Childhood meningitis in the conjugate vaccine era: a prospective cohort study

Neurodevelopmental Outcomes Following Childhood Viral Meningitis in Canterbury New Zealand

BACKGROUND

Most childhood meningitis is viral in countries with widespread conjugate vaccine use. This study assessed clinical features and neurodevelopmental outcomes in preschool children following enteroviral and parechoviral meningitis.

METHODS

Children 18-42 months of age in Canterbury, New Zealand were included, who had enterovirus (EV) or parechovirus (HPEV) meningitis from 2015 to 2021. Comprehensive neurodevelopmental assessments were completed by a psychologist using the Bayley Scale for Infant Development-3 (BSID-3). Mean composite and scaled scores and proportion below the cutoff were assessed in each domain. Clinical data was analyzed.

RESULTS

There were 79 children 18-42 months old with previous EV or HPEV meningitis. BSID assessments were completed for 33 children (55% male), median age 32 months, from 2019 to 2022 including 23 with EV and 10 HPEV meningitis. At diagnosis, 32 (97%) received intravenous/intramuscular antibiotics, and 6 received a fluid bolus. Parents reported developmental speech concerns in 6 children, and delayed motor milestones in 1 child. There was no reported sensorineural hearing loss. BSID mean composite scores were in the expected range for cognition 102 (confidence interval: 98-106), language 96 (93-100) and motor 102 (98-106) domains. Overall, 12/33 (36%) children had below expected scores in 1 developmental domain, including scores 1-2 SD below the normative mean for cognition (2/33; 6%), receptive language (6/33; 18%), expressive language (5/33; 15%) and gross motor (6/33; 18%). There were no differences between scores in EV and HPEV meningitis.

CONCLUSION

Following viral meningitis, more than a third of preschool children had a mild developmental delay with comprehensive neurodevelopmental assessment, suggesting targeted follow-up should be considered.

Epidemiological trends in viral meningitis in England: Prospective national surveillance, 2013-2023

BACKGROUND

In the conjugate vaccine era, viruses are the most common cause of meningitis. Here, we evaluated epidemiological trends in laboratory-confirmed viral meningitis across all age-groups over an 11-year period in England.

METHODS

In England, hospital laboratories routinely report laboratory-confirmed infections electronically to the UK Health Security Agency. Records of positive viral detections in cerebrospinal fluid during 2013-2023 were extracted. Incidence rates with confidence intervals were calculated using mid-year resident population estimates.

RESULTS

There were 22,114 laboratory-confirmed viral meningitis cases, including 15,299 cases during 2013-19 (pre COVID-19), with a gradual increase in incidence from 3.5/100,00 (95%CI: 3.3-3.6) to 3.9/100,000 (95%CI: 3.6-4.1). During 2020-21 when pandemic restrictions were in place, there were 2061 cases (1.8/100,000; 1.7-1.9), which increased to 4754 (4.2/100,000; 4.0-4.3) during 2022-23 (post pandemic restrictions). Infants aged <3 months accounted for 39.4% (8702/22,048) of all cases, with a stable incidence 2013-19 (504/100,000, 95%CI: 491-517), followed by a significant decline during 2020-21 (204/100,000; 188-221) and then an increase during 2022-23 (780/100,000; 749-812), with enteroviruses being the commonest cause (84.9%, 7387/8702; 424.74/100,000; 95%CI: 415.12-434.51), followed by parechoviruses (9.1%, 792/8702; 45.54/100,000; 95%CI: 42.42-48.82) and herpes simplex virus (4.4%, 380/8702; 21.85/100,000; 95%CI: 19.71-24.16). Pandemic restrictions were associated with significant declines in the incidence of enterovirus (77.7%) and parechoviruses (64% lower), with rebounds after societal restrictions were lifted.

CONCLUSIONS

Rates of viral meningitis have returned to pre-pandemic levels since societal restrictions were lifted. The highest incidence of viral meningitis remains in infants aged <3 months and most commonly due to enteroviral infection.

Evaluating the Impact of the BioFire FilmArray in Childhood Meningitis: An Observational Cohort Study

BACKGROUND

Multiplex polymerase chain reaction assays have the potential to reduce antibiotic use and shorten length of inpatient stay in children with suspected central nervous system infection by obtaining an early microbiological diagnosis. The clinical impact of the implementation of the BioFire FilmArray Meningitis/Encephalitis Panel on the management of childhood meningitis was evaluated at the John Radcliffe Hospital in Oxford and Children's Health Ireland at Temple Street in Dublin.

METHODS

Children who had lumbar punctures performed as part of a septic screen were identified retrospectively through clinical discharge coding and microbiology databases from April 2017 to December 2018. Anonymized clinical and laboratory data were collected. Comparison of antibiotic use, length of stay and outcome at discharge was made with a historical cohort in Oxford (2012-2016), presenting before implementation of the FilmArray.

RESULTS

The study included 460 children who had a lumbar puncture as part of an evaluation for suspected central nervous system infection. Twelve bacterial cases were identified on the FilmArray that were not detected by conventional bacterial culture. Bacterial culture identified one additional case of bacterial meningitis, caused by Escherichia coli , which had not been identified on the FilmArray. Duration of antibiotics was shorter in children when FilmArray was used than before its implementation; enterovirus meningitis (median: 4 vs. 5 days), human parechovirus meningitis (median: 4 vs. 4.5 days) and culture/FilmArray-negative cerebrospinal fluid (median: 4 vs. 6 days).

CONCLUSIONS

The use of a FilmArray can identify additional bacterial cases of meningitis in children that had been negative by traditional culture methods. Children with viral meningitis and culture-negative meningitis received shorter courses of antibiotics and had shorter hospital stays when FilmArray was used. Large studies to evaluate the clinical impact and cost effectiveness of incorporating the FilmArray into routine testing are warranted.

The epidemiology of aseptic meningitis in New Zealand children from 1991 to 2020

AIM

Aseptic meningitis, including culture negative and viral meningitis, contributes a significant health-care burden, including unnecessary antibiotic use and hospitalisation to treat possible bacterial meningitis. This study analysed aseptic meningitis hospitalisations in New Zealand (NZ) children over 29 years.

METHODS

In this population-based study, aseptic meningitis hospitalisations in NZ children <15 years old were analysed from 1991 to 2020. Incident rate ratios were calculated using Poisson regression models. Variations in hospitalisations by age, year, sex, ethnicity, geographical region and socio-economic deprivation were analysed.

RESULTS

There were 5142 paediatric aseptic meningitis hospitalisations from 1991 to 2020. Most were unspecified viral meningitis (64%), followed by enterovirus (29%). Hospitalisation rates varied annually with a median of 18.4/100 000 children including a peak in 2001 of 56.4/100 000 (51.7-61.6). From 2002 to 2019, rates increased by 8.4%/year (7.2-9.5%) in infants <90 days old but decreased in all other age groups. In 2020, a reduction in hospitalisations to 9.6/100 000 (7.9-11.8) occurred, and in infants <90 days old were 0.37 times expected. Hospitalisations were 1.50 times (1.49-1.68) higher in males than females; higher in children of Māori (P < 0.001) and Pacific (P < 0.001) versus European ethnicity; and higher for children living in the most (2.44 times, (2.16-2.75)) versus least deprived households; and in northern versus southern NZ.

CONCLUSIONS

Aseptic meningitis hospitalisations increased in young infants during 29 years of surveillance, apart from 2020 when admissions reduced during the COVID-19 pandemic. In contrast, hospitalisations decreased in children aged >1 year. Further investigation into reasons for higher admissions by ethnic group, geographical location and increased deprivation are required.

Schwer verlaufende Meningitis und Enzephalitis bei Kindern und Jugendlichen

Die bakterielle Meningitis und die virale Enzephalitis sind die infektiösen Erkrankungen des Zentralnervensystems (ZNS), die meist mit schwerwiegenden Folgeerscheinungen bis hin zum Tod einhergehen. Trotz Fortschritten in der Prävention durch Impfungen ist die globale Krankheitslast der bakteriellen Meningitis enorm. Die Inzidenz der viralen Enzephalitis im Kindesalter war vor der durch die „coronavirus disease 2019“ (COVID-19) ausgelösten Pandemie zunehmend. Dies hängt mit der wachsenden Verbreitung von „emerging pathogens“ wie dem Enterovirus-A71 und dem West-Nil-Virus in den hiesigen Breitengraden zusammen, aber auch mit der häufigeren Anwendung von Immunsuppressiva und der häufigeren Durchführung von Stammzelltransplantationen im Kindesalter.

In der vorliegenden Übersichtsarbeit werden Häufigkeit und klinische Zeichen von infektiösen ZNS-Erkrankungen zusammengefasst und die aktuellen Therapieempfehlungen dargestellt.

Systematic review of host genomic biomarkers of invasive bacterial disease: Distinguishing bacterial from non-bacterial causes of acute febrile illness

Background

Infectious diseases play a significant role in the global burden of disease. The gold standard for the diagnosis of bacterial infection, bacterial culture, can lead to diagnostic delays and inappropriate antibiotic use. The advent of high- throughput technologies has led to the discovery of host-based genomic biomarkers of infection, capable of differentiating bacterial from other causes of infection, but few have achieved validation for use in a clinical setting.

Methods

A systematic review was performed. PubMed/Ovid Medline, Ovid Embase and Scopus databases were searched for relevant studies from inception up to 30/03/2022 with forward and backward citation searching of key references. Studies assessing the diagnostic performance of human host genomic biomarkers of bacterial infection were included. Study selection and assessment of quality were conducted by two independent reviewers. A meta-analysis was undertaken using a diagnostic random-effects model. The review was registered with PROSPERO (ID: CRD42021208462).

Findings

Seventy-two studies evaluating the performance of 116 biomarkers in 16,216 patients were included. Forty-six studies examined TB-specific biomarker performance and twenty-four studies assessed biomarker performance in a paediatric population. The results of pooled sensitivity, specificity, negative and positive likelihood ratio, and diagnostic odds ratio of genomic biomarkers of bacterial infection were 0.80 (95% CI 0.78 to 0.82), 0.86 (95% CI 0.84 to 0.88), 0.18 (95% CI 0.16 to 0.21), 5.5 (95% CI 4.9 to 6.3), 30.1 (95% CI 24 to 37), respectively. Significant between-study heterogeneity (I² 77%) was present.

Interpretation

Host derived genomic biomarkers show significant potential for clinical use as diagnostic tests of bacterial infection however, further validation and attention to test platform is warranted before clinical implementation can be achieved.

Funding

No funding received.

Development of a multiplex droplet digital PCR assay for detection of enterovirus, parechovirus, herpes simplex virus 1 and 2 simultaneously for diagnosis of viral CNS infections

Background

Enterovirus (EV), parechovirus (HPeV), herpes simplex virus 1 and 2 (HSV1/2) are common viruses leading to viral central nervous system (CNS) infections which are increasingly predominant but exhibit deficiency in definite pathogen diagnosis with gold-standard quantitative PCR method. Previous studies have shown that droplet digital PCR (ddPCR) has great potential in pathogen detection and quantification, especially in low concentration samples.

Methods

Targeting four common viruses of EV, HPeV, HSV1, and HSV2 in cerebrospinal fluid (CSF), we developed a multiplex ddPCR assay using probe ratio-based multiplexing strategy, analyzed the performance, and evaluated it in 97 CSF samples collected from patients with suspected viral CNS infections on a two-channel ddPCR detection system.

Results

The four viruses were clearly distinguished by their corresponding fluorescence amplitude. The limits of detection for EV, HPeV, HSV1, and HSV2 were 5, 10, 5, and 10 copies per reaction, respectively. The dynamic range was at least four orders of magnitude spanning from 2000 to 2 copies per reaction. The results of 97 tested clinical CSF specimens were identical to those deduced from qPCR/qRT-PCR assays using commercial kits.

Conclusion

The multiplex ddPCR assay was demonstrated to be an accurate and robust method which could detect EV, HPeV, HSV1, and HSV2 simultaneously. It provides a useful tool for clinical diagnosis and disease monitoring of viral CNS infections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01798-y.

Challenges in the Diagnosis of Viral Encephalitis in Children: The Case of Two Siblings

Encephalitis in children may lead to adverse outcomes and long-term neurodevelopmental sequelae. The prompt identification of the causative agent is important to guide proper management in cases with encephalitis; however, the etiology often remains undetermined. The use of polymerase chain reaction (PCR) analysis in the cerebrospinal fluid (CSF) has increased the diagnostic yield in encephalitis cases; however, it may be occasionally misleading. In this article, we describe the case of a male immunocompetent child with encephalitis in which human herpesvirus-7 (HHV-7) was detected in CSF by PCR. As the detection of HHV-7 DNA in the CSF alone is insufficient to prove an etiologic association of severe encephalitis in immunocompetent children, alternative diagnoses were pursued. Enterovirus (E-11) was detected by PCR analysis of the nasopharyngeal and rectal swabs of the male patient. The final diagnosis was facilitated by the findings in his sibling, which presented concurrently with enteroviral encephalitis. Failure to detect enterovirus in the CSF by PCR does not exclude enteroviral encephalitis; screening of other samples, from other body sites, may be necessary to identify the virus, and physicians should take into consideration all evidence, including history, clinical presentation, and sick contacts’ clinical status.

Epidemiology of Pediatric Meningitis in South Korea From 2010 to 2018: A Population-based Retrospective Cohort Study

BACKGROUND

Studies evaluating the epidemiology of pediatric meningitis are limited in our region. This study aimed to describe recent trends in the incidence of pediatric meningitis.

METHODS

We estimated national trends in hospitalization rates for pediatric meningitis (<18 years) by analyzing data from the Health Insurance Review and Assessment database between 2010 and 2018. Meningitis cases were identified based on International Classification of Diseases, Tenth Revision (ICD-10) codes and hospitalization rates were calculated.

RESULTS

In this national population-based study, a total of 119,644 hospitalizations and 58 deaths due to pediatric meningitis were identified. The hospitalization rates of pediatric bacterial meningitis have declined by 50.0%, from 3.4 per 100,000 in 2010 to 1.7 per 100,000 in 2018. The mortality rates for bacterial and viral meningitis were 2.0% and 0.002%, respectively. Despite the decreased annual incidence of bacterial meningitis, its mortality rate did not change significantly during the study period. The only risk factor identified for mortality in bacterial meningitis patients among age group, sex, region of residence, and season was age below 1 year (P < 0.001). As children under 1 year have a high-mortality rate (4.2%), patients in this age group require close monitoring. The reasons behind indistinct seasonal patterns of bacterial meningitis warrant further investigation.

CONCLUSIONS

Childhood bacterial meningitis has shown a significant decline in incidence from 2010 to 2018. In contrast, viral meningitis has not shown a trend over time. Knowledge of these changes may aid clinicians in the decision-making process and management of meningitis patients.

Update on Viral Infections Involving the Central Nervous System in Pediatric Patients

Infections of the central nervous system (CNS) are mainly caused by viruses, and these infections can be life-threatening in pediatric patients. Although the prognosis of CNS infections is often favorable, mortality and long-term sequelae can occur. The aims of this narrative review were to describe the specific microbiological and clinical features of the most frequent pathogens and to provide an update on the diagnostic approaches and treatment strategies for viral CNS infections in children. A literature analysis showed that the most common pathogens worldwide are enteroviruses, arboviruses, parechoviruses, and herpesviruses, with variable prevalence rates in different countries. Lumbar puncture (LP) should be performed as soon as possible when CNS infection is suspected, and cerebrospinal fluid (CSF) samples should always be sent for polymerase chain reaction (PCR) analysis. Due to the lack of specific therapies, the management of viral CNS infections is mainly based on supportive care, and empiric treatment against herpes simplex virus (HSV) infection should be started as soon as possible. Some researchers have questioned the role of acyclovir as an empiric antiviral in older children due to the low incidence of HSV infection in this population and observed that HSV encephalitis may be clinically recognizable beyond neonatal age. However, the real benefit-risk ratio of selective approaches is unclear, and further studies are needed to define appropriate indications for empiric acyclovir. Research is needed to find specific therapies for emerging pathogens. Moreover, the appropriate timing of monitoring neurological development, performing neuroimaging evaluations and investigating the effectiveness of rehabilitation during follow-up should be evaluated with long-term studies.

Severity of parechovirus infections in infants under 3 months of age and comparison with enterovirus infections: A French retrospective study

While enteroviruses (EV) are a well-recognized cause of aseptic meningitis in children, human parechoviruses (HPeV), especially genotype 3, have been increasingly reported as a frequent cause of sepsis-like illness and meningitis among young infants. The aim of this study was to describe the epidemiological, clinical, and laboratory characteristics of HPeV infections in infants and to compare them with those of well-known EV infections. This monocentric retrospective study was carried out at the pediatric unit of Nantes University Hospital from January 2015 to August 2018. All patients under 18 years of age with diagnosis codes referring to fever, for whom viral infection was suspected and cerebrospinal fluid (CSF) specimens were collected, were included. All CSF specimens were screened by duplex real-time polymerase chain reaction (PCR) assay that allows for the simultaneous detection of EV and HPeV in clinical samples. During the study period, 1373 CSF specimens from patients under 18 were included. A total of 312 CSF samples were positive for HPeV (n=34) or EV (n=278). Among the 34 HPeV-positive patients, 97% (33/34) were under 3 months of age, whereas the rate was 54% (149/278) for EV-positive patients (P<0.001); thus, patients under 3 months of age were defined as the study population for the rest of this work. A review of the medical records was carried out for the positive cases. In this population, the HPeV detection rate was 5.6% versus 25.3% (P<0.001) for EV. All but one of the HPeV samples available for genotyping were HPeV-3. No seasonality was observed for HPeV infections. Length of hospital stay tended to be longer for children infected with HPeV compared with those infected by EV (3 days vs. 2 days, P=0.05). Clinicians reported more severe illness presentations among HPeV-infected infants, with more frequent administration of fluid bolus (P<0.02). Regarding laboratory characteristics, a significant lack of cellular reaction in the CSF (P=0.004) as well as lower C-reactive protein (CRP) levels (P=0.006) and neutrophil counts (P<0.001) were noted for HPeV infections compared with EV infections. Our results confirm the early onset of HPeV infections (more than 95% of patients aged under 3 months). The clinical presentation and laboratory characteristics of the two infections was similar. However, some higher clinical severity criteria and a lack of CSF pleocytosis were regularly observed in patients with HPeV infections. Considering the significant proportion (5.6%; 95% CI, 3.7-7.5) of all CSF samples in our series, HPeV detection should be systematically included in the microbiological diagnosis of febrile children under 3 months of age.

Differential Diagnosis and Hospital Emergency Management for Fastlane Treatment of Central Nervous System Infection Under the COVID-19 Epidemic in Changsha, China

Importance: Corona virus disease 2019 (COVID-19) has long latent period, strong infectivity, and non-specific symptoms and signs in the upper respiratory tract. Some initial neurological symptoms appear, including dizziness, headache, seizures, slurred speech, disturbance of consciousness, and limb paralysis among a few COVID-19 patients, which share similar manifestations with central nervous system (CNS) infection. Improving the diagnostic efficiency of suspected CNS infection patients on the basis of preventing and controlling COVID-19 plays a key role in preventing nosocomial and cross infections. This study intends to formulate a hospital emergency management system of fastlane treatment of CNS infection for epidemic prevention and control, aiming at providing references and guidelines for the government and medical institutions to improve the efficiency of treating CNS infection patients in the clinical practice during COVID-19. Observations: This study formulated a framework of a fastlane treatment of CNS infection based on the cooperation of resources and experience, aiming at the key and difficult problems faced by the hospital emergency management system during the COVID-19 outbreak in Changsha, China. The main problem of formulating the hospital emergency management system is efficiently identifying whether CNS infection was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The framework improves the efficiency of diagnosing and treating CNS infections by standardizing the diagnosis and treatment process of patients in emergency observation and strengthening the management of inpatient wards, aiming at assisting medical staff during clinical practice. Conclusions and Relevance: The hospital emergency management system of a fastlane treatment of CNS infection for epidemic prevention and control of the COVID-19 outbreak is a professional and multisystem project, which needs the cooperation of various resources and the experience of clinical leadership.

Closer and closer? Maternal immunization: current promise, future horizons

This state-of-the art manuscript highlights our current understanding of maternal immunization-the practice of vaccinating pregnant women to confer protection on them as well as on their young infants, and thereby reduce vaccine-preventable morbidity and mortality. Advances in our understanding of the immunologic processes that undergird a normal pregnancy, studies from vaccines currently available and recommended for pregnant women, and vaccines for administration in special situations are beginning to build the case for safe scale-up of maternal immunization. In addition to well-known diseases, new diseases are emerging which pose threats. Several new vaccines are currently under development and increasingly include pregnant women. In this manuscript, targeted at clinicians, vaccinologists, scientists, public health practitioners, and policymakers, we also outline key considerations around maternal immunization introduction and delivery, discuss noninfectious horizons for maternal immunization, and provide a framework for the clinician faced with immunizing a pregnant woman.

Cytokine characteristic of cerebrospinal fluid from children with enteroviral meningitis compared to bacterial meningitis

Background

Enteroviruses are the most common etiological agent for viral encephalitis, but it is uncertain whether the cytokines have the ability to differentiate enteroviral meningitis (EVM) from bacterial meningitis (BM).

Methods

A retrospective study was performed at the Children's Hospital, Zhejiang University School of Medicine from August 2016 and August 2019. CSF and/or blood specimens were collected for microbiological culture, viruses, and cytokine detection.

Results

Forty‐three patients were confirmed with meningitis, 27 patients with EVM, and 16 with BM. Children with EVM were older compared with BM and Control group (P < .001). The most common presenting symptom in children with EVM was fever (96.3%) followed by headache (88.9%) and vomiting (66.7%). The occurrence of seizure was lower in both EVM and BM groups (P < .001). Serum IL‐6 and serum IL‐10 were lower in EVM group than BM (P = .02) and control group (IL‐6, P = .01; IL‐10, P < .001). IL‐6, IL‐10, and IFN‐γ levels showed obviously increase in CSF (P < .001, respectively) in EVM group, while only IL‐6 increased in CSF (P < .001) in BM group. CSF concentrations of cytokines IL‐6, IL‐10, TNF, and IFN‐γ in children with EVM and BM were both higher than Control group (P < .001). But compared EVM group to BM group, CSF IL‐2 (P = .13), IL‐6 (P = .37), IL‐10 (P = .98), TNF (P = .54), and IFN‐γ (P = .53) showed no difference between two groups.

Conclusions

CSF cytokines elevated in both virus and bacterial meningitis, while serum elevation only occurred in bacterial infection. Still, we could not distinguish enteroviral meningitis from bacterial meningitis with the parameters of CSF cytokines IL‐2, IL‐6, IL‐10, TNF, and IFN‐γ.

Optimizing Laboratory Diagnostic Services for Infectious Meningitis in the Meningitis Belt of sub-Saharan Africa

For longer than a century, the "meningitis belt" of sub-Saharan Africa has experienced the largest-ever global meningitis epidemic. Whereas HIV-associated immunosuppression drives higher susceptibility to environmental infectious organisms with tropism for the central nervous system (CNS), most diagnostic laboratories in the belt stick to N. meningitidis, H. influenzae, and S. pneumoniae. Cryptococcus neoformans has been the leading cause of death (incidence, 89%; death, 75%). To establish whether diagnostic services target geographically important pathogens, there is a need to know the current spectrum of etiology. Given Africa's agro-silvo-pastoralism, the One Health diagnostic approach is recommended. Considering  multipathogen detection capacity, needed speed for corticosteroid therapy decision, and susceptibility/resistance to antimicrobials with improved CNS penetration, proposed laboratory categorization will help neurologists to choose suitable services.

Epidemics of meningococcal meningitis in Northern Nigeria focus on preventive measures

Throughout the past 200 years, epidemics of meningococcal infection have been noted in Northern Nigeria. Consequently, control of meningococcal meningitis is one of the major priorities in infection control in the region. The proportions of cases of invasive meningococcal disease (IMD) caused by the five common serotypes (A, B, C, Y, and W135) vary among different regions and within specific geographic locations. Hence, effective and comprehensive disease control can only be achieved with the use of vaccines that target all of these disease-causing serotypes. Vaccines for the majority of meningococcal serogroups implicated in causing IMD are available in developed countries and have proven effective in reducing the disease incidence. However, the overall success of a vaccine depends on its coverage of the at-risk population as well as safety and effectiveness of the vaccine at preventing disease. Therefore, maximizing the global impact of these vaccines requires having them made available in regions with the high incidence of the disease, like Northern Nigeria, where rates of meningococcal disease are several times higher than in industrialized nations, and the reported mortality is usually high.

To LP or not to LP? Identifying the Etiology of Pediatric Meningitis

Introduction of conjugate vaccines against Haemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis has led to a substantial reduction in cases of acute bacterial meningitis in countries with high routine childhood immunization coverage. The majority of children hospitalized with meningitis in high-income countries have viral or aseptic meningitis and do not require antibiotic treatment. Cerebrospinal fluid analysis is irreplaceable in appropriately diagnosing and treating bacterial meningitis and avoiding unnecessary antibiotics and prolonged hospitalizations in children with viral meningitis. New diagnostic tests have improved detection of bacterial and viral pathogens in cerebrospinal fluid, underscoring the importance of promptly performing lumbar puncture when meningitis is suspected. This article provides an overview of acute bacterial and viral meningitis in children, focusing on the changing epidemiology, the advantages and limitations of conventional and newer diagnostic methods, and considerations for clinical practice.

Enterovirus and parechovirus meningitis in infants younger than 90 days old in the UK and Republic of Ireland: a British Paediatric Surveillance Unit study

OBJECTIVES

This study aimed to prospectively collect detailed clinical information for all enterovirus (EV) and human parechovirus (HPeV) meningitis cases in infants aged <90 days in the UK and Ireland.

PARTICIPANTS, DESIGN AND SETTING

Prospective, active national surveillance during July 2014 to July 2015 through the British Paediatric Surveillance Unit. Reporting paediatricians completed questionnaires requesting information on clinical presentation, investigations, management and outcomes at hospital discharge and after 12 months.

MAIN OUTCOME MEASURES

To describe the clinical burden of EV and HPeV meningitis in infants aged <90 days.

RESULTS

During the 13-month surveillance period, 703 cases (668 EV, incidence0.79/1,000 live- births; 35 HPeV, 0.04/1,000 live-births) were identified. The most common clinical presentations were fever (EV: 570/668(85%); HPeV: 28/35(80%)), irritability (EV: 441/668(66%); HPeV: 23/35(66%)) and reduced feeding (EV: 363/668(54%); HPeV 23/35(66%)). Features of circulatory shock were present in 27% (182/668) of EV and 43% (15/35) of HPeV cases. Overall, 11% (76/668) of EV and 23% (8/35) of HPeV cases required intensive care support. Nearly all cases (678/703, 96%) were confirmed by cerebrospinal fluid (CSF) PCR, with 52% (309/600) having normal CSF white cell count for age. Two infants with EV meningitis died (2/668, 0.3%) and four survivors (4/666, 0.6%) had long-term complications at 12 months' follow-up. Infants with HPeV meningitis survived without sequelae. Overall 189 infants had a formal hearing test and none had sensorineural hearing loss.

CONCLUSION

The incidence of laboratory-confirmed EV/HPeV meningitis in young infants is more than twice that for bacterial meningitis. Less than 1% will develop severe neurological complications or die of their infection. Further studies are required to formally assess long-term neurodevelopmental sequelae.

Serocorrelates of protection against infant group B streptococcus disease

Group B streptococcus (GBS) is a leading cause of young infant mortality and morbidity globally, with vaccines being developed for over four decades but none licensed to date. A serocorrelate of protection against invasive disease in young infants is being considered to facilitate vaccine early licensure, followed by demonstration of efficacy assessed postlicensure. In this Review, we synthesise the available scientific evidence to define an immune correlate associated with GBS disease risk reduction on the basis of studies of natural infection. We summarise studies that have investigated GBS serum anticapsular or anti-protein antibodies, and studies measuring the association between antibody function and disease risk reduction. We highlight how knowledge on the development of correlates of protection from existing vaccines could be harnessed to facilitate GBS vaccine development. These lessons include aggregation of serocorrelates of protection for individual serotypes, understanding the relationship between immunity derived from natural exposure of adults and vaccine-induced immunity, or using extrapolation of protection from in-vitro immunoassay results. We also highlight key considerations for the assessment of the role of antibodies to derive a serocorrelate of risk reduction in future seroepidemiological studies of GBS disease.

Management of suspected paediatric meningitis: a multicentre prospective cohort study

OBJECTIVE

To quantify delays during management of children with suspected meningitis.

DESIGN

Multicentre prospective cohort study.

SETTING

Three UK tertiary paediatric centres; June 2011-June 2012 PATIENTS: 388 children aged <16 years hospitalised with suspected meningitis or undergoing lumbar puncture (LP) during sepsis evaluation.

MAIN OUTCOME MEASURES

Time of prehospital and in-hospital assessments, LP, antibiotic treatment and discharge; types of prehospital medical assessment and microbiological results. Data collected from hospital records and parental interview.

RESULTS

220/388 (57%) children were seen by a medical professional prehospitalisation (143 by a general practitioner). Median times from initial hospital assessment to LP and antibiotic administration were 4.8 hours and 3.1 hours, respectively; 62% of children had their LP after antibiotic treatment. Median time to LP was shorter for children aged <3 months (3.0 hours) than those aged 3-23 months (6.2 hours, P<0.001) or age ≥2 years (20.3 hours, P<0.001). In meningitis of unknown cause, cerebrospinal fluid (CSF) PCR was performed for meningococcus in 7%, pneumococcus in 10% and enterovirus in 76%. When no pathogen was identified, hospital stay was longer if LP was performed after antibiotics (median 12.5 days vs 5.0 days, P=0.037).

CONCLUSIONS

Most children had LP after antibiotics were administered, reducing yield from CSF culture, and PCRs were underused despite national recommendations. These deficiencies reduce the ability to exclude bacterial meningitis, increasing unnecessary hospital stay and antibiotic treatment.

A 2-transcript host cell signature distinguishes viral from bacterial diarrhea and it is influenced by the severity of symptoms

Recently, a biomarker signature consisting of 2-transcript host RNAs was proposed for discriminating bacterial from viral infections in febrile children. We evaluated the performance of this signature in a different disease scenario, namely a cohort of Mexican children (n = 174) suffering from acute diarrhea of different infectious etiologies. We first examined the admixed background of the patients, indicating that most of them have a predominantly Native American genetic ancestry with a variable amount of European background (ranging from 0% to 57%). The results confirm that the RNA test can discriminate between viral and bacterial causes of infection (t-test; P-value = 6.94×10⁻¹¹; AUC = 80%; sensitivity: 68% [95% CI: 55%–79%]; specificity: 84% [95% CI: 78%–90%]), but the strength of the signal differs substantially depending on the causal pathogen, with the stronger signal being that of Shigella (P-value = 3.14 × 10⁻¹²; AUC = 89; sensitivity: 70% [95% CI: 57%–83%]; specificity: 100% [95% CI: 100%–100%]). The accuracy of this test improves significantly when excluding mild cases (P-value = 2.13 × 10⁻⁶; AUC = 85%; sensitivity: 79% [95% CI: 58%–95%]; specificity: 78% [95% CI: 65%–88%]). The results broaden the scope of previous studies by incorporating different pathogens, variable levels of disease severity, and different ancestral background of patients, and add confirmatory support to the clinical utility of these 2-transcript biomarkers.

Clinical usefulness and accuracy of polymerase chain reaction in the detection of bacterial meningitis agents in pediatric cerebrospinal fluid

Bacterial meningitis poses enormous healthcare challenges due to a high mortality, morbidity and sequelae. Neisseria (N.) meningitidis, Haemophilus (H.) influenzae, Streptococcus (S.) pneumoniae and S. agalactiae remain among the most prevalent infectious agents that cause bacterial meningitis in children. The objective of this study was the simultaneous detection of these pathogens in suspected cerebrospinal fluid (CSF) by using multiplex polymerase chain reaction (mPCR) and compare PCR results with standard diagnostics currently used in clinical practice. CSF specimens were obtained from 515 children (<5 years) clinically suspected of having acute bacterial meningitis. Based on bacterial culture, four isolates of salmonella sp and one Citrobacter freundii isolate were identified. The remaining 510 CSF specimens, having negative culture, were subjected to mPCR. Twenty-three (4.51%) CSF samples yielded a PCR positive signal. The pathogens identified were: S. pneumoniae (n=13), H. influenzae (n=7) and N. meningitidis (n=3). S. agalactiae was not detected. Using sequential multiplex PCR, serogrouping of S. pneumoniae revealed 3 different serotypes: serotype 19A (n=6), 19F (n=4) and serotype 23F (n=3). Only the serotype A was identified for the 3N. meningitidis isolates. Despite vaccination, S. pneumoniae remains a leading cause of pediatric invasive disease. Detecting causative organism remains the most critical aspect for management of children with suspected meningitis. PCR method is more sensitive and rapid than culture for detecting the infectious agents. Institution of PCR diagnostics is recommended for early and appropriate therapy.

USE OF SCORE AND CEREBROSPINAL FLUID LACTATE DOSAGE IN DIFFERENTIAL DIAGNOSIS OF BACTERIAL AND ASEPTIC MENINGITIS

Objective:

To evaluate Bacterial Meningitis Score (BMS) on its own and in association with Cerebrospinal Fluid (CSF) lactate dosage in order to distinguish bacterial from aseptic meningitis.

Methods:

Children diagnosed with meningitis at a tertiary hospital between January/2011 and December/2014 were selected. All data were obtained upon admission. BMS was applied and included: CSF Gram staining (2 points); CSF neutrophil count ≥1,000 cells/mm³ (1 point); CSF protein ≥80 mg/dL (1 point); peripheral blood neutrophil count ≥10,000 cells/mm³ (1 point) and seizures upon/before arrival (1 point). Cutoff value for CSF lactate was ≥30 mg/dL. Sensitivity, specificity and negative predictive value of several BMS cutoffs and BMS associated with high CSF lactate were evaluated for prediction of bacterial meningitis.

Results:

Among 439 eligible patients, 94 did not have all data available to complete the score, and 345 patients were included: 7 in bacterial meningitis group and 338 in aseptic meningitis group. As predictive factors of bacterial meningitis, BMS ≥1 had 100% sensitivity (95%CI 47.3-100), 64.2% specificity (58.8-100) and 100% negative predictive value (97.5-100); BMS ≥2 or BMS ≥1 associated with high CSF lactate also showed 100% sensitivity (47.3-100); but 98.5% specificity (96.6-99.5) and 100% negative predictive value (98.3-100).

Conclusions:

2 point BMS in association with CSF lactate dosage had the same sensitivity and negative predictive value, with increased specificity for diagnosis of bacterial meningitis when compared with 1-point BMS.

Comparison of enterovirus detection in cerebrospinal fluid with Bacterial Meningitis Score in children

Objective

To measure the role of enterovirus detection in cerebrospinal fluid compared with the Bacterial Meningitis Score in children with meningitis.

Methods

A retrospective cohort based on analysis of medical records of pediatric patients diagnosed as meningitis, seen at a private and tertiary hospital in São Paulo, Brazil, between 2011 and 2014. Excluded were patients with critical illness, purpura, ventricular shunt or recent neurosurgery, immunosuppression, concomitant bacterial infection requiring parenteral antibiotic therapy, and those who received antibiotics 72 hours before lumbar puncture.

Results

The study included 503 patients. Sixty-four patients were excluded and 94 were not submitted to all tests for analysis. Of the remaining 345 patients, 7 were in the Bacterial Meningitis Group and 338 in the Aseptic Meningitis Group. There was no statistical difference between the groups. In the Bacterial Meningitis Score analysis, of the 338 patients with possible aseptic meningitis (negative cultures), 121 of them had one or more points in the Bacterial Meningitis Score, with sensitivity of 100%, specificity of 64.2%, and negative predictive value of 100%. Of the 121 patients with positive Bacterial Meningitis Score, 71% (86 patients) had a positive enterovirus detection in cerebrospinal fluid.

Conclusion

Enterovirus detection in cerebrospinal fluid was effective to differentiate bacterial from viral meningitis. When the test was analyzed together with the Bacterial Meningitis Score, specificity was higher when compared to Bacterial Meningitis Score alone.

Impact of meningitis on intelligence and development: A systematic review and meta-analysis

Background

We undertook a systematic review and meta-analysis to address the question “what is the impact of meningitis on IQ and development.”

Methods

Search: conducted using standardized search terms across Medline, PsychInfo and EMBASE to 06/2014. Eligibility: human studies of any infectious aetiology of meningitis reporting IQ or infant developmental age or stage outcomes. Quality: Centre for Evidence Based Medicine, Oxford, quality tools. Analysis: random effects meta-analysis by organism.

Results

39 studies were included in the review, 34 providing data on IQ (2015 subjects) and 12 on developmental delay (382 subjects). Across all bacterial organisms, meningitis survivors had a mean IQ 5.50 (95% CI: -7.19, -3.80; I² = 47%, p = 0.02) points lower than controls. IQ was significantly lower than controls for Neisseria meningitides (NM: 5 points) and Haemophilus influenzae b (Hib: 6 points) but not in viral meningitis, with only single studies included for Streptococcus pneumoniae (SP) and group B streptococcus (GBS). The pooled relative risk (RR) for low IQ (IQ<70) in survivors of bacterial meningitis compared with controls was 4.99 (95% CI: 3.17, 7.86) with no significant heterogeneity (I2 = 49%, p = 0.07). Developmental delay of approximately 0.5SD was reported in studies of bacterial meningitis but no delay in the only study of viral meningitis.

Conclusions

We found moderate evidence that surviving bacterial meningitis has a deleterious impact on IQ and development but no evidence that viral meningitis had meaningful cognitive impacts. Survivors of bacterial meningitis should be routinely offered screening for cognitive deficits and developmental delay in addition to hearing loss.

Etiology and prognosis of acute viral encephalitis and meningitis in Chinese children: a multicentre prospective study

BACKGROUND

In China, there were few studies about the pathogens of acute viral encephalitis and meningitis in children in recent years. The aims of this study were to characterize the etiology and prognosis of acute viral encephalitis and meningitis in Chinese children.

METHODS

This was a multicentre prospective study. Two hundred and sixty one viral encephalitis patients and 285 viral meningitis patients were enrolled. The mean age of viral encephalitis and meningitis were 5.88 ± 3.60 years and 6.39 ± 3.57 years, respectively. Real-time reverse transcription PCR and multiplex PCR were used to detect human enteroviruses and herpes viruses in cerebrospinal fluid (CSF) of patients with encephalitis or meningitis. The enzyme-linked immune absorbent assay (ELISA) was used for detecting IgM antibody against Japanese encephalitis virus (JEV) in CSF and against mumps virus, tick-borne encephalitis virus (TBEV), dengue virus and rubella virus in acute serum. The clinical and outcome data were collected during patients' hospitalization.

RESULTS

The etiology of viral encephalitis was confirmed in 52.5% patients. The primary pathogen was human enteroviruses (27.7%) in viral encephalitis. The incidence of sequelae and the fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The etiology of viral meningitis was identified in 42.8% cases. The leading pathogen was also human enteroviruses (37.7%) in viral meningitis. The prognosis of viral meningitis was favorable with only 0.7% patients had neurological sequelae.

CONCLUSIONS

Human enteroviruses were the leading cause both in acute viral encephalitis and viral meningitis in children. The incidence of sequelae and fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The prognosis of viral meningitis was favorable compared to viral encephalitis.

Fifteen-minute consultation: enterovirus meningitis and encephalitis-when can we stop the antibiotics?

Enterovirus (EV) is the most common cause of aseptic meningitis and has a benign course, unlike EV encephalitis, which can result in long-term neurological sequelae. There are no active treatments or prophylactic agents, and management is purely supportive. Obtaining an EV-positive cerebrospinal fluid result usually allows antimicrobial treatment to be stopped. This review will answer some of the common questions surrounding EV meningitis/encephalitis.

Diagnostic Test Accuracy of a 2-Transcript Host RNA Signature for Discriminating Bacterial vs Viral Infection in Febrile Children

IMPORTANCE

Because clinical features do not reliably distinguish bacterial from viral infection, many children worldwide receive unnecessary antibiotic treatment, while bacterial infection is missed in others.

OBJECTIVE

To identify a blood RNA expression signature that distinguishes bacterial from viral infection in febrile children.

DESIGN, SETTING, AND PARTICIPANTS

Febrile children presenting to participating hospitals in the United Kingdom, Spain, the Netherlands, and the United States between 2009-2013 were prospectively recruited, comprising a discovery group and validation group. Each group was classified after microbiological investigation as having definite bacterial infection, definite viral infection, or indeterminate infection. RNA expression signatures distinguishing definite bacterial from viral infection were identified in the discovery group and diagnostic performance assessed in the validation group. Additional validation was undertaken in separate studies of children with meningococcal disease (n = 24) and inflammatory diseases (n = 48) and on published gene expression datasets.

EXPOSURES

A 2-transcript RNA expression signature distinguishing bacterial infection from viral infection was evaluated against clinical and microbiological diagnosis.

MAIN OUTCOMES AND MEASURES

Definite bacterial and viral infection was confirmed by culture or molecular detection of the pathogens. Performance of the RNA signature was evaluated in the definite bacterial and viral group and in the indeterminate infection group.

RESULTS

The discovery group of 240 children (median age, 19 months; 62% male) included 52 with definite bacterial infection, of whom 36 (69%) required intensive care, and 92 with definite viral infection, of whom 32 (35%) required intensive care. Ninety-six children had indeterminate infection. Analysis of RNA expression data identified a 38-transcript signature distinguishing bacterial from viral infection. A smaller (2-transcript) signature (FAM89A and IFI44L) was identified by removing highly correlated transcripts. When this 2-transcript signature was implemented as a disease risk score in the validation group (130 children, with 23 definite bacterial, 28 definite viral, and 79 indeterminate infections; median age, 17 months; 57% male), all 23 patients with microbiologically confirmed definite bacterial infection were classified as bacterial (sensitivity, 100% [95% CI, 100%-100%]) and 27 of 28 patients with definite viral infection were classified as viral (specificity, 96.4% [95% CI, 89.3%-100%]). When applied to additional validation datasets from patients with meningococcal and inflammatory diseases, bacterial infection was identified with a sensitivity of 91.7% (95% CI, 79.2%-100%) and 90.0% (95% CI, 70.0%-100%), respectively, and with specificity of 96.0% (95% CI, 88.0%-100%) and 95.8% (95% CI, 89.6%-100%). Of the children in the indeterminate groups, 46.3% (63/136) were classified as having bacterial infection, although 94.9% (129/136) received antibiotic treatment.

CONCLUSIONS AND RELEVANCE

This study provides preliminary data regarding test accuracy of a 2-transcript host RNA signature discriminating bacterial from viral infection in febrile children. Further studies are needed in diverse groups of patients to assess accuracy and clinical utility of this test in different clinical settings.

Prevention of Meningococcal Infection in the United States: Current Recommendations and Future Considerations

Neisseria meningitidis is a common cause of bacterial meningitis and septicemia that can lead to permanent sequelae or death. N meningitidis is classified into serogroups based on the composition of the capsular polysaccharide, with serogroups A, B, C, W, X, and Y recognized as the major disease-causing organisms. The unpredictability of infection coupled with the poor prognosis for some patients suggests immunization as an effective preventive strategy. Importantly, four of the six disease-causing serogroups (A, C, Y, and W) may be prevented with available quadrivalent capsular polysaccharide-protein conjugate vaccines; these vaccines have been successfully implemented into immunization programs in the United States. Unfortunately, quadrivalent conjugate vaccines are not effective against serogroup B, now the most common cause of invasive meningococcal disease. Two recombinant protein vaccines recently were licensed for prevention of serogroup B disease. Recommendations for use of these serogroup B vaccines in the United States have been made by the Advisory Committee on Immunization Practices. This article will discuss all available meningococcal vaccines, current recommendations for use, lessons learned from previous experiences, and future considerations, with the hope of further understanding how use of these vaccines may help reduce incidence of meningococcal disease in the United States.