Neonatal group B streptococcal disease--screening and prevention

C-reactive protein and thrombocytopenia as essential early indicators: Subtle approach to neonatal sepsis

Introduction

Early diagnosis of neonatal sepsis is very essential part of newborn care to prevent mortality and decrease morbidity in newborns.

Aim

The aim of this study is to correlate an increase in C-reactive protein (CRP) titre and a decrease in platelet count with an increased incidence of neonatal septicemia, for an effective subtle approach in neonatal septicemia.

Materials and Methods

A retrospective study was conducted in the neonatal intensive care unit (NICU) of a tertiary care hospital from Jan 2022 to July 2023. Neonates admitted to the NICU with suspected sepsis were screened for sepsis. Screening was done by taking blood culture samples before administration of antibiotics, serum samples for CRP and blood samples for platelet count.

Result

A total of 270 newborns with suspected sepsis were included in the study. Blood culture positivity was seen in 27.7 (27/75) cases. About 32.9% (89/270) of the neonates with suspected sepsis and 61.3% (46/75) neonates with confirmed sepsis had raised CRP; 32.2% (87/270) neonates with suspected sepsis and 64% (48/75) with confirmed sepsis had decreased platelet count. Both an increase in CRP and a decrease in platelets were seen in 61.3% (46/75) of confirmed cases.

Conclusion

In our study, both raised CRP and decreased platelet count were seen in around 60% of confirmed cases of sepsis. So, CRP titre and platelet count can be used as early, rapid diagnostic markers for confirmed sepsis.

Sublingual immunisation with GBS serotype III capsular polysaccharide-tetanus toxoid conjugate vaccine induces systemic and mucosal antibody responses which are opsonophagocytic and inhibit GBS colonisation of vaginal epithelial cells

No vaccines are currently licensed against Group B streptococcus (GBS), an important cause of morbidity and mortality in babies and adults. Using a mouse model, and in vitro opsonophagocytosis and colonisation assays, we evaluated the potential of a sublingually-administered polysaccharide-conjugate vaccine against GBS serotype III. Sublingual immunisation of mice with 10 µg of GBS conjugate vaccine once a week for 5 weeks induced a substantial systemic IgG anti-polysaccharide response which was similar to the level induced by subcutaneous immunsation. In addition, sublingual immunisation also induced mucosal (IgA) antibody responses in the mouth, intestines and vagina. Immune sera and intestinal washes were functionally active at mediating killing of the homologous GBS serotype III in an opsonophagocytosis assay. In addition, intestinal and vaginal washes inhibited the colonisation of mouse vaginal epithelial cells by the vaccine homologous strain. These results suggest that, in addition to the induction of high levels of IgG antibodies that could be transduced from the immunised mother to the foetus to protect the newborn against GBS infection, sublingual immunisation can elicit a substantial mucosal antibody response which might play an important role in the prevention of GBS colonisation in immunised women, thereby eliminating the risk of GBS transmission from the mother to the baby during pregnancy or at birth.

A high percentage of hospital-acquired neonatal bacteraemia but rare resistance to standard antibiotic regimens

AIM

We examined community and hospital-acquired bacteraemia, namely bloodstream infections or meningitis, and looked at the clinical features and outcomes of cases.

METHODS

The study comprised infants under 3 months of age, who were admitted to a tertiary referral centre in northern Israel with bacteraemia from 2010-2019. Causative pathogens, antibiotic susceptibility and mortality were retrospectively recorded.

RESULTS

We identified 314 infants, 325 episodes of bacteraemia and 344 pathogens. Meningitis was identified in 22 (7.0%) infants. Hospital-acquired bacteraemia accounted for 84.8% of the 325 episodes. Coagulase-negative staphylococci (33.9%) was the most prevalent pathogen in the hospital-acquired cases, while Escherichia coli (37.2%) dominated the community-acquired cases. The susceptibility of Gram-negative early-onset sepsis cases to ampicillin-gentamicin or ampicillin-cefotaxime was 96% and 94.7% for hospital-acquired cases and 91.7% and 88% for community-acquired cases, respectively. Susceptibility to piperacillin-tazobactam or amikacin in late-onset sepsis were 92.8% and 98%, respectively, in hospital-acquired cases. The 30-day mortality was 5.7% in infants with hospital-acquired cases. Risk factors were Arab ethnicity (p < 0.028), haemodynamic instability (<0.001) and Gram-negative sepsis (0.043).

CONCLUSION

Most cases of bacteraemia were acquired during hospitalisation and these accounted for the majority of the deaths. Resistance to standard antibiotic regimens was rare.

Risk of infection in neonates born in accidental out-of-hospital deliveries

Accidental out-of-hospital deliveries (OHDs) are known to have a higher incidence of maternal and neonatal complications. However, neonatal infection related to OHDs has not been studied. The aim of this study was to determine the infection risk of OHDs. This retrospective cohort study enrolled neonates admitted at a children’s hospital in an urban setting from January 2004 to December 2017. Accidental OHDs were compared with in-hospital births, and neonatal infection was assessed. This study also investigated both maternal and neonatal risk factors associated with OHDs. A cohort of 158 OHD neonates was enrolled, of whom 29 (23.2%) were preterm. Prematurity and low birth weight were significantly associated with OHD. Eight neonates in the OHD cohort had a documented infection within the first 72 hours of life, which was 11-fold higher than infections documented for the in-hospital births. Multivariate analysis identified low birth weight as the only factor independently associated with increased risk of infection in OHD neonates. Several specific characteristics of mothers with OHDs were identified. Forty-nine (31%) OHD mothers lacked antenatal care, and 10 (6.3%) were unaware of their pregnancies. The OHD group comprised of more teenage mothers compared to the in-hospital deliveries category. Neonatal infection was more prevalent among OHDs than for in-hospital deliveries, and the infection rate was associated with low birth weight. Hospitalization for further care and observation is suggested for the OHD neonates. Social support should be provided for populations with an increased risk of OHD, such as teenage mothers.

Neonatal Nasopharyngeal Bacterial Colonization: Prevalence, Antimicrobial Resistance, and Concomitant Early-onset Sepsis

Background: Early-onset neonatal sepsis (ENOS) is one of the most common causes of mortality in neonates. The bacteria causing ENOS are generally transferred from the mother to the infant before or during labor. Objectives: This study aimed to determine the prevalence rate of nasopharyngeal colonization with common bacterial agents causing ENOS and their relationship with blood culture outcomes in neonates. Methods: All neonates transferred to the neonatal intensive care unit were included in the study. Posterior pharynx secretions were swabbed and cultured in blood agar and MacConkey agar. Also, a blood specimen from each neonate was inoculated into a blood culture bottle. The grown bacteria were identified by biochemical standard tests. The antibiotic sensitivity test was performed by the disk diffusion method using Mueller-Hinton agar, and the results were evaluated according to the CLSI guidelines. Results: The pharyngeal specimens collected from 114 newborns were positive in 83 (72.8%) cases. Staphylococcus epidermidis was the most common bacterium in all weight groups. However, the isolates of Klebsiella, Escherichia coli, S. aureus, and Streptococcus agalactiae were also high. Thirteen newborns died. Neonates’ pharyngeal specimens were positive among 11 (84.6%) cases who died and 101 (71.2%) neonates who survived. Twelve neonates had positive blood cultures. Simultaneous positive blood and pharyngeal cultures were reported in eight (7%) cases, in which the bacterial isolates from blood and pharyngeal samples were similar in three cases (37.5%). Among pharyngeal isolates, E. coli was resistant to ampicillin in 100% and gentamicin, cefotaxime, and ceftazidime in 50% of the cases. Also, S. epidermidis and Acinetobacter isolates from blood samples were resistant to ampicillin in 100% of the cases. Conclusions: Staphylococcus epidermidis accounted for 38.6% of bacteria cultured from pharyngeal swabs and 66.7% of bacteria cultured from blood samples, 37.5% of which were resistant to ampicillin and 100% were sensitive to vancomycin. One-hundred percent of E. coli cultures from neonatal pharynges were resistant to ampicillin and about 50% of them were resistant to gentamicin, cefotaxime, and ceftriaxone.

Evaluation of Implementation of Early-Onset Sepsis Calculator in Newborns in Israel

OBJECTIVE

To evaluate the recommendations based on the early-onset sepsis (EOS) calculator in the first 2 years of its implementation in Israel.

STUDY DESIGN

Prospective 2-year surveillance of a cohort of infants born at gestational age of ≥34 weeks in Bnai Zion Medical Center, who were evaluated using the EOS calculator because of peripartum risk factors.

RESULTS

We evaluate 1146 newborns with peripartum risk factors using the EOS calculator. The percentage of infants who had laboratory evaluation decreased to 4.6%, and the EOS calculator recommended empiric antibiotic therapy in only 2.2%. During the study period, there were 4 early-onset infections (EOS incidence of 0.6 in 1000 live births). Three had group B streptococcus (GBS) and one had Escherichia coli infection. Only 2 of these infants had perinatal risk factors and the EOS calculator identified them and recommended laboratory evaluation and empiric antibiotics. However, 2 infants with GBS EOS had no perinatal risk factors or clinical symptoms at delivery, and were discovered clinically at older ages.

CONCLUSIONS

The Israeli EOS calculator-based guidelines seem to be appropriate and are associated with less laboratory evaluations, and little use of empiric antibiotics. Concerns are related to the current recommendation of no GBS universal screening in Israel, and the inability of the calculator-based approach to identify GBS EOS in infants born to mothers with unknown GBS who have no peripartum risk factors before presentation of clinical symptoms.

Optimizing antibiotic use for early onset sepsis: A tertiary NICU experience

BACKGROUND

Neonatal antibiotic use is associated with a greater risk of nosocomial infection, necrotizing enterocolitis, and mortality. It can induce drug-resistant pathogens that contribute to increased neonatal morbidity/mortality, healthcare costs, and length of stay. Prior to the antibiotic stewardship program, decisions to obtain blood cultures and empiric antibiotics for possible Early-onset Sepsis (EOS) in late preterm and term infants upon NICU admission were provider-dependent rather than algorithm-based. We aimed to decrease empiric antibiotic prescription from 70% to 56% (20% decrease) in infants ≥34 weeks gestation admitted to the NICU.

METHODS

The stewardship initiative comprised the following practice changes: (1) use of the Neonatal Sepsis Risk Calculator (SRC); and (2) a 36-hour time-out for prescribed empiric antibiotics. Data was retrospectively collected and analyzed for inborn infants pre-intervention (January 2015-December 2015; n = 263) and post-intervention (August 2016-September 2017; n = 279). Data regarding compliance with the new antibiotic guideline were collected and disseminated to the team every week. Overlap between CDC guidelines and calculator recommendations were studied.

RESULTS

Pre-and post-intervention outcomes were analyzed using chi-square tests. There was a significant post-intervention reduction in the rate of both antibiotic prescriptions (29.4% decline; 70.3% vs. 49.6%; p < 0.001) and sepsis evaluations (24.3% decline; 90.9% vs. 68.8%; p < 0.001). No difference (p = 0.271) in culture-positive EOS cases was observed. There was 92% overlap in blood culture recommendations and 95% overlap between antibiotic recommendations when current CDC guidelines were compared to the SRC.

CONCLUSION

A significant reduction in antibiotic use and sepsis evaluations was achieved for late preterm and term infants upon NICU admission. No clinical deterioration occurred in post-intervention infants who did not receive antibiotics. There is significant overlap between CDC guidelines and SRC recommendations.

Nationwide epidemiology of early-onset sepsis in Israel 2010-2015, time to re-evaluate empiric treatment

AIM

Early-onset neonatal sepsis (EOS) may lead to significant morbidity and mortality, yet the recommended antimicrobials have not changed for many years. We aimed to optimise EOS treatment by examining EOS pathogens, resistance rates and resistance risk factors.

METHODS

A retrospective, nationwide cohort study analysing 2010-2015 EOS data in Israel.

RESULTS

The 21 participating centres constitute 92% of the total birth cohort (around 180 000 live births/year). Of 549 EOS neonates (0.57/1000 live births), 306 (56%) and 243 (44%) were full-term and preterm, respectively (0.35 vs. 2.94 per/1000 live births). Gram-negative pathogens predominated, especially in preterms. Escherichia coli and Streptococcus agalactiae were most common pathogens (0.2 and 0.19 per 1000 live births, respectively). In 277 Gram-negatives, 16%, 14%, 8% and 3% were gentamicin-resistant, extended-spectrum beta-lactamase (ESBL)-positive, gentamicin-resistant and ESBL-positive, and amikacin-resistant, respectively; preterms had higher resistance rates. No risk factors for antimicrobial resistance were identified. Mortality was reported in 21% of Gram-negative EOS versus 7% of Gram-positive EOS [OR 3.4 (95% CI 1.8-6.2), p < 0.01].

CONCLUSION

In this nationwide study, EOS was caused predominantly by Gram-negatives, with high gentamicin resistance and ESBL phenotype rates, without identifiable resistance risk factors. As EOS is life-threatening, modification of empiric therapy for amikacin-based regimens should be considered, mainly in preterms.

Group B Streptococcal Cellulitis and Necrotizing Fasciitis in Infants: A Systematic Review

BACKGROUND

There is no consensus regarding approaches to infantile group B streptococcal (GBS) head and neck cellulitis and necrotizing fasciitis. We present a case of GBS necrotizing cellulitis and summarize the literature regarding the presentation and management of infantile head and neck GBS cellulitis and necrotizing fasciitis.

METHODS

The literature was searched using PubMed, Web of Science, EMBASE and Medline (inception to April 2017) by 2 independent review authors. Inclusion criteria encompassed case reports or case series of infants less than 12 months of age with GBS cellulitis of the head and neck or with GBS necrotizing fasciitis without restriction to the head and neck. Data were extracted using tables developed a priori by 2 independent review authors, and discrepancies were resolved by consensus.

RESULTS

An infant presenting at 33 days of age with GBS facial necrotizing fasciitis was successfully treated conservatively with antibiotics. Our literature search identified 40 infants with GBS head and neck cellulitis. Late-onset (98%), male gender (65%) and prematurity (58%) predominated. Penicillin is the main therapy used (97%). The 12 identified cases of necrotizing fasciitis were associated with polymicrobial etiology (36%) and broad-spectrum antibiotic use. Seventy-five percent required debridement, including 4 of 5 (80%) cases involving the head and neck.

CONCLUSIONS

Skin and soft tissue involvement is an uncommon manifestation of late-onset GBS infection which requires antibiotic therapy and possibly surgical debridement cases with necrotizing fasciitis.

Risk factors for Group B Streptococcus colonisation and disease in Gambian women and their infants

OBJECTIVES

To determine risk factors for GBS colonisation in Gambian mothers and in their infants from birth to day 60-89 of age.

METHODS

Swabs and breastmilk from mothers/infant pairs were collected and cultured on selective agar. Negative samples were analysed for GBS DNA via real-time PCR. Positive isolates were serotyped using multiplex PCR and gel-agarose electrophoresis.

RESULTS

Seven hundred and fifty women/infant pairs were recruited. 253 women (33.7%) were GBS-colonised at delivery. The predominant serotypes were: V (55%), II (16%), III (10%), Ia (8%) and Ib (8%). 186 infants were colonised (24.8%) at birth, 181 (24.1%) at 6 days and 96 at day 60-89 (14%). Infants born before 34 weeks of gestation and to women with rectovaginal and breastmilk colonisation at delivery had increased odds of GBS colonisation at birth. Season of birth was associated with increased odds of persistent infant GBS colonisation (dry season vs. wet season AOR 2.9; 95% CI 1.6-5.2).

CONCLUSION

GBS colonisation is common in Gambian women at delivery and in their infants to day 60-89 and is dominated by serotype V. In addition to maternal colonisation, breastmilk and season of birth are important risk factors for infant GBS colonisation.

Clinical, Laboratory, and Placental Findings in Perinatal Listeriosis

Clinical, laboratory, and placental manifestations of perinatal listeriosis are highly variable. Herein, we retrospectively analyzed all patients treated for neonatal listeriosis at the Charité University Medical Center in Berlin, Germany, 1999-2013. A total of 16 cases were identified. In 14 patients listeriosis was confirmed in neonatal specimens, while in two only the placenta tested positive. Elevated C-reactive protein and/or interleukin-6 levels were only inconsistently found, while a marked white blood cell left shift was present in all infants, if available. All but one infant manifested symptoms on the first day of life. Most patients required respiratory support, while none developed meningoencephalitis as evidenced by clinical or cerebrospinal fluid findings. Two patients died, all other patients survived without sequelae. In conclusion, perinatal listeriosis is still associated with significant morbidity and mortality. Clinical and laboratory findings are highly heterogeneous, but extreme leukocyte left shift seems to be a common feature.

Chorioamnionitis and Culture-Confirmed, Early-Onset Neonatal Infections

BACKGROUND

Current guidelines for prevention of neonatal group B streptococcal disease recommend diagnostic evaluations and empirical antibiotic therapy for well-appearing, chorioamnionitis-exposed newborns. Some clinicians question these recommendations, citing the decline in early-onset group B streptococcal disease rates since widespread intrapartum antibiotic prophylaxis implementation and potential antibiotic risks. We aimed to determine whether chorioamnionitis-exposed newborns with culture-confirmed, early-onset infections can be asymptomatic at birth.

METHODS

Multicenter, prospective surveillance for early-onset neonatal infections was conducted during 2006-2009. Early-onset infection was defined as isolation of a pathogen from blood or cerebrospinal fluid collected ≤ 72 hours after birth. Maternal chorioamnionitis was defined by clinical diagnosis in the medical record or by histologic diagnosis by placental pathology. Hospital records of newborns with early-onset infections born to mothers with chorioamnionitis were reviewed retrospectively to determine symptom onset.

RESULTS

Early-onset infections were diagnosed in 389 of 396,586 live births, including 232 (60%) chorioamnionitis-exposed newborns. Records for 229 were reviewed; 29 (13%) had no documented symptoms within 6 hours of birth, including 21 (9%) who remained asymptomatic at 72 hours. Intrapartum antibiotic prophylaxis exposure did not differ significantly between asymptomatic and symptomatic infants (76% vs 69%; P = .52). Assuming complete guideline implementation, we estimated that 60 to 1400 newborns would receive diagnostic evaluations and antibiotics for each infected asymptomatic newborn, depending on chorioamnionitis prevalence.

CONCLUSIONS

Some infants born to mothers with chorioamnionitis may have no signs of sepsis at birth despite having culture-confirmed infections. Implementation of current clinical guidelines may result in early diagnosis, but large numbers of uninfected asymptomatic infants would be treated.

Early-onset neonatal sepsis

Early-onset sepsis remains a common and serious problem for neonates, especially preterm infants. Group B streptococcus (GBS) is the most common etiologic agent, while Escherichia coli is the most common cause of mortality. Current efforts toward maternal intrapartum antimicrobial prophylaxis have significantly reduced the rates of GBS disease but have been associated with increased rates of Gram-negative infections, especially among very-low-birth-weight infants. The diagnosis of neonatal sepsis is based on a combination of clinical presentation; the use of nonspecific markers, including C-reactive protein and procalcitonin (where available); blood cultures; and the use of molecular methods, including PCR. Cytokines, including interleukin 6 (IL-6), interleukin 8 (IL-8), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), and cell surface antigens, including soluble intercellular adhesion molecule (sICAM) and CD64, are also being increasingly examined for use as nonspecific screening measures for neonatal sepsis. Viruses, in particular enteroviruses, parechoviruses, and herpes simplex virus (HSV), should be considered in the differential diagnosis. Empirical treatment should be based on local patterns of antimicrobial resistance but typically consists of the use of ampicillin and gentamicin, or ampicillin and cefotaxime if meningitis is suspected, until the etiologic agent has been identified. Current research is focused primarily on development of vaccines against GBS.

Identification of high immunoreactive proteins from Streptococcus agalactiae isolates recognized by human serum antibodies

The aim of the studies was to identify immunogenic proteins of Streptococcus agalactiae (group B streptococcus; GBS) isolates. Investigation of the immunoreactivity with human sera allowed us to determine major immunogenic proteins which might be potential candidates for the development of vaccine. For the study, we have selected 60 genetically different, well-characterized GBS clinical isolates. The proteins immunoreactivity with 24 human sera from patients with GBS infections, carriers, and control group without GBS was detected by SDS-PAGE and Western blotting. As a result, some major immunogenic proteins were identified, of which four proteins with molecular masses of about 45 to 50 kDa, which exhibited the highest immunoreactivity features, were analyzed by LC-MS/MS. The proteins were identified by comparative analysis of peptides masses using MASCOT and statistical analysis. The results showed known molecules such as enolase (47.4 kDa), aldehyde dehydrogenase (50.6 kDa), and ones not previously described such as trigger factor (47 kDa) and elongation factor Tu (44 kDa). The preliminary results indicated that some GBS proteins that elicit protective immunity hold promise not only as components in a vaccine as antigens but also as carriers or adjuvants in polysaccharide conjugate vaccines, but more studies are needed.

Rapid polymerase chain reaction assay to detect herpes simplex virus in the genital tract of women in labor

OBJECTIVE

To develop a rapid quantitative real-time polymerase chain reaction (PCR) to detect herpes simplex virus (HSV) in the genital secretions of women that may be used in labor.

METHODS

Samples of genital secretions from women in labor, swabs of active genital lesions, and swabs of buffer solution were analyzed using a newly developed rapid HSV PCR assay to detect HSV glycoprotein B gene and quantitate virion copy number. A previously validated TaqMan PCR to detect HSV glycoprotein B gene was performed as the comparator gold standard. Positivity determination that optimized sensitivity and specificity was determined with receiver operating characteristic curves.

RESULTS

The median time to result for rapid HSV PCR was 2 hours (range 1.5-3.5 hours). A positivity determination rule that required both wells of the rapid test to detect 150 copies or greater of HSV per milliliter maximized specificity (96.7%) without appreciable loss of sensitivity (99.6%). Among positive samples, the correlation between the rapid test and TaqMan for the quantity of HSV isolated was excellent (R=0.96, P<.001). The rapid test had a positive predictive value of 96.7% and a negative predictive value of 99.6% in a population with HSV shedding prevalence of 10.8%, based on the prevalence of genital HSV previously found among HSV-2 seropositive women in labor.

CONCLUSION

Rapid HSV PCR provides results with excellent sensitivity and specificity within a timeframe that could inform clinical decision making for identifying neonates at risk of neonatal HSV infection.

LEVEL OF EVIDENCE

II.

Comparative evaluation of the AccuProbe Group B Streptococcus Culture Test, the BD GeneOhm Strep B assay, and culture for detection of group B streptococci in pregnant women

We compared a rigorous culture method with the Gen-Probe AccuProbe Group B Streptococcus Culture Test (APGB) and the BD GeneOhm StrepB assay (GOSB) for the detection of group B streptococci (GBS) from an 18- to 24-h LIM broth. Culture (95.3%) and GOSB (95.3%) were more sensitive than APGB (86.5%) for the detection of GBS.

Group B streptococcus colonization of pregnant women and their children observed on obstetric and neonatal wards of the University Hospital in Krakow, Poland

The study was arranged to assess the actual rates of colonization of pregnant women and their children with group B streptococcus (GBS) in a Polish university hospital. Resistance of these cocci to macrolides and clindamycin was also tested and routes of transmission of GBS were followed in some cases using molecular typing. Colonization with GBS was checked in 340 pregnant women living in the south-eastern region of Poland (Małopolska) in the years 2004–2006. Women with a complicated pregnancy were more often colonized than those with a normal pregnancy (20.0 % versus 17.2 %). Moreover, women with a complicated pregnancy were twice as often colonized with GBS strains with the MLSB phenotype indicating resistance to macrolides and clindamycin. Regarding neonatal colonization by GBS, we found that neonates born from the colonized mothers with a complicated pregnancy were more often colonized with GBS than those from the mothers with a normal pregnancy (35 % versus 26.7 %). By molecular typing of the GBS strains isolated from mothers and their newborns we have been able to suggest the possibility of horizontal transmission of the strains from the hospital environment to newborns. Our results clearly indicate that rates of GBS colonization among pregnant women and neonates in a Polish university hospital have reached levels comparable to those reported in other European clinical centres.

Sensibilité aux antibiotiques des souches de Streptococcus agalactiae à Monastir

OBJECTIVE

The aim of this study was to determine the antimicrobial susceptibility of Streptococcus agalactiae strains in Monastir (Tunisia).

METHOD

This retrospective study included 300 strains of S. agalactiae from several pathological samples collected at the Monastir Fattouma Borguiba Hospital. The identification was based on conventional bacteriological features. Serogrouping was performed using agglutination tests. The susceptibility to antibiotics was studied according to the Antibiogram Committee of the French Society of Microbiology recommendations.

RESULTS

S. agalactiae was mainly isolated from patients with vaginal infections (31.3%) and urinary tract infections (24.7%). All strains were susceptible to penicillin G. Resistance was mostly observed to erythromycin (38.5%) and lincomycin (36.6%). 6.5% were highly resistant to kanamycin and 0.6% to gentamicin.

CONCLUSION

Penicillin remains the most effective antibiotic, but resistance to other antibiotics is emerging. This justifies the routine studying of antimicrobial susceptibility in S. agalactiae stains.

A trial of preventing early- and late-onset Group B streptococcal sepsis with combined intrapartum chemoprophylaxis and universal neonatal screening

BACKGROUND

Prevention of early-onset Group B Streptococcal (GBS) infection has been attempted by employing universal maternal screening for GBS, intrapartum chemoprophylaxis, and a single dose of penicillin given to neonates in the first hour of life. This strategy, however, does not seem to prevent the occurrence of late-onset neonatal group B streptococcal disease.

STUDY DESIGN

We assessed early and late-onset GBS disease with the use of a before-after study designed to evaluate the implementation of intrapartum antimicrobial prophylaxis. Moreover, universal neonatal screening for colonization of GBS was carried out with swabs of the external ear canal. Newborns with GBS colonization received a preventive treatment with oral amoxicillin for 10 days.

RESULTS

Early-onset GBS infection decreased from 0.5 per thousand at baseline period to 0.19 per thousand at the study period. The incidence of late-onset GBS disease decreased from 1:1348 (0.74 per thousand) to 1:20,710 (0.048 per thousand). The overall cost for universal neonatal screening paid for by the Italian Health System in the study period was 31,065 US dollars with an antibiotic prophylaxis cost of 2,399 US dollars.

CONCLUSIONS

A combined strategy based on GBS culture screening and assessment of risk factors for perinatal GBS disease can significantly reduce the rate of both early and late-onset GBS infections.

Water birth: is the water an additional reservoir for group B streptococcus?

OBJECTIVE

Water birth became popular in the last years, despite the fact that many questions like the risk of infection for the newborn remain unanswered. Group B streptococcal (GBS) infections in the newborn remain a challenge in obstetrics and neonatology.

METHOD

We conducted a prospective trial to study the impact of water birth on the colonization rate of the bath water and, more importantly, the GBS-colonization rate of the newborn.

RESULT

After water birth the bath water was significantly more often colonized with GBS than after immersion followed by a delivery in bed. The newborns, however, showed no difference in GBS colonization and there was even a trend towards less GBS colonization of the newborn after a water delivery.

CONCLUSION

Regarding GBS colonization of the newborn during water birth there might be a wash out effect, which protects the children during the delivery.

Beyond screening: identifying new barriers to early onset group B streptococcal disease prevention

BACKGROUND

Group B streptococcal infections remain an important cause of morbidity and mortality in newborns.

METHODS

Neonatal group B streptococcal cases were identified by active surveillance in 4 urban Tennessee counties. Medical records of mothers of cases and a sample of other pregnant women with live births from the same population were reviewed to determine whether the screening or risk-based approach was used for prevention of early onset group B streptococcal disease and to assess other factors affecting preventability of cases.

RESULTS

During 1998 and 1999, 43% of women underwent prenatal group B streptococcal screening. County of residence was the only factor independently associated with not being screened [odds ratio, 7.85; 95% confidence interval (4.69, 13.16)]. Ten affected babies were born to screened mothers (0.40 per 1000). In 9 of these 10, problems were identified: mothers had positive screening cultures but did not receive optimal intrapartum antibiotics (n = 3 of 4); mothers had negative screening cultures (n = 4); and mothers were screened, but the results were unknown, and intrapartum antibiotics were not given (n = 2).

CONCLUSIONS

Challenges to implementation of group B streptococcal screening and prophylaxis include insufficient screening, suboptimal intrapartum antibiotics, disease despite negative screening cultures and timely communication of screening results at delivery. An awareness of such problems may lead to supplemental measures to further reduce group B streptococcal disease.

Evaluation of a real-time fluorescent PCR assay for rapid detection of Group B Streptococci in neonatal blood

Streptococcus agalactiae (Group B Streptococcus: GBS) is the major causative agent of neonatal sepsis. Neonates at risk for GBS infections are empirically administered broad-spectrum antibiotics for at least 48 h pending blood culture results. A rapid assay to expedite detection of GBS would facilitate initiation of specific antibiotic therapy. Conversely, expeditious proof of absence of infection will avoid unnecessary antibiotic use. Using the LightCycler, we evaluated a hybridization probe polymerase chain reaction (PCR) assay to detect GBS-specific cfb gene target DNA sequence in blood specimens. Both sensitivity and specificity of the real-time PCR assay was 100%. The assay demonstrated 100% specificity when tested against 26 non-GBS bacteria. This method is capable of detecting as few as approximately 100 copies or 10 pg of GBS genomic DNA. This real-time PCR method is rapid, sensitive, and specific for the detection of GBS in neonatal blood samples and holds great promise in its utility in the diagnostic laboratory.

Perinatal Infections Due to Group B Streptococci

Group B streptococci (GBS) emerged dramatically in the 1970s as the leading cause of neonatal infection and as an important cause of maternal uterine infection. We review the epidemiology, diagnosis, and therapy of GBS perinatal infection. In 1996, the first national consensus guidelines were released. Since then, there has been a 70% reduction in early-onset neonatal GBS infection, but no decrease in late-onset neonatal GBS disease. In 2002, new national guidelines were released recommending 1) solely a screen-based prevention strategy, 2) a new algorithm for patients with penicillin allergy, and 3) more specific practices in certain clinical scenarios. Yet many clinical issues remain, including implementation of new diagnostic techniques, management of preterm rupture of membranes, use of alternative antibiotic approaches, improvement of compliance, prevention of low birth weight infants, emergence of resistant organisms, and vaccine development.

Method for quantitative detection and presumptive identification of group B streptococci on primary plating

Maternal prenatal screening for group B streptococci (GBS) followed by offering of intrapartum chemoprophylaxis to carriers is one of the strategies used to reduce the incidence of neonatal early-onset GBS infections. Culturing of vaginal and anorectal swab specimens in selective broth is the screening procedure recommended by the Centers for Disease Control and Prevention. This technique is sensitive; it does not, however, allow either evaluation of the degree of colonization or detection of cocolonization with several GBS clones. We have examined the carriage rate and population dynamics of GBS in a group of Danish women during pregnancy and 1 year after delivery using a new detection method. In the present paper we describe a mixed blood agar medium (MB agar) that identifies GBS in the primary cultures by detection of a double hemolysis pattern consisting of characteristic, large zones of partial hemolysis ("CAMP zones") and of narrow zones of complete hemolysis. The MB agar was at least as sensitive as culturing in selective broth for detection of GBS in vaginal and anorectal swab specimens, and GBS strains could be identified directly on the primary plate due to the CAMP zones without the need for subculturing. The carriage rate of GBS in a group of Danish women was found to be more than 30%, a figure considerably higher than the rate that was reported previously.

Screening for the early detection of disease, the need for evidence

BACKGROUND

Screening for the early detection of disease has had a spotted history. Structured approaches to the process of gathering and evaluating evidence, with the emphasis on well-controlled randomized studies, have greatly improved the beneficial potential of appropriate and effective screening. Good quality evidence will contribute to quality health care.

ISSUES

The volunteer participants in screening programs must give fully informed consent. This means that they must be presented with clear and accurate statements of the advantages and disadvantages of the screening program. Among the screening programs that have been conducted include hyperhomocysteinemia and coronary artery disease, Down's syndrome, Neonatal Group B streptococcal disease, Type 2 diabetes mellitus and endometrial cancer. The evidence in these studies has strengths and weaknesses as to how they support or oppose a particular intervention. The laboratory has a major role to play in establishing and validating standards of accuracy for diagnostic tests. Agreement on standards and their application does not mean the end of different interpretation and controversy.

CONCLUSIONS

Laboratory physicians and scientists will be very effective consultants if they have the best available, high quality evidence for the appropriate use of laboratory tests.

Group B streptococcal neonatal infections in Rio Grande do Sul, Brazil

Group B Streptococcus is the most common pathogen found in neonatal sepsis in North America.

OBJECTIVES

We describe 15 cases of neonatal infections by Group B Streptococcus (Streptococcus agalactiae) at a Neonatal Intensive Care Unit of a public and teaching hospital.

METHODS

We conducted a study at Hospital de Clínicas de Porto Alegre, from January 1st, 1996 to June 30, 1999. Diagnosis of neonatal infection was established according to the findings of Group B Streptococcus in blood culture associated with alterations resembling sepsis on the basis of clinical picture and laboratory findings.

RESULTS

Fifteen cases of neonatal infections by Group B Streptococcus were detected. Eleven cases consisted of early-onset sepsis, 2 cases of occult bacteremia and 2 cases of late-onset sepsis. Eight cases had septic shock (53%), 8 cases had pneumonia (53%), and 4 cases had meningitis (27%). Fourteen cases were diagnosed from a positive blood culture, and 1 case from evidence of these bacteria in pulmonary anatomopathological examination. Thirteen cases (87%) were diagnosed before 72 hours of life. We had 3 deaths (20%), and 3 cases of meningitis developing neurological deficits.

CONCLUSIONS

Streptococcus Group B is one of the most important pathogens in the etiology of early-onset neonatal sepsis at our hospital, with high mortality and morbidity. However, we do not know the incidence of GBS neonatal infections at other hospitals. More data are needed to establish a basis for trials of different strategies to reduce these infections.

Molecular methods for rapid detection of group B streptococci

Group B streptococci (GBS) are an important cause of neonatal sepsis and meningitis. Implementation of selective intrapartum chemoprophylaxis based on either a screening-based approach or a risk-based approach has led to a substantial decrease in the morbidity and mortality of GBS disease. Current 'gold-standard' detection methods for GBS are selective broth cultures of combined vaginal and anal specimens collected at 35-37 week's gestation. Rapid immunological detection methods, including latex agglutination test, enzyme immunoassay and optical immunoassay, as well as hybridization-based test, are available. These methods are useful in rapid identification of heavily colonized women, but are unable to detect light GBS colonization due to poor sensitivity. Recent development of real-time PCR and fluorescence labeling technologies has provided new detection platforms for bacterial identification. GBS-specific PCR assays using these new technologies offer promising tools for sensitive and specific detection of GBS directly from clinical specimens. The application of these assays in the current prevention strategy will simplify the prevention practice and rationalize antibiotic use.

Implementation of guidelines for preventing early onset group B streptococcal infection

Early onset Group B Streptococcus (EOGBS) disease, defined by an onset within the first 72 hours of life, occurs in 1.3 to 3.7 per 1,000 live births. The authors sought to determine the impact of the new CDC/AAP/ACOG guidelines on the prepartum screening practice, intrapartum management, incidence of EOGBS infection, and evaluation of neonates born to GBS colonized women at University Macdonald Women's Hospital (Cleveland, OH). A retrospective analysis by chart review was conducted from January 1, 1995 to December 31, 1997 of women identified as GBS colonized during prenatal screening. These women were then divided into 2 groups: period I, women who delivered January 1, 1995 to June 30, 1996 (before institutional implementation of the guidelines for management of GBS colonization]; and period II, women who delivered July 1, 1996 to December 31, 1997 after implementation of the guidelines. A chart review was conducted for infants 72 hours old, and GBS culture positive (blood or CSF) for the same time period. In complying with the new screening and treatment guidelines, there was a significant increase in the number of mothers screened and the detection of maternal colonization, plus a 63% reduction in EOGBS. There was also a substantial reduction in the number of invasive procedures on the neonates. The authors conclude that the new guidelines are both medically and economically effective.