Early onset neonatal bacterial meningitis in term infants: the clinical features, perinatal conditions, and in-hospital outcomes: A single center retrospective analysis

Neonatal Bacterial Meningitis: What Have We Learned From the Last Decade?

Bacterial meningitis is a devastating disease with significant morbidity and mortality, especially in neonates and young infants. The overall incidence of meningitis has decreased with focused screening, public health interventions, and vaccination, but the disease remains a significant concern in high-risk groups. In this review, we provide an update on bacterial meningitis in children younger than age 60 days, including epidemiology, clinical presentation, diagnostic approaches, treatment, and prognosis. [Pediatr Ann. 2024;53(11):e425-e432.].

Global Case Fatality of Bacterial Meningitis During an 80-Year Period: A Systematic Review and Meta-Analysis

Importance

The impact of vaccination, antibiotics, and anti-inflammatory treatment on pathogen distribution and outcome of bacterial meningitis over the past century is uncertain.

Objective

To describe worldwide pathogen distribution and case fatality ratios of community-acquired bacterial meningitis.

Data Sources

Google Scholar and MEDLINE were searched in January 2022 using the search terms bacterial meningitis and mortality.

Study Selection

Included studies reported at least 10 patients with bacterial meningitis and survival status. Studies that selected participants by a specific risk factor, had a mean observation period before 1940, or had more than 10% of patients with health care-associated meningitis, tuberculous meningitis, or missing outcome were excluded.

Data Extraction and Synthesis

Data were extracted by 1 author and verified by a second author. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Random-effects models stratified by age (ie, neonates, children, adults), Human Development Index (ie, low-income or high-income countries), and decade and meta-regression using the study period's year as an estimator variable were used.

Main Outcome and Measure

Case fatality ratios of bacterial meningitis.

Results

This review included 371 studies performed in 108 countries from January 1, 1935, to December 31, 2019, describing 157 656 episodes. Of the 33 295 episodes for which the patients' sex was reported, 13 452 (40%) occurred in females. Causative pathogens were reported in 104 598 episodes with Neisseria meningitidis in 26 344 (25%) episodes, Streptococcus pneumoniae in 26 035 (25%) episodes, Haemophilus influenzae in 22 722 (22%), other bacteria in 19 161 (18%) episodes, and unidentified pathogen in 10 336 (10%) episodes. The overall case fatality ratio was 18% (95% CI, 16%-19%), decreasing from 32% (95% CI, 24%-40%) before 1961 to 15% (95% CI, 12%-19%) after 2010. It was highest in meningitis caused by Listeria monocytogenes at 27% (95% CI, 24%-31%) and pneumococci at 24% (95% CI, 22%-26%), compared with meningitis caused by meningococci at 9% (95% CI, 8%-10%) or H influenzae at 11% (95% CI, 10%-13%). Meta-regression showed decreasing case fatality ratios overall and stratified by S pneumoniae, Escherichia coli, or Streptococcus agalactiae (P < .001).

Conclusions and Relevance

In this meta-analysis with meta-regression, declining case fatality ratios of community-acquired bacterial meningitis throughout the last century were observed, but a high burden of disease remained.

Mild/asymptomatic COVID-19 in unvaccinated pregnant mothers impairs neonatal immune responses

Maternal SARS-CoV-2 infection triggers placental inflammation and alters cord blood immune cell composition. However, most studies focus on outcomes of severe maternal infection. Therefore, we analyzed cord blood and chorionic villi from newborns of unvaccinated mothers who experienced mild/asymptomatic SARS-CoV-2 infection during pregnancy. We investigated immune cell rewiring using flow cytometry, single-cell RNA sequencing, and functional readouts using ex vivo stimulation with TLR agonists and pathogens. Maternal infection was associated with increased frequency of memory T and B cells and nonclassical monocytes in cord blood. Ex vivo T and B cell responses to stimulation were attenuated, suggesting a tolerogenic state. Maladaptive responses were also observed in cord blood monocytes, where antiviral responses were dampened but responses to bacterial TLRs were increased. Maternal infection was also associated with expansion and activation of placental Hofbauer cells, secreting elevated levels of myeloid cell-recruiting chemokines. Moreover, we reported increased activation of maternally derived monocytes/macrophages in the fetal placenta that were transcriptionally primed for antiviral responses. Our data indicate that even in the absence of vertical transmission or symptoms in the neonate, mild/asymptomatic maternal COVID-19 altered the transcriptional and functional state in fetal immune cells in circulation and in the placenta.

Microbial signatures of neonatal bacterial meningitis from multiple body sites

As a common central nervous system infection in newborns, neonatal bacterial meningitis (NBM) can seriously affect their health and growth. However, although metagenomic approaches are being applied in clinical diagnostic practice, there are some limitations for whole metagenome sequencing and amplicon sequencing in handling low microbial biomass samples. Through a newly developed ultra-sensitive metagenomic sequencing method named 2bRAD-M, we investigated the microbial signatures of central nervous system infections in neonates admitted to the neonatal intensive care unit. Particularly, we recruited a total of 23 neonates suspected of having NBM and collected their blood, cerebrospinal fluid, and skin samples for 2bRAD-M sequencing. Then we developed a novel decontamination method (Reads Level Decontamination, RLD) for 2bRAD-M by which we efficiently denoised the sequencing data and found some potential biomarkers that have significantly different relative abundance between 12 patients that were diagnosed as NBM and 11 Non-NBM based on their cerebrospinal fluid (CSF) examination results. Specifically, we discovered 11 and 8 potential biomarkers for NBM in blood and CSF separately and further identified 16 and 35 microbial species that highly correlated with the physiological indicators in blood and CSF. Our study not only provide microbiological evidence to aid in the diagnosis of NBM but also demonstrated the application of an ultra-sensitive metagenomic sequencing method in pathogenesis study.

Obstetric Risk Factors and Serological Characteristics of Early-Onset Neonates Bacterial Infections

Purpose

To analyze the obstetric high-risk factors and serological characteristics of early-onset neonatal bacterial infections (EONBI).

Methods

119 neonates with early-onset bacterial infection who were admitted to the neonatal ward of our hospital from October 2020 to December 2021 were recorded as the study group, and 100 neonates without bacterial infection who were admitted during the same period were used as the reference group. Comparative analysis of obstetric high-risk factors and serological characteristics of EONBI.

Results

There was no statistical difference between the two groups in terms of gender and age at admission (P > 0.05). The gestational age and birth weight of newborns in the study group were lower than those in the reference group (P < 0.001). Comparing the maternal factors of EONBI between the two groups, there was no statistical difference in age, number of obstetric inspections, whether to use antibiotics, and mode of delivery (P > 0.05). Univariate analysis showed that preterm birth, unexplained asphyxia, fecal contamination of amniotic fluid, maternal infection during pregnancy, and premature rupture of membranes ≥18 h were significantly associated with EONBI (P < 0.05); while there was no significant difference between the two groups in the comparison between diabetic mother and child and maternal fever at delivery (P > 0.05). Multifactorial analysis showed that preterm birth, fecal contamination of amniotic fluid, maternal infection during pregnancy, and premature rupture of membranes ≥18 h had a good multivariate dependence on EONBI (P < 0.05), while there was no significant association with unexplained asphyxia, diabetic mother and child, and maternal fever at delivery (P > 0.05). The incidence of neonatal temperature >37.9°C was higher in the study group than in the reference group (P < 0.05), and there were no statistical differences in the comparison of other clinical manifestations (P > 0.05). The CRP level of neonates in the study group (47.33 ± 4.14) mg/L was higher than that of the reference group (4.84 ± 1.03) mg/L (P < 0.001). The WBC level of neonates in the study group (5.64 ± 1.18) 10⁹/L was higher than that of the reference group (0.28 ± 0.04) 10⁹/L (P < 0.001). The PCT level of neonates in the study group (5.41 ± 0.85) µg/L was higher than that of the reference group (0.24 ± 0.07) µg/L (P < 0.001).

Conclusion

EONBI is closely associated with several obstetric high-risk factors, including preterm birth, fecal contamination of amniotic fluid, maternal infection during pregnancy, and premature rupture of membranes ≥18 h; EONBI has no specific symptoms and signs, but serum CRP, WBC, and PCT levels are significantly higher than those of newborns without co-infection with bacteria.

Escherichia coli Causing Neonatal Meningitis During 2001-2020: A Study in Eastern China

Background and Objective

Neonatal meningitis (NM) caused by Escherichia coli remains a major health problem in industrialized countries. Currently, information on the epidemiology and antimicrobial susceptibility patterns of NM in developing countries such as China is relatively scarce. Therefore, the present study investigated changes in the antimicrobial susceptibility of E. coli causing NM in a perinatal center in eastern China over the past 20 years.

Methods

This survey was conducted during three periods: 2001–2006, 2007–2012, and 2013–2020. NM was diagnosed according to the number of white blood cells in the cerebrospinal fluid (CSF) and the presence of a single potential pathogenic bacterium in the culture prepared from the blood or CSF of a newborn baby. Changes in the antimicrobial susceptibility of E. coli were analyzed.

Results

In total, 182 NM cases were identified. E. coli was identified in 69 of these cases, and in 21 of these cases, extended-spectrum beta-lactamase (ESBL) production was detected. E. coli was the main cause of NM identified in this study. The overall susceptibility of E. coli to third-generation cephalosporins such as cefotaxime decreased from 100% during 2001–2006 to 50% during 2007–2012 and, subsequently, increased to 71.0% during 2013–2020. This pattern of change is correlated with bacterial ESBL production. Only 8.3% of E. coli found in samples collected from infants with early onset meningitis (EOM) produced ESBL, while 37.3% of E. coli isolated from children with late-onset meningitis (LOM) produced ESBL.

Conclusion

E. coli remains the primary pathogen of NM. Compared with that isolated from infants with LOM, the percentage of ESBL-producing multidrug-resistant E. coli isolated from infants with EOM is significantly lower. Clinicians should consider this trend when determining appropriate and effective antibiotics as empirical treatment for NM.