Development and validation of a multivariable predictive model to distinguish bacterial from aseptic meningitis in children in the post-Haemophilus influenzae era

Validation of a Clinical Prediction Rule for Distinguishing Bacterial and Aseptic Meningitis in Pediatric Patients

Introduction The treatments and prognosis of bacterial meningitis differ greatly from those of aseptic meningitis, making early identification and differentiation essential. Several different clinical prediction rules have been developed to distinguish bacterial meningitis from aseptic meningitis. We sought to validate one clinical prediction rule for pediatric patients utilizing a centralized data warehouse that collects daily data from 184 hospitals across the United States. Methods We retrospectively collected data on all patients aged 29 days to 14 years who presented to Hospital Corporation of America (HCA) Healthcare hospitals from January 1, 2016, to May 31, 2021, with a diagnosis of meningitis. Our study replicated the original study of the meningitis score for emergencies (MSE) for the pediatric clinical prediction rule and assigned 3 points for procalcitonin (PCT) >1.2 ng/dL, 2 points for CSF protein >80 mg/dL, and 1 point for each of the other variables of C-reactive protein (CRP) >40 mg/L and CSF absolute neutrophil count >1000 cells per mm3. Patients were categorized either as having bacterial or aseptic meningitis. Using the clinical prediction rule, a calculation of the sensitivity, specificity, positive predictive value, negative predictive value, and receiver operating characteristic (ROC) curve was performed. Results The optimum test characteristic was found to have a score of ≥ 3, showing a sensitivity of 92.86% (95% CI, 83.3-100), a specificity of 65.22% (95% CI, 51.5-79), a positive predictive value of 61.90% (95% CI, 47.2-76.6), and a negative predictive value of 93.75% (95% CI, 85.4-100). The ROC curve from this study showed an area under the curve (AUC) of 0.7892 (95% CI, 0.681-0.897). Conclusion Our study validated a high sensitivity for distinguishing bacterial meningitis from aseptic meningitis, suggesting the clinical prediction rule has clinical utility as a predictive screening tool. Although the original MSE advised a cutoff score of ≥1, our study suggests that a score ≥3 would give the best test performance.

Development a prediction model for identifying bacterial meningitis in young infants aged 29-90 days: a retrospective analysis

BACKGROUND

The early diagnosis and treatment of bacterial meningitis (BM) in young infants was very critical. But, it was difficult to make a definite diagnosis in the early stage due to nonspecific clinical symptoms. Our objectives were to find the risk factors associated with BM and develop a prediction model of BM especially for young infants.

METHODS

We retrospectively reviewed the clinical data of young infants with meningitis between January 2011 and December 2020 in Children's Hospital of Soochow University. The independent risk factors of young infants with BM were screened using univariate and multivariate logistic regression analyses. The independent risk factors were used to construct a new scoring model and compared with Bacterial Meningitis Score (BMS) and Meningitis Score for Emergencies (MSE) models.

RESULTS

Among the 102 young infants included, there were 44 cases of BM and 58 of aseptic meningitis. Group B Streptococcus (22, 50.0%) and Escherichia coli (14, 31.8%) were the main pathogens of BM in the young infants. Multivariate logistic regression analysis identified procalcitonin (PCT), cerebrospinal fluid (CSF) glucose, CSF protein as independent risk factors for young infants with BM. We assigned one point for CSF glucose ≤ 1.86 mmol/L, two points were assigned for PCT ≥ 3.80 ng/ml and CSF protein ≥ 1269 mg/L. Using the not low risk criterion (score ≥ 1) with our new prediction model, we identified the young infantile BM with 100% (95% CI 91.9%-100%) sensitivity and 60.3% (95% CI 46.4%-72.9%) specificity. Compared with BMS and MSE model, our prediction model had larger area under receiver operating characteristic curve and higher specificity, the differences were statistically significant.

CONCLUSION

Our new scoring model for young infants can facilitate early identification of BM and has a better performance than BMS and MSE models.

Viral meningitis in Sudanese children: Differentiation, etiology and review of literature

Diagnosis of viral meningitis (VM) is uncommon practice in Sudan and there is no local viral etiological map. We therefore intended to differentiate VM using standardized clinical codes and determine the involvement of herpes simplex virus types-1 and 2 (HSV-1/2), varicella zoster virus, non-polio human enteroviruses (HEVs), and human parechoviruses in meningeal infections in children in Sudan. This is a cross-sectional hospital-based study. Viral meningitis was differentiated in 503 suspected febrile attendee of Omdurman Hospital for Children following the criteria listed in the Clinical Case Definition for Aseptic/Viral Meningitis. Patients were children age 0 to 15 years. Viral nucleic acids (DNA/RNA) were extracted from cerebrospinal fluid (CSF) specimens using QIAamp® UltraSens Virus Technology. Complementary DNA was prepared from viral RNA using GoScriptTM Reverse Transcription System. Viral nucleic acids were amplified and detected using quantitative TaqMan® Real-Time and conventional polymerase chain reactions (PCRs). Hospital diagnosis of VM was assigned to 0%, when clinical codes were applied; we considered 3.2% as having VM among the total study population and as 40% among those with proven infectious meningitis. Two (0.4%) out of total 503 CSF specimens were positive for HSV-1; Ct values were 37.05 and 39.10 and virus copies were 652/PCR run (261 × 103/mL CSF) and 123/PCR run (49.3 × 103/mL CSF), respectively. Other 2 (0.4%) CSF specimens were positive for non-polio HEVs; Ct values were 37.70 and 38.30, and the approximate virus copies were 5E2/PCR run (~2E5/mL CSF) and 2E2/PCR run (~8E4/mL CSF), respectively. No genetic materials were detected for HSV-2, varicella zoster virus, and human parechoviruses. The diagnosis of VM was never assigned by the hospital despite fulfilling the clinical case definition. Virus detection rate was 10% among cases with proven infectious meningitis. Detected viruses were HSV-1 and non-polio HEVs. Positive virus PCRs in CSFs with normal cellular counts were seen.

Reassessing the Value of CSF Protein and Glucose Measurement in Pediatric Infectious Meningitis

OBJECTIVES

Infectious meningitis (IM) in US children is increasingly rare and new rapid multiplex PCR-based testing is increasingly available. We evaluated the added value of cerebrospinal fluid (CSF) protein and glucose tests to predict IM when compared with information provided by CSF white blood cell count (WBC) and multiplex polymerase chain reaction (PCR).

METHODS

We retrospectively reviewed CSF results from October 2015 to August 2017 in patients 0 to 18 years at a US children's hospital. Noninfectious evaluations were excluded. Test characteristics were calculated for CSF WBC, protein, and glucose in isolation and in parallel for prediction of microbiologically confirmed IM. Chart review was performed to identify consideration of protein and glucose in medical decision-making (MDM).

RESULTS

We identified 735 patients including 446 <2 months; 45 (6.1%) had microbiologically-confirmed IM, including 23 (5.2%) age <2 months. Multiplex PCR and/or CSF WBC identified all IM patients. When added to CSF WBC, measurement of glucose made no contribution to sensitivity, specificity, positive predictive value (PPV) or negative predictive value (NPV), and protein had no impact on sensitivity and decreased the specificity, PPV, and NPV compared with CSF WBC alone. Abnormal protein was documented in MDM in 6 (0.8%) patients, all of whom had elevated WBC counts also cited. Glucose was not mentioned in MDM.

CONCLUSIONS

Multiplex PCR testing and WBC may be sufficient to predict meningitis in children in low incidence settings. Protein and glucose did not contribute significant additional information. More intentional use of protein and glucose testing in patients with suspected IM may achieve higher value care.

Viral capture sequencing detects unexpected viruses in the cerebrospinal fluid of adults with meningitis

OBJECTIVES

Many patients with meningitis have no aetiology identified leading to unnecessary antimicrobials and prolonged hospitalisation. We used viral capture sequencing to identify possible pathogenic viruses in adults with community-acquired meningitis.

METHODS

Cerebrospinal fluid (CSF) from 73 patients was tested by VirCapSeq-VERT, a probe set designed to capture viral targets using high throughput sequencing. Patients were categorised as suspected viral meningitis - CSF pleocytosis, no pathogen identified (n = 38), proven viral meningitis - CSF pleocytosis with a pathogen identified (n = 15) or not meningitis - no CSF pleocytosis (n = 20).

RESULTS

VirCapSeq-VERT detected virus in the CSF of 16/38 (42%) of those with suspected viral meningitis, including twelve individual viruses. A potentially clinically relevant virus was detected in 9/16 (56%). Unexpectedly Toscana virus, rotavirus and Saffold virus were detected and assessed to be potential causative agents.

CONCLUSION

VirCapSeq-VERT increases the probability of detecting a virus. Using this agnostic approach we identified Toscana virus and, for the first time in adults, rotavirus and Saffold virus, as potential causative agents in adult meningitis. Further work is needed to determine the prevalence of atypical viral candidates as well as the clinical impact of using sequencing methods in real time. This knowledge can help to reduce antimicrobial use and hospitalisations leading to both patient and health system benefits.

Ability of Procalcitonin and C-Reactive Protein for Discriminating between Bacterial and Enteroviral Meningitis in Children Using Decision Tree

Bacterial meningitis (BM) is a public health burden in developing countries, including Central Asia. This disease is characterized by a high mortality rate and serious neurological complications. Delay with the start of adequate therapy is associated with an increase in mortality for patients with acute bacterial meningitis. Cerebrospinal fluid culture, as a gold standard in bacterial meningitis diagnosis, is time-consuming with modest sensitivity, and this is unsuitable for timely decision-making. It has been shown that bacterial meningitis differentiation from viral meningitis could be done through different parameters such as clinical signs and symptoms, laboratory values, such as PCR, including blood and cerebrospinal fluid (CSF) analysis. In this study, we proposed the method for distinguishing the bacterial form of meningitis from enteroviral one. The method is based on the machine learning process deriving making decision rules. The proposed fast-and-frugal trees (FFTree) decision tree approach showed an ability to determine procalcitonin and C-reactive protein (CRP) with cut-off values for distinguishing between bacterial and enteroviral meningitis (EVM) in children. Such a method demonstrated 100% sensitivity, 96% specificity, and 98% accuracy in the differentiation of all cases of bacterial meningitis in this study. These findings and proposed method may be useful for clinicians to facilitate the decision-making process and optimize the diagnostics of meningitis.

Cerebrospinal fluid proteome maps detect pathogen-specific host response patterns in meningitis

Meningitis is a potentially life-threatening infection characterized by the inflammation of the leptomeningeal membranes. Many different viral and bacterial pathogens can cause meningitis, with differences in mortality rates, risk of developing neurological sequelae, and treatment options. Here, we constructed a compendium of digital cerebrospinal fluid (CSF) proteome maps to define pathogen-specific host response patterns in meningitis. The results revealed a drastic and pathogen-type specific influx of tissue-, cell-, and plasma proteins in the CSF, where, in particular, a large increase of neutrophil-derived proteins in the CSF correlated with acute bacterial meningitis. Additionally, both acute bacterial and viral meningitis result in marked reduction of brain-enriched proteins. Generation of a multiprotein LASSO regression model resulted in an 18-protein panel of cell- and tissue-associated proteins capable of classifying acute bacterial meningitis and viral meningitis. The same protein panel also enabled classification of tick-borne encephalitis, a subgroup of viral meningitis, with high sensitivity and specificity. The work provides insights into pathogen-specific host response patterns in CSF from different disease etiologies to support future classification of pathogen type based on host response patterns in meningitis.

An improved clinical prediction rule for identifying neonatal bacterial meningitis: a multicenter cohort study

BACKGROUND

To refine the bacterial meningitis (BM) score by improving its predictability of neonatal BM.

METHODS

A multicenter, ambispective cohort study was conducted in China, comprising 9 hospitals (retrospective cohort: January 2001 to December 2017; prospective cohort: January 2018 to August 2019). Of 3,504 eligible full-term neonates, 475 neonates with cerebrospinal fluid (CSF) pleocytosis were included. Based on the receiver operating characteristic (ROC) curve and logistic regression analyses, the BM score was refined by changing the thresholds of CSF protein level and the CSF absolute neutrophil count (ANC), and removing some variables (the peripheral blood ANC and a history of seizure before or at the time of presentation).

RESULTS

Of 475 neonates, 94 (19.8%) had BM. Based on the refined BM score, neonates with none of the following high-risk predictors were classified as being at very low risk for BM: CSF protein level ≥1,650 mg/L, CSF ANC ≥84×10⁶ cells/L, and positive CSF Gram stain result. The refined score showed 100% sensitivity in identifying BM and much higher specificity compared to that for the BM score (70.9% vs. 19.4%).

CONCLUSIONS

The refined BM score effectively identifies neonatal BM, and further studies are required to confirm our findings in prospective studies.

Management of Acute Bacterial Meningitis in Children

Acute community-acquired bacterial meningitis (ABM) in children continues to have high rates of neurological morbidity and mortality despite the overall declining rates of infection attributed to the use of vaccines and intrapartum Group B Streptococcus prophylaxis. Prompt diagnosis and early antibiotic therapy are crucial and should not be delayed to obtain cranial imaging. Differentiating bacterial from viral meningitis continues to be a clinical dilemma especially in patients with previous antibiotic exposure. Clinical models and inflammatory biomarkers can aid clinicians in their diagnostic approach. Multiplex polymerase chain reaction and metagenomic next-generation sequencing are promising tools that can help in early and accurate diagnosis. This review will present the epidemiology of ABM in children, indications of cranial imaging, role of different models and serum biomarkers in diagnosing ABM, and management including the use of adjunctive therapies and methods of prevention.

Clinical Prediction Rule for Distinguishing Bacterial From Aseptic Meningitis

BACKGROUND

New biomarkers like procalcitonin and C-reactive protein may help design an accurate decision support tool used to identify children with pleocytosis at low or high risk of bacterial meningitis. Our objective was to develop and validate a score (that we call the meningitis score for emergencies [MSE]) to distinguish bacterial meningitis from aseptic meningitis in children with pleocytosis when initially evaluated at the emergency department.

METHODS

We included children between 29 days and 14 years old with meningitis admitted to 25 Spanish emergency departments. A retrospective cohort from between 2011 and 2016 was used as the derivation set and a prospective cohort recruited during 2017 and 2018 was used as the validation set.

RESULTS

Among the 1009 patients included, there were 917 cases of aseptic meningitis and 92 of bacterial meningitis. Using multivariable logistic regression analysis, we identified the following predictors of bacterial meningitis from the derivation set: procalcitonin >1.2 ng/mL, cerebrospinal fluid (CSF) protein >80 mg/dL, CSF absolute neutrophil count >1000 cells per mm³, and C-reactive protein >40 mg/L. Using the derivation set, we developed the MSE, assigning 3 points for procalcitonin, 2 points for CSF protein, and 1 point for each of the other variables. An MSE ≥1 predicted bacterial meningitis with a sensitivity of 100% (95% confidence interval [CI]: 95.0%-100%), a specificity of 83.2 (95% CI: 80.6-85.5), and a negative predictive value of 100% (95% CI 99.4-100.) CONCLUSIONS: The MSE accurately distinguishes bacterial from aseptic meningitis in children with CSF pleocytosis.

Etiology, Clinical Presentation and Incidence of Infectious Meningitis and Encephalitis in Polish Children

Little is known about the causes and the frequency of meningitis and encephalitis in Poland. We did a retrospective single-center cohort study of children under 18 years old hospitalized with infectious meningitis or encephalitis. Incidence rates were calculated using collected data from patients from the North-East Poland only. A total of 374 children hospitalized between 1 January 2015 and 31 December 2019 were included in the study. A total of 332 (89%) children had meningitis, and 42 (11%) had encephalitis. The etiology of the infection was established in 331 (89%) cases. Enteroviruses accounted for 224 (60%) of all patients. A total of 68 (18%) cases were tick-borne infections. Bacterial pathogens were detected in 26 (7%) children. The median length of hospital stay for children with enteroviral meningitis was 7 days (IQR 7–9), increasing to 11 days (8–13) in those treated with antibiotics. The incidence of meningitis was estimated to be 32.22 (95% CI, 25.33–40.98) per 100,000 and that of encephalitis to be 4.08 (95% CI, 2.07–8.02) per 100,000. By the broad use of molecular diagnostic methods, we managed to identify etiology of the infection in the majority of children. Our data suggest that thorough diagnostics of central nervous system infections are needed to rationalize treatment.

Epidemiology of herpes simplex and varicella zoster virus in cerebrospinal fluid of patients suffering from meningitis in Iran

From the early 18th century that “meningitis” outbreak was firstly recorded in Geneva, it is one of the alarming health problems worldwide. Different infectious risk factors may contribute to the progression of meningitis. Herpes simplex virus (HSV) and Varicella-zoster virus (VZV) are just some noticeable risk factors among many involved in the progression of this disease. In this study, 415 meningitis suspected patients were recruited with some symptoms, such as fever, headache, nausea or vomiting, seizure, rash, dizziness from four different hospitals of Iran and molecular examinations of samples were performed by using specific primers of HSV½ and VZV via real-time PCR. Out of 415 included patient 41 (9.8 %) were VZV and six (1.4 %) cases were HSV ½ positive. Fever was the most frequent symptom by 315 (76 %) of patients with median temperature of 38 °C in all included patients. The median WBS counts of CSF in VZV positive, HSV½ positive, and all included cases were 1567 × 10⁶ /L, 1257 × 10⁶ /L, and 766 × 10⁶ /L (range 0-21200), respectively. In conclusion, as the rate of VZV infection was high among children patients and it was associated with the absence of vaccination program for chickenpox in Iran, we suggested that VZV is one of the plausible hallmarks in meningitis.

Systematic review and validation of diagnostic prediction models in patients suspected of meningitis

OBJECTIVES

Diagnostic prediction models have been developed to assess the likelihood of bacterial meningitis (BM) in patients presented with suspected central nervous system (CNS) infection. External validation in patients suspected of meningitis is essential to determine the diagnostic accuracy of these models.

METHODS

We prospectively included patients who underwent a lumbar puncture for suspected CNS infection. After a systematic review of the literature, we applied identified models for BM to our cohort. We calculated sensitivity, specificity, predictive values, area under the curve (AUC) and, if possible, we evaluated the calibration of the models.

RESULTS

From 2012-2015 we included 363 episodes. In 89 (24%) episodes, the patient received a final diagnosis of a CNS infection, of whom 27 had BM. Seventeen prediction models for BM were identified. Sensitivity of these models ranged from 37% to 100%. Specificity of these models ranged from 44% to 99%. The cerebrospinal fluid model of Oostenbrink reached the highest AUC of 0.95 (95% CI 0.91-0.997). Calibration showed over- or underestimation in all models.

CONCLUSION

None of the existing models performed well enough to recommend as routine use in individual patient management. Future research should focus on differences between diagnostic accuracy of the prediction models and physician's therapeutic decisions.

Bacterial meningitis in Sudanese children; critical evaluation of the clinical decision using clinical prediction rules

BACKGROUND

Sudan falls in the meningitis belt where most global cases of bacterial meningitis are reported. Highly accurate decision support tools have been developed by international specialized societies to guide the diagnosis and limit unnecessary hospital admissions and prolonged antibiotic use that have been frequently reported from countries around the world. The goals of this study are to critically evaluate the clinical decision of bacterial meningitis in children in Sudan using clinical prediction rules and to identify the current bacterial aetiology.

METHODS

This cross-sectional hospital-based study was conducted in October to July of 2010 in a major referral pediatric hospital in Khartoum, Sudan. Febrile children age 1 day to 15 years who were provisionally diagnosed as having meningitis on admission were included (n = 503). Cerebrospinal fluid (CSF) specimens were obtained from all patients while clinical and demographic data were available for only 404. Conventional laboratory investigations were performed. The clinical decision was evaluated by the International Classification of Diseases-Clinical Modification code 320.9 and the Bacterial Meningitis Score. Ethical clearance and permissions were obtained.

RESULTS

Out of 503 provisionally diagnosed bacterial meningitis patients, the final clinical confirmation was assigned to 55.9%. When codes were applied; 5.7% (23/404) with CSF pleocytosis were re-classified as High Risk for bacterial meningitis and 1.5% (6/404) with confirmed bacterial aetiology as Proven Bacterial Meningitis. Neisseria meningitidis was identified in 0.7% (3/404) and Streptococcus pneumoniae in another 0.7%. Typical laboratory findings (i.e. CSF pleocytosis and/or low glucose and high protein concentrations, Gram positive or Gram negative diplococcic, positive bacterial culture) were seen in 5 (83%). Clinically, patients showed fever, seizures, chills, headache, vomiting, stiff neck and bulging fontanelle. All confirmed cases were less than 5 years old and were admitted in summer. All patients were prescribed with antibiotics; they were all recovered and discharged.

CONCLUSIONS

Bacterial meningitis is over-diagnosed in hospitals in Khartoum therefore clinical prediction rules must be adopted and applied to guide the clinical decision. The sole bacterial aetiology in this selected group of Sudanese children remain N. meningitidis and S. pneumoniae, but with significant decrease in prevalence. Some cases showed atypical clinical and laboratory findings.

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.

A Prediction Model to Identify Febrile Infants ≤60 Days at Low Risk of Invasive Bacterial Infection

OBJECTIVES

To derive and internally validate a prediction model for the identification of febrile infants ≤60 days old at low probability of invasive bacterial infection (IBI).

METHODS

We conducted a case-control study of febrile infants ≤60 days old who presented to the emergency departments of 11 hospitals between July 1, 2011 and June 30, 2016. Infants with IBI, defined by growth of a pathogen in blood (bacteremia) and/or cerebrospinal fluid (bacterial meningitis), were matched by hospital and date of visit to 2 control patients without IBI. Ill-appearing infants and those with complex chronic conditions were excluded. Predictors of IBI were identified with multiple logistic regression and internally validated with 10-fold cross-validation, and an IBI score was calculated.

RESULTS

We included 181 infants with IBI (155 [85.6%] with bacteremia without meningitis and 26 [14.4%] with bacterial meningitis) and 362 control patients. Twenty-three infants with IBI (12.7%) and 138 control patients (38.1%) had fever by history only. Four predictors of IBI were identified (area under the curve 0.83 [95% confidence interval (CI): 0.79-0.86]) and incorporated into an IBI score: age <21 days (1 point), highest temperature recorded in the emergency department 38.0-38.4°C (2 points) or ≥38.5°C (4 points), absolute neutrophil count ≥5185 cells per μL (2 points), and abnormal urinalysis results (3 points). The sensitivity and specificity of a score ≥2 were 98.8% (95% CI: 95.7%-99.9%) and 31.3% (95% CI: 26.3%-36.6%), respectively. All 26 infants with meningitis had scores ≥2.

CONCLUSIONS

Infants ≤60 days old with fever by history only, a normal urinalysis result, and an absolute neutrophil count <5185 cells per μL have a low probability of IBI.

Eosinopenia as a marker of diagnosis and prognostic to distinguish bacterial from aseptic meningitis in pediatrics

Procalcitonin (PCT) has proven its efficacy to distinguish bacterial from aseptic meningitis in children. Nevertheless, its use in routine is limited by its cost and availability, especially in low- and middle-income countries. It is now acknowledged that eosinopenia is a marker of infection and/or severity of the systemic inflammatory response. Although no study ever demonstrated that eosinopenia could differentiate bacterial from viral infection, we decided to conduct a study concerning meningitis in children. This bicentric and retrospective study was conducted between January 2012 and October 2018, in children hospitalized for meningitis. The white blood cell was systematically gathered at the admission to evaluate the eosinophil count. Characteristic data were compared between 2 groups: documented bacterial meningitis (DBP) and aseptic meningitis which includes documented viral meningitis (DVM) and non-documented meningitis (ND). Among 190 patients admitted for meningitis, 151 were analyzed, including DBM (n = 45), DVM (n = 73), and ND (n = 33) meningitis. Groups were comparable. Mean age was 33 ± 48 months with a sex ratio of 1.6. Mean of eosinophil count was 15 ± 34/mm³ in the DBM group versus 132 ± 167/mm³ for the aseptic meningitis group (p < 0.0001). Best threshold for the diagnosis of bacterial meningitis was an eosinophil count < 5/mm³ with a sensitivity of 80% and specificity of 73% and a likelihood ratio of 2.9. Eosinopenia seems to be a reliable and non-invasive marker of bacterial meningitis in pediatrics. The absence of extra cost makes it very interesting in low- and middle-income countries or when usual biomarkers such as PCT are unavailable.

Utility of Clinical and Laboratory Decision Rules in Identifying Bacterial Meningitis Among Children with Suspicion of Central Nervous System Infections in a Malaria-Endemic Area, Mbarara, Uganda

Several decision rules combining clinical and biological parameters have been proposed to distinguish bacterial from aseptic meningitis, but have not been evaluated in Africa. In children hospitalized with suspected central nervous system infections in Uganda, we found that the Bacterial Meningitis Score and Meningitest showed lower performance than in European children, and that a decision rule designed specifically using parameters associated with bacterial meningitis also showed inadequate diagnostic performance for clinical use.

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.

Epidemiology and Etiology of Invasive Bacterial Infection in Infants ≤60 Days Old Treated in Emergency Departments

OBJECTIVES

To help guide empiric treatment of infants ≤60 days old with suspected invasive bacterial infection by describing pathogens and their antimicrobial susceptibilities.

STUDY DESIGN

Cross-sectional study of infants ≤60 days old with invasive bacterial infection (bacteremia and/or bacterial meningitis) evaluated in the emergency departments of 11 children's hospitals between July 1, 2011 and June 30, 2016. Each site's microbiology laboratory database or electronic medical record system was queried to identify infants from whom a bacterial pathogen was isolated from either blood or cerebrospinal fluid. Medical records of these infants were reviewed to confirm the presence of a pathogen and to obtain demographic, clinical, and laboratory data.

RESULTS

Of the 442 infants with invasive bacterial infection, 353 (79.9%) had bacteremia without meningitis, 64 (14.5%) had bacterial meningitis with bacteremia, and 25 (5.7%) had bacterial meningitis without bacteremia. The peak number of cases of invasive bacterial infection occurred in the second week of life; 364 (82.4%) infants were febrile. Group B streptococcus was the most common pathogen identified (36.7%), followed by Escherichia coli (30.8%), Staphylococcus aureus (9.7%), and Enterococcus spp (6.6%). Overall, 96.8% of pathogens were susceptible to ampicillin plus a third-generation cephalosporin, 96.0% to ampicillin plus gentamicin, and 89.2% to third-generation cephalosporins alone.

CONCLUSIONS

For most infants ≤60 days old evaluated in a pediatric emergency department for suspected invasive bacterial infection, the combination of ampicillin plus either gentamicin or a third-generation cephalosporin is an appropriate empiric antimicrobial treatment regimen. Of the pathogens isolated from infants with invasive bacterial infection, 11% were resistant to third-generation cephalosporins alone.

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.

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.

Diagnostic value of lactate, procalcitonin, ferritin, serum-C-reactive protein, and other biomarkers in bacterial and viral meningitis: A cross-sectional study

There are many difficulties distinguishing bacterial from viral meningitis that could be reasonably solved using biomarkers. The aim of this study was to evaluate lactate, procalcitonin (PCT), ferritin, serum-CRP (C-reactive protein), and other known biomarkers in differentiating bacterial meningitis from viral meningitis in children.All children aged 28 days to 14 years with suspected meningitis who were admitted to Mofid Children's Hospital, Tehran, between October 2012 and November 2013, were enrolled in this prospective cross-sectional study. Children were divided into 2 groups of bacterial and viral meningitis, based on the results of cerebrospinal fluid (CSF) culture, polymerase chain reaction, and cytochemical profile. Diagnostic values of CSF parameters (ferritin, PCT, absolute neutrophil count [ANC], white blood cell count, and lactate) and serum parameters (PCT, ferritin, CRP, and erythrocyte sedimentation rate [ESR]) were evaluated.Among 50 patients with meningitis, 12 were diagnosed with bacterial meningitis. Concentrations of all markers were significantly different between bacterial and viral meningitis, except for serum (P = .389) and CSF (P = .136) PCT. The best rates of area under the receiver operating characteristic (ROC) curve (AUC) were achieved by lactate (AUC = 0.923) and serum-CRP (AUC = 0.889). The best negative predictive values (NPV) for bacterial meningitis were attained by ANC (100%) and lactate (97.1%).The results of our study suggest that ferritin and PCT are not strong predictive biomarkers. A combination of low CSF lactate, ANC, ESR, and serum-CRP could reasonably rule out the bacterial meningitis.

Cerebrospinal fluid pleocytosis in infectious and noninfectious central nervous system disease: A retrospective cohort study

Cerebrospinal fluid (CSF) analysis is the most important tool for assessing central nervous system (CNS) disease. An elevated CSF leukocyte count rarely provides the final diagnosis, but is almost always an indicator of inflammation within the CNS.The present study investigated the variety of diseases associated with CSF pleocytosis.CSF analyses were identified through the biochemical database used in the capital region of Denmark in the period from 2003 to 2010. In patients >15 years, clinical diagnoses associated with the finding of a CSF leukocyte count >10 × 10 cells/L were obtained from discharge records and patient files.A total of 1058 CSF samples from 1054 patients were included in the analysis. The median age was 50 (interquartile range: 36-67) and 53% were male. Eighty-one different diagnoses were identified in 1058 cases with an elevated CSF leukocyte count, besides unknown causes. Infections were the most common cause of CSF pleocytosis (61.4%) followed by miscellaneous causes (12.7%), vascular (9.7%), neurodegenerative (7%), neoplastic (5%), and inflammatory conditions (4.2%). Only infections presented with leukocyte counts >10,000 × 10/L. Infections represented 82.6% of all cases with a leukocyte count >100 × 10/L whereas 56.3% of cases with at leukocyte counts <100 × 10/L were dominated by disease not related to infection.The present study may serve as a reminder to clinicians of what diseases and disease categories to suspect when patients present with CSF biochemistry indicating CNS inflammation.

Soluble triggering receptor expressed on myeloid cell-1 (sTREM-1): a potential biomarker for the diagnosis of infectious diseases

Sensitive and useful biomarkers for the diagnosis and prognosis of infectious diseases have been widely developed. An example of these biomarkers is triggering receptor expressed on myeloid cell-1 (TREM-1), which is a cell surface receptor expressed on monocytes/macrophages and neutrophils. TREM-1 amplifies inflammation by activating the TREM-1/DAP12 pathway. This pathway is triggered by the interaction of TREM-1 with ligands or stimulation by bacterial lipopolysaccharide. Consequently, pro-inflammatory cytokines and chemokines are secreted. Soluble TREM-1 (sTREM-1) is a special form of TREM-1 that can be directly tested in human body fluids and well-known biomarker for infectious diseases. sTREM-1 level can be potentially used for the early diagnosis and prognosis prediction of some infectious diseases, including infectious pleural effusion, lung infections, sepsis, bacterial meningitis, viral infections (e.g., Crimean Congo hemorrhagic fever and dengue fever), fungal infections (e.g., Aspergillus infection), and burn-related infections. sTREM-1 is a more sensitive and specific biomarker than traditional indices, such as C-reactive protein and procalcitonin levels, for these infectious diseases. Therefore, sTREM-1 is a feasible biomarker for the targeted therapy and rapid and early diagnosis of infectious diseases.

Diagnosis and Treatment of Central Nervous System Infections in the Emergency Department

Central nervous system (CNS) infections, including meningitis, encephalitis, and brain abscess, are rare but time-sensitive emergency department (ED) diagnoses. Patients with CNS infection can present to the ED with nonspecific signs and symptoms, including headache, fever, altered mental status, and behavioral changes. Neuroimaging and CSF fluid analysis can appear benign early in the course of disease. Delaying therapy negatively impacts outcomes, particularly with bacterial meningitis and herpes simplex virus encephalitis. Therefore, diagnosis of CNS infection requires vigilance and a high index of suspicion based on the history and physical examination, which must be confirmed with appropriate imaging and laboratory evaluation.

The usefulness of serum delta neutrophil index for differentiating bacterial and viral meningitis in the emergency department

OBJECTIVE

When managing patients with acute meningitis in an emergency department (ED), early diagnosis of the type of infection (bacterial or viral) considerably affects the clinical course and treatment because of the high mortality and morbidity associated with bacterial meningitis (BM). The serum delta neutrophil index (DNI), a new inflammatory marker, reflects the fraction of circulating immature granulocytes and is elevated in cases of bacterial infection. The objective of this study was to evaluate whether serum DNI can be used to differentiate between BM and viral meningitis (VM) in the ED.

METHODS

This retrospective, observational study included 104 consecutive patients (aged >18 years) diagnosed with acute meningitis from January 2012 to November 2014 in a regional emergency center. White blood cell and neutrophil counts, C-reactive protein level, and DNI were evaluated regarding their usefulness for differentiating BM and VM.

RESULTS

Serum DNI was not significantly higher in the BM group (n=12) than in the VM group (n=92) (0 [interquartile range, 0% to 2.73%] vs. 0 [interquartile range, 0 to 0%], P=0.057). However, the white blood cell count and C-reactive protein level were statistically higher in the BM group (P=0.034 and P=0.026, respectively). Serum DNI was not found to be a statistically useful differential diagnostic parameter (area under the curve, 0.628; 95% confidence interval, 0.438 to 0.818).

CONCLUSION

Currently, there is no evidence that the serum DNI aids in differentiating acute BM from acute VM in the ED.

Proposal for a New Score-Based Approach To Improve Efficiency of Diagnostic Laboratory Workflow for Acute Bacterial Meningitis in Adults

Microbiological tests on cerebrospinal fluid (CSF) utilize a common urgent-care procedure that does not take into account the chemical and cytological characteristics of the CSF, resulting sometimes in an unnecessary use of human and diagnostic resources. The aim of this study was to retrospectively validate a simple scoring system (bacterial meningitis-Careggi score [BM-CASCO]) based on blood and CSF sample chemical/cytological parameters for evaluating the probability of acute bacterial meningitis (ABM) in adults. BM-CASCO (range, 0 to 6) was defined by the following parameters: CSF cell count, CSF protein levels, CSF lactate levels, CSF glucose-to-serum glucose ratio, and peripheral neutrophil count. BM-CASCO was retrospectively calculated for 784 cases of suspected ABM in adult subjects observed during a four-and-a-half-year-period (2010 to 2014) at the emergency department (ED) of a large tertiary-care teaching hospital in Italy. Among the 28 confirmed ABM cases (3.5%), Streptococcus pneumoniae was the most frequent cause (16 cases). All ABM cases showed a BM-CASCO value of ≥3. Most negative cases (591/756) exhibited a BM-CASCO value of ≤1, which was adopted in our laboratory as a cutoff to not proceed with urgent microbiological analysis of CSF in cases of suspected ABM in adults. During a subsequent 1-year follow-up, the introduction of the BM-CASCO in the diagnostic workflow of ABM in adults resulted in a significant decrease in unnecessary microbiological analysis, with no false negatives. In conclusion, BM-CASCO appears to be an accurate and simple scoring system for optimization of the microbiological diagnostic workflow of ABM in adults.

Clinical decision rules for acute bacterial meningitis: current insights

Acute community-acquired bacterial meningitis (BM) requires rapid diagnosis so that suitable treatment can be instituted within 60 minutes of admitting the patient. The cornerstone of diagnostic examination is lumbar puncture, which enables microbiological analysis and determination of the cerebrospinal fluid (CSF) cytochemical characteristics. However, microbiological testing is not sufficiently sensitive to rule out this diagnosis. With regard to the analysis of standard CSF cytochemical characteristics (polymorphonuclear count, CSF glucose and protein concentration, and CSF:serum glucose), this is often misleading. Indeed, the relatively imprecise nature of the cutoff values for these BM diagnosis markers can make their interpretation difficult. However, there are two markers that appear to be more efficient than the standard ones: CSF lactate and serum procalcitonin levels. Scores and predictive models are also available; however, they only define a clinical probability, and in addition, their use calls for prior validation on the population in which they are used. In this article, we review current methods of BM diagnosis.

Following the (Clinical Decision) Rules: Opportunities for Improving Safety and Resource Utilization With the Bacterial Meningitis Score

BACKGROUND

The Bacterial Meningitis Score accurately classifies children with cerebrospinal fluid (CSF) pleocytosis at very low risk (VLR) versus not very low risk (non-VLR) for bacterial meningitis. Most children with CSF pleocytosis detected during emergency department evaluation are hospitalized despite the high accuracy of this prediction rule and the decreasing incidence of bacterial meningitis. The lack of widespread use of this rule may contribute to unnecessary risk exposure and costs.

METHODS

This cross-sectional study included 1049 patients who, between January 2010 and May 2013, had suspicion for meningitis and underwent both a complete blood cell count and CSF studies during their emergency department evaluation. We then examined their hospitalizations to characterize exposure to drugs, radiologic studies, and the costs associated with their care to determine the safety and value repercussions of these VLR admissions. Primary outcomes include duration of antibiotics, exposure to drugs and radiology studies, safety events, and costs incurred during these VLR admissions.

RESULTS

Twenty patients classified as VLR were admitted to the hospital. On average they received 35 hours of antibiotic therapy. There was 1 adverse drug event and 1 safety event.

CONCLUSIONS

The VLR patients admitted to the hospital were exposed to risk and costs despite their low risk stratification. Systematic application of the Bacterial Meningitis Score could prevent these exposures and costs.

Applying the bacterial meningitis score in children with cerebrospinal fluid pleocytosis: a single center's experience

PURPOSE

The widespread introduction of bacterial conjugate vaccines has decreased the risk of cerebrospinal fluid (CSF) pleocytosis due to bacterial meningitis (BM) in children. However, most patients with CSF pleocytosis are hospitalized and treated with parenteral antibiotics for several days. The bacterial meningitis score (BMS) is a validated multivariate model derived from a pediatric population in the postconjugate vaccine era and has been evaluated in several studies. In the present study, we examined the usefulness of BMS in South Korean patients.

METHODS

This study included 1,063 patients with CSF pleocytosis aged between 2 months and 18 years. The BMS was calculated for all patients, and the sensitivity and negative predictive value (NPV) of the test were evaluated.

RESULTS

Of 1,063 patients, 1,059 (99.6%) had aseptic meningitis (AM). Only four patients (0.4%) had BM. The majority of patients (98%) had a BMS of ≤1, indicating a diagnosis of AM. The BMS was 0 in 635 patients (60%) and 1 in 405 patients (38%). All four BM patients had a BMS of ≥4.

CONCLUSION

To our knowledge, this is the first study to investigate the diagnostic strength of the BMS in South Korea. In our study, the BMS showed 100% sensitivity and 100% NPV. Therefore, we believe that the BMS is a good clinical prediction rule to identify children with CSF pleocytosis who are at a risk of BM.

Clinical prediction rules in practice: review of clinical guidelines and survey of GPs

BACKGROUND

The publication of clinical prediction rules (CPRs) studies has risen significantly. It is unclear if this reflects increasing usage of these tools in clinical practice or how this may vary across clinical areas.

AIM

To review clinical guidelines in selected areas and survey GPs in order to explore CPR usefulness in the opinion of experts and use at the point of care.

DESIGN AND SETTING

A review of clinical guidelines and survey of UK GPs.

METHOD

Clinical guidelines in eight clinical domains with published CPRs were reviewed for recommendations to use CPRs including primary prevention of cardiovascular disease, transient ischaemic attack (TIA) and stroke, diabetes mellitus, fracture risk assessment in osteoporosis, lower limb fractures, breast cancer, depression, and acute infections in childhood. An online survey of 401 UK GPs was also conducted.

RESULTS

Guideline review: Of 7637 records screened by title and/or abstract, 243 clinical guidelines met inclusion criteria. CPRs were most commonly recommended in guidelines regarding primary prevention of cardiovascular disease (67%) and depression (67%). There was little consensus across various clinical guidelines as to which CPR to use preferentially.

SURVEY

Of 401 responders to the GP survey, most were aware of and applied named CPRs in the clinical areas of cardiovascular disease and depression. The commonest reasons for using CPRs were to guide management and conform to local policy requirements.

CONCLUSION

GPs use CPRs to guide management but also to comply with local policy requirements. Future research could focus on which clinical areas clinicians would most benefit from CPRs and promoting the use of robust, externally validated CPRs.

Aseptic meningitis

This chapter describes the clinical presentation, diagnosis, and treatment of patients with both aseptic meningitis and encephalitis. It also addresses the major causes of aseptic meningitis. Although bacterial meningitis is quite rare in an era of widespread conjugate vaccines, diagnosis often depends on the results of bacterial cultures which may take several days. Aseptic meningitis, on the other hand, is typically a benign childhood infection requiring supportive care alone. It also reviews available clinical decision rules that may assist the clinician in distinguishing which children with aseptic meningitis are at very low risk of bacterial meningitis using predictors available at the time of clinical presentation.

Fever in the pediatric patient

Fever is the most common reason that children and infants are brought to emergency departments. Emergency physicians face the challenge of quickly distinguishing benign from life-threatening conditions. The management of fever in children is guided by the patient's age, immunization status, and immune status as well as the results of a careful physical examination and appropriate laboratory tests and radiographic views. In this article, the evaluation and treatment of children with fevers of known and unknown origin are described. Causes of common and dangerous conditions that include fever in their manifestation are also discussed.

The bacterial meningitis score to distinguish bacterial from aseptic meningitis in children from Sao Paulo, Brazil

In a retrospective cohort of 494 children with meningitis in Sao Paulo, Brazil, the Bacterial Meningitis Score identified all the children with bacterial meningitis (sensitivity 100%, 95% confidence interval: 92-100% and negative predictive value 100%, 95% confidence interval: 98-100%). Addition of cerebrospinal fluid lactate to the score did not improve clinical prediction rule performance.

Role of biomarkers in the management of antibiotic therapy: an expert panel review II: clinical use of biomarkers for initiation or discontinuation of antibiotic therapy

Biomarker-guided initiation of antibiotic therapy has been studied in four conditions: acute pancreatitis, lower respiratory tract infection (LRTI), meningitis, and sepsis in the ICU. In pancreatitis with suspected infected necrosis, initiating antibiotics best relies on fine-needle aspiration and demonstration of infected material. We suggest that PCT be measured to help predict infection; however, available data are insufficient to decide on initiating antibiotics based on PCT levels. In adult patients suspected of community-acquired LRTI, we suggest withholding antibiotic therapy when the serum PCT level is low (<0.25 ng/mL); in patients having nosocomial LRTI, data are insufficient to recommend initiating therapy based on a single PCT level or even repeated measurements. For children with suspected bacterial meningitis, we recommend using a decision rule as an aid to therapeutic decisions, such as the Bacterial Meningitis Score or the Meningitest®; a single PCT level ≥0.5 ng/mL also may be used, but false-negatives may occur. In adults with suspected bacterial meningitis, we suggest integrating serum PCT measurements in a clinical decision rule to help distinguish between viral and bacterial meningitis, using a 0.5 ng/mL threshold. For ICU patients suspected of community-acquired infection, we do not recommend using a threshold serum PCT value to help the decision to initiate antibiotic therapy; data are insufficient to recommend using PCT serum kinetics for the decision to initiate antibiotic therapy in patients suspected of ICU-acquired infection. In children, CRP can probably be used to help discontinue therapy, although the evidence is limited. In adults, antibiotic discontinuation can be based on an algorithm using repeated PCT measurements. In non-immunocompromised out- or in- patients treated for RTI, antibiotics can be discontinued if the PCT level at day 3 is < 0.25 ng/mL or has decreased by >80-90%, whether or not microbiological documentation has been obtained. For ICU patients who have nonbacteremic sepsis from a known site of infection, antibiotics can be stopped if the PCT level at day 3 is < 0.5 ng/mL or has decreased by >80% relative to the highest level recorded, irrespective of the severity of the infectious episode; in bacteremic patients, a minimal duration of therapy of 5 days is recommended.

Bacterial meningitis post-PCV7: declining incidence and treatment

The epidemiology of bacterial meningitis in the United States has changed tremendously in the past 20 years. Since the introduction of the Haemophilus influenzae type b vaccine in 1988, the incidence of H. influenzae type b meningitis has declined by at least 97%, and Streptococcus pneumoniae has emerged as the most common etiologic agent. The PCV7 (7-valent pneumococcal conjugate vaccine [Prevnar]; Wyeth Pharmaceuticals) vaccine, which targets 7 pneumococcal serotypes, was introduced in 2000 and has had an enormous impact on both the incidence and epidemiology of bacterial meningitis. This article reviews the impact of the PCV7 vaccine and the most up-to-date evidence on diagnosis and empiric therapy of suspected bacterial meningitis in the current day.

Serum procalcitonin in septic meningitis

OBJECTIVE

To evaluate the role of serum procalcitonin (PCT) in diagnosis of septic meningitis in children and its efficacy in differential diagnosis.

METHODS

The study included 40 children of septic meningitis admitted in pediatric ward with fever, headache, vomiting and seizure, up to 14 y of age. The diagnosis of septic meningitis was based on clinical features; physical examination, blood and cerebrospinal fluid (CSF) cytochemical findings, gram's stain and bacterial culture. Fifteen cases of aseptic meningitis admitted during same period were also included in the study, and 15 children with normal CSF were taken as control. Serum PCT was measured by ELISA Kit.

RESULTS

Serum PCT level was significantly higher in children with septic meningitis than those with aseptic meningitis or in controls (p < 0.001). In culture and gram's stain positive 7 cases, serum procalcitonin was significantly elevated (24,768.21 ± 6,567.45 pg/mL) than aseptic meningitis(14,451.24 ± 4,266.15 pg/mL) (p < 0.001). Further its level was found significantly elevated in partially treated septic meningitis as compared to aseptic meningitis cases (p < 0.001). At optimum cut off value of ≥ 5,000 pg/mL, based on area under ROC curve, PCT showed sensitivity, specificity, positive predictive value and negative predictive value of 98.5 %, 93.5 %, 98.6 % and 93.3 % respectively. Serum PCT with cut off level of 15,000 pg/ml showed sensitivity, specificity, PPV and NPV of 92 %, 67 %, 91.4 % and 71.4 % respectively for the differentiation of septic from aseptic meningitis.

CONCLUSIONS

Serum PCT may be used as diagnostic marker for septic meningitis and its differentiation from aseptic meningitis.

Risk score for identifying adults with CSF pleocytosis and negative CSF Gram stain at low risk for an urgent treatable cause

BACKGROUND

We aimed to derive and validate a risk score that identifies adults with cerebrospinal fluid (CSF) pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause.

METHODS

Patients with CSF pleocytosis and a negative CSF Gram stain were stratified into a prospective derivation (n = 193) and a retrospective validation (n = 567) cohort. Clinically related baseline characteristics were grouped into three composite variables, each independently associated with a set of predefined urgent treatable causes. We subsequently derived a risk score classifying patients into low (0 composite variables present) or high (≥ 1 composite variables present) risk for an urgent treatable cause. The sensitivity of the risk score was determined in the validation cohort and in a prospective case series of 214 adults with CSF-culture proven bacterial meningitis, CSF pleocytosis and a negative Gram stain.

FINDINGS

A total of 41 of 193 patients (21%) in the derivation cohort and 71 of 567 (13%) in the validation cohort had an urgent treatable cause. Sensitivity of the dichotomized risk score to detect an urgent treatable cause was 100.0% (95% CI 93.9-100.0%) in the validation cohort and 100.0% (95% CI 97.8-100.0%) in bacterial meningitis patients.

INTERPRETATION

The risk score can be used to identify adults with CSF pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause.