Dilemmas in the diagnosis of acute community-acquired bacterial meningitis

Differentiation between viral and autoimmune limbic encephalitis: a prospective cohort study with development and validation of a diagnostic model

BACKGROUND

Distinguishing between viral encephalitis (VE) and autoimmune limbic encephalitis (ALE) presents a clinical challenge due to the overlap in symptoms. We aimed to develop and validate a diagnostic prediction model to differentiate VE and ALE.

METHODS

A prospective observational multicentre cohort study, which continuously enrolled patients diagnosed with either ALE or VE from October 2011 to April 2023. The demographic data, clinical features, and laboratory test results were collected and subjected to logistic regression analyses. The model was displayed as a web-based nomogram and then modified into a scored prediction tool. Model performance was assessed in both derivation and external validation cohorts.

RESULTS

A total of 2423 individuals were recruited, and 1001 (496 VE, 505 ALE) patients were included. Based on the derivation cohort (389 VE, 388 ALE), the model was developed with eight variables including age at onset, acuity, fever, headache, nausea/vomiting, psychiatric or memory complaints, status epilepticus, and CSF white blood cell count. The model showed good discrimination and calibration in both derivation (AUC 0.890; 0.868-0.913) and external validation (107 VE, 117 ALE, AUC 0.872; 0.827-0.917) cohorts. The scored prediction tool had a total point that ranged from - 4 to 10 also showing good discrimination and calibration in both derivation (AUC 0.885, 0.863-0.908) and external validation (AUC 0.868, 0.823-0.913) cohorts.

CONCLUSIONS

The prediction model provides a reliable and user-friendly tool for differentiating between the VE and ALE, which would benefit early diagnosis and appropriate treatment and alleviate economic burdens on both patients and society.

Granulocytes in cerebrospinal fluid of adults suspected of a central nervous system infection: a prospective study of diagnostic accuracy

PURPOSE

Cerebrospinal fluid (CSF) granulocytes are associated with bacterial meningitis, but information on its diagnostic value is limited and primarily based on retrospective studies. Therefore, we assessed the diagnostic accuracy of CSF granulocytes.

METHODS

We analyzed CSF granulocytes (index test) from all consecutive patients in two prospective cohort studies in the Netherlands. Both studies included patients ≥ 16 years, suspected of a central nervous system (CNS) infection, who underwent a diagnostic lumbar puncture. All episodes with elevated CSF leukocytes (≥ 5 cells per mm3) were selected and categorized by clinical diagnosis (reference standard).

RESULTS

Of 1261 episodes, 625 (50%) had elevated CSF leukocytes and 541 (87%) were included. 117 of 541 (22%) were diagnosed with bacterial meningitis, 144 (27%) with viral meningoencephalitis, 49 (9%) with other CNS infections, 76 (14%) with CNS autoimmune disorders, 93 (17%) with other neurological diseases and 62 (11%) with systemic diseases. The area under the curve to discriminate bacterial meningitis from other diagnoses was 0.97 (95% confidence interval [CI] 0.95-0.98) for CSF granulocyte count and 0.93 (95% CI 0.91-0.96) for CSF granulocyte percentage. CSF granulocyte predominance occurred in all diagnostic categories. A cutoff at 50% CSF granulocytes gave a sensitivity of 94% (95% CI 90-98), specificity of 80% (95% CI 76-84), negative predictive value of 98% (95% CI 97-99) and positive predictive value of 57% (95% CI 52-62).

CONCLUSION

CSF granulocytes have a high diagnostic accuracy for bacterial meningitis in patients suspected of a CNS infection. CSF granulocyte predominance occurred in all diagnostic categories, limiting its value in clinical practice.

Microbiomes detected by cerebrospinal fluid metagenomic next-generation sequencing among patients with and without HIV with suspected central nervous system infection

BACKGROUND

Opportunistic infections in the central nervous system (CNS) can be a serious threat to people living with HIV. Early aetiological diagnosis and targeted treatment are crucial but difficult. Metagenomic next-generation sequencing (mNGS) has significant advantages over traditional detection methods. However, differences in the cerebrospinal fluid (CSF) microbiome profiles of patients living with and without HIV with suspected CNS infections using mNGS and conventional testing methods have not yet been adequately evaluated.

METHODS

We conducted a retrospective cohort study in the first hospital of Changsha between January 2019 and June 2022 to investigate the microbiomes detected using mNGS of the CSF of patients living with and without HIV with suspected CNS infections. The pathogens causing CNS infections were concurrently identified using both mNGS and traditional detection methods. The spectrum of pathogens identified was compared between the two groups.

RESULTS

Overall, 173 patients (140 with and 33 without HIV) with suspected CNS infection were enrolled in our study. In total, 106 (75.7%) patients with and 16 (48.5%) patients without HIV tested positive with mNGS (p = 0.002). Among the enrolled patients, 71 (50.7%) with HIV and five (15.2%) without HIV tested positive for two or more pathogens (p < 0.001). Patients with HIV had significantly higher proportions of fungus (20.7% vs. 3.0%, p = 0.016) and DNA virus (59.3% vs. 21.2%, p < 0.001) than those without HIV. Epstein-Barr virus (33.6%) was the most commonly identified potential pathogen in the CSF of patients living with HIV using mNGS, followed by cytomegalovirus (20.7%) and torque teno virus (13.8%). The top three causative pathogens identified in patients without HIV were Streptococcus (18.2%), Epstein-Barr virus (12.1%), and Mycobacterium tuberculosis (9.1%). In total, 113 patients living with HIV were diagnosed as having CNS infections. The rate of pathogen detection in people living with HIV with a CNS infection was significantly higher with mNGS than with conventional methods (93.8% vs. 15.0%, p < 0.001).

CONCLUSION

CSF microbiome profiles differ between patients living with and without HIV with suspected CNS infection. mNGS is a powerful tool for the diagnosis of CNS infection among people living with HIV, especially in those with mixed infections.

A multicenter clinical epidemiology of pediatric pneumococcal meningitis in China: results from the Chinese Pediatric Bacterial Meningitis Surveillance (CPBMS) 2019-2020

Objective

To analyze the clinical epidemiological characteristics including clinical features, disease prognosis of pneumococcal meningitis (PM), and drug sensitivity of S. pneumoniae isolates in Chinese children.

Methods

A retrospective analysis was performed on the clinical, laboratory microbiological data of 160 hospitalized children less than 15 years of age with PM from January 2019 to December 2020 in 33 tertiary hospitals in China.

Results

A total of 160 PM patients were diagnosed, including 103 males and 57 females The onset age was 15 days to 15 years old, and the median age was 1 year and 3 months. There were 137 cases (85.6%) in the 3 months to <5 years age group, especially in the 3 months to <3 years age group (109 cases, 68.2%); S. pneumoniae was isolated from cerebrospinal fluid (CSF) culture in 95(35.6%), and 57(35.6%) in blood culture. The positive rates of S. pneumoniae detection by CSF metagenomic next-generation sequencing (mNGS)and antigen detection method were 40.2% (35/87) and 26.9% (21/78). Fifty-five cases (34.4%) had one or more predisposing factors of bacterial meningitis; and 113 cases (70.6%) had one or more extracranial infection diseases Fever (147, 91.9%) was the most common clinical symptom, followed by vomiting (61, 38.1%) and altered mental status (47,29.4%). Among 160 children with PM, the main intracranial imaging complications were subdural effusion and (or) empyema in 43 cases (26.9%), hydrocephalus in 24 cases (15.0%), cerebral abscess in 23 cases (14.4%), intracranial hemorrhage in 8 cases (5.0%), and other cerebrovascular diseases in 13 cases (8.1%) including encephalomalacia, cerebral infarction, and encephalatrophy. Subdural effusion and (or) empyema and hydrocephalus mainly occurred in children < 1 years old (90.7% (39/43) and 83.3% (20/24), respectively). 17 cases with PM (39.5%) had more than one intracranial imaging abnormality. S. pneumoniae isolates were completely sensitive to vancomycin (100.0%, 75/75), linezolid (100.0%,56/56), ertapenem (6/6); highly sensitive to levofloxacin (81.5%, 22/27), moxifloxacin (14/17), rifampicin (96.2%, 25/26), and chloramphenicol (91.3%, 21/23); moderately sensitive to cefotaxime (56.1%, 23/41), meropenem (51.1%, 23/45) and ceftriaxone (63.5, 33/52); less sensitive to penicillin (19.6%, 27/138) and clindamycin (1/19); completely resistant to erythromycin (100.0%, 31/31). The cure and improvement rate were 22.5% (36/160)and 66.3% (106/160), respectively. 18 cases (11.3%) had an adverse outcome, including 6 cases withdrawing treatment therapy, 5 cases unhealed, 5 cases died, and 2 recurrences. S. pneumoniae was completely susceptible to vancomycin (100.0%, 75/75), linezolid (100.0%, 56/56), and ertapenem (6/6); susceptible to cefotaxime, meropenem, and ceftriaxone in the order of 56.1% (23/41), 51.1% (23/45), and 63.5 (33/52); completely resistant to erythromycin (100.0%, 31/31).

Conclusion

Pediatric PM is more common in children aged 3 months to < 3 years old. Intracranial complications mostly occur in children < 1 year of age with fever being the most common clinical manifestations and subdural effusion and (or) empyema and hydrocephalus being the most common complications, respectively. CSF non-culture methods can facilitate improving the detection rate of pathogenic bacteria. More than 10% of PM children had adverse outcomes. S. pneumoniae strains are susceptible to vancomycin, linezolid, ertapenem, levofloxacin, moxifloxacin, rifampicin, and chloramphenicol.

Diagnostic accuracy of inflammatory markers in adults with suspected central nervous system infections

OBJECTIVES

We aimed to determine diagnostic accuracy of inflammatory markers in plasma and cerebrospinal fluid (CSF) for the diagnosis of central nervous system (CNS) infections and specifically bacterial meningitis.

METHODS

We analyzed 12 cytokines, chemokines, and acute phase reactants in CSF and plasma of 738 patients with suspected neurological infection included in a multicenter prospective cohort. We determined diagnostic accuracy for predicting any CNS infection and bacterial meningitis.

RESULTS

We included 738 episodes between 2017 and 2022, split into a derivation (n = 450) and validation cohort (n = 288). Of these patients, 224 (30%) were diagnosed with CNS infection, of which 81 (11%) with bacterial meningitis, 107 (14%) with viral meningitis or encephalitis, and 35 patients (5%) with another CNS infection. Diagnostic accuracy of CRP, IL-6, and Il-1β in CSF was high, especially for diagnosing bacterial meningitis. Combining these biomarkers in a multivariable model increased accuracy and provided excellent discrimination between bacterial meningitis and all other disorders (AUC = 0.99), outperforming all individual biomarkers as well as CSF leukocytes (AUC = 0.97). When applied to the population of patients with a CSF leukocyte count of 5-1000 cells/mm3, accuracy of the model also provided a high diagnostic accuracy (AUC model = 0.97 vs. AUC CSF leukocytes = 0.80) with 100% sensitivity and 92% specificity. These results remained robust in a temporal validation cohort.

CONCLUSIONS

Inflammatory biomarkers in CSF are able to differentiate CNS infections and especially bacterial meningitis from other disorders. When these biomarkers are combined, their diagnostic accuracy exceeds that of CSF leukocytes alone and as such these markers have added value to current clinical practice.

Diagnostic accuracy of clinical and laboratory characteristics in suspected non-surgical nosocomial central nervous system infections

BACKGROUND

The diagnosis of meningitis in non-surgical hospitalized patients is often difficult and diagnostic accuracy of clinical, laboratory, and radiological characteristics is unknown.

AIM

To assess diagnostic accuracy for individual clinical characteristics of patients suspected of non-surgical nosocomial central nervous system (CNS) infections.

METHODS

In a prospective multi-centre cohort study in the Netherlands with adults suspected of CNS infections, consecutive patients who underwent a lumbar puncture for the suspicion of a non-surgical nosocomial CNS infection were included. All episodes were categorized into five final clinical diagnosis categories, as reference standard: CNS infection, CNS inflammatory disease, systemic infection, other neurological disease, or non-systemic, non-neurological disease.

FINDINGS

Between 2012 and 2022, 114 out of 1275 (9%) patients included in the cohort had suspected non-surgical nosocomial CNS infection: 16 (14%) had a confirmed diagnosis, including four (25%) with bacterial meningitis, nine (56%) with viral CNS infections, two (13%) fungal meningitis, and one (6%) parasitic meningitis. Diagnostic accuracy of individual clinical characteristics was generally low. Elevated CSF leucocyte count had the highest sensitivity (81%; 95% confidence interval (CI): 54-96) and negative predictive value (NPV) (96%; 95% CI: 90-99). When combining the presence of abnormalities in neurological or CSF examination, sensitivity for diagnosing a CNS infection was 100% (95% CI: 79-100) and NPV 100% (95% CI: 78-100). CSF examination changed clinical management in 47% of patients.

CONCLUSION

Diagnostic accuracy for individual clinical characteristics was low, with elevated CSF leucocyte count having the highest sensitivity and NPV.

Diagnostic Accuracy of Cerebrospinal Fluid Multiplex Polymerase Chain Reaction Panel Testing in Patients With Suspected Central Nervous System Infections: A Multi-Center Study in the United Arab Emirates

Background Delays in diagnosis and treatment of central nervous system (CNS) infections can lead to significant morbidity and mortality among children and adults. Prior antibiotic treatment is a major hurdle to accurate diagnosis due to falsely negative cerebrospinal fluid (CSF) cultures in partially treated patients. Increasingly, molecular diagnostic methods using multiplex polymerase chain reaction (mPCR) testing on CSF samples are being utilized in clinical practice for timely and accurate diagnosis. However, there is no data regarding the diagnostic accuracy or clinical impact of CSF mPCR testing in the Middle East region. We sought to compare the diagnostic accuracy of an automated mPCR CSF panel with routine CSF culture, the current gold standard, in the United Arab Emirates (UAE).  Methods This single-gated, multi-center, diagnostic accuracy study included patients from birth onwards who were admitted to any of the three participating hospitals with an initial diagnosis of meningitis or encephalitis, between January 2017 and March 2021, and had CSF samples collected for mPCR and culture. Sociodemographic, clinical, and molecular data were collected for all. Results A total of 353 CSF samples were collected from patients from 0-90 years old hospitalized for suspected CNS infection. Children constituted 51% of the study population, and males were slightly over-represented (55.2%). Pathogens were detected by mPCR in 78 (22%) CSF samples, of which 19 (24%) were bacteria and 59 (76%) were viruses. No fungal pathogens were detected. Enteroviruses were the most prevalent CNS pathogen among our cohort (40%), followed by herpes simplex virus type 2 (HSV-2) (12.5%). Children constituted 69% of positive samples for enterovirus, while HSV-2 was exclusively detected among adults. Using CSF culture as the diagnostic gold standard, the mPCR panel demonstrated high specificity (100%) and sensitivity (96.3%) in diagnosing CNS infection among all age groups. mPCR testing demonstrated a high overall percentage of agreement (OPA) with CSF culture (98.9%). Patients with bacterial meningitis had a significantly longer hospitalization (p=0.004) and duration of antibiotic therapy (p=0.001) compared to those with viral meningitis. Three CSF samples were negative on mPCR testing but positive on culture. These pathogens included: methicillin-sensitive Staphylococcus aureus(MSSA), Bacillus cereus, and Mycobacterium Tuberculosis (MTB). In addition, 13 patients had negative CSF cultures but tested positive on CSF mPCR. These pathogens included Streptococcus pneumoniae (seven patients), Haemophilus influenzae (three patients), Streptococcus agalactiae (two patients), and Escherichia coli (one patient). All discordant results were confirmed by reviewing the patient's clinical presentation, CSF analysis, clinical course, and final diagnosis. Conclusion CSF mPCR panel is a highly sensitive and specific diagnostic tool for the diagnosis of CNS infections among all age groups in the UAE. Routine use of CSF mPCR panels can decrease healthcare costs by reducing the length of stay and can also aid antibiotic stewardship efforts by reducing antibiotic overuse in patients with viral CSF infections. CSF culture and mPCR complement each other by identifying CNS pathogens in patients with prior antibiotic exposure who would otherwise be missed if relying on CSF culture alone. However, concomitant CSF culture samples should be sent to avoid missing unusual CNS pathogens.

Evaluation of cerebrospinal fluid levels for ALOX5, S100B, DEFA1, and GFAP in infectious meningitis

BACKGROUND

The aim of this study was to determine how the levels of peptide and protein-based biomarkers in cerebrospinal fluid change in bacterial, tuberculous, and aseptic meningitis, and to determine the success of these agents in distinguishing between different types of infectious meningitis.

METHODS

The levels of arachidonate-5-lipoxygenase, S100 calcium-binding protein B, defensin-α 1, and glial fibrillary acidic protein in cerebrospinal fluid samples from 20 tuberculosis, 40 bacterial, 25 aseptic meningitis patients, and 55 control groups were measured and compared using an enzyme-linked immunosorbent assay.

RESULTS

The mean age of the patients was 37.9 ± 14.4 years. The parameter that contributed the most to the differential diagnosis of the infectious meningitis groups was S100 calcium-binding protein B. The S100 calcium-binding protein B levels were significantly higher in the tuberculous meningitis group than in the other groups, and arachidonate-5-lipoxygenase levels were significantly higher in the tuberculous meningitis and bacterial meningitis groups (P < .05).

CONCLUSION

This study showed that cerebrospinal fluid arachidonate-5-lipoxygenase, and S100 calcium-binding protein B levels may differ in bacterial, aseptic, and tuberculous meningitis, and the results obtained may be quite effective as important potential biomarkers in the differential diagnosis of different types of meningitis.

Are cerebrospinal fluid biochemical parameters valid to predict positive results in microbiological molecular diagnostic platforms? A 4-year experience with the FilmArray® Panel Meningitis/Encephalitis for detection of community-acquired bacterial meningitis

OBJECTIVE

To demonstrate whether the use of the FilmArray® Meningitis/Encephalitis panel (M/E) in the diagnosis of bacterial meningitis can be optimized based on the screening of cerebrospinal fluid biochemical parameters and whether there is a correlation between biochemical data and positive results of the technique.

MATERIAL AND METHODS

We used data from La Paz University Hospital between September 5, 2017 and December 1, 2021, from patients who had had the FilmArray® panel M/E performed on cerebrospinal fluid samples.

RESULTS

Bacterial meningitis was suspected in 63.9% of the patients; 38.15% had a positive result on the FilmArray® panel M/E, of which 68.97% were isolated in culture. Of the biochemical parameters studied in cerebrospinal fluid, white blood cell count, lactate, and protein were increased in PCR-positive patients, but glucose was decreased.

DISCUSSION

Only lactate showed a significant contribution to the model, with a cut-off point of 4.65 mmol/L with a sensitivity of 81.5% and a specificity of 96.4%.

The application value of metagenomic next-generation sequencing in community-acquired purulent meningitis after antibiotic intervention

BACKGROUND

Bacteria account for nearly one third of the causes of community-acquired central nervous system infections, and traditional diagnostic methods are based on culture results, which are time-consuming and have a low detection rate leading to delayed diagnosis and treatment. Since metagenomic next-generation sequencing (mNGS) has the advantages of high timeliness and only detecting microbial trace gene fragments, it has been used more widely in recent years. Based on this, we explored whether the application of cerebrospinal fluid (CSF) mNGS is advantageous in patients with community-acquired purulent meningitis, especially in people who have already used antibiotics.

METHODS

This was a retrospective study of 63 patients with community-acquired purulent meningitis admitted to the Department of Neurology of Shanxi Bethune Hospital from March 2018 to November 2022. Data were systematically collected and classified into CSF culture group, blood culture group and CSF mNGS group according to different detection methods, and the total detection rate of each method was calculated. Each group of patients was divided into two subgroups according to whether antibiotics were used before sampling. The detection rates of the three groups were compared within and between groups to explore whether mNGS has advantages over traditional methods and the influence of antibiotic use on detection rates of the three methods.

RESULTS

Among the 63 patients, the cases of CSF culture, blood culture and CSF mNGS were 56, 46, 44, respectively. The total detection rates of the three methods were 17.86%, 36.96%, 81.82%, with statistical differences (p < 0.05),suggesting that the detection rate of mNGS was higher than CSF culture (p < 0.05) and blood culture (p < 0.05),and the detection rate of blood culture higher than CSF culture (p < 0.05). Further grouping found that without antibiotics, the detection rates of CSF culture, blood culture and CSF mNGS were 28.57%, 56.25% and 88.89%, with statistical differences (p < 0.05), and the detection rate of CSF mNGS was higher than that of CSF culture (p < 0.05), but there was no statistical difference between CSF and blood culture (p > 0.05), nor between blood culture and CSF mNGS (p > 0.05). The detection rates of the three groups with antibiotics were 14.29%, 26.67% and 80.00%, with statistical differences (p < 0.05), and the detection rate of CSF mNGS was still higher than CSF culture (p < 0.05) and blood culture (p < 0.05). However, the detection rate of CSF mNGS also decreased after antibiotics were used for more than 3 days.

CONCLUSIONS

The detection rate of CSF mNGS in patients with purulent meningitis is higher than traditional methods, especially in patients who have been given antibiotics, but the detection rate will decrease with the extension of antibiotic use.

A Multicenter Epidemiological and Pathogenic Characteristics Study of Community-Acquired Bacterial Meningitis Children in China: Results from the Chinese Pediatric Bacterial Meningitis Surveillance (CPBMS) 2019-2020

Objective

To explore the epidemiological and pathogenic characteristics of children with community-acquired bacterial meningitis.

Methods

A multicenter, retrospective study was conducted among CABM patients under 15 years old from 33 hospitals in China from 2019 to 2020. The medical record, laboratory, and microbiological data were collected and analyzed.

Results

A total of 1610 children with CABM were identified and presented at a median onset age of 45 days of whom 955 (59.3%) were males. CABM occurred mostly in infants <1 year of age (84.0%, 1352/1610). In etiology-confirmed cases, the pathogens were isolated from CSF culture in 515 (32.0%), 400 (24.8%) in blood culture, and 186 (11.6%) both in CSF and blood culture. In total, 126 pathogens were identified through CSF mNGS in 330 CABM cases; 21 S. pneumoniae isolates were detected in 83 CABM cases by antigen detection method. Major pathogens were E. coli (195, 24.7%), GBS (170, 21.5%), and S. pneumoniae (157, 19.9%). GBS (29.3%, 22/75) was the first pathogen of CABM in neonates aged 0-6 days old, while E. coli (44.7%, 76/170) in 7 to 28 days of age; S. pneumoniae (96.2%, 151/157) was the most common pathogen in >3 months old cases. About 9.7% (19/195) strains of E. coli produced ultra‑broad‑spectrum β‑lactamases. The common intracranial imaging complications were subdural effusion and (or) empyema in 349 (21.7%), hydrocephalus in 233 (14.5%), and cerebral abscess in 178 (11.1%). A total of 389 (24.2%) cases were completely cured and 1088 (67.6%) cases improved. Among 166 patients (10.3%) with adverse outcomes, 32 cases (2.0%) died, and 37 cases (2.3%) relapsed.

Conclusion

The onset age of CABM in children is usually within 1 year of age, especially <3 months. The primary pathogens in infants less than 3 months old are E. coli and GBS, and the dominant pathogen in children older than 3 months old is S. pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. CABM should not be excluded even if CSF leukocyte counts are within normal range. Due to the low detection rate of pathogens in children with CABM, standardized CSF bacteriological examination should be paid more attention to increase the pathogen detection rate. Non‑culture CSF detection methods may facilitate pathogenic diagnosis.

[A case of community-acquired Listeria monocytogenes meningitis]

Meningitis caused by Listeria monocytogenes is a rare disease in immunocompetent individuals, however, in the presence of certain risk factors with clinical signs indicating infection of the central nervous system it should not be ignored. In this case report, we present the medical history of a 72-year-old man, suffering from hypertension and liver cirrhosis, who was diagnosed with meningitis caused by L. monocytogenes. The patient was admitted to our Department with the symptoms of weakness, dizziness, high fever and urinary incontinence. Laboratory tests showed elevated inflammatory and liver enzyme values as well as low white blood cell and platelet counts were confirmed. Imaging tests did not prove any abnormalities. Due to septic parameters, after microbiological samples were collected, empiric ceftriaxon and metronidazol treatment was started. Despite our therapeutic efforts, the condition of the patient had not improved significantly. The patient still suffered from high fever; increasing agitation and tremor, coordination disorder appeared, raising the possibility of a bacterial infection of the central nervous system. Examination of the cerebrospinal fluid confirmed the diagnosis of bacterial meningitis. In the meantime, findings of microbiological cultures verified the infection of L. monocytogenes, however, cerebrospinal fluid culture did not detect any pathogen. Following that, the therapy continued with targeted ampicillin which resulted in rapid improvement of the patient's condition; fevers and neurological symptoms have ceased to exist. We considered the case worthy of presentation because of the pitfalls of the diagnosis, the emerging differential diagnostic difficulties and the favorable outcome due to the effectiveness of targeted antibiotic treatment. Orv Hetil. 2023; 164(36): 1437-1441.

Diagnostic value of cerebrospinal fluid Neutrophil Gelatinase-Associated Lipocalin for differentiation of bacterial meningitis from tuberculous meningitis or cryptococcal meningitis: a prospective cohort study

BACKGROUND

The early differential diagnosis between bacterial meningitis (BM) and tuberculous meningitis (TBM) or cryptococcal meningitis (CM) remains a significant clinical challenge. Neutrophil Gelatinase-Associated Lipocalin (NGAL) has been reported as a novel inflammatory biomarker in the early stages of infection. This study aimed to investigate whether cerebrospinal fluid (CSF) NGAL can serve as a potential biomarker for distinguishing between BM and TBM or CM.

METHODS

We prospectively enrolled the patients with suspected CNS infections at admission and divided them into three case groups: BM (n = 67), TBM (n = 55), CM (n = 51), and an age- and sex-matched hospitalized control (HC, n = 58). Detected the CSF NGAL and assessed its diagnostic accuracy in distinguishing between BM and TBM or CM. Additionally, longitudinally measured the CSF NGAL levels in patients with BM to evaluate its potential as a monitoring tool for antibacterial treatment.

RESULTS

The concentration of CSF NGAL in BM was significantly higher than in TBM, CM, and HC (all P < 0.05), while the serum NGAL did not show significant differences among the three case groups. The ROC analysis demonstrated that CSF NGAL presented a good diagnostic performance with an AUC of 0.834 (0.770-0.886) and at the optimal cutoff value of 74.27 ng/mL with 70.15% sensitivity and 77.36% specificity for discriminating BM with TBM and CM. Additionally, the CSF NGAL in the convalescent period of BM was significantly lower than in the acute period (P < 0.05).

CONCLUSIONS

CSF NGAL may serve as a potential biomarker for distinguishing between acute BM and TBM or CM. Additionally, it holds clinical significance in monitoring the effectiveness of antibiotic therapy for BM.

Acute Bacterial Meningitis in Healthy Adult Patients: A Prospective Cohort Study

Spontaneous bacterial meningitis (BM) is more common among patients with underlying conditions, but its characteristics in previously healthy patients are not well described. We analyzed the time trends of BM in terms of characteristics, and outcomes in patients without comorbidities.

PATIENTS AND METHODS

Single-center, prospective observational cohort study of 328 adults with BM hospitalized in a tertiary university hospital in Barcelona (Spain). We compared the features of infections diagnosed in 1982-2000 and 2001-2019. The main outcome measure was in-hospital mortality.

RESULTS

The median age of the patients increased from 37 to 45 years. Meningococcal meningitis significantly diminished (56% versus 31%, p < 0.000) whereas listerial meningitis increased (1.2% versus 8%, p = 0.004). Systemic complications were more common in the second period, although mortality did not vary significantly between periods (10.4% versus 9.2%). However, after adjusting for relevant variables, infection in the second period was associated with lower risk death.

CONCLUSIONS

Adult patients without underlying comorbidities that developed BM in recent years were older and more likely to have pneumococcal or listerial infections and systemic complications. In-hospital death was less likely in the second period, after adjusting for risk factors of mortality.

Cerebro-spinal fluid glucose and lactate concentrations changes in response to therapies in patIents with primary brain injury: the START-TRIP study

INTRODUCTION

Altered levels of cerebrospinal fluid (CSF) glucose and lactate concentrations are associated with poor outcomes in acute brain injury patients. However, no data on changes in such metabolites consequently to therapeutic interventions are available. The aim of the study was to assess CSF glucose-to-lactate ratio (CGLR) changes related to therapies aimed at reducing intracranial pressure (ICP).

METHODS

A multicentric prospective cohort study was conducted in 12 intensive care units (ICUs) from September 2017 to March 2022. Adult (> 18 years) patients admitted after an acute brain injury were included if an external ventricular drain (EVD) for intracranial pressure (ICP) monitoring was inserted within 24 h of admission. During the first 48-72 h from admission, CGLR was measured before and 2 h after any intervention aiming to reduce ICP ("intervention"). Patients with normal ICP were also sampled at the same time points and served as the "control" group.

RESULTS

A total of 219 patients were included. In the intervention group (n = 115, 53%), ICP significantly decreased and CPP increased. After 2 h from the intervention, CGLR rose in both the intervention and control groups, although the magnitude was higher in the intervention than in the control group (20.2% vs 1.6%; p = 0.001). In a linear regression model adjusted for several confounders, therapies to manage ICP were independently associated with changes in CGLR. There was a weak inverse correlation between changes in ICP and CGRL in the intervention group.

CONCLUSIONS

In this study, CGLR significantly changed over time, regardless of the study group. However, these effects were more significant in those patients receiving interventions to reduce ICP.

The Diagnostic Value of Cerebrospinal Fluid Lactate for Detection of Sepsis in Community-Acquired Bacterial Meningitis

Community-acquired bacterial meningitis conveys significant morbidity and mortality due to intracranial and systemic complications, and sepsis is a major contributor to the latter. While cerebrospinal fluid (CSF) analysis is essential in the diagnosis of bacterial meningitis, its predictive utility for detection of sepsis is unknown. We investigated the diagnostic performance of CSF parameters for sepsis defined by the Sepsis-3 criteria in a retrospective cohort of patients with community-acquired bacterial meningitis. Among 103 patients, 69.5% developed sepsis. CSF lactate was associated with sepsis with an odds ratio of 1.11 (p = 0.022), while CSF cell counts, glucose and protein levels were not (all p > 0.4). Employing the optimal cutoff of 8.2 mmol/L, elevated CSF lactate resulted in a sensitivity of 81.5% and specificity of 61.5% for sepsis. In exploratory analyses, CSF lactate was also associated with in-hospital mortality with an odds ratio of 1.21 (p = 0.011). Elevated CSF lactate might contribute to early diagnosis of sepsis as well as prognostication in patients with community-acquired bacterial meningitis.

High risk and low prevalence diseases: Adult bacterial meningitis

INTRODUCTION

Acute bacterial meningitis in adults is a rare but serious condition that carries a high rate of morbidity.

OBJECTIVE

This review highlights pearls and pitfalls of acute bacterial meningitis in adults, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Meningitis encompasses a broad spectrum of disease involving inflammation of the meninges and subarachnoid space. It classically presents with fever, nuchal rigidity, and altered mental status, but this triad is not present in all cases. Up to 95% of patients will have at least two of the following four cardinal symptoms: fever, nuchal rigidity, altered mental status, and headache. The most common bacterial etiologies are S. pneumoniae and N. meningitidis. Cerebrospinal fluid testing obtained by lumbar puncture remains the gold standard in diagnosis. Head computed tomography prior to lumbar puncture may not be necessary in most patients. Empiric treatment consists of vancomycin, ceftriaxone, and dexamethasone. Elevated intracranial pressure should be managed using established neurocritical care strategies.

CONCLUSION

A better understanding of the pearls and pitfalls of acute bacterial meningitis can assist emergency clinicians in pursuing its timely diagnosis and management.

Edwardsiella tarda is an Important Causative Agent of Maternal-Fetal Infections in Pregnant Women: a Case Report and Japanese Literature Review

We present a case study of a 6-day-old male infant who was referred to our hospital for fever, jaundice, and poor suckling, and was diagnosed with meningitis due to Edwardsiella tarda. We were able to detect E. tarda DNA after performing broad-range polymerase chain reaction targeting the bacterial 16S rRNA gene followed by a Basic Local Alignment Search Tool analysis of the DNA extracted from the cerebrospinal fluid. Furthermore, Japanese literature review showed that E. tarda caused perinatal invasive infections in mothers and infants and that the risk of fetal meningitis might be related to the food preference of Japanese people for raw fish. It is crucial to disseminate the information that pregnant women should refrain from eating high-risk raw fish, including freshwater fish.

Utility of metagenomics next-generation sequencing in the diagnosis and treatment of severe infectious diseases in the intensive care unit

BACKGROUND

Metagenomic next-generation sequencing (mNGS) is a new method that combines high-throughput sequencing and bioinformatics analysis. However, it has not become as popular due to the limited testing equipment and high costs and lack of family awareness with not much relevant intensive care unit (ICU) research data.

OBJECTIVE

To explore the clinical use and value of metagenomics next-generation sequencing (mNGS) in patients with sepsis in the ICU.

METHODS

We conducted a retrospective analysis of 102 patients with sepsis admitted to the ICU of Peking University International Hospital from January 2018 to January 2022. Based on whether mNGS was performed, the identified patients were divided into the observation group (n= 51) and the control group (n= 51), respectively. Routine laboratory tests, including routine blood test, C-reactive protein, procalcitonin, and culture of suspicious lesion specimens were performed in both groups within 2 hours after admission to the ICU, while mNGS tests were performed in the observation group. Patients in both groups were routinely given initial anti-infective, anti-shock, and organ support treatment. Antibiotic regimens were optimized in a timely manner according to the etiological results. Relevant clinical data were collected.

RESULTS

The testing cycle of mNGS was shorter than that of the conventional culture (30.79 ± 4.01 h vs. 85.38 ± 9.94 h, P< 0.001), while the positive rate of mNGS was higher than that of the conventional culture (82.35% vs. 45.1%, P< 0.05), with obvious superiority in the detection of viruses and fungus. There were significant differences in the optimal time of antibiotics (48 h vs.100 h) and length of ICU stay (11 d vs. 16 d) between the observation group and control group (P< 0.01) respectively, with no difference in 28-day mortality (33.3% vs. 41.2%, P> 0.05).

CONCLUSION

mNGS is useful in the detection of sepsis-causing pathogens in the ICU with the advantages of short testing time and high positive rate. There was no difference in the 28-day outcome between the two groups, which may be related to other confounding factors such as small sample size. Additional studies with extended sample size are needed.

Characteristics of patients with meningitis after lumbar epidural steroid injection

To investigate the clinical, laboratory, and radiological features of meningitis after lumbar epidural steroid injection (M-ESI) without accompanying spinal infection, data of patients with meningitis admitted between January 2014 and December 2021 in a single center were retrospectively reviewed. Among them, patients with a recent history of lumbar ESI were identified, and their medical records were collected. Patients with concomitant infections other than meningitis, including spinal epidural abscess, were excluded. Seven patients with M-ESI were identified. All patients presented with headache and fever without focal neurological deficits, and headache developed shortly after a procedure (median, 4 hours). Cerebrospinal fluid (CSF) analysis showed neutrophilic pleocytosis (median, 6729/μL), elevated protein level (median, 379.1 mg/dL), decreased ratio of CSF glucose to serum glucose (median, 0.29), and elevated lactate level (median, 8.64 mmol/L). Serum level of C-reactive protein was elevated in 6, but serum procalcitonin level was within normal range. No causative pathogen was identified in the microbiological studies. The most frequent radiologic feature was sulcal hyperintensity on fluid-attenuated inversion recovery images (57%), followed by pneumocephalus (43%). Symptoms subsided in a short period (median, 1 day) after initiating treatment with antibiotics and adjuvant intravenous corticosteroids. None of the patients experienced neurological sequelae. Though the cardinal symptoms and CSF findings of M-ESI were comparable to those of bacterial meningitis, M-ESI seems to have distinctive characteristics regarding the clinical course, laboratory parameters, and pneumocephalus.

Bacterial ribosomal RNA detection in cerebrospinal fluid using a viromics approach

BACKGROUND

In patients with central nervous system (CNS) infections identification of the causative pathogen is important for treatment. Metagenomic next-generation sequencing techniques are increasingly being applied to identify causes of CNS infections, as they can detect any pathogen nucleic acid sequences present. Viromic techniques that enrich samples for virus particles prior to sequencing may simultaneously enrich ribosomes from bacterial pathogens, which are similar in size to small viruses.

METHODS

We studied the performance of a viromic library preparation technique (VIDISCA) combined with low-depth IonTorrent sequencing (median ~ 25,000 reads per sample) for detection of ribosomal RNA from common pathogens, analyzing 89 cerebrospinal fluid samples from patients with culture proven bacterial meningitis.

RESULTS

Sensitivity and specificity to Streptococcus pneumoniae (n = 24) before and after optimizing threshold parameters were 79% and 52%, then 88% and 90%. Corresponding values for Neisseria meningitidis (n = 22) were 73% and 93%, then 67% and 100%, Listeria monocytogenes (n = 24) 21% and 100%, then 27% and 100%, and Haemophilus influenzae (n = 18) 56% and 100%, then 71% and 100%. A higher total sequencing depth, no antibiotic treatment prior to lumbar puncture, increased disease severity, and higher c-reactive protein levels were associated with pathogen detection.

CONCLUSION

We provide proof of principle that a viromic approach can be used to correctly identify bacterial ribosomal RNA in patients with bacterial meningitis. Further work should focus on increasing assay sensitivity, especially for problematic species (e.g. L. monocytogenes), as well as profiling additional pathogens. The technique is most suited to research settings and examination of idiopathic cases, rather than an acute clinical setting.

Seizures in adults with suspected central nervous system infection

Background

Seizures can be part of the clinical presentation of central nervous system (CNS) infections. We describe patients suspected of a neurological infection who present with a seizure and study diagnostic accuracy of clinical and laboratory features predictive of CNS infection in this population.

Methods

We analyzed all consecutive patients presenting with a seizure from two prospective Dutch cohort studies, in which patients were included who underwent cerebrospinal fluid (CSF) examination because of the suspicion of a CNS infection.

Results

Of 900 episodes of suspected CNS infection, 124 (14%) presented with a seizure. The median age in these 124 episodes was 60 years (IQR 45–71) and 53% of patients was female. CSF examination showed a leukocyte count ≥ 5/mm³ in 41% of episodes. A CNS infection was diagnosed in 27 of 124 episodes (22%), a CNS inflammatory disorder in 8 (6%) episodes, a systemic infection in 10 (8%), other neurological disease in 77 (62%) and in 2 (2%) episodes another systemic disease was diagnosed. Diagnostic accuracy of clinical and laboratory characteristics for the diagnosis of CNS infection in this population was low. CSF leukocyte count was the best predictor for CNS infection in patients with suspected CNS infection presenting with a seizure (area under the curve 0.94, [95% CI 0.88 – 1.00]).

Conclusions

Clinical and laboratory features fail to distinguish CNS infections from other causes of seizures in patients with a suspected CNS infection. CSF leukocyte count is the best predictor for the diagnosis of CNS infection in this population.

The Next Frontier in Neurocritical Care in Resource-Constrained Settings

Neurocritical care (NCC) is an emerging field within critical care medicine, reflecting the widespread prevalence of neurologic injury in critically ill patients. Morbidity and mortality from neurocritical illness (NCI) have been reduced substantially in resource-rich settings (RRS), owing to the development of advanced technologies, neuro-specific units, and subspecialized medical training. Despite shouldering much of the burden of NCI worldwide, resource-limited settings (RLS) face immense hurdles when implementing guidelines generated in RRS. This review summarizes the current epidemiology, management, and outcomes of the most common NCIs in RLS and offers commentary on future directions in NCC practiced in RLS.

A Little Neutrophil Predominance May Not Be a Harbinger of Death: Clinical and Laboratory Characteristics of Meningitis in Jordan

Background This study aims to evaluate the clinical features, laboratory findings, and outcomes of children and adults diagnosed with meningitis in Jordan. Methodology This is a retrospective chart review study that targeted patients diagnosed with meningitis at King Abdullah University Hospital, a tertiary care center in Northern Jordan, from March 21, 2015, to March 31, 2019. Patients were included in this study if they were older than 28 days and had no risk factors for meningitis. Results A total of 169 patients met the inclusion criteria. Males were overrepresented (67%) and were significantly younger than females (6 vs. 17 years, p = 0.01). Positive meningeal signs were not predictive of greater cerebrospinal fluid leukocytosis (p = 0.348), and they did not provide sufficient sensitivity to be used as screening tools. The most common etiology was aseptic (49%), followed by enterovirus (43%), while bacterial meningitis was an uncommon diagnosis (3.5%). Nearly half of the patients took antibiotics prior to their hospital presentation. During in-hospital admission, six patients died, four of whom had bacterial and two had aseptic meningitis. Enteroviral meningitis showed neutrophil predominance in 44% of cases on lumbar puncture and had a higher neutrophil proportion compared to aseptic meningitis (p = 0.026). Streptococcus pneumoniae was the most common bacterial etiology identified. Conclusions Meningitis in Jordan is most commonly of aseptic and enteroviral origin, and these etiologies carry significantly more favorable outcomes compared to bacterial meningitis. Enteroviral meningitis displays a higher percentage of neutrophils in cerebrospinal fluid compared to aseptic meningitis. S. pneumoniae is the leading cause of bacterial meningitis. Slight neutrophil predominance above half is a weak predictor of bacterial meningitis due to the small contribution of bacteria as a cause among enteroviruses and aseptic etiologies.

Diagnostic and treatment dilemmas in well children with petechial rash in the emergency department

This article presents a discussion based on a case study of an eight-month-old boy with petechial rash who presented at the emergency department (ED). Blood tests were obtained and intravenous antibiotics were administered. The patient was admitted to the children's ward and was discharged the next day. It was suspected that the rash was caused by a non-specific viral illness. Non-blanching rashes, such as petechial rash, in well children often lead to diagnostic and treatment dilemmas in the ED. Clinicians fear missing the diagnosis of invasive meningococcal disease, which results in blood tests, cannulation and early administration of antibiotics. Non-blanching rashes have many potential causes and extensive tests and antibiotic treatment may not always be necessary and have the potential to cause harm. A tailored approach to investigate, treat and discharge well children with petechial rash from the ED is advocated.

Neurofilament light chain in central nervous system infections: a prospective study of diagnostic accuracy

Diagnosing central nervous system (CNS) infections quickly is often difficult. Neurofilament light chain (NfL) is a component of the axonal cytoskeleton and identified as marker of neuronal damage in several CNS diseases. We evaluated the diagnostic accuracy of NfL for diagnosing CNS infections. We included patients from a prospective cohort of consecutive patients in whom a lumbar puncture was performed for suspected CNS infection in an academic hospital in The Netherlands. The index test was NfL in cerebrospinal fluid (CSF) and reference standard the final clinical diagnosis. Diagnostic accuracy was determined using the area-under-the-curve (AUC) with 95% confidence intervals (CI). The association of CSF NfL with clinical characteristics, diagnosis and outcome was evaluated. Between 2012 and 2015, 273 episodes in adults of which sufficient CSF was available were included. CNS infection was diagnosed in 26%(n = 70), CNS inflammatory disease in 7%(n = 20), systemic infection in 32%(n = 87), and other neurological disorders in 33%(n = 90). Median CSF NfL level was 593 pg/ml (IQR 249–1569) and did not discriminate between diagnostic categories or CNS infection subcategories. AUC for diagnosing any CNS infection compared to patients without CNS infections was 0.50 (95% CI 0.42–0.59). Patients presenting with an altered mental status had higher NfL levels compared to other patients. We concluded that NfL cannot discriminate between causes in patients suspected of CNS infections. High concentrations of NfL are associated with severe neurological disease and the prognostic value of NfL in patients with CNS infections should be investigated in future research.

A comparative study between children and adults with bacterial neuroinfections

Abstract.

Multidrug-Resistant Corynebacterium striatum Developed During Treatment of Ommaya Reservoir Infection

Corynebacterium striatum, a common component of the skin and mucosal microbiota of both immunocompetent and immunocompromised individuals, has become an emerging pathogen, colonizing indwelling medical devices and causing infections at multiple sites. A 3-year-old boy with an Ommaya reservoir in the right ventricle and a medical history of grade 3 intraventricular hemorrhage, Hirschsprung disease, catheter-related methicillin-resistant Staphylococcus aureus bacteremia, and congenital central hypoventilation syndrome was hospitalized for Ommaya reservoir infection with C. striatum. He was treated with ampicillin, to which the initial isolate was susceptible. C. striatum may have acquired multiple-drug resistance during the antibiotic treatment due to biofilm production. The Ommaya reservoir was replaced by external ventricular drainage. Cultures of the removed Ommaya reservoir, and cerebrospinal fluid samples grew C. striatum, which was susceptible to meropenem and vancomycin and resistant to other antibiotics. The antibiotic was switched to vancomycin to treat this new multidrug-resistant strain. After 8 days of vancomycin treatment, the cerebrospinal fluid culture obtained by a lumbar puncture was negative for C. striatum. In cases of device-associated infections caused by biofilm-producing bacteria, it is desirable to remove the device as soon as possible.

Fc-MBL-modified Fe3O4 magnetic bead enrichment and fixation in Gram stain for rapid detection of low-concentration bacteria

Functional bacterial enrichment magnetic beads (Fe₃O₄@SiO₂@Fc-MBL) and Gram staining were combined for the fast diagnosis of infecting bacteria in meningitis. Fe₃O₄@SiO₂@Fc-MBL has excellent microbial binding ability and can be used for bacterial enrichment from cerebrospinal fluid (CSF). The enriched bacteria are recognized by Gram stain at very low concentrations (10 CFU·mL^-1). The feasibility of this method was verified by five common bacteria in meningitis infection (Gram-positive: Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus capitis; Gram-negative: Klebsiella pneumoniae and Escherichia coli). The extraction efficiency of Fc-MBL-modified Fe₃O₄ magnetic beads was approximately 90% in artificial CSF for the selected bacteria, with the exception of E. coli (~ 60%). The bacteria were successfully recognized by Gram staining and microscopic observation. Fe₃O₄@SiO₂@Fc-MBL acts by capturing and fixing the bacteria in a magnetic field throughout the experiment. Compared with traditional CSF Gram staining, this new method avoids interference by inflammatory cells and red blood cells during microscopic examination. Furthermore, the sensitivity of this method is much better than the centrifugation smear method. The whole process can be accomplished within 30 min. This novel method may have potential as a clinical tool for analysis of bacteria in the CSF.

Length of preoperative hospital stay is the dominating risk factor for surgical site infection in neurosurgery: A cohort data-driven analysis

Background:

The number of days of preoperative hospital stay (PHS) is a modifiable variable that has shown contradictory surgical site infection (SSI) risk factor results in neurosurgery. We sought to pinpoint the day of PHS length related with a marked increase of risk of SSI.

Methods:

From a tertiary teaching hospital, January 2015–December 2017, prospectively collected nonpercutaneous neurosurgery procedures with standard antibiotic prophylaxis and 1-year follow-up were evaluated. SSI risk factors were assessed through multiple logistic regression models with different thresholds of PHS.

Results:

A total of 1012 procedures were included in the study. Incidence of SSI was 4.4%. The median PHS was higher in those with SSI than in those without (1 day, interquartile range [IQR]: 7 vs. 0 days, IQR: 1, respectively, P = 0.002). By the amount of six days of PHS, this exposure risk past the threshold of significance for impact on wound infection (OR 2.8; CI 1.23–6.39, P = 0.014). Operative time past 4 h (OR 2.11; CI 1.12-3.98; P = 0.021), and in some models, previous surgery at same admission were also identified by multivariate analysis as increasing postoperative SSI risk.

Conclusion:

The gradual increase of the SSI OR associated with longer PHS days was the highest risk factor of SSI in our cohort of patients. Studies directed to reduce this complication should consider the PHS.

BACTERIAL MENINGITIS PRESENTING WITH A NORMAL CEREBROSPINAL FLUID LEUKOCYTE COUNT

OBJECTIVES

We describe clinical characteristics and outcome of adults with bacterial meningitis presenting with a normal CSF leukocyte count.

METHODS

We studied community-acquired bacterial meningitis with a normal CSF leukocyte count (≤ 5 per mm³) in adults from a prospective nationwide cohort study.

RESULTS

From 2006 through 2020, 39 of 2,357 (2%) episodes presented with a normal CSF leukocyte count. Immunocompromising conditions were present in 19 of 39 patients (49%), compared to 690 of 2303 (30%) in patients with elevated leukocytes (P=0.02). The triad of fever, neck stiffness, and altered consciousness was present in 6 of 34 patients (18%). CSF protein was abnormal in 25 of 37 patients (68%). We identified 3 clinical subgroups: those with severe pneumococcal meningitis (20 patients [51%]), with mainly sepsis (8 [21%]), and a miscellaneous group (11 [28%]). All patients with severe pneumococcal meningitis presented with high CSF protein levels and 18 of 19 (95%) had bacteria in the CSF Gram stain. Outcome was unfavorable in 23 of 39 (59%) patients and 12 (31%) died.

CONCLUSION

Patients with bacterial meningitis may present with normal CSF leukocyte counts. In these patients, CSF protein levels and Gram staining are important diagnostic parameters.

Comparison of Four International Guidelines on the Utility of Cranial Imaging Before Lumbar Puncture in Adults with Bacterial Meningitis

BACKGROUND

International guidelines exist for obtaining a head computed tomography (CT) scan before a lumbar puncture (LP) in adults with suspected meningitis but there are no studies comparing them in their ability to identify intracranial abnormalities.

METHODS

A retrospective study of 202 cases of adults with community-acquired bacterial meningitis at 16 hospitals in Houston from December 2004 until May 2019 to compare the 4 guidelines' ability in identifying minor and major intracranial findings, cases in which CT findings changed management, and patients who suffered cerebral herniation.

RESULTS

Minor and major intracranial findings were seen in 69 (34.1%) and in 24 (11.8%) of the patients, respectively. A total of nine (37.5%) of the major intracranial findings prompted a neurosurgical intervention. A total of four (1.9%) patients had cerebral herniation. The Infectious Diseases of America (IDSA), the United Kingdom (UK), the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and the Swedish guidelines for cranial imaging were met in 92.1%, 54%, 41.6%, and in 23.3% of the patients, respectively. The IDSA, UK, European, and the Swedish guidelines missed 0%, 20.8%, 41.7%, and 70.8% of the major intracranial findings and 0, 1, 3 and 4 of the 9 patients that prompted a neurosurgical intervention, respectively. All four patients with cerebral herniation met the criteria for all four guidelines.

CONCLUSION

Out of the four international guidelines, only the IDSA recommendations for cranial imaging did not miss any major intracranial abnormality or any finding that prompted a neurosurgical intervention but all guidelines identified herniation.

Diagnostic Model for Discrimination Between Tuberculous Meningitis and Bacterial Meningitis

Background

The differential diagnosis between tuberculous meningitis (TBM) and bacterial meningitis (BM) remains challenging in clinical practice. This study aimed to establish a diagnostic model that could accurately distinguish TBM from BM.

Methods

Patients with TBM or BM were recruited between January 2017 and January 2021 at Tongji Hospital (Qiaokou cohort) and Sino-French New City Hospital (Caidian cohort). The detection for indicators involved in cerebrospinal fluid (CSF) and T-SPOT assay were performed simultaneously. Multivariate logistic regression was used to create a diagnostic model.

Results

A total of 174 patients (76 TBM and 98 BM) and another 105 cases (39 TBM and 66 BM) were enrolled from Qiaokou cohort and Caidian cohort, respectively. Significantly higher level of CSF lymphocyte proportion while significantly lower levels of CSF chlorine, nucleated cell count, and neutrophil proportion were observed in TBM group when comparing with those in BM group. However, receiver operating characteristic (ROC) curve analysis showed that the areas under the ROC curve (AUCs) produced by these indicators were all under 0.8. Meanwhile, tuberculosis-specific antigen/phytohemagglutinin (TBAg/PHA) ratio yielded an AUC of 0.889 (95% CI, 0.840–0.938) in distinguishing TBM from BM, with a sensitivity of 68.42% (95% CI, 57.30%–77.77%) and a specificity of 92.86% (95% CI, 85.98%–96.50%) when a cutoff value of 0.163 was used. Consequently, we successfully established a diagnostic model based on the combination of TBAg/PHA ratio, CSF chlorine, CSF nucleated cell count, and CSF lymphocyte proportion for discrimination between TBM and BM. The established model showed good performance in differentiating TBM from BM (AUC: 0.949; 95% CI, 0.921–0.978), with 81.58% (95% CI, 71.42%–88.70%) sensitivity and 91.84% (95% CI, 84.71%–95.81%) specificity. The performance of the diagnostic model obtained in Qiaokou cohort was further validated in Caidian cohort. The diagnostic model in Caidian cohort produced an AUC of 0.923 (95% CI, 0.867–0.980) with 79.49% (95% CI, 64.47%–89.22%) sensitivity and 90.91% (95% CI, 81.55%–95.77%) specificity.

Conclusions

The diagnostic model established based on the combination of four indicators had excellent utility in the discrimination between TBM and BM.

Impact of a 24/7 multiplex-PCR on the management of patients with confirmed viral meningitis

Objectives

The relevance of syndromic multiplex-PCR for the etiological diagnosis of meningitis or meningoencephalitis is still a matter of debate. Here, we studied the impact of a 24/7 multiplex-PCR on the management of patients consulting in the emergency department for suspicion of community-acquired meningitis.

Methods

We conducted a single-center retrospective study at the Emergency department of Lariboisière University Hospital (Paris, France) including all patients suspected of meningitis. During period 1 (April 2014-March 2017), the molecular assays used for the detection of infectious agents in the cerebrospinal fluid (CSF) were performed during the daytime. During period 2 (April 2017-March 2019), multiplex-PCR (BioFire® Filmarray® Meningitis/Encephalitis Panel [ME], bioMérieux) was performed 24/7.

Results

During the periods 1 and 2, 4 100 and 3 574 patients were included and 284 (6.9%) and 308 (8.6%) meningitis were diagnosed, respectively. During the periods 1 and 2, the most common causes of meningitis were enterovirus (23.9% and 29.5%), varicella zoster virus (10.2% and 6.8%) and herpes simplex virus-2 (4.2% and 8.1%). For patients with confirmed viral meningitis, a significant decrease was found between period 1 and period 2, respectively for the rate of hospitalization (73.9% vs 42.0%; p < 0.05), the length of stay (3[2–5] vs 2[1–3] days; p < 0.05), the empirical antiviral (26.1% vs 14.5%) and antibacterial administrations (29.3% vs 14.5%; p < 0.05).

Conclusions

Multiplex-PCR is an important tool in the diagnosis of infectious meningitis in the emergency department and is relevant in the management of meningitis by screening for patients who do not require hospitalization and antibacterial therapy.

Infectious Meningitis and Encephalitis

Infectious meningitis and encephalitis are associated with significant morbidity and mortality worldwide. Acute bacterial meningitis is rapidly fatal and early recognition and institution of therapy are imperative. Viral meningitis is typically a benign self-limited illness. Chronic meningitis (defined as presenting with >4 weeks of symptoms) is most often caused by tuberculosis and fungal infection. Because the diagnostic testing for tuberculous meningitis is insensitive and cultures often take weeks to grow, therapy is often initiated empirically when the diagnosis is suspected. Human simplex virus encephalitis is the most common cause of encephalitis and requires prompt treatment with intravenous acyclovir.

Community-acquired bacterial meningitis

Progress has been made in the prevention and treatment of community-acquired bacterial meningitis during the past three decades but the burden of the disease remains high globally. Conjugate vaccines against the three most common causative pathogens (Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae) have reduced the incidence of disease, but with the replacement by non-vaccine pneumococcal serotypes and the emergence of bacterial strains with reduced susceptibility to antimicrobial treatment, meningitis continues to pose a major health challenge worldwide. In patients presenting with bacterial meningitis, typical clinical characteristics (such as the classic triad of neck stiffness, fever, and an altered mental status) might be absent and cerebrospinal fluid examination for biochemistry, microscopy, culture, and PCR to identify bacterial DNA are essential for the diagnosis. Multiplex PCR point-of-care panels in cerebrospinal fluid show promise in accelerating the diagnosis, but diagnostic accuracy studies to justify routine implementation are scarce and randomised, controlled studies are absent. Early administration of antimicrobial treatment (within 1 hour of presentation) improves outcomes and needs to be adjusted according to local emergence of drug resistance. Adjunctive dexamethasone treatment has proven efficacy beyond the neonatal age but only in patients from high-income countries. Further progress can be expected from implementing preventive measures, especially the development of new vaccines, implementation of hospital protocols aimed at early treatment, and new treatments targeting checkpoints of the inflammatory cascade.

Suspected Central Nervous System Infections in HIV-Infected Adults

Objectives: To study the differential diagnosis of HIV-infected patients with suspected central nervous system (CNS) infections and the association of CD4 counts with the final diagnosis. Methods: We analyzed HIV-infected patients from a prospective cohort study on the diagnostic accuracy of clinical and laboratory characteristics in adults with suspected CNS infections in an academic hospital in Amsterdam, the Netherlands, who underwent cerebrospinal fluid (CSF) examination. Results: Thirty-four (9.4%) out of 363 patients with suspected CNS infections were HIV-positive of whom 18 (53%) were diagnosed to have CNS infection, with median CD4 counts of 255 cells/μl. The spectrum of CNS infections consisted of progressive multifocal leukoencephalopathy in three patients (17%); cryptococcal meningoencephalitis, toxoplasma encephalitis, angiostrongylus eosinophilic meningitis, and HIV encephalitis each in two (11%); and cytomegalovirus encephalitis, neurosyphilis, tuberculous meningoencephalitis, histoplasma encephalitis, and varicella-zoster virus meningitis each in one (6%). Clinical characteristics and blood parameters did not differ between HIV-infected patients with CNS infections and other diagnoses. The best predictor for CNS infections was the CSF leukocyte count (AUC = 0.77, 95 CI% 0.61-0.94). The diagnosis of CNS infection was not associated with the CD4 count (median 205 vs. 370, p = 0.21). Two patients (11%) with CNS infections died and two (11%) had neurological sequelae. Conclusions: Half of the patients with suspected CNS infections are diagnosed with a CNS infection, and this was not related to CD4 counts. The best predictor for CNS infections was the CSF leukocyte count.

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.

The Epidemiology and Outcomes of Meningitis among Iranian Children in a Period of 10 Years

Background:

One of the important causes of childhood febrile illness is meningitis. It causes bacterial, viral, fungal, parasitic, and non-infectious agents. Pediatric bacterial meningitis is one of the most important causes of infant mortality, especially in premature infants. This study aimed to identify the outcome and mortality of children with meningitis.

Methods and Materials:

All children with meningitis in the Pediatric Department of Rasool Akram Hospital from December 23, 2007, to December 16, 2017, were included. Signs and symptoms (fever, consciousness, neck rigidity, and seizure) were collected and Cerebrospinal fluid analysis in children was made. Based on these findings, patients were divided into two groups, which include bacterial and non-bacterial meningitis. Then we recalled all families and examined them to discover the child’s outcome and complications at least after two years.

Results:

During the ten-year study period, 202 children were included in the study. Patients aged less than 12 months were found to be more frequently affected. Fever was the most common presentation (83.4%) followed by seizure (51.5%) and vomiting (49%). 119 (58.9%) of the patients were male and 83 (41.1%) were female. Definite bacterial meningitis was the final diagnosis in 35.6% (72) of patients (mean age 34.1± 48.3 months), and non-bacterial meningitis was diagnosed in 64.4% (130) of cases (mean age 46.3± 52.4 months). The most common organism in bacterial meningitis (by all methods) was Streptococcus pneumonia. Among children, 187 (92.1%) were survivors and 15 (%7.9) were non-survivors. Neurological sequelae such as motor deficit and epilepsy were identified in 9 (4.8%) and 5 (2.6%) subjects, respectively, and that they were all caused by bacterial meningitis. There was no death or neurological sequelae observed during follow-up in children with non-bacterial meningitis. Gender, age, signs and symptoms of patients at the time of admission were not significantly different between the bacterial and non-bacterial meningitis groups (p>0.05). Hydrocephalus, CSF characteristic, morbidity and mortality were significantly different between the bacterial and non-bacterial meningitis groups.

Conclusion:

This study showed that elevated LDH and low glucose levels in CSF are characteristic of bacterial meningitis. Increased LDH is significantly related to death in children (P-value > 0.001) with meningitis. Beneficial empirical antibiotics and sufficient follow-up by parents cause good prognosis in children with meningitis. Also in a child with fever and seizure, we should think of meningitis, even though in the absence of positive neurological examinations. It seems that increased CSF LDH, elevated CSF protein and age under one year are significant mortality risk factors in children with meningitis.

Microbial aspects and potential markers for differentiation between bacterial and viral meningitis among adult patients

OBJECTIVES

Meningitis is a medical emergency with permanent disabilities and high mortality worldwide. We aimed to determine causative microorganisms and potential markers for differentiation between bacterial and viral meningitis.

METHODOLOGY

Adult patients with acute meningitis were subjected to lumber puncture. Cerebrospinal fluid (CSF) microorganisms were identified using Real-time PCR. PCT and CRP levels, peripheral and CSF-leucocyte count, CSF-protein and CSF-glucose levels were assessed.

RESULTS

Out of 80 patients, infectious meningitis was confirmed in 75 cases; 38 cases were bacterial meningitis, 34 cases were viral meningitis and three cases were mixed infection. Higher PCT, peripheral and CSF-leukocytosis, higher CSF-protein and lower CSF-glucose levels were more significant in bacterial than viral meningitis patients. Neisseria meningitides was the most frequent bacteria and varicella-zoster virus was the most common virus. Using ROC analyses, serum PCT and CSF-parameters can discriminate bacterial from viral meningitis. Combined ROC analyses of PCT and CSF-protein significantly improved the effectiveness in predicting bacterial meningitis (AUC of 0.998, 100%sensitivity and 97.1%specificity) than each parameter alone (AUC of 0.951 for PCT and 0.996 for CSF-protein).

CONCLUSION

CSF-protein and serum PCT are considered as potential markers for differentiating bacterial from viral meningitis and their combination improved their predictive accuracy to bacterial meningitis.

Elevated Free Phosphatidylcholine Levels in Cerebrospinal Fluid Distinguish Bacterial from Viral CNS Infections

The identification of CSF biomarkers for bacterial meningitis can potentially improve diagnosis and understanding of pathogenesis, and the differentiation from viral CNS infections is of particular clinical importance. Considering that substantial changes in CSF metabolites in CNS infections have recently been demonstrated, we compared concentrations of 188 metabolites in CSF samples from patients with bacterial meningitis (n = 32), viral meningitis/encephalitis (n = 34), and noninflamed controls (n = 66). Metabolite reprogramming in bacterial meningitis was greatest among phosphatidylcholines, and concentrations of all 54 phosphatidylcholines were significantly (p = 1.2 × 10⁻²⁵–1.5 × 10⁻⁴) higher than in controls. Indeed, all biomarkers for bacterial meningitis vs. viral meningitis/encephalitis with an AUC ≥ 0.86 (ROC curve analysis) were phosphatidylcholines. Four of the five most accurate (AUC ≥ 0.9) phosphatidylcholine biomarkers had higher sensitivity and negative predictive values than CSF lactate or cell count. Concentrations of the 10 most accurate phosphatidylcholine biomarkers were lower in meningitis due to opportunistic pathogens than in meningitis due to typical meningitis pathogens, and they correlated most strongly with parameters reflecting blood–CSF barrier dysfunction and CSF lactate (r = 0.73–0.82), less so with CSF cell count, and not with blood CRP. In contrast to the elevated phosphatidylcholine concentrations in CSF, serum concentrations remained relatively unchanged. Taken together, these results suggest that increased free CSF phosphatidylcholines are sensitive biomarkers for bacterial meningitis and do not merely reflect inflammation but are associated with local disease and a shift in CNS metabolism.

Cerebroprotective Effects of 2-Ethyl-6-methyl-3-hydroxypyridine-2,6-dichlorophenyl(amino)phenylethanoic Acid in the Treatment of Purulent Meningitis

Purulent meningitis (PM) is a severe disease, characterized by high mortality and a formation of a residual neurological deficit. Loss of treatment of PM leads to the lethal outcome in 100% of cases. In addition, death and the development of residual neurological complications are possible despite adequate therapy. The aim of the study was to evaluate the cerebroprotective effects of a new pharmacological compound 2-ethyl-6-methyl-3-hydroxypyridine-2,6-dichlorophenyl(amino)phenylethanoic acid (EMHDPA) on the bacterial purulent meningitis in a model of experimental pneumococcal meningitis. Meningitis was simulated by intrathecal injection of the suspension containing Streptococcus pneumoniae at the concentration of 5 × 10⁹ CFU/mL. The cerebroprotective effect was evaluated by survival rates, the severity of neurological deficit, investigatory behaviors, and results of short-term and long-term memory tests. The group administered with EMHDPA showed high survival rates, 80%. Animals treated with the studied compound showed a higher clinical assessment of the rat health status and specific force, and a lesser intensity of neurological deficit compared to the control group (p < 0.05). Locomotor activity of the animals treated with EMHDPA was significantly higher compared to the control group (p < 0.05). There is a decrease in the activity of all estimated indicators of oxidative stress in the group administered with 2-ethyl-6-methyl-3-hydroxypyridine-2,6-dichlorophenyl(amino)phenylethanoic acid relative to the control group: a decrease in the activity of catalase—17%, superoxide dismutase—34%, malondialdehyde and acetylhydroperoxides—50%, and nitric oxide—85% (p < 0.05). Analysis of the data obtained during the experiment leads to the conclusion about the effectiveness of 2-ethyl-6-methyl-3-hydroxypyridine-2,6-dichlorophenyl(amino)phenylethanoic acid in the treatment of the experimental PM.

Accuracy of cerebrospinal fluid ferritin for purulent meningitis

OBJECTIVE

To evaluate the use of cerebrospinal fluid (CSF) ferritin levels in the diagnosis of purulent meningitis (PM).

METHOD

We studied 81 children between 28 days and 12 years of age who presented with clinical suspicion of meningitis to the emergency department. CSF ferritin levels were measured and compared between diagnostic groups (PM, aseptic meningitis (AM) and no meningitis).

RESULTS

The median age was 24 (IQR 8-69) months. There were 32 patients with AM (39%), 23 with PM (28%) and 26 with no meningitis (32%). Median CSF ferritin was 4.2 ng/mL (IQR 3.0-6.5), 52.9 ng/mL (IQR 30.7-103 ng/mL) and 2.4 ng/mL (IQR 2-4), respectively. CSF ferritin was higher in children with PM compared with AM (p<0.001) or no meningitis (p<0.001). There was no difference between AM and no meningitis.

CONCLUSION

CSF ferritin may be a useful biomarker to discriminate PM in children with clinical symptoms of this disease.

Evaluating Infectious, Neoplastic, Immunological, and Degenerative Diseases of the Central Nervous System with Cerebrospinal Fluid-Based Next-Generation Sequencing

Cerebrospinal fluid (CSF) is a clear and paucicellular fluid that circulates within the ventricular system and the subarachnoid space of the central nervous system (CNS), and diverse CNS disorders can impact its composition, volume, and flow. As conventional CSF testing suffers from suboptimal sensitivity, this review aimed to evaluate the role of next-generation sequencing (NGS) in the work-up of infectious, neoplastic, neuroimmunological, and neurodegenerative CNS diseases. Metagenomic NGS showed improved sensitivity—compared to traditional methods—to detect bacterial, viral, parasitic, and fungal infections, while the overall performance was maximized in some studies when all diagnostic modalities were used. In patients with primary CNS cancer, NGS findings in the CSF were largely concordant with the molecular signatures derived from tissue-based molecular analysis; of interest, additional mutations were identified in the CSF in some glioma studies, reflecting intratumoral heterogeneity. In patients with metastasis to the CNS, NGS facilitated diagnosis, prognosis, therapeutic management, and monitoring, exhibiting higher sensitivity than neuroimaging, cytology, and plasma-based molecular analysis. Although evidence is still rudimentary, NGS could enhance the diagnosis and pathogenetic understanding of multiple sclerosis in addition to Alzheimer and Parkinson disease. To conclude, NGS has shown potential to aid the research, facilitate the diagnostic approach, and improve the management outcomes of all the aforementioned CNS diseases. However, to establish its role in clinical practice, the clinical validity and utility of each NGS protocol should be determined. Lastly, as most evidence has been derived from small and retrospective studies, results from randomized control trials could be of significant value.

SOP: emergency workup in patients with suspected acute bacterial meningitis

Introduction

Despite antibiotic therapy, adjunctive treatment with dexamethasone, and care on modern intensive care units, bacterial meningitis remains a life-threatening disease with a high mortality and morbidity. One of most critical factors that influences outcome is a targeted quick but profound workup and early initiation of therapy in the Emergency Department. This standardized operating procedure was designed to guide physicians through the workup of patients with suspected acute bacterial meningitis.

First steps

In patients with suspected community-acquired bacterial meningitis, the first steps aim at establishing a diagnosis and at starting empiric therapy without delay. Therefore, physicians need to seek for an early lumbar puncture that can be done safely without prior imaging if clinical signs that point at contraindications of a lumbar puncture are absent. Immediately after lumbar puncture, empiric therapy with ceftriaxone, ampicillin and dexamethasone should be started. In regions with a critical resistance rate of pneumococci against third generation cephalosporines, vancomycin or rifampicin need to be added.

Comments

Clinical signs that are associated with intracranial conditions that are a contraindication for a lumbar puncture are severely decreased consciousness, new onset focal neurological signs, and epileptic seizures. If any of these clinical signs are present, cerebral imaging is recommended before lumbar puncture. Whenever lumbar puncture is delayed, empiric therapy needs to be begun before cerebrospinal fluid is obtained.

Conclusion

Suspected acute bacterial meningitis is an emergency and requires attention with high priority in the emergency department to ensure a quick workup and early start of therapy.

Cranial Imaging and Lumbar Puncture in Patients With Suspected Central Nervous System Infection

BACKGROUND

Performing cranial imaging prior to lumbar punctures (LPs) in patients with suspected central nervous system (CNS) infections has been associated with delayed treatments and poor outcomes. Various guidelines provide different criteria for cranial imaging prior to LP.

METHODS

We describe the use of cranial imaging in a cohort of adult patients with suspected CNS infections, and evaluated adherence to the recommendations made in the Infectious Disease Society of America (IDSA), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), Swedish, and Dutch guidelines. We also analyzed the association between cranial imaging and the time between emergency department entrance and intravenous antibiotic administration.

RESULTS

From 2012-2015, 203 patients with suspected CNS infections were included, of whom 56 (27%) were diagnosed with CNS infections and 16 were diagnosed with bacterial meningitis (8%). Cranial imaging, in all cases computed tomography (CT), was performed in 130 patients (64%) and led to the deferral of LPs in 7 (5%). Criteria by the IDSA, ESCMID, Swedish, and Dutch guidelines showed indications for imaging in 64%, 39%, 39%, and 40% of patients, respectively. The times between emergency department arrivals and the start of antibiotic therapy between patients with and without CT before LP were similar (median 134 [interquartile range (IQR) 58-292] vs. 141 minutes [IQR 52-227], respectively; Mann-Whitney U P = .74).

CONCLUSIONS

A cranial CT prior to LP was done in the majority of patients with a suspected CNS infection, irrespective of guideline indications. The ESCMID, Swedish, and Dutch guidelines were more restrictive in advising imaging, compared to the IDSA guidelines. Performing cranial imaging prior to LP was not associated with treatment delays in this Dutch cohort study.