An 18-year retrospective study on the epidemiology of early-onset neonatal sepsis - emergence of uncommon pathogens

Non-Susceptibility of Early-Onset Sepsis Pathogens to the Combination of Ampicillin and Gentamicin Among Neonates in Thailand

Background/Objectives: Empirical antimicrobial therapy for neonatal early-onset sepsis (EOS) comprises ampicillin and gentamicin. However, multidrug-resistant organisms are increasing worldwide, thus inflicting a global burden. We identified the incidence and risk factors of neonates with pathogenic isolates that were not susceptible to treatment comprising a combination of ampicillin and gentamicin (non-susceptible group). Methods: This retrospective study included neonates diagnosed with EOS between 2004 and 2023. All patients with EOS and positive culture results within 72 h of birth were reviewed. Patients in the non-susceptible and susceptible groups were analyzed using a multivariable logistic regression model. Results: Sixty pathogenic isolates and 55 neonates with EOS were observed over the course of 20 years. The incidence and case fatality rates of EOS were 0.88 per 1000 live births and 41.8%, respectively. Acinetobacter baumannii was the most common EOS pathogenic isolate (19/60 pathogenic isolates; 12/19 resistant to carbapenems). Pathogenic isolates were susceptible to ampicillin or gentamicin (59%), ampicillin or cefotaxime (42%), and ampicillin or amikacin (72%). Data regarding susceptibility to ampicillin and gentamicin of 49 neonates were available. A multivariable analysis revealed that patients in the non-susceptible group (n = 18) were more likely to experience late-onset EOS (48-72 h; p = 0.01) and require endotracheal intubation on day 1 (p = 0.04) compared to patients in the susceptible group (n = 31). Conclusions: In areas with high multidrug resistance, broader-spectrum antibiotic therapy (ampicillin plus amikacin) should be considered for neonates who develop clinical sepsis within 48-72 h of birth and experience respiratory failure at birth.

Global patterns of antibiotic resistance in group B Streptococcus: a systematic review and meta-analysis

Objectives

Streptococcus agalactiae, or group B Streptococcus (GBS), is a significant pathogen associated with severe infections in neonates, particularly sepsis and meningitis. The increasing prevalence of antibiotic resistance among GBS strains is a growing public health concern, necessitating a comprehensive meta-analysis to evaluate the prevalence of this resistance globally.

Methods

We conducted a comprehensive systematic search across four major scientific databases: Scopus, PubMed, Web of Science, and EMBASE, targeting articles published until December 13, 2023. This meta-analysis focused on studies that examined antibiotic resistance in GBS strains. The Joanna Briggs Institute tool was employed to assess the quality of the included studies. This meta-analysis applied a random-effects model to synthesize data on antibiotic resistance in GBS, incorporating subgroup analyses and regression techniques to explore heterogeneity and trends in resistance rates over time. Outliers and influential studies were identified using statistical methods such as Cook's distance, and funnel plot asymmetry was assessed to evaluate potential publication bias. All analyses were conducted using R software (version 4.2.1) and the metafor package (version 3.8.1).

Results

This study included 266 studies from 57 countries, revealing significant variability in GBS antibiotic resistance rates. The highest resistance rates were observed for tetracycline (80.1, 95% CI: 77.1-82.8%), while tedizolid (0.1, 95% CI: 0.0-0.8%) showed the lowest resistance rates. Significant heterogeneity in resistance rates was observed, particularly for antibiotics such as azithromycin and gentamicin (I 2 = 97.29%), variability across studies. On the other hand, tigecycline and ceftaroline exhibited no heterogeneity (I 2 = 0%), suggesting consistent resistance patterns. Subgroup analyses revealed disparities in resistance rates based on country, continent, and methodological categories. Significant increase in resistance rates for several antibiotics over time, including clindamycin, erythromycin, ceftriaxone, cefuroxime, ciprofloxacin, levofloxacin, moxifloxacin, chloramphenicol, and ofloxacin. Ofloxacin and cefuroxime showed particularly steep trends. Conversely, a declining resistance trend was observed for oxacillin.

Conclusion

This study emphasizes the growing issue of antibiotic resistance in GBS strains. Notable resistance to older and newer antibiotics, increasing resistance over time, regional disparities, and methodological variations are noted. Rising resistance trends for multiple antibiotics underscore the urgent need for global surveillance and improved antibiotic stewardship.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024566269, CRD42024566269.

Assessment of Culture-Negative Neonatal Early-Onset Sepsis: Risk Factors and Utility of Currently Used Serum Biomarkers

INTRODUCTION

Neonatal sepsis is a severe and life-threatening condition caused by pathogens in the systemic circulation within the first 28 days of life. The classical definition of neonatal sepsis implies positive central cultures, but recent findings discuss culture-negative sepsis (clinical sepsis associated with laboratory findings). Since infected neonates initially express few non-specific clinical signs and there are unreliable biochemical markers to identify sepsis in the early stages, it is essential to improve the accuracy of diagnosis and reduce unnecessary antibiotic exposure.

OBJECTIVE

Our study aims to assess the influence of risk factors and the utility of currently used biomarkers in culture-negative neonatal early-onset sepsis (CN-EOS).

MATERIALS AND METHODS

We performed a retrospective study at Bucharest University Hospital, which included 131 preterm and term newborns at risk for EOS admitted in the Neonatal Intensive Care Unit (NICU) over 12 months. The neonates included were classified into two groups: confirmed negative-culture early-onset sepsis (CN-EOS) and suspected early-onset sepsis (S-EOS). Patients from both groups received antibiotic therapy from the first day of life; the type and duration of antibiotic therapy were different in the two groups. For all the patients, we measured C-reactive protein (CRP), procalcitonin (PCT) and white blood count (WBC) at birth and after 72 h, tested blood culture in the first 24 h of life and correlated the results with clinical signs and prenatal risk factors. Categorical variables were presented as frequencies and percentages, while the continuous variables were the mean and the standard deviation. The differences between the continuous variable groups were determined by Student's t-test or the Mann-Whitney U test, whereas for the categorical variables, the Chi-square test (X2) was employed. The performance of laboratory biomarkers (CRP and PCT) in diagnosing confirmed EOS was calculated. All the tests were statistically significant at a p-value < 0.05.

RESULTS

The findings support the significance of low birth weight and gestational age and low Apgar scores as potential indicators for EOS; PROM diagnosed with chorioamnionitis and smoking during the pregnancy were also important predictive risk factors. Respiratory signs, such as apnea and respiratory distress syndrome, were most encountered in the clinical evaluation of infants with CN-EOS. Inflammatory markers were inconsistent in CN-EOS cases, proving that they are not reliable enough for initiating, continuing or stopping antibiotic therapy.

CONCLUSIONS

Culture-negative neonatal sepsis remains a significant challenge for the neonatologist, since the time elapsed between the moment sepsis is suspected and the initiation of empirical therapy can make the difference between survival and death. Continued efforts are needed to develop more reliable and effective diagnostic tools for timely and appropriate intervention.

Maternal Infections, Antibiotics, Steroid Use, and Diabetes Mellitus Increase Risk of Early-Onset Sepsis in Preterm Neonates: A Nationwide Population-Based Study

The global evolution of pathogens causing early-onset sepsis (EOS), a critical condition in preterm infants, necessitates a re-evaluation of risk factors to develop updated prevention and treatment strategies. This nationwide case-control study in Taiwan analyzed data from the National Health Insurance Research Database, Birth Reporting Database, and Maternal and Child Health Database from 2010 to 2019. The study included 176,681 mother-child pairs with preterm births. We identified 2942 clinical EOS cases from 5535 diagnosed sepsis cases, excluding unlikely cases. A control group of 14,710 preterm neonates without EOS was selected at a 1:5 ratio. Clinical EOS increased since 2017. Adjusted logistic regression identified significant EOS risk factors in preterm infants, including maternal fever, chorioamnionitis, maternal diabetes mellitus, maternal antibiotic usage, very preterm birth, birth weight (all with p < 0.001), maternal pneumonia (p = 0.002), and maternal CS (p = 0.004). Effective treatment of maternal conditions like diabetes, fever, and infections is essential to prevent EOS in preterm infants. Key measures include reducing unnecessary antibiotics or steroids, minimizing unnecessary cesarean sections, avoiding premature or prolonged rupture of membranes (PPROM), and increasing gestational age and neonatal birth weight. High-risk preterm neonates should be closely monitored for EOS and considered for antibiotics when warranted.

A practical predictive model to predict 30-day mortality in neonatal sepsis

OBJECTIVE

Neonatal sepsis is a serious disease that needs timely and immediate medical attention. So far, there is no specific prognostic biomarkers or model for dependable predict outcomes in neonatal sepsis. The aim of this study was to establish a predictive model based on readily available laboratory data to assess 30-day mortality in neonatal sepsis.

METHODS

Neonates with sepsis were recruited between January 2019 and December 2022. The admission information was obtained from the medical record retrospectively. Univariate or multivariate analysis was utilized to identify independent risk factors. The receiver operating characteristic curve was drawn to check the performance of the predictive model.

RESULTS

A total of 195 patients were recruited. There was a big difference between the two groups in the levels of hemoglobin and prothrombin time. Multivariate analysis confirmed that hemoglobin>133 g/L (hazard ratio: 0.351, p=0.042) and prothrombin time >16.6 s (hazard ratio: 4.140, p=0.005) were independent risk markers of 30-day mortality. Based on these results, a predictive model with the highest area under the curve (0.756) was built.

CONCLUSION

We established a predictive model that can objectively and accurately predict individualized risk of 30-day mortality. The predictive model should help clinicians to improve individual treatment, make clinical decisions, and guide follow-up management strategies.

Maternal GBS vaccination for preventing group B streptococcus disease in newborns: A mini review of current evidence

Group B streptococcus (GBS) poses a significant threat to neonates, leading to morbidity and mortality. Intrapartum antibiotics, although effective, have limitations, prompting the exploration of maternal vaccination. This study reviews the current evidence for maternal GBS vaccination in the prevention of early-onset GBS disease in newborns. A search on Google Scholar, PubMed, and Scopus identified studies assessing the impact of maternal GBS vaccination on early-onset GBS disease. Inclusion criteria comprised English-language clinical trials or observational studies. Data extraction included study details, immunogenicity profiles, effectiveness, safety outcomes, and relevant findings. Qualitative synthesis was employed for data analysis. Five studies meeting the inclusion criteria were reviewed. Maternal GBS vaccines demonstrated efficacy with sustained immunogenicity. Adverse events, although documented, were predominantly non-severe. Variability in immune responses and maternal-to-infant antibody ratios show the need for tailored vaccination approaches. Long-term follow up and surveillance are essential to assess persistence and identify unintended effects. Positive outcomes in vaccine efficacy support GBS vaccination integration into maternal health programs. Implementation challenges in diverse healthcare infrastructures require tailored approaches, especially in resource-limited settings. Overcoming cultural barriers and ensuring healthcare provider awareness are crucial for successful vaccination.

Intrapartum antibiotic prophylaxis to prevent Group B streptococcal infections in newborn infants: a systematic review and meta-analysis comparing various strategies

Background

Early-onset Group B Streptococcus (EOGBS) infection leads to substantial morbidity and mortality in newborn infants. Intrapartum antibiotic prophylaxis (IAP) prevents EOGBS infection, but IAP strategies vary. The approach to the provision of IAP can be risk-based, universal or a combination of the two strategies. Previous systematic reviews reported that universal strategies might be most optimal in lowering EOGBS infection, but there is no consensus. Therefore, we aimed to provide up-to-date evidence on effectiveness of different strategies by comparing perinatal outcomes.

Methods

A systematic search for EOGBS prevention strategies was performed in MEDLINE, Embase and Web of Science on May 2024. Studies were included if they reported on different strategies and outcomes of interest, including EOGBS infection, IAP administration and antimicrobial resistance regardless of publication date. Summary data was extracted from published reports. Study quality was assessed using the ROBINS-I tool. Random-effects meta-analyses were used to determine risk ratios (RR) and 95%-confidence intervals. PROSPERO registration CRD42023411806.

Findings

A total of 6293 records were identified, of which 72 observational studies were included for synthesis with more than 10 million live births. Meta-analysis demonstrated that implementation of any strategy (n = 34 studies, RR 0.46 (0.36-0.60)), risk-based strategies (n = 11 studies, RR 0.65 (0.48-0.87)), or universal strategies (n = 16 studies, RR 0.37 (0.25-0.55)) was associated with a reduced risk of EOGBS infection compared to no strategy. In direct comparison, universal strategies were associated with a reduced risk of EOGBS compared to a risk-based strategy (n = 17 studies, RR 0.41 (0.30-0.55)), while the proportion of women receiving IAP did not differ between risk-based (16%) and universal (21%) strategies (n = 9 studies, RR 1.29 (0.95-1.75)). There was no antimicrobial resistance of EOGBS isolates to penicillin or ampicillin (n = 11 studies).

Interpretation

Any IAP strategy could reduce the risk of EOGBS infection without evidence of increasing antimicrobial resistance. Universal strategies give the largest reduction in the EOGBS burden, while not exposing a significantly higher proportion of pregnancies to IAP compared to risk-based strategies.

Funding

UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction, a cosponsored programme executed by the World Health Organization.

Investigating the Association between Serum and Hematological Biomarkers and Neonatal Sepsis in Newborns with Premature Rupture of Membranes: A Retrospective Study

(1) Background: Neonatal early-onset sepsis (EOS) is associated with important mortality and morbidity. The aims of this study were to evaluate the association between serum and hematological biomarkers with early onset neonatal sepsis in a cohort of patients with prolonged rupture of membranes (PROM) and to calculate their diagnostic accuracy. (2) Methods: A retrospective cohort study was conducted on 1355 newborns with PROM admitted between January 2017 and March 2020, who were divided into two groups: group A, with PROM ≥ 18 h, and group B, with ROM < 18 h. Both groups were further split into subgroups: proven sepsis, presumed sepsis, and no sepsis. Descriptive statistics, analysis of variance (ANOVA) and a Random Effects Generalized Least Squares (GLS) regression were used to evaluate the data. (3) Results: The statistically significant predictors of neonatal sepsis were the high white blood cell count from the first (p = 0.005) and third day (p = 0.028), and high C-reactive protein (CRP) values from the first day (p = 0.004). Procalcitonin (area under the curve-AUC = 0.78) and CRP (AUC = 0.76) measured on the first day had the best predictive performance for early-onset neonatal sepsis. (4) Conclusions: Our results outline the feasibility of using procalcitonin and CRP measured on the first day taken individually in order to increase the detection rate of early-onset neonatal sepsis, in the absence of positive blood culture.

Late-Onset Meningitis in a Preterm Infant Caused by Streptococcus gallolyticus Subsp. Pasteurianus in Saudi Arabia: A Case Report and Literature Review

This report describes the progression of meningitis in a 24-day-old preterm male infant infected with Streptococcus gallolyticus subsp. pasteurianus (SGSP) and its medical care, pathogen detection, antibiotic treatment, and monitoring, ultimately leading to a positive outcome of successful recovery. Neonatal meningitis (NM) is a serious and potentially life-threatening condition, particularly in immunocompromised preterm infants. This report from Saudi Arabia presents a rare case of late-onset neonatal meningitis caused by SGSP in a preterm male infant. The 24-day-old preterm neonate presented with fever, lethargy, poor feeding, and respiratory distress. SGSP was confirmed by cerebral spinal fluid analysis showing the presence of pleocytosis and a low glucose ratio. Prompt antibiotic therapy with intravenous Ampicillin and Cefotaxime led to decreased pleocytosis, and the infant was discharged after 21 days. This report highlights the importance of vigilance, diagnosis, and management of neonatal infections caused by uncommon pathogens such as SGSP. The rarity of SGSP-caused meningitis emphasizes the need to monitor pregnant women for potential transmission and to implement early diagnostic and management strategies. This case report also encompasses a review of recent globally reported cases of neonatal S. gallolyticus infection, highlighting the distinctiveness of this report as the first of its type in Saudi Arabia.

Advancement in biomarker based effective diagnosis of neonatal sepsis

Neonatal sepsis is considered as alarming medical emergency and becomes the common global reason of neonatal mortality. Non-specific symptoms and limitations of conventional diagnostic methods for neonatal sepsis mandate fast and reliable method to diagnose disease for point of care application. Recently, disease specific biomarkers have gained interest for rapid diagnosis that led to the development of electrochemical biosensor with enhanced specificity, sensitivity, cost-effectiveness and user-friendliness. Other than conventional biomarker C-reactive protein to diagnose neonatal sepsis, several potential biomarkers including Procalcitonin (PCT), Serum amyloid A (SAA) and other candidates are extensively investigated. The present review provides insights on advancements and diagnostic abilities of protein and nucleotide based biomarkers with their incorporation in developing electrochemical biosensors by employing novel fabrication strategies. This review provides an overview of most promising biomarker and its capability for neonatal sepsis diagnosis to fulfil future demand to develop electrochemical biosensor for point-of-care applications.