Early-onset neonatal sepsis in the era of group B streptococcal prevention

Clinical Findings of Listeria monocytogenes Infections with a Special Focus on Bone Localizations

Listeria monocytogenes is a Gram-positive pathogenic bacterium which can be found in soil or water. Infection with the microorganism can occur after ingestion of contaminated food products. Small and large outbreaks of listeriosis have been described in the past. L. monocytogenes can cause a number of different clinical syndromes, most frequently sepsis, meningitis, and rhombencephalitis, particularly in immunocompromised hosts. L. monocytogenes systemic infections can develop following tissue penetration across the gastrointestinal tract or to hematogenous spread to sterile sites, possibly evolving towards bacteremia. L. monocytogenes only rarely causes bone or joint infections, usually in the context of prosthetic material that can provide a site for bacterial seeding. We describe here the clinical findings of invasive listeriosis, mainly focusing on the diagnosis, clinical management, and treatment of bone and vertebral infections occurring in the context of invasive listeriosis.

Akt Inhibition Promotes Autophagy and Clearance of Group B Streptococcus from the Alveolar Epithelium

Group B Streptococcus (GBS) is a gram-positive bacterium that is harmless for healthy individuals but may provoke invasive disease in young infants and immunocompromised hosts. GBS invades the epithelial barriers to enter the bloodstream, and thus strategies that enhance epithelial cell responses may hamper GBS invasion. In the present study, we sought to investigate whether the inhibition of Akt, a kinase that regulates host inflammatory responses and autophagy via suppression of mTOR, can enhance the response of non-phagocytic alveolar epithelial cells against GBS. Treatment of the alveolar epithelial cell line A549 with the Akt inhibitor MK-2206 resulted in the enhanced production of reactive oxygen species and inflammatory mediators in response to GBS. Additionally, Akt inhibition via MK-2206 resulted in elevated LC3II/I ratios and increased autophagic flux in alveolar epithelial cells. Importantly, the inhibition of Akt promoted GBS clearance both in alveolar epithelial cells in vitro and in lung tissue in vivo in a murine model of GBS pneumonia. The induction of autophagy was essential for GBS clearance in MK-2206 treated cells, as knockdown of ATG5, a critical component of autophagy, abrogated the effect of Akt inhibition on GBS clearance. Our findings highlight the role of Akt kinase inhibition in promoting autophagy and GBS clearance in the alveolar epithelium. The inhibition of Akt may serve as a promising measure to strengthen epithelial barriers and prevent GBS invasion in susceptible hosts.

A comprehensive analysis of listeriosis in 13 pregnant women and 27 newborns in Xi'an from 2011 to 2020

BACKGROUND

Listeriosis is a severe foodborne infection associated with high mortality. Pregnant women and newborns are at a particularly high risk of infection. However, the data on epidemiology of maternal-neonatal listeriosis in Xi'an are little known. The aim of this study was to investigate the epidemiological and clinical features of maternal-neonatal listeriosis in Xi'an.

METHODS

A total of 40 cases of listeriosis confirmed by positive cultures [blood or cerebrospinal fluid (CSF)] and admitted to the Northwest Women's and Children's Hospital (NWCH) from 2011 to 2020 were enrolled. Data from all patients were collected from the hospital's electronic medical records. Data analysis and epidemiological investigation were carried out by demographic information, time of onset, clinical and laboratory characteristics. Descriptive statistical indicators were obtained using SPSS21.0 and were expressed as median, mean, standard deviation and interquartile range.

RESULTS

The incidence of maternal and neonatal listeriosis in NWCH over the last decade was 5/100,000 and 10.4/100,000 respectively and Listeriosis was more likely to occur in spring and summer. The most common symptom was as follows: (I) maternal: fever (85%), abdominal pain (77%), vaginal fluid or colporrhagia (46%); (II) neonatal: respiratory distress (52%), fever (33%). Laboratary results were as follows: (I) maternal: elevated C-reactive protein (CRP) (100%), white blood cells (WBC) or neutrophil (NEUT#) (85%), and monocyte counts (MONO#) (77%); (II) neonatal: increased WBC (81%), MONO# (81%), CRP (78%), NEUT# and lymphocytes (73%); and elevated protein (PRO) (95%) and WBC count (86%) in CSF while decreased in glucose (GLU) (73%). Compared to neonatal group, the ratio of neutrophils to lymphocytes in maternal group raise to a higher level (92% to 42%). The outcomes of maternal were favorable and 54% of them suffered acute chorioamnionitism. Yet neonatal deaths account for up to 33%.

CONCLUSIONS

Listeriosis is a rare disease with extremely variable clinical characteristics in Xi'an. Our data indicated that unexplained fever, abdominal pain, signs of premature and respiratory symptoms accompanied by a progressive increase in WBC, CRP, NEUT#, MONO# even include WBC and PRO in CSF while GLU decreased, the possibility of an LM infection should be considered.

Practice Summary of Antimicrobial Therapy for Commonly Encountered Conditions in the Neonatal Intensive Care Unit: A Canadian Perspective

Neonates are highly susceptible to infections owing to their immature cellular and humoral immune functions, as well the need for invasive devices. There is a wide practice variation in the choice and duration of antimicrobial treatment, even for relatively common conditions in the NICU, attributed to the lack of evidence-based guidelines. Early decisive treatment with broad-spectrum antimicrobials is the preferred clinical choice for treating sick infants with possible bacterial infection. Prolonged antimicrobial exposure among infants without clear indications has been associated with adverse neonatal outcomes and increased drug resistance. Herein, we review and summarize the best practices from the existing literature regarding antimicrobial use in commonly encountered conditions in neonates.

The impact of maternal exposure to antibiotics on the development of child gut microbiome

Antibiotics are widely prescribed for mothers in the peripartum period today. Approximately 40% of pregnant women at term are exposed to antibiotics. Antibiotics are useful against infectious conditions such as chorioamnionitis; however, they alter the maternal microbiome. The maternal microbiome, particularly the gut microbiome, is transmitted to their neonates and is one of the major sources that shape the child's gut microbiome. The gut microbiome early in life plays a crucial role in the development of the gut microbiome itself as well as the host health over the entire life. Microbes structure the commensal ecosystem in the host. Simultaneously, microbial components and metabolites influence the host organ functions including the immune system, and vice versa, the various factors of the host impact the microbiome. The alterations of the gut microbiome induced by antibiotics in mothers can lead to gut dysbiosis in children eventually resulting in chronic disease conditions including immune disorders. Knowledge of the lasting impacts of maternal peripartum exposure to antibiotics on the gut microbiome and health in offspring and reconsideration of the adequate use of antibiotics in clinical practice are needed. Avoiding and restoring neonatal dysbiosis following maternal antibiotics-induced dysbiosis could be a new preventive strategy for various diseases.

Protective role of IL-18 in host defenses against group B Streptococcus

The aim of this study was to investigate the role of IL-18, a member of the IL-1 family, in group B Streptococcus (GBS) infection. Both in a neonatal and adult model of GBS infection, IL-18-deficient animals were significantly more susceptible to infection than WT animals. The lack of IL18 was associated with a marked reduction in IFN-γ-levels after bacterial stimulation but did not play a significant role in the recruitment of PMN to sites of GBS infection. Collectively, our data document a fundamental function of IL-18 signaling in boosting the host immune responses against GBS infection.

Antibiotic regimens for early-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality. It is the third leading cause of neonatal mortality globally constituting 13% of overall neonatal mortality. Despite the high burden of neonatal sepsis, high-quality evidence in diagnosis and treatment is scarce. Possibly due to the diagnostic challenges of sepsis and the relative immunosuppression of the newborn, many neonates receive antibiotics for suspected sepsis. Antibiotics have become the most used therapeutics in neonatal intensive care units. The last Cochrane Review was updated in 2004. Given the clinical importance, an updated systematic review assessing the effects of different antibiotic regimens for early-onset neonatal sepsis is needed.

OBJECTIVES

To assess the beneficial and harmful effects of different antibiotic regimens for early-onset neonatal sepsis.

SEARCH METHODS

We searched the following electronic databases: CENTRAL (2020, Issue 8); Ovid MEDLINE; Embase Ovid; CINAHL; LILACS; Science Citation Index EXPANDED and Conference Proceedings Citation Index - Science on 12 March 2021. We searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs comparing different antibiotic regimens for early-onset neonatal sepsis. We included participants from birth to 72 hours of life at randomisation.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence. Our primary outcome was all-cause mortality, and our secondary outcomes were: serious adverse events, respiratory support, circulatory support, nephrotoxicity, neurological developmental impairment, necrotising enterocolitis, and ototoxicity. Our primary time point of interest was at maximum follow-up.

MAIN RESULTS

We included five RCTs (865 participants). All trials were at high risk of bias. The certainty of the evidence according to GRADE was very low. The included trials assessed five different comparisons of antibiotics. We did not conduct any meta-analyses due to lack of relevant data. Of the five included trials one trial compared ampicillin plus gentamicin with benzylpenicillin plus gentamicin; one trial compared piperacillin plus tazobactam with amikacin; one trial compared ticarcillin plus clavulanic acid with piperacillin plus gentamicin; one trial compared piperacillin with ampicillin plus amikacin; and one trial compared ceftazidime with benzylpenicillin plus gentamicin. None of the five comparisons found any evidence of a difference when assessing all-cause mortality, serious adverse events, circulatory support, nephrotoxicity, neurological developmental impairment, or necrotising enterocolitis; however, none of the trials were near an information size that could contribute significantly to the evidence of the comparative benefits and risks of any particular antibiotic regimen. None of the trials assessed respiratory support or ototoxicity. The benefits and harms of different antibiotic regimens remain unclear due to the lack of well-powered trials and the high risk of systematic errors.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support any antibiotic regimen being superior to another. Large RCTs assessing different antibiotic regimens in early-onset neonatal sepsis with low risk of bias are warranted.

Early-onset neonatal sepsis: Organism patterns between 2009 and 2014

OBJECTIVE

To evaluate trends in organisms causing early-onset neonatal sepsis (EONS). Congruent with recent reports, we hypothesized there would be an increase in EONS caused by Escherichia coli.

STUDY DESIGN

National data on infants admitted to neonatal intensive care units from 2009 to 2014 were compared to previously reported data from 2003 to 2008. We report 430 cases of EONS from 2009 to 2014. Bivariate analyses were used to analyze the distribution of causative organisms over time and differences by gestational age. Linear regression was used to estimate trends in causative organisms.

RESULTS

Since 2003, there has been a trend of increasing numbers of cases caused by E coli (P<0.01). The predominant organism was E coli in preterm infants and Group B Streptococcus in term infants.

CONCLUSIONS

With the majority of EONS cases now caused by E coli, our findings emphasize the importance of continued surveillance of causative organism patterns and developing approaches to reduce cases caused by E coli.

Should clinical suspicion shift to ampicillin resistance organisms in certain preterm premature rupture of membranes scenarios?: Case of early-onset sepsis caused by E coli

This case highlights the importance antibiotic stewardship, including reexamining current regimens use for intrapartum antibiotic prophylaxis, which may be accountable for the shift in organism responsible for some cases of early-onset sepsis.

Population-based study of early-onset neonatal sepsis in Canada

OBJECTIVE

To determine the incidence, types of organisms and resistance patterns involved in early-onset neonatal sepsis in Canada.

STUDY DESIGN

Early-onset neonatal sepsis cases were identified through the Canadian Paediatric Surveillance Program. Neonates were excluded if they were asymptomatic or if intracranial procedures preceded a positive cerebrospinal fluid culture.

RESULTS

One hundred and twenty-seven cases were identified (0.17 cases per 1000 live births). Group B Streptococcus accounted for 41.7%, Escherichia coli for 35.4%. Antibiotic resistance was present in 33.9% of all cases. 55.6% of E coli cases were resistant, most commonly to ampicillin. Infecting organism species were associated with gestational age, being very low birth weight, time at sepsis presentation, maternal antibiotic prophylaxis and rupture of membranes lasting over 18 hours. Group B Streptococcus was most common in term and E coli in preterm neonates. Twenty-two per cent of E coli cases presented after 48 hours, compared to 6% of Group B Streptococcus cases.

CONCLUSION

We identify a lower rate of early-onset neonatal sepsis than historically suggested, with differing dominant organisms based on gestational ages and other factors, as well as high rates of resistance especially among E coli cases.

Epidemiology and Clinical Manifestations of Listeria monocytogenes Infection

Listeria monocytogenes is a Gram-positive pathogenic bacterium which can be found in soil or water. Infection with the organism can develop after ingestion of contaminated food products. Small and large outbreaks of listeriosis have been described. Listeria monocytogenes can cause a number of clinical syndromes, most frequently sepsis, meningitis, and rhombencephalitis, particularly in immunocompromised hosts. The latter syndrome mimics the veterinary infection in ruminants called "circling disease". Neonatal infection can occur as a result of maternal chorioamnionitis ("early onset" sepsis) or through passage through a birth canal colonized with Listeria from the gastrointestinal tract. ("late onset" meningitis). Treatment of listeriosis is usually with a combination of ampicillin and an aminoglycoside but other regimens have been used. The mortality rate is high, reflecting the combination of an immunocompromised host and an often delayed diagnosis.

Potential biomarkers for effective screening of neonatal sepsis infections: An overview

Neonatal sepsis, a clinical disorder developed by bacterial blood stream infections (BSI) in neonates, is one of the serious global public health problems that must be addressed. More than one million of the estimated global newborn deaths per year are occurred due to severe infections. The genesis of the infection is divided into early-onset sepsis (EOS) and late-onset sepsis (LOS) of the disease. The clinical complications of neonatal sepsis may be associated with bronchopulmonary dysplasia, ductus arteriosus and necrotizing enterocolitis. The clinical diagnosis and treatment of neonatal sepsis is highly complicated. Over the past few years distinct biomarkers have been identified. Most widely used biomarkers are C-reactive protein, Procalcitonin (PCT) and Serum amyloid A (SAA). Until recently, many potential biomarkers including Cell Surface antigens and Bacterial surface antigens and genetic biomarkers are being investigated. Protein biomarkers, cytokines and chemokines are getting much interest for identification of neonatal sepsis infection.

The role of Escherichia coli in reproductive health: state of the art

Escherichia coli is a well-known commensal of the normal intestinal microbiome that can also colonize the vaginal microbiome, usually without symptoms. However, E. coli can also be a highly virulent and frequently deadly pathogen. In this review, I will discuss the role E. coli has in reproductive health and disease.

Of the Phrensy: an update on the epidemiology and pathogenesis of bacterial meningitis in the pediatric population

In the past century, advances in antibiotics and vaccination have dramatically altered the incidence and clinical outcomes of bacterial meningitis. We review the shifting epidemiology of meningitis in children, including after the implementation of vaccines that target common meningitic pathogens and the introduction of intrapartum antibiotic prophylaxis offered to mothers colonized with Streptococcus agalactiae. We also discuss what is currently known about the pathogenesis of meningitis. Recent studies of the human microbiome have illustrated dynamic relationships of bacterial and viral populations with the host, which may potentiate the risk of bacterial meningitis.

Early and Late Infections in Newborns: Where Do We Stand? A Review

Neonatal sepsis still represents an important cause of mortality and morbidity among infants. According to the onset, we can distinguish "early onset sepsis" when microbiological cultures positive for external pathogens come from newborns during the first 7 days of life (maternal intrapartum transmission); "late onset sepsis" when microbiological cultures positive for external pathogens come from newborns after the first 7 days from delivery (postnatal acquisition). In this review we synthesize the incidence, risk factors, clinical manifestations, and methods of diagnosis and treatment of each type of neonatal infection, in order to better define such a pathological condition which is of great importance in common clinical practice.

The Clinical Characteristics of Neonatal Sepsis Infection in Southwest China

OBJECTIVE

To identify the pathogens responsible for neonatal sepsis in a high-volume women and children's hospital in Southwest China.

METHODS

We retrospectively studied 133 neonates who were admitted to the West China Women and Children's Hospital between 2008 and 2012 for sepsis. The clinical characteristics of the patients were recorded, and the antibiotic sensitivities of the isolated bacteria were determined.

RESULTS

All of the included patients had clinical symptoms of sepsis, and subsequent blood cultures confirmed the infection. Almost 80% of patients were infected with coagulase-negative staphylococci (52.8%), Escherichia coli (23.6%), Klebsiella pneumoniae (16.0%) or Staphylococcus aureus (7.5%). Neonates who were infected with gram-negative bacteria, particularly K. pneumoniae, had lower birth weights and were admitted to hospital within 24 hours of birth. Additionally, 87.5% of the isolated K. pneumoniae strains were resistant to third generation cephalosporins.

CONCLUSION

Coagulase-negative staphylococci were the most common pathogens found in neonatal sepsis. Moreover, neonatal sepsis caused by gram-negative bacteria was more often observed in newborns of low birth weight. The isolated strains of gram-negative bacteria were highly resistant to cephalosporins. This observation highlights the issue of antibiotic-resistant pathogens in the clinical setting, which poses an added risk to infants presenting with sepsis.

Neonatal Escherichia coli Bloodstream Infections: Clinical Outcomes and Impact of Initial Antibiotic Therapy

BACKGROUND

Escherichia coli is a common cause of bloodstream infections (BSIs) in infants and is associated with high mortality and morbidity among survivors. The clinical significance of antibiotic resistance and timing of appropriate antimicrobial therapy in this population is poorly understood.

METHODS

We identified all infants with E. coli BSIs discharged from 77 neonatal intensive care units managed by the Pediatrix Medical Group in 2012. We used multivariable logistic regression to evaluate the association between 30-day mortality and ampicillin-resistant E. coli BSI, as well as the number of active empiric antimicrobial agents administered, controlling for gestational age, small-for-gestational age status, early-onset versus late-onset BSI, oxygen requirement, ventilator support and inotropic support on the day of the first positive blood culture.

RESULTS

We identified 258 episodes of E. coli BSI, including 123 (48%) ampicillin-resistant isolates. Unadjusted 30-day mortality did not significantly differ between infants with ampicillin-resistant versus ampicillin-susceptible E. coli BSI [11 of 123 (9%) vs. 7 of 135 (5%); P = 0.33; adjusted odds ratio = 1.37 (95% confidence interval: 0.39, 4.77)]. Among ampicillin-resistant E. coli BSIs, 30-day mortality was not significantly lower for infants treated with at least one empiric antimicrobial active against ampicillin-resistant E. coli versus infants receiving no active empiric agent [adjusted odds ratio = 1.50 (0.07, 33.6)].

CONCLUSIONS

In this population of infants with E. coli BSI, ampicillin resistance was not associated with significantly increased mortality. Among the subset of infants with ampicillin-resistant E. coli, appropriate empirical antibiotic therapy was not associated with lower mortality.

Neonatal sepsis 2004-2013: the rise and fall of coagulase-negative staphylococci

OBJECTIVES

To evaluate data for the period 2004-2013 to identify changes in demographics, pathogens, and outcomes in a single, level IV neonatal intensive care unit.

STUDY DESIGN

Sepsis episodes were identified prospectively and additional information obtained retrospectively from infants with sepsis while in the neonatal intensive care unit from 2004 to 2013. Demographics, hospital course, and outcome data were collected and analyzed. Sepsis was categorized as early (≤3 days of life) or late-onset (>3 days of life).

RESULTS

Four hundred fifty-two organisms were identified from 410 episodes of sepsis in 340 infants. Ninety percent of cases were late-onset. Rates of early-onset sepsis remained relatively static throughout the study period (0.9 per 1000 live births). For the first time in decades, most (60%) infants with early-onset sepsis were very low birth weight and Escherichia coli (45%) replaced group B streptococcus (36%) as the most common organism associated with early-onset sepsis. Rates of late-onset sepsis, particularly due to coagulase-negative staphylococci, decreased significantly after implementation of several infection-prevention initiatives. Coagulase-negative staphylococci were responsible for 31% of all cases from 2004 to 2009 but accounted for no cases of late-onset sepsis after 2011.

CONCLUSIONS

The epidemiology and microbiology of early- and late-onset sepsis continue to change, impacted by targeted infection prevention efforts. We believe the decrease in sepsis indicates that these interventions have been successful, but additional surveillance and strategies based on evolving trends are necessary.

Antibiotic use and misuse during pregnancy and delivery: benefits and risks

Although pregnancy is considered as a physiological state, most pregnant women in developed countries receive multiple medications to prevent maternal or neonatal complications, with antibiotics among the most frequently prescribed. During pregnancy, antibiotics are often prescribed in the context of preterm labor, intrapartum fever, prevention of neonatal Group B Streptococcus fever, and cesarean section. Outside this period, they are commonly prescribed in the community setting for respiratory, urinary, and ear, nose and throat infection symptoms. Whereas some of the current indications have insightful reasons to justify their use, potential risks related to overuse and misuse may surpass the benefits. Of note, the recent 2014 World Health Assembly expressed serious concern regarding antibiotic resistance due to antibiotic overuse and misuse and urged immediate action to combat antibiotic resistance on a global scale. Most studies in the obstetrics field have focused on the benefits of antibiotics for short-term maternal and neonatal complications, but with very little (if any) interest in long-term consequences.

Molecular-based screening for perinatal group B streptococcal infection: implications for prevention and therapy

Group B streptococci (GBS) are a leading cause of infectious neonatal morbidity and mortality. Timely and accurate identification of colonized pregnant women is imperative to implement intrapartum antibioprophylaxis (IAP) to reduce the risk of early neonatal sepsis. Current guidelines recommend screening for GBS carriage with vaginal-rectal cultures. However, cultures require 24-72 h, thus precluding their use for intrapartum screening and these are only performed at 35-37 weeks gestation. New rapid molecular-based tests can detect GBS within hours. They have the potential to be used intrapartum and to allow for selective IAP in women carrying GBS. An advantage is that they can sometimes be performed by non-laboratory staff in the labor suite, thus avoiding delays in sample transfers to the microbiology laboratory. Another possible use of molecular-based assays is for the diagnosis of neonatal sepsis, where tests with a short turnaround time and high sensitivity and specificity are crucial. In this situation, the detection of microorganisms once antibiotic therapy has already been started is important, as treatment is started immediately once sepsis is suspected without waiting for microbiological confirmation. In this article, we discuss the state-of-the-art molecular-based tests available for GBS screening during pregnancy, as well as their implications for IAP for the diagnosis and prevention of neonatal sepsis.

Significance, management and prevention of Streptococcus agalactiae infection during the perinatal period

The highest annual death rate during the first five decades of life occurs in the first year, particularly during the perinatal period between the onset of labor and 72 h after birth. Invasive bacterial disease evoking the severe inflammatory response syndrome is a leading cause of perinatal morbidity and mortality. Group B streptococcus (Streptococcus agalactiae) is the most important pathogen in this period of life, although the concept of intrapartum antimicrobial prophylaxis has impressively reduced the rate of culture-proven invasive infection in neonates. This strategy, however, has considerable limitations since group B streptococcus-related stillbirths or prematurity and late-onset sepsis cannot be prevented. Moreover, the use of intrapartum antimicrobial prophylaxis has significantly increased the use of antibiotics during labor and therefore may select for intrapartum infections caused by other bacteria, including those resistant to antibiotics. Several advances in the development of vaccines and research on virulence factors and pathways involved in the immune response to group B streptococcus have been accomplished within the last years, including complete sequencing of the group B streptococcus genome. Development of effective vaccines and implementation of vaccination strategies will be one of the key challenges in the future for prevention of neonatal group B Streptococcus infections.

Neonatal sepsis: an old problem with new insights

Neonatal sepsis continues to be a common and significant health care burden, especially in very-low-birth-weight infants (VLBW <1500 g). Though intrapartum antibiotic prophylaxis has decreased the incidence of early-onset group B streptococcal infection dramatically, it still remains a major cause of neonatal sepsis. Moreover, some studies among VLBW preterm infants have shown an increase in early-onset sepsis caused by Escherichia coli. As the signs and symptoms of neonatal sepsis are nonspecific, early diagnosis and prompt treatment remains a challenge. There have been a myriad of studies on various diagnostic markers like hematological indices, acute phase reactants, C-reactive protein, procalcitonin, cytokines, and cell surface markers among others. Nonetheless, further research is needed to identify a biomarker with high diagnostic accuracy and validity. Some of the newer markers like inter α inhibitor proteins have shown promising results thereby potentially aiding in early detection of neonates with sepsis. In order to decrease the widespread, prolonged use of unnecessary antibiotics and improve the outcome of the infants with sepsis, reliable identification of sepsis at an earlier stage is paramount.

Performance evaluation of hematologic scoring system in early diagnosis of neonatal sepsis

OBJECTIVES

The present study was undertaken to evaluate and highlight the importance of hematological scoring system (HSS) in the early detection of neonatal sepsis.

MATERIALS AND METHODS

The cross-sectional study enrolled 110 neonates who were clinically suspected of infection (study group) and normal neonates for comparison (controls), during the 1(st) week of life. All peripheral blood smears were analyzed using HSS of Rodwell et al., by pathologists blinded to the infection status of the newborns. HSS assigns a score of 1 for each of seven findings significantly associated with sepsis: Abnormal total leukocyte count, abnormal total polymorphonuclear neutrophils (PMN) count, elevated immature PMN count, elevated immature: Total (I:T) PMN ratio, immature: Mature (I:M) PMN ratio ≥0.3, platelet count ≤150,000/mm(3), and pronounced degenerative or toxic changes in PMNs. Score of ≤2 was interpreted as sepsis unlikely; score 3-4: Sepsis is possible and ≥5 sepsis or infection is very likely. Blood culture was taken as a standard indicator for septicemia. The perinatal history, clinical profile and laboratory data were recorded and correlated in each case. Each hematological parameter was assessed for its individual performance and also with the culture-proven sepsis. Sensitivity, specificity, positive and negative predictive values (NPVs) were calculated for each parameter and for different gestational ages. P value was also calculated for different parameters.

RESULTS

Out of the 110 infants, based on clinical findings and laboratory data were classified into three categories: Sepsis (n=42), probable infection (n=22) and normal (n=46). Out of these, 42 (38.2%) newborns had positive blood culture. 63 (57%) neonates were preterm and 47 (43%) term. Male: female ratio was 0.96:1. The P value was significant for the different gestational ages (0.0002) and sex ratio (0.003). Immature polymorphonuclear neutrophils (PMN) count was the most sensitive and I:M PMN ratio, the most specific indicator of sepsis. For sepsis and probable sepsis, I:T PMN count and immature PMN count have highest sensitivity whereas I:T and I:M PMN ratio have highest specificity. HSS has much higher sensitivity and specificity in preterms than in term neonates. Positive predictive value and NPV is also higher in preterm than term for HSS. It was also seen that with increasing scores, the likelihood of sepsis also increased.

CONCLUSION

The sensitivities of the various screening parameters were found to be satisfactory in identifying early onset neonatal sepsis. It is a simple and feasible diagnostic tool to guide towards the decision-making for a rationale treatment.

Correlation of bacterial type and antibiotic sensitivity with maternal antibiotic exposure in early-onset neonatal sepsis

BACKGROUND

Antibiotic administration during pregnancy as group B Streptococcus prophylaxis or as treatment of maternal conditions has become widespread.

OBJECTIVE

To assess whether bacterial type and antibiotic resistance in early-onset neonatal sepsis are associated with maternal antibiotic use.

METHODS

All positive blood and/or cerebrospinal fluid cultures (case-only study) and respective antibiotic sensitivities from newborns delivered in Shaare Zedek Medical Center, Jerusalem, Israel, between 01/01/1997 and 31/01/2007, taken during the first 72 h of life, were studied. Clinical and demographic data were obtained from the medical records of the infant/mother dyads. Three groups were defined by type of maternal antibiotic exposure: (1) no exposure, (2) intrapartum antibiotic prophylaxis (IAP), (3) antepartum antibiotic exposure during the month prior to delivery and extending into delivery or with subsequent IAP (AAE). Factors potentially associated with Gram-negative bacteremia and resistance to ampicillin were analyzed using multivariate logistic regression.

RESULTS

Ninety-seven different organisms grew from 94 infants (1.03 per 1,000 live births). By univariate analysis, AAE, gestational age ≤ 32 weeks, chorioamnionitis and rupture of membranes ≥ 18 h, were significantly associated with both Gram-negative sepsis and antibiotic resistance. By multivariate analysis, AAE was significantly associated with both outcomes, while gestational age ≤32 weeks was only associated with antibiotic resistance.

CONCLUSIONS

AAE for more than 24 h is associated with an increased proportion of Gram-negative organisms and ampicillin resistance in early-onset neonatal sepsis. Antepartum antibiotic therapy and its ramifications need to be continuously monitored and prospectively studied.

Prevention of neonatal group B streptococcus disease in the 21st century

There have been significant reductions in early-onset neonatal group B streptococcus (GBS) disease following implementation of maternal intrapartum antibiotic prophylaxis (IAP) policies. Nevertheless, GBS remains a leading cause of neonatal sepsis in Australia and New Zealand resulting in considerable morbidity and mortality, particularly among preterm infants. In the United States, the universal screening-based approach for identifying women for IAP results in apparently lower rates of early-onset neonatal GBS infection than risk-based assessment. In addition, IAP has altered the profile of newborn infants who develop early-onset disease. Many affected infants lack the typical intrapartum risk factors for GBS infection, are born to mothers with a negative GBS screen or represent missed opportunities for prevention. Clinicians should remain alert for signs of sepsis in any newborn infant. We provide an update of GBS preventative management strategies in the perinatal period taking into account recent United States, Australian and New Zealand guidelines.

Clinical sepsis in neonates and young infants, United States, 1988-2006

OBJECTIVE

To describe the burden and characteristics of clinical neonatal sepsis in the United States and evaluate incidence rates after the issuance of intrapartum antibiotic prophylaxis (IAP) guidelines.

STUDY DESIGN

This is a cross-sectional study of hospitalizations of infants aged <3 months diagnosed with sepsis from the 1988-2006 National Hospital Discharge Survey. The National Hospital Discharge Survey collects data annually on inpatient discharges from a national probability sample of approximately 500 short-stay hospitals. We examined sepsis hospitalizations, defined by International Classification of Diseases, Ninth Revision, Clinical Modification codes, and compared sepsis hospitalization rates for 2 time periods after the issuance of IAP guidelines (1996-2001 and 2002-2006) with 1988-1995 using national natality data as the population denominator. We used Joinpoint (Surveillance Research Program, National Cancer Institute, Bethesda, Maryland) regression to assess the average annual percent change (AAPC) in rates.

RESULTS

Between 1988 and 2006, there were more than 2.5 million sepsis-related hospitalizations in infants aged <3 months (112 000-146 000 annually). In 2006, the sepsis hospitalization rate was 30.8/1000 births. The rate was more than 3 times higher in preterm infants compared with term infants (85.4/1000 preterm births vs 23.1/1000 term births). The AAPC in sepsis hospitalization rate was -3.6% (95% CI, -5.1% to 2.0%) [corrected] for term infants during 1996-2002 and did not change significantly after issuance of the revised 2002 guidelines. For preterm infants, the AAPC was -1.2% (95% CI, -2.2% to -0.1%) [corrected] annually from 1988 to 2006.

CONCLUSION

Clinical neonatal sepsis declined in the post-IAP era, mirroring trends observed in group B streptococcal early-onset neonatal sepsis surveillance. Preterm infants were affected disproportionately and exhibited a modest but steady decline in sepsis hospitalization rate.

Methicillin-resistant and susceptible Staphylococcus aureus bacteremia and meningitis in preterm infants

BACKGROUND

Data are limited on the impact of methicillin-resistant Staphylococcus aureus (MRSA) on morbidity and mortality among very low birth weight (VLBW) infants with S aureus (SA) bacteremia and/or meningitis (B/M).

METHODS

Neonatal data for VLBW infants (birth weight 401-1500 g) born January 1, 2006, to December 31, 2008, who received care at centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network were collected prospectively. Early-onset (≤72 hours after birth) and late-onset (>72 hours) infections were defined by blood or cerebrospinal fluid cultures and antibiotic treatment of ≥5 days (or death <5 days with intent to treat). Outcomes were compared for infants with MRSA versus methicillin-susceptible S aureus (MSSA) B/M.

RESULTS

Of 8444 infants who survived >3 days, 316 (3.7%) had SA B/M. Eighty-eight had MRSA (1% of all infants, 28% of infants with SA); 228 had MSSA (2.7% of all infants, 72% of infants with SA). No infant had both MRSA and MSSA B/M. Ninety-nine percent of MRSA infections were late-onset. The percent of infants with MRSA varied by center (P < .001) with 9 of 20 centers reporting no cases. Need for mechanical ventilation, diagnosis of respiratory distress syndrome, necrotizing enterocolitis, and other morbidities did not differ between infants with MRSA and MSSA. Mortality was high with both MRSA (23 of 88, 26%) and MSSA (55 of 228, 24%).

CONCLUSIONS

Few VLBW infants had SA B/M. The 1% with MRSA had morbidity and mortality rates similar to infants with MSSA. Practices should provide equal focus on prevention and management of both MRSA and MSSA infections among VLBW infants.

Identification of genes affecting expression of phosphoglycerate kinase on the surface of group B streptococcus

Group B streptococcal phosphoglycerate kinase (GBS-PGK), a glycolytic enzyme, has previously been identified on the surface of group B streptococcus (GBS). To identify genes involved in surface expression of GBS-PGK, we performed Tn917 mutagenesis followed by quantification of PGK expressed on the GBS surface. Tn917 mutagenesis identified 4 genes (sag0966, sag0979, sag0980, and sag1003) that when disrupted, alter expression of GBS-PGK on the bacterial surface. Three of the identified genes were localized to a region of the GBS genome containing genes (sag0973-sag0977) predicted to be involved in resistance to antimicrobial peptides. One mutant isolate, designated NCS13sag1003::Tn917, was found to have increased sensitivity to the antimicrobial peptides bacitracin and nisin. In addition, all of the mutant strains assayed were found to have decreased β-hemolysis. In conclusion, we have identified genes involved in surface expression of GBS-PGK. These genes also appear to be involved in antimicrobial peptide resistance and regulate expression of the β-hemolysin.

Early hospital discharge of infants born to group B streptococci-positive mothers: a decision analysis

OBJECTIVE

To compare the cost-effectiveness of an additional 24-hour inpatient observation for asymptomatic term neonates born to group B streptococcus (GBS)-colonised mothers with adequate intrapartum antibiotic prophylaxis (IAP) after an initial 24-hour in-hospital observation.

DESIGN

Cost-effectiveness analysis from a societal perspective.

SETTING

United States.

POPULATION

Asymptomatic term neonates born to GBS-colonised mothers with IAP after an initial 24-hour in-hospital observation.

METHODS

Monte Carlo simulation for a decision tree model incorporating the following chance events: development of GBS sepsis during the second 24 hours of life, development of GBS sepsis between 48 hours and 7 days of life, prompt versus delayed treatment for sepsis, neonatal mortality and long-term health sequelae.

MAIN OUTCOME MEASURES

Expected cost and quality-adjusted life years (QALYs), Incremental cost-effectiveness ratio (ICER).

RESULTS

Delayed, versus early, hospital discharge results in similar mean expected QALYs, but substantially higher expected cost. The mean difference in QALY is 0.00016 (95% CI 0.00005-0.00040), whereas the mean difference in cost is $1170.96 (95% CI $750.13-1584.32). The ICER is estimated to be $9,771,520.87 per QALY (95% CI $2,573,139.89-24,407,017.82). The proportion of early-onset GBS that develops during the second 24 hours of life, the cost of 24 hours of inpatient observation, and the probability of long-term sequelae following prompt versus delayed treatment play important roles in determining the cost-effectiveness of delayed hospital discharge.

CONCLUSION

Cost-effectiveness analysis suggests that with adequate IAP, discharging asymptomatic term neonates to home after 24 hours is the preferred approach compared with 48 hours inpatient observation.

Early-onset neonatal sepsis: rate and organism pattern between 2003 and 2008

OBJECTIVE

Organisms causing early-onset neonatal sepsis (EONS) have consistently changed over time. The distribution of organisms in EONS helps to influence the appropriate type of antibiotic prophylaxis strategy during labor and the antibiotics used in neonates with suspected sepsis.

STUDY DESIGN

To compare the organisms distribution for EONS between 2003 and 2008 for infants admitted to neonatal intensive care units (NICUs) in Canada. Data were retrieved from infants with a positive bacterial blood or cerebrospinal fluid culture in the first 72  h after birth who were admitted to NICUs participating in the Canadian Neonatal Network from 2003 to 2008. Comparisons of incidence rate, demographics and causative organisms were carried out between earlier cohort (2003 to 2005) and later cohort (2006 to 2008).

RESULT

A total of 405 infants had positive blood and/or cerebral spinal fluid cultures over the study period. The EONS rate was 6.8/1000 admissions (n=24969) in the earlier cohort compared with 6.2/1000 admissions (n=37484) in the later cohort (P=0.36). Rate of clinical chorioamnionitis was higher in the later cohort (38 vs 26%; P=0.02). For term infants, coagulase-negative Staphylococcus (CONS) (2.4/1000) followed by group B Streptococcus (GBS) (1.9/1000) were the most common organisms identified. For preterm infants, CONS (2.5/1000) followed by Escherichia coli (2.6/1000) were the most common organisms identified. There was a significant reduction in GBS EONS over time (P<0.01) and a trend toward an increase in other organisms.

CONCLUSION

Although the rate of EONS among neonates admitted to NICUs has not changed, the pattern of infection has changed over the past 6 years. With the increased use of prophylactic antibiotics to mothers, careful surveillance of the changing trend of bacterial organisms among neonates is warranted.

Choice and duration of antimicrobial therapy for neonatal sepsis and meningitis

Neonatal sepsis is associated with increased mortality and morbidity including neurodevelopmental impairment and prolonged hospital stay. Signs and symptoms of sepsis are nonspecific, and empiric antimicrobial therapy is promptly initiated after obtaining appropriate cultures. However, many preterm and low birth weight infants who do not have infection receive antimicrobial agents during hospital stay. Prolonged and unnecessary use of antimicrobial agents is associated with deleterious effects on the host and the environment. Traditionally, the choice of antimicrobial agents is based on the local policy, and the duration of therapy is decided by the treating physician based on clinical symptoms and blood culture results. In this paper, we discuss briefly the causative organism of neonatal sepsis in both the developed and developing countries. We review the evidence for appropriate choice of empiric antimicrobial agents and optimal duration of therapy in neonates with suspected sepsis, culture-proven sepsis, and meningitis. Moreover, there is significant similarity between the causative organisms for early- and late-onset sepsis in developing countries. The choice of antibiotic described in this paper may be more applicable in developed countries.

The association of intrapartum antibiotic exposure with the incidence and antibiotic resistance of infantile late-onset serious bacterial infections

BACKGROUND

The widespread use of intrapartum antibiotics (IPA) has raised concerns regarding the adverse effects on the newborn.

OBJECTIVES

To determine if IPA is associated with infantile late-onset serious bacterial infections (SBIs) and with antibiotic resistance.

PATIENTS AND METHODS

From 2005 to 2009, data were prospectively collected for all infants born at our center, aged 7 to 90 days, who were hospitalized for fever. Cases included infants with culture-proven SBIs, and controls included infants without SBIs. Results. A total of 71 cases and 124 controls were included. IPA was documented in 11.3% of cases and in 7.3% of controls (P = .34). Among cases, ampicillin resistance was documented in 85% of antibiotic-exposed infants and in 63% of nonexposed infants (P = .19). Corresponding rates for first-generation cephalosporin resistance in urinary tract infection were 75% and 23.5% (P = .04).

CONCLUSION

IPA is associated with a trend toward increased antibiotic resistance in late-onset SBIs. This should be taken into consideration in the selection of empirical therapy for febrile infants.

Bacterial isolates of early-onset neonatal sepsis and their antibiotic susceptibility pattern between 1998 and 2004: an audit from a center in India

BACKGROUND

Epidemiology and surveillance of neonatal sepsis helps in implementation of rational empirical antibiotic strategy.

OBJECTIVE

To study the frequency of bacterial isolates of early onset neonatal sepsis (EONS) and their sensitivity pattern.

METHODS

In this retrospective study, a case of EONS was defined as an infant who had clinical signs or born to mothers with potential risk factors for infection, in whom blood culture obtained within 72 hours of life, grew a bacterial pathogen. Blood culture sample included a single sample from peripheral vein or artery. Relevant data was obtained from the unit register or neonatal case records.

RESULTS

Of 2182 neonates screened, there were 389 (17.8%) positive blood cultures. After excluding coagulase-negative Staphylococci (160), we identified 229 EONS cases. Preterm neonates were 40.6% and small for gestational age, 18.3%. Mean birth weight and male to female ratio were 2344.5 (696.9) g and 1.16:1 respectively. Gram negative species represented 90.8% of culture isolates. Pseudomonas (33.2%) and Klebsiella (31.4%) were common among them. Other pathogens included Acinetobacter (14.4%), Staphylococcus aureus (9.2%), E.coli (4.4%), Enterobacter (2.2%), Citrobacter (3.1%) and Enterococci (2.2%). In Gram negative group, best susceptibility was to Amikacin (74.5%), followed by other aminoglycosides, ciprofloxacin and cefotaxime. The susceptibility was remarkably low to ampicillin (8.4%). Gram positive group had susceptibility of 42.9% to erythromycin, 47.6% to ciprofloxacin and above 50% to aminoglycosides. Of all isolates, 83.8% were susceptible to either cefotaxime or amikacin

CONCLUSION

Gram-negative species especially Pseudomonas and Klebsiella were the predominant causative organisms. Initial empirical choice of cefotaxime in combination with amikacin appeared to be rational choice for a given cohort.

Does prenatal antibiotic therapy compromise the diagnosis of early-onset infection and management of the neonate?

AIM

To assess the impact of prenatal antibiotic treatment on procalcitonin (PCT) and C-reactive protein (CRP) concentrations in cord blood, and on the rate of positive neonatal blood cultures.

METHODS

Neonates with early-onset infection (Group A; n=46) were compared with healthy controls (Group B; n=240). We evaluated the relationship between prenatal antibiotic therapy and early-onset infection, and for interactions with antibiotic therapy in the neonate immediately after birth.

RESULTS

In the Group A antibiotics were administered significantly more often prenatally and more often to neonates just after birth. The percentage of negative blood cultures in infected neonates was higher when antibiotic treatment was instituted prenatally. Differences in cord blood PCT and CRP concentrations were significant between both groups and were independent of prenatal antibiotic treatment. Streptococcus agalactiae was the most frequent species.

CONCLUSIONS

Almost one-third of neonates present with early-onset infection in spite of prenatal antibiotic therapy. Cord blood PCT and CRP measurements may be helpful in the diagnosis of infection also in cases when antibiotic therapy was started prenatally. Prenatal antibiotic administration reduced the number of positive blood cultures in neonates with early-onset infection and was associated with a greater rate of antibiotic treatment after birth in neonates without infection.

[Prevention of early-onset group B Streptococcus infections. 2. Efficiency of the ANAES guidelines]

OBJECTIVES

To examine the efficiency on early-onset neonatal infections of the ANAES guidelines for early-onset infections prophylaxis, based on a systematic prenatal vaginal swab aiming Group B Streptococcus and/or infection risk factors during delivery.

PATIENTS AND METHODS

This is a retrospective cohort study of early-onset infections during a period of 28 months (6125 deliveries) compared to an earlier period (6141 deliveries).

RESULTS

The number of newborns admitted for suspected infection and the rate of sepsis have been unchanged. But the total number of infections has decreased (1.50 vs 2.02 %, p=0,024), without increase of the number of infections due to other germs such as Escherichia coli. Furthermore, a strategy based only on risk factors would not have allowed the early screening and treatment of 23 Streptococcus B infected newborns.

CONCLUSION

We have proved the efficiency of the protocol in terms of prevention of early-onset infections. However, it has led to a dramatic increase in the consumption of antibiotics, which is worrying concerning maternal and neonatal bacterial ecology.

Incidence and distribution of pathogens in early-onset neonatal sepsis in the era of antenatal antibiotics

In 2001 France issued a new set of guidelines for the use of antenatal antibiotics (AA). These guidelines recommended intrapartum antimicrobial prophylaxis (IAP) to prevent group B streptococcal (GBS) disease and AA to prolong pregnancy in the event of preterm premature rupture of membranes (AA for PPROM). This study aims to determine the effects of AA, recommended by national guidelines, on the incidence and distribution of pathogens in early-onset neonatal sepsis (EONS). We performed a population-based, prospective, observational study of level II and III perinatal centres throughout the region of Alsace, a northeastern area of France, between March 2004 and February 2005. The study population included all neonates with confirmed or probable EONS, who were treated with antibiotics for at least 5 days. We analysed exposure to AA, as well as clinical and microbiological data obtained from medical records. A total of 20 131 neonates were born during the study period, and 217 were included in the study. Of these, 24 subjects had confirmed sepsis, 140 had probable sepsis and 53 had possible EONS. The overall incidence of confirmed EONS was 1.19 per 1000 births. The infecting bacteria was GBS in 15 of 24 (62.5%) confirmed EONS cases (incidence: 0.75 per 1000 births) and in 81 of 140 (58%) probable sepsis cases. Escherichia coli was identified in 6 of 24 (25%) cases of confirmed EONS (incidence: 0.3 per 1000 births) and in 30 of 140 (21%) cases of clinical sepsis. Among E. coli infections (n= 36), amoxicillin resistance (n= 18) was statistically linked with AA use (P = 0.045). This link was significant in cases of PPROM (P = 0.015), but not when IAP was administered to prevent GBS disease (P = 0.264). IAP was not performed in 18 of 60 (30%) cases and 32 of 93 (34%) cases, despite positive screening or the presence of risk factors for EONS, respectively. Group B streptococcus remains the predominant pathogen in the era of AA. Aminopenicillin-resistant E. coli infections seem to be linked to prolonged AA in cases of PPROM and appear to preferentially affect preterm infants. Therefore, postnatal treatment strategies should consider this possible effect. Our data indicate that the current policy of GBS maternal prophylaxis is not associated with an excessive risk of pathogen resistance. Considering the high incidence of GBS EONS in our region, possible progress could result from better observance of guidelines. These results strengthen the need for continuation of surveillance.

International perspective on early-onset neonatal sepsis

Infections are a major cause of neonatal death in developing countries. High-quality information on the burden of early-onset neonatal sepsis and sepsis-related deaths is limited in most of these settings. Simple preventive and treatment strategies have the potential to save many newborns from sepsis-related death. Implementation of public health programs targeting newborn health will assist attainment of Millennium Development Goals of reduction in child mortality.

Group B streptococcal disease in infants: progress in prevention and continued challenges

The burden of early-onset disease caused by group B Streptococcus (GBS) has decreased dramatically in the United States over the past 20 years. Universal culture-based screening at 35 to 37 weeks gestational age and use of intrapartum antibiotic prophylaxis are the cornerstones of prevention measures that have led to this decline. GBS, however, remains the leading cause of early-onset neonatal sepsis in the United States. Revised guidelines for prevention of perinatal GBS are planned for issuance in 2010. This article discusses implementation challenges for clinicians caring for pregnant women and newborns and presents an updated algorithm for neonatal management.

No change in the incidence of ampicillin-resistant, neonatal, early-onset sepsis over 18 years

OBJECTIVE

The objective of this study was to assess the effect of maternal antibiotic exposure on neonatal early-onset sepsis (EOS) rates over an 18-year period.

METHODS

A review was performed of infant and maternal records for all culture- proven cases of EOS in infants delivered at the Brigham and Women's Hospital (Boston, MA) in 1990-2007.

RESULTS

Data were analyzed from 335 EOS cases over periods that differed with respect to hospital policy for intrapartum antibiotic prophylaxis against group B Streptococcus (GBS): 1990-1992 (no prophylaxis); 1993-1996 (risk-based); and 1997-2007 (screening-based). The overall incidence of EOS decreased over these periods (3.70 vs 2.23 vs 1.59 cases per 1000 live births; P < .0001). No change in the incidence of infection with ampicillin-resistant organisms was observed overall or among very low birth weight infants. However, an increased proportion of infections were caused by ampicillin- resistant organisms. Mothers of infants with ampicillin-resistant infections were more likely to have been treated with ampicillin (P = .0001). Overall peripartum antibiotic use increased during the study period primarily because of increased use of penicillin G and clindamycin, with no significant change in the use of ampicillin.

CONCLUSIONS

Predominant use of penicillin G for GBS prophylaxis resulted in decreased incidence of EOS. No change in the incidence of ampicillin-resistant EOS was observed, but resistant cases were associated with peripartum ampicillin exposure. These findings suggest that obstetricians should consider preferential use of penicillin G for GBS prophylaxis.

Prevention of Group B Streptococcus early-onset disease: a toolkit by the California Perinatal Quality Care Collaborative

The California Perinatal Quality Care Collaborative (CPQCC) was organized in 1996 in an effort to improve perinatal outcomes in California. CPQCC has a robust infrastructure of quality improvement resources and expertise and uses a database of demographic and outcome data from neonatal intensive care units in California. In 2004, CPQCC developed a toolkit to provide an evidence-based framework and supporting documents for hospitals to use in systematically addressing persistent early-onset disease (EOD) because of Group B Streptococcus (GBS) in their centers. The CPQCC toolkit was based on the 2002 Centers for Disease Control guideline, 'Prevention of Perinatal Group B Streptococcal Disease.' This article presents an updated version of the CPQCC toolkit reflecting several population studies published since the 2002 guideline. Current epidemiological trends in incidence of EOD with GBS, changes in antibiotic sensitivity and the potential value of newer strategies are discussed.

Induction and termination of inflammatory signaling in group B streptococcal sepsis

SUMMARY

Group B streptococcus (GBS) is part of the normal genital and gastrointestinal flora in healthy humans. However, GBS is a major cause of sepsis and meningitis in newborn infants in the Western world and an important pathogen in many developing countries. The dissection of the host response to GBS may increase the general understanding of innate immunity in sepsis, because newborn infants lack a sufficient adaptive response. Inflammatory signal induction in macrophages by GBS seems largely preserved in newborn infants, as shown both in vitro and in vivo. The engagement of Toll-like receptor 2 (TLR2) by lipoproteins and a myeloid differentiation factor 88 (MyD88)--dependent pathway induced by GBS cell wall are both important in this context. TLR2 activation of microglia by GBS induces neuronal damage, which might account for the high morbidity of GBS meningitis. At the same time, TLR2 mediates activation-induced cell death (AICD), a process involved in the containment of inflammation. In newborn infants, AICD and anti-bacterial polymorphonuclear leukocyte activity appears to be compromised. Accordingly, neonatal aberrations in the pathogen-specific negative control of inflammatory signaling are likely to contribute to excessive inflammation and neurological sequelae in GBS sepsis and meningitis.

Epidemiology of neonatal sepsis in South Korea

BACKGROUND

Neonatal sepsis is a severe clinical syndrome characterized by systemic signs of infection, shock and system organ failure; diagnosis is confirmed on positive culture from a normally sterile site(s). There are few reports comparing incidence, mortality, and risk factors between clinically diagnosed sepsis and that confirmed by culture.

METHODS

All infants diagnosed with early- (within first 72 h after birth) or late-onset (72 h-4 weeks after birth) neonatal sepsis between 1997 and 1999 from four neonatal centers in South Korea, were investigated.

RESULTS

The estimated incidence rate of neonatal sepsis during the 3 years was 30.5 per 1000 live births for clinical sepsis and 6.1 per 1000 live births for sepsis with positive culture, with case-fatality rates of 4.7% and 2.2%, respectively. When only early-onset sepsis was considered, the incidence and fatality rates were 25.1 per 1000 live births and 6.1% for clinical sepsis, and 4.3 per 1000 live births and 2.5% for culture-confirmed sepsis, respectively. For the 179 patients (185 causative organisms) of proven sepsis, Staphylococcus spp. including S. aureus were the most frequent isolates. In early-onset clinical sepsis, having very low birthweight (<or=1500 g), a low Apgar score at 5 min (<or=7), and being male were related to higher rates of case-fatality (relative risk: 11.3, 6.8 and 2.5, respectively).

CONCLUSIONS

Clinical sepsis was more common than culture-confirmed sepsis and had a higher case-fatality rate. It seems prudent to take rapid and decisive steps toward better management of the high-risk group whether the sepsis is clinically diagnosed or culture confirmed.