Cerebrospinal fluid pleocytosis in children in the era of bacterial conjugate vaccines: distinguishing the child with bacterial and aseptic meningitis

FilmArray® Meningoencephalitis panel in the diagnosis of central nervous system infections: stewardship and cost analysis in a paediatric hospital in Chile

BACKGROUND

Central nervous system (CNS) infection has been an ongoing concern in paediatrics. The FilmArray® Meningoencephalitis (FAME) panel has greater sensitivity in identifying the aetiology of CNS infections. This study's objective was to compare the aetiological identification and hospitalization costs among patients with suspected CNS infection before and after the use of FAME.

METHODS

An analytical observational study was carried out using a retrospective cohort for the pre-intervention (pre-FAME use) period and a prospective cohort for the post-intervention (post-FAME use) period in children with suspected CNS infection.

RESULTS

A total of 409 CSF samples were analysed, 297 pre-intervention and 112 post-intervention. In the pre-intervention period, a total of 85.5% of patients required hospitalization, and in the post-intervention period 92.7% required hospitalization (p < 0.05). Median of ICU days was significantly lower in the post-intervention period than it was in the pre-intervention period. The overall positivity was 9.4 and 26.8%, respectively (p < 0.001). At ages 6 months and below, we found an increase in overall positivity from 2.6 to 28.1%, along with an increased detection of viral agents, S. agalactiae, S. pneumoniae, and N. meningitidis. The use of this diagnostic technology saved between $2916 and $12,240 USD in the cost of ICU bed-days. FAME use provided the opportunity for more accurate aetiological diagnosis of the infections and thus the provision of adequate appropriate treatment.

CONCLUSIONS

The cost/benefit ratio between FAME cost and ICU bed-day cost savings is favourable. Implementation of FAME in Chilean public hospitals saves public resources and improves the accuracy of aetiological diagnosis.

Bulging fontanelle in febrile infants as a predictor of bacterial meningitis

It is common practice to perform a lumbar puncture in infants presenting with fever and a bulging fontanelle in order to rule out bacterial meningitis. However, most of these infants have benign, self-limiting diseases. The objective was to determine whether there is an association between bulging fontanelle and bacterial meningitis in febrile infants. This retrospective cohort study included febrile children with a bulging fontanelle who underwent lumbar puncture at Meir Medical Center from 2005 through 2015. A total of 764 children ages 2-18 months underwent lumbar puncture during the study period. Among them, 304 had a bulging fontanelle and fever on evaluation and cerebrospinal fluid pleocytosis was found in 115 (37.8%), including 1 case of bacterial meningitis (0.3%). None of the infants described on admission as appearing well on presentation was found to have bacterial meningitis. Of the 764 children who underwent lumbar puncture, 10 infants were diagnosed with bacterial meningitis, and only one (10%) presented with a bulging fontanelle.Conclusion: The finding of a bulging fontanelle has very low sensitivity and specificity for bacterial meningitis. Most causes of a bulging fontanelle in febrile infants are self-limiting diseases. The routine approach of performing a lumbar puncture in febrile infants with a bulging fontanelle should be reconsidered. What is Known: • It is common to perform a lumbar puncture in febrile infants with a bulging fontanelle, to rule out bacterial meningitis. • However, there are only few researches regarding the relationship between bulging fontanelle and bacterial meningitis. What is New: • The finding of a bulging fontanelle has very low sensitivity and specificity for bacterial meningitis • The need for routine lumbar puncture in these cases should be reconsidered.

Diagnosing enterovirus meningitis via blood transcriptomics: an alternative for lumbar puncture?

BACKGROUND

Meningitis can be caused by several viruses and bacteria. Identifying the causative pathogen as quickly as possible is crucial to initiate the most optimal therapy, as acute bacterial meningitis is associated with a significant morbidity and mortality. Bacterial meningitis requires antibiotics, as opposed to enteroviral meningitis, which only requires supportive therapy. Clinical presentation is usually not sufficient to differentiate between viral and bacterial meningitis, thereby necessitating cerebrospinal fluid (CSF) analysis by PCR and/or time-consuming bacterial cultures. However, collecting CSF in children is not always feasible and a rather invasive procedure.

METHODS

In 12 Belgian hospitals, we obtained acute blood samples from children with signs of meningitis (49 viral and 7 bacterial cases) (aged between 3 months and 16 years). After pathogen confirmation on CSF, the patient was asked to give a convalescent sample after recovery. 3' mRNA sequencing was performed to determine differentially expressed genes (DEGs) to create a host transcriptomic profile.

RESULTS

Enteroviral meningitis cases displayed the largest upregulated fold change enrichment in type I interferon production, response and signaling pathways. Patients with bacterial meningitis showed a significant upregulation of genes related to macrophage and neutrophil activation. We found several significantly DEGs between enteroviral and bacterial meningitis. Random forest classification showed that we were able to differentiate enteroviral from bacterial meningitis with an AUC of 0.982 on held-out samples.

CONCLUSIONS

Enteroviral meningitis has an innate immunity signature with type 1 interferons as key players. Our classifier, based on blood host transcriptomic profiles of different meningitis cases, is a possible strong alternative for diagnosing enteroviral meningitis.

Risk Classification for Enteroviral Infection in Children With Meningitis and Negative Gram Stain

OBJECTIVES

Enterovirus is the most common cause of aseptic meningitis in children. This study aimed at identifying baseline variables associated with a positive cerebrospinal fluid (CSF) Enterovirus polymerase chain reaction (PCR) to aid clinicians in targeting patients who could be tested and treated as outpatients.

METHODS

We performed a retrospective review of children (2 months to 17 years old) admitted to the Children's Memorial Hermann Hospital in Houston, TX, between January 2005 and December 2010 with symptoms of meningitis, CSF white cell count of greater than 5 cells/mm, and a negative CSF Gram stain, who had a CSF Enterovirus PCR.

RESULTS

One hundred thirty-seven children were reviewed; median age was 4.7 (0.1-17.1) years, and 79 (58%) were male. Fifty patients (37%) had positive CSF Enterovirus PCR. Only 13 (15%) of the Enterovirus PCR-negative patients had an identifiable etiology. All patients were hospitalized. The mean hospital stay for patients with Enterovirus was 2.9 days; 88% received empiric antibiotics. Rates of antibiotic administration were not different between PCR-positive and PCR-negative groups (P > 0.05). All patients with Enterovirus had a favorable clinical outcome.A predictive model was created using 3 baseline variables independently associated with a positive Enterovirus PCR (P < 0.05): May to November presentation, CSF protein of less than 100 mg/dL, and absence of focal neurologic signs. The model classified patients into 2 risk categories for a positive Enterovirus PCR (low risk, 0% [0/17 patients]; high risk, 42% [50/120 patients]; P < 0.001).

CONCLUSIONS

Our predictive model can be used to identify children for whom Enterovirus PCR testing is warranted. Such testing could avoid unnecessary hospitalization and antibiotic administration.

Outpatient management of children at low risk for bacterial meningitis

OBJECTIVE

To determine the outcome of children aged 2-14 years with cerebrospinal fluid (CSF) pleocytosis and at very low risk for bacterial meningitis managed as outpatients without antibiotics.

METHODS

Multicentre, prospective, observational study conducted at nine Spanish paediatric EDs. Patients were diagnosed with meningitis based on clinical suspicion of meningitis and CSF pleocytosis when evaluated in the ED. Children between 2 and 14 years of age with pleocytosis and very low-risk criteria for bacterial meningitis (well appearing, Bacterial Meningitis Score (BMS)=0, procalcitonin (PCT)<0.5 ng/mL and observation without deterioration for less than 24 hours in the ED) were treated as outpatients without antibiotics pending CSF cultures. The primary composite outcome was a final diagnosis of bacterial meningitis or return to the ED for clinical deterioration.

RESULTS

Of 182 children between 2 and 14 years old diagnosed with meningitis, 56 met the very low-risk criteria and 45 were managed as outpatients. None was diagnosed with bacterial meningitis or returned due to clinical deterioration. Another 31 patients with BMS=1 (due to a peripheral absolute neutrophil count (ANC)>10 000/mm³) and PCT <0.5 ng/mL were managed as outpatients, diagnosed with aseptic meningitis and did well. BMS using PCT had the same sensitivity but greater specificity than classic BMS.

CONCLUSIONS

This set of low-risk criteria appears safe for the outpatient management without antibiotics of children with CSF pleocytosis. Larger studies are needed to evaluate the predictive values of replacing peripheral ANC with PCT in the BMS.

Factors influencing neurological outcome of children with bacterial meningitis at the emergency department

We performed a cohort study of children who survived bacterial meningitis after the neonatal period at a single pediatric center in France over a 10-year period (1995-2004) to identify predictors of death and long-term neurological deficits in children with bacterial meningitis. We performed multivariate regression to determine independent predictors of death and neurologic deficits. We identified 101 children with bacterial meningitis of which 19 died during initial hospitalization. Need for mechanical ventilation [hazard ratio (HR) 11.5, 95 % confidence interval (CI) 2.4-55.5)] and thrombocytopenia defined as a platelet count <150 × 10(9) per liter (HR 0.6, 95 % CI 0.4-0.9) at presentation were associated with death during initial hospitalization. At final assessment, 42 of the 70 survivors had no neurologic deficits identified; 20 had a single deficit, and eight had multiple deficits. A delay in initiation of antibiotics (HR 1.3, 95 % CI 1.1-1.7) and hydrocephalus on computed tomographic scan (HR 2.6, 95 % CI 1.1-6.0) were associated with having one or more long-term neurologic deficits. Identification of children at risk of death or long-term neurologic sequelae may allow therapeutic interventions to be directed to children at the highest risk.

Diagnostic accuracy of clinical symptoms and signs in children with meningitis

BACKGROUND

The diagnostic accuracy of the classic symptoms and signs of meningitis in infants and children has not been established.

METHODS

All children aged 2 months to 16 years with clinically suspected meningitis were eligible for this prospective cohort study at 2 large medical centers between February 2006 and October 2007. Exclusion criteria were severe chronic disease, severe immune deficiency, or idiopathic intracranial hypertension. The emergency department physician obtained information on clinical symptoms and signs and cerebrospinal fluid analysis. Meningitis was defined as white blood cell count of 6 or higher per microliter of cerebrospinal fluid.

RESULTS

A total of 108 patients with suspected meningitis were enrolled. Meningitis was diagnosed in 58 patients (53.7%; 6 bacterial and 52 aseptic). Sensitivity and specificity were 76% and 53% for headache (among the verbal patients) and 71% and 62% for vomiting, respectively. Photophobia was highly specific (88%) but had low sensitivity (28%). Clinical examination revealed nuchal rigidity (in patients without open fontanel) in 32 (65%) of the patients with meningitis and in 10 (33%) of the patients without meningitis. Brudzinski and Kernig signs were present in 51% and 27% of the patients with meningitis, respectively, and had relatively high positive predictive values (81% and 77%, respectively). Bulging fontanel in patients with open fontanel was present in 50% of the patients with meningitis but had a positive predictive value of only 38%.

CONCLUSIONS

Classic clinical diagnostic signs have limited value in establishing the diagnosis of meningitis in children and should not be the sole determinants for referral to further diagnostic testing and lumbar puncture.