compared with no screening, costing $114,445 per neonatal quality-adjusted life-year gained. The cost to prevent an adverse outcome from GBS exceeded $400,000. If greater than 28% of women were GBS-positive, greater than 29% labored before their scheduled delivery, or greater than 10% delivered vaginally, universal screening became cost effective. Universal GBS screening in women with a singleton pregnancy planning a repeat cesarean delivery may not be cost-effective in all populations. However, in populations with a high GBS prevalence, women at high risk of laboring before their scheduled cesarean delivery, or women who may ultimately opt for a vaginal delivery, GBS screening may be cost effective.

The prevalence of asymptomatic group B streptococcal infection and antimicrobial sensitivity pattern among parturients at Ahmadu Bello University Teaching Hospital, Zaria, Nigeria

Background: Early-onset Group B Streptococcal (GBS) infection is an important cause of perinatal morbidity and mortality. Policy of active prevention by antepartum screening and treatment is not a popular practice in resource-constrained settings. Objectives: This study determined the prevalence of asymptomatic GBS infection and antimicrobial sensitivity pattern. It also determined the outcome of Intrapartum antimicrobial prophylaxis (IAP). Methodology: It was a prospective and longitudinal study done in Ahmadu Bello University Teaching Hospital, Zaria, between June 2014 and April 2015. Two hundred and twenty consenting pregnant women with gestational ages between 35 and 37 completed weeks were participated in the study. Vagina and rectum were swabbed using different rayon swab sticks. Swabs were placed in Amies, nonnutritive transport medium. Bacteriological procedures to culture GBS and confirmation with biochemical tests and serological test were done. Antibiotic sensitivity pattern was determined. Participants who had GBS rectovaginal colonization had intrapartum antibiotic prophylaxis with penicillin G. All participants were followed up till to a week after birth. Results: Out of the 220 pregnant participants, 19 (8.6%) had GBS rectovaginal colonization. Antibiotic sensitivity pattern revealed that GBS isolates were all sensitive to penicillin, ampicillin, and cefazolin while 4 (21.1%) were resistant to ceftriaxone and 6 (31.6%) were resistant to both erythromycin and clindamycin. None of the isolates were resistant to erythromycin and sensitive to clindamycin or vice versa. Of the 19 participants with GBS rectovaginal colonization, 2 (10.5%) delivered low birth weight baby, but there was no incidence of early-onset GBS disease. Conclusion: The prevalence of GBS rectovaginal colonization in this study is similar to figures from other parts of the country. The GBS sensitivity pattern to penicillin was similar to those reported elsewhere. Fetal outcome following intrapartum antibiotic prophylaxis was good.

Risk factors for group B streptococcal disease in neonates of mothers with negative antenatal testing.

ObjectiveThe aim of this study was to identify risk factors for early-onset GBS (EOGBS) disease in neonates of mothers with negative antenatal screening.Study DesignWe performed a retrospective cohort study of neonates born to mothers with negative antenatal GBS screening between 2002–2012. Our primary outcome was EOGBS infection. We used multivariable logistic regression to assess factors associated with EOGBS.ResultsEOGBS was confirmed in 492 of the 179,818 neonates that met the study inclusion criteria. Risk factors for EOGBS included black race (reference: white, odds ratio [OR] =1.81 [95% confidence interval; 1.43, 2.31]), maternal age <18 years (reference: >35 years, OR=2.63 [1.54, 4.51]), and maternal age 18–35 years (reference: >35 years, OR=1.94 [1.30, 2.88]).ConclusionMaternal age <18 years and black race were the strongest predictors of EOGBS. Further research investigating contributors to the discordance between screening results and neonatal outcomes in these populations is needed.

Challenges in reducing group B Streptococcus disease in African settings

Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis in high-income settings and is associated with high rates of neonatal mortality and morbidity. There is now...

Disease Burden of Group B Streptococcus Among Infants in Sub-Saharan Africa: A Systematic Literature Review and Meta-analysis.

Group B streptococcus (GBS) is a leading neonatal sepsis pathogen globally. Investment in GBS disease prevention, such as maternal vaccination, requires evidence of disease burden, particularly in high infant mortality regions like sub-Saharan Africa. We aimed to provide such evidence by conducting a systematic literature review and meta-analysis to estimate maternal colonization proportion, GBS disease incidence and GBS serotype distribution. MEDLINE, MEDLINE in process and Cochrane Library were searched for studies published during 1990-2014, pertaining to sub-Saharan Africa. Eligible studies were used to estimate the proportion of pregnant women colonized with GBS, early-onset GBS disease incidence, late-onset GBS disease incidence and respective serotype distributions. Random effects meta-analysis was conducted to estimate weighted means and confidence intervals (CIs). We identified 17 studies of colonization, 9 of disease incidence, and 6 of serotype distribution meeting inclusion criteria. 21.8% (95% CI: 18.3, 25.5) of expectant women were colonized with GBS. The incidence of early-onset GBS disease was 1.3 per 1000 births (95% CI: 0.81, 1.9), that of late-onset GBS disease 0.73 per 1000 births (95% CI: 0.48, 1.0). The most common disease-causing serotype was 3, followed by 1a. Serotypes 1b, 2 and 5 were next most common in frequency. Despite methodological factors leading to underestimation, GBS disease incidence appears high in sub-Saharan Africa. A small number of GBS serotypes cause almost all disease. GBS disease burden in sub-Saharan Africa suggests that safe, effective and affordable GBS disease prevention is needed.

Group B streptococcus antimicrobial resistance in neonates born to group B streptococcus-colonized mothers: Single-center survey.

In this study, we collected group B streptococcus (GBS) screening data and analyzed screening rate, antimicrobial resistance rate, and neonatal observation room (NOR) admission rate due to inadequate chemoprophylaxis. The GBS screening data for January 2006-December 2013 were retrospectively collected and analyzed. We also collected data for neonates admitted to NOR due to inadequate chemoprophylaxis during the period 1 April 2010-31 December 2013. A total of 12 200 pregnant women received rectovaginal culture during the 8-year study period. The overall screening rate was 53.8% and maternal colonization rate was 20.7%. The GBS screening rate increased remarkably, from 23.2% in 2006 to 70% in 2013. Antimicrobial resistance was common. The resistance rates for each antimicrobial used in pregnancy were as follows: clindamycin, 49.51%; erythromycin, 49.51%. A total of 297 neonates were admitted to NOR due to inadequate antibiotic prophylaxis during 1 April 2010-31 December 2013. The overall NOR admission rate due to inadequate chemoprophylaxis was 2.67%, and the inadequate chemoprophylaxis rate for those GBS colonized mothers was 19.6%. None of these 297 infants had positive blood culture for GBS sepsis. The GBS screening rate increased remarkably, reaching 70% in 2013. The NOR admission rate due to inadequate chemoprophylaxis was 2.67% and there was no early onset GBS disease in a total of 11 123 deliveries in this 4-year cohort study.

Relationship between group B Streptococcus colonization in late pregnancies and neonatal infection

Objective To study the effects of group B Streptococcus (GBS) colonization in late pregnancies on neonatal GBS infection. Methods A total of 17 019 pregnant women who received antenatal care and delivered in Xiamen Maternal and Child Care Hospital from June 1, 2014 to May 31, 2015 were enrolled in this study. Secretions from the lower third of the vagina in the pregnant women at 35-37 weeks of gestation or having premature baby(regardless of gestational age) were obtained to test GBS by standard bacterial culture, and 1 472 cases underwent GBS DNA test by real-time fluorescent quantitative-polymerase chain reaction (PCR) meanwhile. The pregnant women colonized with GBS (GBS culture and/or PCR DNA test positive) were given intrapartum antibiotic prophylaxis (IAP) during parturition or rupture of fetal membranes. Detection rate of the two methods was compared, and the effects of GBS colonization and IAP on neonatal GBS infection were analyzed to identify the risk factors of neonatal early-onset GBS disease (GBS-EOD). Two independent samples t-test, Chi-square test and Logistic regression analysis were used for statistical analysis. Results The detection rate of GBS culture and PCR DNA test was 14.43% (2 456/17 019) and 14.13%(288/1 472), respectively. The total colonization rate was 14.52%(2 472/17 019). Based on the culture results as golden criteria, the sensitivity, specificity, positive predictive value and negative predictive value of PCR assay were 95.05%, 98.74%, 92.31% and 99.21%, respectively. There were 17 332 deliveries from the 17 019 pregnant women, of which 31 cases had GBS-EOD. The incidence of neonatal GBS-EOD in maternal GBS colonization [1.05%(26/2 472)] was 31 times higher than in pregnant women without GBS colonization [0.34‰(5/14 547)]. Among the 31 infants with GBS-EOD, 24 had pneumonia, five had sepsis, and two had meningitis. The case fatality rate was 6.45%(2/31). Logistic regression analysis found that chorioamnionitis was an independent risk factor of neonatal GBS-EOD (OR=40.425, 95%CI: 7.514-379.782, P=0.000). Compared with the non-IAP group,IAP group had a lower incidence of GBS-EOD among the pregnant women colonized with GBS [0.94%(23/2 443) vs 10.34%(3/29), χ2=24.350, P<0.01]. Conclusions GBS colonization in late pregnant women has adverse effects. Therefore, routine maternal rectovaginal culture of GBS may be necessary and IAP should be applied in those with GBS colonization. Key words: Pregnancy trimester, third; Vagina; Streptococcus agalactiae; Streptococcal infections; Infant, newborn