Epidemiology of Meningitis and Encephalitis in the United States, 2011-2014

Sociodemographic and Clinical Factors Associated With Clinical Outcome in Neuroinfectious Diseases: A Multicenter Retrospective Cohort Study

Objective

To evaluate sociodemographic and clinical factors associated with clinical outcomes in patients hospitalized with neuroinfectious diseases at three tertiary care centers in New York City.

Methods

This retrospective cohort study was conducted at three large urban tertiary care centers between January 1, 2010 and December 31, 2017. Poor clinical outcome was defined as length of hospital stay (LOS) ≥2 weeks and/or discharge to a location other than home. Sociodemographic and clinical factors were obtained from electronic medical records and descriptively analyzed. Multivariate logistic regression analysis investigated relationships between sociodemographic and clinical factors, and outcomes.

Results

Among 205 patients with definitive neuroinfectious diagnoses, older patients were more likely to have a LOS ≥2 weeks (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.01-1.05) and less likely to be discharged home (OR: 0.96; 95% CI: 0.94-0.98) than younger patients. Patients with an immunocompromised state were more likely to have a LOS ≥2 weeks (OR: 2.80; 95% CI: 1.17-6.69). Additionally, patients admitted to the intensive care unit (ICU) were more likely to have a LOS ≥2 weeks (OR: 4.65; 95% CI: 2.13-10.16) and less likely to be discharged home (OR: 0.14; 95% CI: 0.06-0.34). There were no statistically significant associations between sex, race, ethnicity, English proficiency, substance use, or poverty index, and clinical outcome.

Conclusions

In this multicenter cohort of hospitalized neuroinfectious diseases, older age, history of immunocompromised state, and admission to the ICU were significantly associated with poor clinical outcome.

Dexamethasone in adults with viral meningitis: an observational cohort study

OBJECTIVES

To investigate whether there is a dose-dependent association between empiric dexamethasone and outcome in viral meningitis.

METHODS

Observational cohort study of adults hospitalized for viral meningitis, both with and without a microbiologically confirmed diagnosis, in Denmark between 2015 and 2020. Dose-dependent associations between dexamethasone (one dose = 10 mg) and an unfavourable outcome (Glasgow Outcome Scale score 1-4) at 30 days after discharge were assessed using weighted logistic regression. Entropy balancing was used to compute weights.

RESULTS

Of 1025 included patients, 658 (64%) did not receive dexamethasone, 115 (11%) received 1-2 doses, 131 (13%) received 3-4 doses, and 121 (12%) received ≥5 doses. Among patients treated with dexamethasone, the median number of doses was higher for those without an identified pathogen than for those with a microbiologically confirmed viral aetiology (5 [interquartile range (IQR) 3-8] vs. 3 [IQR 2-5]; p < 0.001). Using no doses of dexamethasone as a reference, the weighted OR for an unfavourable outcome were 0.55 (95% CI, 0.29-1.07) for 1-2 doses, 1.13 (95% CI, 0.67-1.89) for 3-4 doses, and 1.43 (95% CI, 0.77-2.64) for ≥5 doses. In the subgroup of enteroviral meningitis, the weighted OR was 3.08 (95% CI, 1.36-6.94) for ≥5 doses, but decreased to 2.35 (95% CI, 0.65-8.40) when the reference group was restricted to patients treated with antibiotics for suspected bacterial meningitis.

DISCUSSION

This study showed no dose-dependent association between dexamethasone and an unfavourable outcome in patients with viral meningitis. In enteroviral meningitis, ≥5 doses were associated with an increased risk of an unfavourable outcome. However, sensitivity analysis indicated that the association was affected by unmeasured or residual confounding by severity.

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

Importance

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

Objective

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

Data Sources

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

Study Selection

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

Data Extraction and Synthesis

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

Main Outcome and Measure

Case fatality ratios of bacterial meningitis.

Results

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

Conclusions and Relevance

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

Clinical application and evaluation of metagenomic next-generation sequencing in pathogen detection for suspected central nervous system infections

Central nervous system Infections (CNSIs) is a disease characterized by complex pathogens, rapid disease progression, high mortality rate and high disability rate. Here, we evaluated the clinical value of metagenomic next generation sequencing (mNGS) in the diagnosis of central nervous system infections and explored the factors affecting the results of mNGS. We conducted a retrospective study to compare mNGS with conventional methods including culture, smear and etc. 111 suspected CNS infectious patients were enrolled in this study, and clinical data were recorded. Chi-square test were used to evaluate independent binomial variables, taking p < 0.05 as statistically significant threshold. Of the 111 enrolled cases, 57.7% (64/111) were diagnosed with central nervous system infections. From these cases, mNGS identified 39.6% (44/111) true-positive cases, 7.2% (8/111) false-positive case, 35.1% (39/111) true-negative cases, and 18.0% (20/111) false-negative cases. The sensitivity and specificity of mNGS were 68.7% (44/64) and 82.9% (39/47), respectively. Compared with culture, mNGS provided a higher pathogen detection rate in CNSIs patients (68.7% (44/64) vs. 26.5% (17/64), p < 0.0001). Compared to conventional methods, positive percent agreement and negative percent agreement was 84.60% (44/52) and 66.1% (39/59) separately. At a species-specific read number (SSRN) ≥ 2, mNGS performance in the diagnosis of definite viral encephalitis and/or meningitis was optimal (area under the curve [AUC] 0.758, 95% confidence interval [CI] 0.663-0.854). In bacterial CNSIs patients with significant CSF abnormalities (CSF WBC > 300*106/L), the positive rate of CSF mNGS is higher. To sum up, conventional microbiologic testing is insufficient to detect all neuroinvasive pathogens, and mNGS exhibited satisfactory diagnostic performance in CNSIs and with an overall detection rate higher than culture (p < 0.0001).

Antibody-positive autoimmune encephalitis and paraneoplastic neurological syndrome: A Swedish case series

OBJECTIVE

This study aimed to explore the clinical characteristics and temporal disease course of patients with autoimmune encephalitis (AE) and paraneoplastic neurological syndrome (PNS) in Sweden.

METHODS

Thirty-seven antibody-positive AE and PNS cases were identified in the Healthcare region Mid Sweden between 2015 and 2019. Clinical data were collected through a retrospective review of electronic health records. Patients were divided into three subgroups based on antibody type: neuronal surface antibodies (NSAbs), onconeural antibodies, and anti-GAD65 antibodies.

RESULTS

Nineteen patients had NSAbs, 11 onconeural antibodies, and seven anti-GAD65 antibodies. Anti-LGI1 and anti-NMDAR were the most frequently detected NSAbs, with anti-NMDAR cases having an older-than-expected age distribution (median age 40, range 17-72). Only 11 of 32 (30%) of patients had findings suggesting encephalitis on initial MRI, but 28 of 31 (90%) had pathological findings on initial cerebrospinal fluid analysis. All patients but one had abnormal EEG findings. Median time to immunotherapy was comparable among the three subgroups, whereas patients with anti-LGI1, anti-CASPR2, and anti-IgLON5 had an eightfold longer time to immunotherapy than anti-NMDAR and anti-GABA-B (p = .0016). There was a seasonal variation in onset for patients with non-tumor-related NSAbs and anti-GAD65 antibodies, with most patients (72%) falling ill in spring or summer.

CONCLUSION

Swedish patients with AE and PNS had similar clinical characteristics as previously described cohorts from other geographical regions except for anti-NMDAR encephalitis, with older onset than expected. The onset of non-tumor-related AE occurred predominantly in the warm seasons, and AE with a more insidious onset was associated with delayed treatment initiation.

Utilization of a Meningitis/Encephalitis PCR panel at the University Hospital Basel - a retrospective study to develop a diagnostic decision rule

Background

The Biofire® FilmArray® Meningitis/Encephalitis (ME) PCR panel covers 14 viral, bacterial, and fungal pathogens and has been implemented in many institutions worldwide. Post-marketing studies indicate a reduced sensitivity and overutilization underscoring the need for a more targeted usage. The aim of our study is to describe the utilization of the ME panel and to develop a diagnostic-stewardship based decision rule.

Materials

Adult patients, who underwent CSF analysis with the ME panel between August 2016 and June 2021 at the University Hospital Basel, were included. Demographic, clinical, microbiological, and laboratory data were extracted from the electronic health record. Factors associated with a positive ME panel result were identified, and a decision rule was developed to potentially optimize the diagnostic yield and reduce the number of unnecessary tests.

Results

1,236 adult patients received at least one panel in the observed period, of whom 106 panels tested positive (8.6%). The most frequently observed pathogens were Varicella Zoster Virus (VZV, 27%), Streptococcus pneumoniae (19%), Enterovirus (16%), Herpes simplex Virus 1/2 (16%), and Human Herpesvirus 6 (HHV-6, 13%). Fever, vomiting, headache, and photophobia were more frequently present in test positive patients as were significantly higher CSF leukocytes and protein concentrations. When simulating a decision rule based on CSF leukocytes and protein concentration, only 35% of all patients would have qualified for a ME panel tests, thereby increasing the positivity rate to 22.7%. 10 of 106 positive ME panels would have been missed, only involving HHV-6 and VZV (6 and 4 cases, respectively). As these subjects were either severely immunocompromised or had clinical features of shingles we propose extending the testing algorithm by including those criteria.

Conclusion

The ME panel positivity rate at our institution was similar as previously published. Our results highlight the need for diagnostic-stewardship interventions when utilizing this assay by implementing a stepwise approach based on a limited number of clinical and laboratory features. This decision rule may improve the pretest probability of a positive test result, increase the quality of test utilization, and reduce costs.

Prevalence of Penicillin Resistance Among Streptococcus pneumoniae Isolates in a General Hospital in Southwest Saudi Arabia: A Five-Year Retrospective Study

Background The rise in infections caused by penicillin-resistant strains of Streptococcus pneumoniae has become a global concern. However, the magnitude of this problem in Southwest Saudi Arabia has never been investigated. Therefore, this study aims to determine the prevalence of this bacteria in the region using in vitro data. Materials and methods This study retrospectively studied pneumococcal isolates collected by the Microbiology Laboratory of a general hospital in Al Baha, Saudi Arabia, from January 2013 to December 2017. A minimum inhibitory concentration (MIC) ≥ 8 mg/L was used as a cutoff concentration to detect the resistant isolates. Results A total of 201 S. pneumoniae isolates were identified using the VITEK® 2 system (bioMérieux SA, Marcy-l'Étoile, France). Most of these isolates (61%) were obtained from respiratory specimens, including sputum, tracheal aspirates, and bronchoalveolar lavage. Eye swabs accounted for 15% of the isolates, blood samples contributed 12%, ear swabs accounted for 7%, and cerebrospinal fluid (CSF) 3.4%. The resistance of S. pneumoniae during the five years varied from 61% to 76%, with an overall resistance of 70% (141/201). The resistance rate per year was 71% (43/60) in 2013, 76% (35/46) in 2014, 61% (22/36) in 2015, 68% (20/29) in 2016, and 66% (21/30) in 2017. Conclusion The data confirm the presence of penicillin-resistant S. pneumoniae in Southwest Saudi Arabia. Furthermore, the high resistance suggests a potential concern, emphasizing the need for penicillin control, surveillance, and vaccination to address this growing problem.

Impact of direct ICU admission of pneumococcal meningitis in France: a retrospective analysis of a French medico-administrative (PMSI) database

BACKGROUND

Current guidelines for adult patients with pneumococcal meningitis (PM) recommend initial management in intermediate or intensive care units (ICU), but evidence to support these recommendations is limited. We aimed to describe ICU admission practices of patients with PM.

METHODS

We conducted a retrospective analysis of the French medico administrative database of consecutive adult patients with PM and sepsis criteria hospitalized between 2011 and 2020. We defined two groups, "Direct ICU" corresponding to a direct ICU admission and "Delayed ICU" corresponding to a secondary ICU admission.

RESULTS

We identified 4052 patients hospitalized for a first episode of PM, including 2006 "Direct ICU" patients (50%) and 2046 "delayed ICU" patients (50%). The patients were mainly males [n = 2260 (56%)] with median age of 61 years [IQR 50-71] and a median Charlson index of 1 [0-3]. Among them, median SAPS II on admission was 46 [33-62], 2173 (54%) had a neurological failure on admission with 2133 (53%) in coma, 654 (16%) with brainstem failure, 488 (12%) with seizures and 779 (19%) with focal signs without coma. PM was frequently associated with pneumonia [n = 1411 (35%)], and less frequently with endocarditis [n = 317 (8%)]. The median ICU length of stay and hospital length of stay were 6 days [2-14] and 21 days [13-38], respectively. In-hospital mortality was 27% (n = 1100) and 640 (16%) patients were secondarily transferred to rehabilitation care unit. Direct ICU group was significantly more severe but after adjustment for age, sex, comorbidities, organ failures on admission and admission from home, direct ICU admission was significantly associated with a lower mortality (Odds ratio 0.67 [0.56-0.80], p < 0.01). This corresponded to one death avoided for 11 PM directly admitted in ICU.

CONCLUSIONS

Among patients with PM and sepsis, direct ICU admission was associated with lower mortality rates when compared to delayed admission.

NLRP3 Activation Contributes to Memory Impairment in an Experimental Model of Pneumococcal Meningitis

Bacterial meningitis is considered a life-threatening condition with high mortality rates. In response to the infection, signaling cascades, producing pro-inflammatory mediators trigger an exacerbated host immune response. Another inflammatory pathway occurs through the activation of inflammasomes. Studies highlight the role of the NLR family pyrin domain containing 3 (NLRP3) in central nervous system disorders commonly involved in neuroinflammation. We aimed to investigate the role of NLRP3 and its inhibitor MCC950 on neurochemical, immunological, and behavioral parameters in the early and late stages of experimental pneumococcal meningitis. For this, adult male Wistar rats received an intracisternal injection of Streptococcus pneumoniae or artificial cerebrospinal fluid as a placebo. The animals were divided into control/saline, control/MCC950, meningitis/saline, and meningitis/MCC950. Immediately after the meningitis induction, the animals received 140 ng/kg MCC950 via intracisternal injection. For the acute protocol, 24 h after induction, brain structures were collected to evaluate cytokines, NLRP3, and microglia. In the long-term group, the animals were submitted to open field and recognition of new objects tests at ten days after the meningitis induction. After the behavioral tests, the same markers were evaluated. The animals in the meningitis group at 24 h showed increased levels of cytokines, NLRP3, and IBA-1 expression, and the use of the MCC950 significantly reduced those levels. Although free from infection, ten days after meningitis induction, the animals in the meningitis group had elevated cytokine levels and demonstrated behavioral deficits; however, the single dose of NLRP3 inhibitor rescued the behavior deficits and decreased the brain inflammatory profile.

The clinical epidemiology, management, and outcomes of patients diagnosed with encephalitis in North Carolina, 2015-2020

IMPORTANCE

Despite the relatively high mortality and the difficulty in diagnosis, nearly one-third of patients hospitalized with a documented diagnosis of encephalitis did not undergo a lumbar puncture (LP). When an LP was performed, pathogen-specific testing was greatly underutilized. Infectious etiologies were most common, but over 40% of cases were idiopathic at discharge. These findings suggest that there is a substantial opportunity to improve the quality of care through more accurate and timely diagnosis.

Real-World Continuous EEG Utilization and Outcomes in Hospitalized Patients With Acute Cerebrovascular Diseases

PURPOSE

Continuous electroencephalography (cEEG) is recommended for hospitalized patients with cerebrovascular diseases and suspected seizures or unexplained neurologic decline. We sought to (1) identify areas of practice variation in cEEG utilization, (2) determine predictors of cEEG utilization, (3) evaluate whether cEEG utilization is associated with outcomes in patients with cerebrovascular diseases.

METHODS

This cohort study of the Premier Healthcare Database (2014-2020), included hospitalized patients age >18 years with cerebrovascular diseases (identified by ICD codes). Continuous electroencephalography was identified by International Classification of Diseases (ICD)/Current Procedural Terminology (CPT) codes. Multivariable lasso logistic regression was used to identify predictors of cEEG utilization and in-hospital mortality. Propensity score-matched analysis was performed to determine the relation between cEEG use and mortality.

RESULTS

1,179,471 admissions were included; 16,777 (1.4%) underwent cEEG. Total number of cEEGs increased by 364% over 5 years (average 32%/year). On multivariable analysis, top five predictors of cEEG use included seizure diagnosis, hospitals with >500 beds, regions Northeast and South, and anesthetic use. Top predictors of mortality included use of mechanical ventilation, vasopressors, anesthetics, antiseizure medications, and age. Propensity analysis showed that cEEG was associated with lower in-hospital mortality (Average Treatment Effect -0.015 [95% confidence interval -0.028 to -0.003], Odds ratio 0.746 [95% confidence interval, 0.618-0.900]).

CONCLUSIONS

There has been a national increase in cEEG utilization for hospitalized patients with cerebrovascular diseases, with practice variation. cEEG utilization was associated with lower in-hospital mortality. Larger comparative studies of cEEG-guided treatments are indicated to inform best practices, guide policy changes for increased access, and create guidelines on triaging and transferring patients to centers with cEEG capability.

Encephalitis in HIV-infected adults in the antiretroviral therapy era

INTRODUCTION

Encephalitis presents with high morbidity and mortality in both HIV-infected and HIV-negative patients. There are currently no studies comparing HIV-infected and HIV-negative patients admitted to the hospital with acute encephalitis.

METHODS

We conducted a multicenter, retrospective study of adults admitted to the hospital with a diagnosis of encephalitis in Houston, Texas between 2005 and 2020. We describe the clinical manifestations, etiology, and outcomes of these patients with a focus on those infected with HIV.

RESULTS

We identified 260 patients with encephalitis, 40 of whom were infected with HIV. Viral etiology was identified in 18 of the 40 HIV-infected patients (45.0%); bacterial in 9 (22.5%); parasitic in 5 (12.5%); fungal in 3 (7.5%); immune-mediated in 2 (5.0%). Eleven cases had unclear etiology (27.5%). More than one disease process was identified in 12 (30.0%) patients. HIV-infected persons were more likely to have neurosyphilis (8/40 vs. 1/220; OR 55; 95%CI 6.6-450), CMV encephalitis [5/18 vs. 1/30; OR 11.2 (1.18-105)], or VZV encephalitis (8/21 vs. 10/89; OR 4.82; 1.62-14.6) compared to the HIV-negative patients. Inpatient mortality was similar in the HIV-infected and HIV-negative patients, 15.0% vs 9.5% [p = 0.4, OR 1.67 (0.63-4.44)], but one-year mortality was higher for the HIV-infected patients, 31.3% vs 16.0% [p = 0.04, OR 2.40 (1.02-5.55)].

CONCLUSION

This large, multicenter study shows that HIV-infected patients with encephalitis have a distinct pattern of disease when compared with HIV-negative patients, and that this population has nearly twice the odds of mortality in the year following hospitalization.

Viral meningitis and encephalitis: an update

PURPOSE OF REVIEW

The most common infectious etiologies of meningitis and encephalitis are viruses. In this review, we will discuss current epidemiology, prevention, diagnosis, and treatment of the most common causes of viral meningitis and encephalitis worldwide.

RECENT FINDINGS

Viral meningitis and encephalitis are increasingly diagnosed as molecular diagnostic techniques and serologies have become more readily available worldwide but recent progress in novel antiviral therapies remains limited. Emerging and re-emerging viruses that have caused endemic or worldwide outbreaks or epidemics are arboviruses (e.g., West Nile virus, Japanese encephalitis, Tick borne encephalitis, Dengue, Zika, Toscana), enteroviruses (e.g., Enterovirus 71, Enterovirus D68), Parechoviruses, respiratory viruses [e.g., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza, metapneumoviruses, measles, mumps], and herpes viruses [e.g., herpes simplex virus (HSV) type 1 (HSV-1), HSV-2, human herpes (HV) 6, varicella zoster virus (VZV)]. Future efforts should concentrate in increasing availability for those viruses with effective vaccination [e.g., Japanese encephalitis, Tick borne encephalitis, varicella zoster viruses, SARS-CoV-2, influenza], prompt initiation of those with encephalitis with treatable viruses (e.g., HSV-1, VZV), increasing the diagnostic yield by using novel techniques such as metagenomic sequencing and avoiding unnecessary antibiotics in those with viral meningitis or encephalitis.

SUMMARY

We review the current epidemiology, clinical presentation, diagnosis, and treatment of the common causative agents of viral meningitis and encephalitis worldwide.

Candida meningitis/ventriculitis over a decade. Increased morbidity and length of stay a concern

AIM

The primary aim of this study was to review the diagnosis, management and outcome of Candida meningitis/ventriculitis in our hospital over a ten-year period.

MATERIALS AND METHODS

We retrospectively reviewed all culture and 18s rRNA nucleic acid positive CSF specimens processed between 1st January 2010 and 31st December 2020. Patient records were subsequently reviewed to assess the significance of the isolate.

RESULTS

Of 851 culture-positive cerebrospinal fluid (CSF) specimens, Candida spp. were isolated from 29 (3.4%), representing infection in 12 patients. One culture-negative specimen was positive for Candida on 18s rRNA testing. Of the 13 patients, eight were male; 61.5% and the median age was 47 years; range: 20-70. The median interval from admission to onset of infection and culture positivity was 24 days (range: 1-63 days). All patients had a central nervous system (CNS) device in situ (external ventricular drain: 11; ventriculoperitoneal shunt: 1; lumbar drain: 1). Four were colonised with Candida spp. before meningitis/ventriculitis diagnosis, from wounds (n = 3), respiratory (n = 3), and urine (n = 1) specimens. On culture, the most common species was Candida albicans (n = 8), followed by C. parapsilosis (n = 2), C. tropicalis (n = 1), and C. dubliniensis (n = 1). The median number of follow-up CSFs per patient was nine (range; 3-22), with a median of 6 days to CSF sterility (range 3-10 days). Treatment included; liposomal amphotericin B (n = 5), fluconazole (n = 2), liposomal amphotericin B, and flucytosine (n = 2), liposomal amphotericin B, fluconazole and flucytosine (n = 3), and intra-ventricular amphotericin B (n = 1). Median treatment duration was 25 days (range 11-76) and CNS device removal occurred in 12 patients. The median length-of-stay (LOS) was 58 days (range 24-406). On discharge, moderate to severe disability (Modified Rankin Scale [mRS] 3-5) was evident in eight patients. Two patients died and one was lost to follow-up.

CONCLUSION

Meningitis/ventriculitis due to Candida spp. is an uncommon but challenging infection, usually associated with a device, increased morbidity, LOS, and necessitating prolonged treatment. Neurosurgeons need to be aware of these issues in managing and in communicating with such complex patients.

Rational Use of Microbiological Tests in the Diagnosis of Central Nervous System Infections Using Restrictive Criteria: a Retrospective Study

Microbiological testing in general and in the setting of central nervous system (CNS) infection in particular are often excessive, leading to superfluous laboratory work and costs. In this regard, restrictive criteria, named Reller criteria, have been developed to reduce unnecessary CSF herpes simplex virus 1 (HSV-1) PCR testing when suspecting encephalitis.

Seasonal Trends in the Prevalence and Incidence of Viral Encephalitis in Korea (2015-2019)

Viral infections are a common cause of encephalitis. This study investigated the relationship between the incidence of encephalitis and that of respiratory and enteric viral infections in all age groups from 2015 to 2019, using the Health Insurance Review and Assessment (HIRA) Open Access Big Data Platform. We identified monthly incidence patterns and seasonal trends using the autoregressive integrated moving average (ARIMA). The Granger causality test was used to analyze correlations between encephalitis incidence and the positive detection rate (PDR) at 1-month intervals. A total of 42,775 patients were diagnosed with encephalitis during the study period. The incidence of encephalitis was highest in the winter (26.8%). The PDRs for respiratory syncytial virus (HRSV) and coronavirus (HCoV) were associated with the trend in encephalitis diagnosis in all age groups, with a 1-month lag period. In addition, an association with norovirus was observed in patients aged over 20 years, and with influenza virus (IFV) in patients aged over 60 years. This study found that HRSV, HCoV, IFV, and norovirus tended to precede encephalitis by 1 month. Further research is required to confirm the association between these viruses and encephalitis.

Diagnostic accuracy of rapid antigen tests in cerebrospinal fluid for pneumococcal meningitis: a systematic review and meta-analysis

BACKGROUND

Streptococcus pneumoniae is a leading cause of bacterial meningitis worldwide. Conventional microbiological assays take several days and require the use of various drugs for empirical treatment. Rapid antigen tests in cerebrospinal fluid (CSF) may be useful to triage pneumococcal meningitis immediately.

OBJECTIVES

To elucidate whether rapid antigen tests in CSF are useful in the triage of pneumococcal meningitis.

METHODS

Data sourcesCochrane CENTRAL, MEDLINE, EMBASE, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov databases were searched. Study eligibility criteriaAll types of cohort studies except multiple-group studies, where the sensitivity and specificity of rapid antigen tests in CSF compared with CSF culture can be extracted. ParticipantsPatients with suspected meningitis. TestsRapid antigen tests in CSF. Reference standardsOne or more of the following: blood culture, CSF culture, and polymerase chain reaction in CSF. Assessment of risk of biasThe methodological quality of the included studies was assessed using QUADAS-2. Methods of data synthesisWe used a random-effects bivariate model for the meta-analysis. We conducted a subgroup analysis by dividing studies into types of antigen tests, adults and children, low-income and high-income countries, and with or without exposure to antibiotics before lumbar puncture.

RESULTS

Forty-four studies involving 14 791 participants were included. Most studies had a moderate-to-low methodological quality. Summary sensitivity and specificity were 99.5% (95% confidence interval (CI), 92.4-100%) and 98.2% (95% CI, 96.9-98.9%), respectively. Positive predictive values and negative predictive values at the median prevalence (4.2%) in the included studies were 70.8% (95% CI, 56.6-79.9%) and 100% (95% CI, 99.7-100%), respectively. The diagnostic accuracy was consistent across the various subgroups, except for slightly reduced sensitivity in high-income countries.

CONCLUSIONS

Rapid antigen tests in CSF would be useful in triaging pneumococcal meningitis. Further studies are warranted to investigate the clinical benefit of ruling out pneumococcal meningitis based on the results of rapid antigen tests.

Enterovirus characterized from cerebrospinal fluid in a cohort from the Eastern United States

BACKGROUND

Enteroviruses (EVs) are predominant causes of a spectrum of neurological diseases. To better understand the origins of the outbreaks of disease associated with EV, it is essential to develop an efficient surveillance system that identifies the circulating EVs and correlate their genomic evolution with the disease presentations.

METHODS

The clinical presentations of patients with positive EV from cerebrospinal fluid (CSF) between 2014 and 2022, diagnosed at the Johns Hopkins Medical Microbiology Laboratory, were compared from year to year. EV typing and whole genome sequencing were performed and correlated to the spectrum of disease.

RESULTS

A total of 95 CSF specimens were positive for EV between 2014 and 2022. The percentage positivity ranged from the lowest of 1.1% in 2020 to the highest of 3.2% in 2015. The median ages declined from 22 years in 2014 to less than one year starting in 2016 to 34 in 2022. Typing using VP1 sequencing revealed that E30 and E6 were associated with meningitis in adults but coxsackieviruses (CVs-B3 and B5) were detected from pediatric patients with fever. Whole genome sequencing revealed multiple recombination events. In 2020, a recombinant CV-A9 was detected in a CSF sample associated with unusual presentation of sepsis, profound acute bilateral sensory neural hearing loss, and myofasciitis.

CONCLUSIONS

EV genomic surveillance is needed for a better understanding of the genetic determinants of neurovirulence. Whole genome sequencing can reveal recombination events missed by traditional molecular surveillance methods.

Mystery of fatal 'staggering disease' unravelled: novel rustrela virus causes severe meningoencephalomyelitis in domestic cats

'Staggering disease' is a neurological disease entity considered a threat to European domestic cats (Felis catus) for almost five decades. However, its aetiology has remained obscure. Rustrela virus (RusV), a relative of rubella virus, has recently been shown to be associated with encephalitis in a broad range of mammalian hosts. Here, we report the detection of RusV RNA and antigen by metagenomic sequencing, RT-qPCR, in-situ hybridization and immunohistochemistry in brain tissues of 27 out of 29 cats with non-suppurative meningoencephalomyelitis and clinical signs compatible with'staggering disease' from Sweden, Austria, and Germany, but not in non-affected control cats. Screening of possible reservoir hosts in Sweden revealed RusV infection in wood mice (Apodemus sylvaticus). Our work indicates that RusV is the long-sought cause of feline 'staggering disease'. Given its reported broad host spectrum and considerable geographic range, RusV may be the aetiological agent of neuropathologies in further mammals, possibly even including humans.

Bacterial meningitis in adults: a retrospective study among 148 patients in an 8-year period in a university hospital, Finland

BACKGROUND

Bacterial meningitis (BM) causes significant morbidity and mortality. We investigated predisposing factors, clinical characteristics, spectrum of etiological bacteria, and clinical outcome of community-acquired and nosocomial BM.

METHODS

In this retrospective study we analyzed data of 148 adults (age > 16 years) with BM treated in Turku University Hospital, Southwestern Finland, from 2011 to 2018. Besides culture- or polymerase chain reaction (PCR)-positive cases we also included culture-negative cases with laboratory parameters strongly suggestive of BM and those with meningitis-related findings in imaging. We used Glasgow Outcome Scale (GOS) score 1-4 to determine unfavorable outcome.

RESULTS

The median age of patients was 57 years and 48.6% were male. Cerebrospinal fluid (CSF) culture for bacteria showed positivity in 50 (33.8%) cases, although pre-diagnostic antibiotic use was frequent (85, 57.4%). The most common pathogens in CSF culture were Streptococcus pneumoniae (11, 7.4%), Staphylococcus epidermidis (7, 4.7%), Staphylococcus aureus (6, 4.1%) and Neisseria meningitidis (6, 4.1%). Thirty-nine patients (26.4%) presented with the triad of fever, headache, and neck stiffness. A neurosurgical procedure or an acute cerebral incident prior BM was recorded in 74 patients (50%). Most of the patients had nosocomial BM (82, 55.4%) and the rest (66, 44.6%) community-acquired BM. Ceftriaxone and vancomycin were the most used antibiotics. Causative pathogens had resistances against the following antibiotics: cefuroxime with a frequency of 6.8%, ampicillin (6.1%), and tetracycline (6.1%). The case fatality rate was 8.8% and the additional likelihood of unfavorable outcome 40.5%. Headache, decreased general condition, head computed tomography (CT) and magnetic resonance imaging (MRI), hypertension, altered mental status, confusion, operative treatment, neurological symptoms, pre-diagnostic antibiotic use and oral antibiotics on discharge were associated with unfavorable outcome.

CONCLUSIONS

The number of cases with nosocomial BM was surprisingly high and should be further investigated. The usage of pre-diagnostic antibiotics was also quite high. Headache was associated with unfavorable outcome. The frequency of unfavorable outcome of BM was 40.5%, although mortality in our patients was lower than in most previous studies.

Case report: Clinical and virological characteristics of aseptic meningitis caused by a recombinant echovirus 18 in an immunocompetent adult

Echovirus 18 has been recognized as an important causative pathogen of aseptic meningitis in young children worldwide, and echovirus 18-induced meningitis is rarely found in adults with immunocompetence. In this case study, we report the clinical and virological characteristics of aseptic meningitis caused by recombinant echovirus 18 in an adult with immunocompetence. A 31-year-old woman with immunocompetence was admitted to our hospital with fever, dizziness, severe headache, nausea, and vomiting for the past 1 day and was diagnosed with viral meningitis based on the clinical manifestations and laboratory results from cerebrospinal fluid (CSF). The patient received antiviral treatment with ribavirin and interferon as soon as the enterovirus infection was identified using qRT-PCR and was cured after 4 days. From the oropharyngeal swab and CSF samples, two echovirus 18 strains were isolated with a single nucleotide difference located at the 5' UTR. Phylogenetic analyses based on the VP1 gene showed that the two strains belonged to the subgenotype C2 and were clustered with sequences obtained from China after 2015, while the results from the 3D polymerase region showed that the two strains were closely related to the E30 strains. Bootscanning results using the 5' UTR to 2A region and the 2B to 3' UTR region showed that potential intertypic recombination had occurred in the 2B gene. Recombination analyses further confirmed that the two strains (echovirus 18) presented genome recombination with echovirus 30 in the nucleotide regions of the 2B gene. To the best of our knowledge, this is the first report of echovirus 18-induced meningitis in an adult with immunocompetence from mainland China, highlighting the need for close surveillance of echovirus 18 both in children and adults in the future.

Multiplex detection of meningitis and encephalitis pathogens: A study from laboratory to clinic

Introduction

Infectious meningitis and encephalitis (ME) are life-threatening conditions are caused by various pathogens. Conventional laboratory tests with low sensitivity and specificity cannot help with early diagnosis.

Methods

A prospective study using the novel multiplex PCR detection for 18 pathogens of ME (MME-18) was conducted to investigate the clinical utilization and the epidemiology characteristics of ME in southwestern China. Patients with suspected intracranial infection were recruited between May and October 2019 at West China Hospital of Sichuan University. The MME-18 was used to detect cerebrospinal fluid, and conventional experiments including cryptococcal capsular antigen detection, GeneXpert, real-time PCR, and clinical feedback were used to verify the result of MME-18.

Results

Among 581 tested patients, 139 eligible individuals were enrolled in the study. Among them, Mycobacterium tuberculosis was the most common pathogen in mono-infection. Viruses and Cryptococcus neoformans were also frequently detected. Of 139 infected patients, 12 cases were diagnosed by MME-18 only, 57 patients by conventional testing only, and 70 cases by both comparator tests and MME-18. There were 96.3% (79/82) diagnoses made by MME-18 had a favorable outcome, and two of twelve diagnoses, made solely by MME-18, had a likely unclear clinical significance.

Discussion

The MME-18 showed satisfactory consistency with expert clinical consensus for patients presenting with ME. Combined with conventional testing and clinical suspicion, MME-18 may help clinicians with the early identification of pathogens.

Progress and Challenges in Bacterial Meningitis: A Review

IMPORTANCE

Bacterial meningitis is a worldwide health problem, with incidence rates ranging from approximately 0.9 per 100 000 individuals per year in high-income countries to 80 per 100 000 individuals per year in low-income countries. In low-income countries, bacterial meningitis has a mortality rate of up to 54%. Up to 24% of those who survive develop chronic neurological sequelae, such as hearing loss or focal neurological deficits.

OBSERVATIONS

Streptococcus pneumoniae causes about 72% and Neisseria meningitidis causes about 11% of cases of bacterial meningitis in people older than 16 years. Escherichia coli and Streptococcus agalactiae cause about 35% of cases of early-onset neonatal meningitis. In adults, risk factors for bacterial meningitis include older age and immunosuppressive conditions. The most common symptoms are headache (84%), fever (74%), stiff neck (74%), altered mental status (median [IQR] Glasgow Coma Scale score of 11 [9-14] on a scale ranging from 3-15), and nausea (62%). Brain imaging should be performed before lumbar puncture if patients present with altered mental status, focal neurological deficits, papilledema, or history of immunocompromising conditions or central nervous system disease. Bacterial meningitis should be suspected if any of the following are present on admission: serum leukocytes greater than 10.0 ×109/L, cerebrospinal fluid (CSF) leukocytes greater than 2000/μL, CSF granulocytes greater than 1180/μL, CSF protein greater than 2.2 g/L, CSF glucose less than 34.23 mg/dL, or fever. A positive Gram stain result for bacteria is diagnostic, but the sensitivity of a positive Gram stain result for bacterial meningitis ranges from 50% to 90%. In countries in which the prevalence of ceftriaxone-resistant Streptococcus pneumoniae exceeds 1%, vancomycin and ceftriaxone are the empirical antibiotics of choice, with the addition of ampicillin in neonates, older patients, and immunocompromised patients. Adjunctive dexamethasone should be used in patients with bacterial meningitis but stopped if Listeria monocytogenes is confirmed.

CONCLUSIONS AND RELEVANCE

Bacterial meningitis affects approximately 0.9 per 100 000 individuals to 80 per 100 000 individuals per year and has a mortality rate as high as 54%. First-line therapy is prompt empirical intravenous antibiotic therapy and adjunctive dexamethasone.

Analysis of the Clinical Impact of the BioFire FilmArray Meningitis Encephalitis Panel on Antimicrobial Use and Duration of Therapy at an Academic Medical Center

The purpose of this study was to assess the clinical impact of the BioFire FilmArray Meningitis/Encephalitis (ME) panel on antimicrobial use and clinical outcomes. This retrospective, quasi-experiment evaluated adult and pediatric patients with suspected ME, evidenced by cerebrospinal fluid (CSF) culture. Hospital-acquired meningitis patients and patients who received antimicrobials >48 h prior to lumbar puncture were excluded. The primary endpoint was days of antimicrobial therapy pre- and post-implementation of the ME panel. Secondary endpoints included total length of stay, 30-day readmission, and individual days of antimicrobial therapy. Two hundred and sixty-four total adult and pediatric patients were included. Antimicrobial days of therapy had a median of 3 days (IQR 0−5) in the pre vs. post group with a median of 2 days (2−5) (p = 0.099). Days of therapy for acyclovir were significantly decreased in the post group (median 2 days [IQR 1−3] vs. 3 days [IQR 2.5−4.5], p = 0.0002). There were no significant differences in the secondary endpoints. Overall, implementation of the ME panel impacted the duration of antimicrobials, particularly acyclovir; however, opportunities for further education regarding antimicrobial de-escalation and utilization of the panel were identified. Antimicrobial stewardship program intervention is critical to maximize benefit of this rapid diagnostic test.

The cerebrospinal fluid neutrophil to lymphocyte ratio is a sensitive biomarker for bacterial meningitis in children

BACKGROUND

The cerebrospinal fluid neutrophil-to-lymphocyte ratio (CSF NLR) as a diagnostic biomarker of bacterial meningitis has been reported in adult trials. The aim of this study was to evaluate the CSF NLR as a diagnostic biomarker of bacterial meningitis in children and to define an optimal CSF NLR concentration.

METHODS

We performed a retrospective cohort study of children with clinical findings compatible with meningitis. CSF NLR was calculated as the ratio of neutrophil count to lymphocyte count in cerebrospinal fluid (CSF). Initial data included clinical, radiological, and laboratory diagnostics.

RESULTS

We determined CSF parameters from children with infectious meningitis (n = 348) and subdivided them into bacterial meningitis (n = 112) and viral meningitis (n = 236). CSF NLR was significantly higher in bacterial meningitis than in viral meningitis (P < 0.001), and its level was higher in Gram-negative bacterial infections than in Gram-positive bacterial infections (P = 0.01). In the receiver operating characteristic curve analysis, CSF NLR was better than CSF protein/sugar/WBC in the ability to distinguish bacterial meningitis from viral meningitis (AUC 0.91 ± 0.02 versus 0.88 ± 0.03/0.87 ± 0.03/0.86 ± 0.03), and using a cutoff point of 0.68, the sensitivity was 0.90, and the specificity was 0.75. Compared with Gram-positive infection, CSF NLR with Gram-negative infection was higher (media, IQR (1.18 (0.19-2.33) versus 3.90 (1.50-8.91), P = 0.01).

CONCLUSION

CSF NLR is a more useful diagnostic tool to distinguish between bacterial meningitis and viral meningitis in children. While at a cutoff value of 0.68, CSF NLR has better sensitivity and specificity for bacterial meningitis, and the higher level of CSF NLR could be related to Gram-negative bacterial infection.

Outcomes of implementation of the FilmArray meningoencephalitis panel in a tertiary hospital between 2017 and 2020

Background

Acute meningoencephalitis is encountered commonly in the acute hospital setting and is associated with significant morbidity and mortality, in addition to significant healthcare costs. Multiplex PCR panels now allow syndromic testing for central nervous system infection. The BioFire® FilmArray® Meningoencephalitis (ME) allows testing of 14 target pathogens using only 0.2mls of cerebrospinal fluid (CSF). We conducted a retrospective observational study to assess the performance of the assay and secondarily to observe the clinical utility of negative results by comparing clinical outcomes of aseptic meningitis to bacterial and viral meningoencephalitis.

Methods

Data for CSF samples tested using the FilmArray ME panel from October 2017 to October 2020 were analysed. Detection of bacterial and viral targets was analysed. Admission to critical care area, 90-day readmission rates, average length of stay and 30-day and 90-day mortality were analysed for three groups with following diagnoses: bacterial meningitis, viral meningoencephalitis, or aseptic meningitis.

Results

From October 2017 to October 2020, 1926 CSF samples were received in the Clinical Microbiology laboratory. Of those, 543 CSF samples from 512 individual patients were tested using the FilmArray ME panel. Twenty-one bacterial targets and 56 viral targets were detected during the study period. For viral targets, the cumulative specificity was 98.9% (95% confidence interval: 93.1–99.9) when compared to the reference laboratory methods. The outcomes for 30- and 90-day mortality of the aseptic meningitis group were non-inferior relative to the viral meningoencephalitis and bacterial meningitis group. Patients with bacterial meningitis had a longer average length of stay. Aseptic meningitis was associated with a higher 90-day readmission rate than the other 2 groups, but without statistical significance.

Conclusion

In our hands, implementation of the FilmArray ME panel was relatively straightforward. We experienced a transition in our workflow processes that enabled streamlining of CSF diagnostics and the safe removal of Gram staining in those samples being tested by this molecular assay. Coupled to this improvement, there was a positive clinical impact on patient care due to rapid turnaround time to results.

Role of Non-Coding RNA in Neurological Complications Associated With Enterovirus 71

Enterovirus 71 (EV71) is the main pathogenic virus that causes hand, foot, and mouth disease (HFMD). Studies have reported that EV71-induced infections including aseptic meningitis, acute flaccid paralysis, and even neurogenic pulmonary edema, can progress to severe neurological complications in infants, young children, and the immunosuppressed population. However, the mechanisms through which EV71 causes neurological diseases have not been fully explored. Non-coding RNAs (ncRNAs), are RNAs that do not code for proteins, play a key role in biological processes and disease development associated with EV71. In this review, we summarized recent advances concerning the impacts of ncRNAs on neurological diseases caused by interaction between EV71 and host, revealing the potential role of ncRNAs in pathogenesis, diagnosis and treatment of EV71-induced neurological complications.

Integrating central nervous system metagenomics and host response for diagnosis of tuberculosis meningitis and its mimics

The epidemiology of infectious causes of meningitis in sub-Saharan Africa is not well understood, and a common cause of meningitis in this region, Mycobacterium tuberculosis (TB), is notoriously hard to diagnose. Here we show that integrating cerebrospinal fluid (CSF) metagenomic next-generation sequencing (mNGS) with a host gene expression-based machine learning classifier (MLC) enhances diagnostic accuracy for TB meningitis (TBM) and its mimics. 368 HIV-infected Ugandan adults with subacute meningitis were prospectively enrolled. Total RNA and DNA CSF mNGS libraries were sequenced to identify meningitis pathogens. In parallel, a CSF host transcriptomic MLC to distinguish between TBM and other infections was trained and then evaluated in a blinded fashion on an independent dataset. mNGS identifies an array of infectious TBM mimics (and co-infections), including emerging, treatable, and vaccine-preventable pathogens including Wesselsbron virus, Toxoplasma gondii, Streptococcus pneumoniae, Nocardia brasiliensis, measles virus and cytomegalovirus. By leveraging the specificity of mNGS and the sensitivity of an MLC created from CSF host transcriptomes, the combined assay has high sensitivity (88.9%) and specificity (86.7%) for the detection of TBM and its many mimics. Furthermore, we achieve comparable combined assay performance at sequencing depths more amenable to performing diagnostic mNGS in low resource settings.

Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study

BACKGROUND

Acute meningitis or encephalitis (AME) results from a neurological infection causing high case fatality and severe sequelae. AME lacked comprehensive surveillance in China.

METHODS

Nation-wide surveillance of all-age patients with AME syndromes was conducted in 144 sentinel hospitals of 29 provinces in China. Eleven AME-causative viral and bacterial pathogens were tested with multiple diagnostic methods.

FINDINGS

Between 2009 and 2018, 20,454 AME patients were recruited for tests. Based on 9,079 patients with all-four-virus tested, 28.43% (95% CI: 27.50%‒29.36%) of them had at least one virus-positive detection. Enterovirus was the most frequently determined virus in children <18 years, herpes simplex virus and Japanese encephalitis virus were the most frequently determined in 18-59 and ≥60 years age groups, respectively. Based on 6,802 patients with all-seven-bacteria tested, 4.43% (95% CI: 3.94%‒4.91%) had at least one bacteria-positive detection, Streptococcus pneumoniae and Neisseria meningitidis were the leading bacterium in children aged <5 years and 5-17 years, respectively. Staphylococcus aureus was the most frequently detected in adults aged 18-59 and ≥60 years. The pathogen spectrum also differed statistically significantly between northern and southern China. Joinpoint analysis revealed age-specific positive rates, with enterovirus, herpes simplex virus and mumps virus peaking at 3-6 years old, while Japanese encephalitis virus peaked in the ≥60 years old. As age increased, the positive rate for Streptococcus pneumoniae and Escherichia coli statistically significantly decreased, while for Staphylococcus aureus and Streptococcus suis it increased.

INTERPRETATION

The current findings allow enhanced identification of the predominant AME-related pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures in China, and a possible reassessment of vaccination strategy.

FUNDING

China Mega-Project on Infectious Disease Prevention and the National Natural Science Funds.

Inflammatory Disease Affecting the Central Nervous System in Dogs: A Retrospective Study in England (2010–2019)

The epidemiology of inflammatory diseases affecting the central nervous system (CNS) in dogs is largely unknown. We aimed to report the relative proportion of different causes of inflammatory disease affecting the CNS in dogs and identify predictors for infectious vs. immune-mediated conditions and predictors for the most common diseases affecting the brain and the spinal cord. This was a retrospective cohort study over a 10-year period in 2 referral institutions using multivariable and multinomial logistic regression for identification of risk factors. In total, 1,140 client-owned dogs diagnosed with inflammatory disease affecting the CNS were included. Fifteen different diagnoses were identified, with immune-mediated (83.6%) disease being more common than infectious conditions (16.4%). The most common immune-mediated conditions diagnosed were meningoencephalitis of unknown origin (47.5%) and steroid-responsive meningitis–arteritis (30.7%), and the most common infectious conditions were discospondylitis (9.3%) and otogenic intracranial infection (2.2%). Older age (p < 0.001, OR = 1.019, 95% CI: 1.014–1.024), higher body weight (p < 0.001, OR = 1.049, 95% CI: 1.025–1.074), male sex (p = 0.009, OR = 1.685, 95% CI: 1.141–2.488), longer duration of the clinical signs before presentation (p < 0.001, OR = 1.011, 95% CI: 1.006–1.017), progressive nature of the clinical signs (p < 0.001, OR = 2.295, 95% CI: 1.463–3.599), identification of a possibly associated preceding event (p = 0.0012, OR = 1.93, 95% CI: 1.159–3.213), and hyperesthesia on presentation (p < 0.001, OR = 2.303, 95% CI: 1.528–3.473) were associated with a diagnosis of infectious diseases. Our data shows that immune-mediated diseases are more common than infectious conditions as a cause for inflammatory CNS disease in dogs. The risk factors for the most common diagnoses were identified from signalment, history, and findings of the physical and neurological examinations to give valuable information that can guide clinicians with their investigations.

Changes in Function and Muscle Strength of Encephalitis Survivors After Inpatient Rehabilitation

OBJECTIVE

To investigate the clinical demographics and rehabilitative assessments of encephalitis survivors admitted to a rehabilitation center, and to confirm the effects of inpatient rehabilitation manifested by changes in muscle strength and function after hospitalization.

METHODS

Data of encephalitis survivors who received rehabilitation at our institution from August 2009 to August 2019 were reviewed. Medical charts were retrospectively reviewed, and motor, functional, and cognitive assessments were collected. Manual muscle testing (MMT), Fugl-Meyer Assessment (FMA), Berg Balance Scale (BBS), Functional Ambulation Category (FAC), Korean version of Modified Barthel Index (K-MBI), grip strength, Box and Block Test (BBT), and Korean version of Mini-Mental State Examination (K-MMSE) were performed, and the results upon admission and discharge were compared and analyzed.

RESULTS

Most of the patients with encephalitis admitted to our institution had viral or autoimmune etiologies. The assessment results of 18 encephalitis patients upon admission and discharge were compared. The total K-MBI score, FAC, grip strength, and BBT significantly improved, but not the MMT and FMA. Subgroup analysis was performed for viral and autoimmune encephalitis, which are the main causes of the disease, but there was no difference in items with significant changes before and after hospitalization.

CONCLUSION

Encephalitis survivors showed a significant improvement in functional assessment scale during their hospital stay through rehabilitation, without significant changes in motor strength. Hence, we can conclude that encephalitis survivors benefit from inpatient rehabilitation, targeting functional gains in activities of daily living training more than motor strength.

[A clear cerebrospinal fluid - but an unclear diagnosis]

HISTORY

 A 35-year-old, previously healthy woman presented with short history of headache and fever. Several other family members reported active hand, foot, and mouth disease.

FINDINGS

 Clinical findings showed subfebrile temperatures and a prominent meningism. Cerebrospinal fluid and computed tomography of the head were unrevealing. Subsequent PCR-analysis of the cerebrospinal fluid was positive for Enteroviral-RNA.

DIAGNOSIS AND THERAPY

 Enteroviral-meningitis was diagnosed. The empirically administered antimicrobial therapy was stopped and further diagnostic tests could be withheld.

COURSE

 Symptom-oriented therapy resulted in complete resolution within the next few days.

CONCLUSIONS

 Our case emphasizes that, in patients with typical signs of meningeal irritation, normal cellular analysis of the cerebrospinal fluid does not exclude the presence of infectious meningitis. The astute clinician should be reminded that this constellation is highly suggestive of enteroviral meningitis.

Epidemiological characteristics and cerebrospinal fluid cytokine profiles of enterovirus encephalitis in children in Hangzhou, China

Enteroviruses (EVs) are common causes of viral encephalitis in children. To better understand the epidemiological and pathological characteristics of EV encephalitis, we enrolled suspected encephalitis patients younger than 15 years old in Hangzhou, China, from October 2016 to September 2019 for cerebrospinal fluid (CSF) collection and analyses. A total of 7735 CSF samples were collected, among which 330 (4.27%) were positive for the EV genome. The positivity rate was significantly higher in boys than girls (χ²  =  5.68, p =  0.02). The monthly case numbers peaked from June to August (80.30%). Among the different age groups, the 0-2 months age group showed the highest number of cases (28.48% of all cases). The 6-7 years (10.82%) and 9-10 years (9.29%) age groups showed the highest EV-positivity rates among suspected encephalitis cases. Sixty-two EV-positive and 53 control CSF samples were collected for Bio-Plex Pro human cytokine assays that simultaneously tested 48 cytokines. Principle component analyses showed significant separation between EV-positive and control samples, but insignificant separation between children and newborns. The levels of 28 cytokines and chemokines were significantly elevated in the EV-positive group including many proinflammatory and a few anti-inflammatory cytokines, as well as chemokines belonging to the CC and CXC subfamilies. Only one cytokine, stem cell growth factor-β, showed a decrease in the EV-positive group. Thus, this study revealed age, sex, and seasonal preferences for EV encephalitis incidences in children and identified many cytokines dysregulated during EV encephalitis.

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.

The Most Influential Papers in Infectious Meningitis Research: A Bibliometric Study

Background

Bibliometric analyses allow detecting citation trends within a field, including assessments of the most cited journals, countries, institutions, topics, types of study, and authors.

Objective

The aim of this study was to perform a bibliometric analysis of the 100 most cited papers within infectious meningitis research.

Materials and Methods

The 100 most cited publications and their data were retrieved from Scopus and Web of Science during 2019.

Results

The New England Journal of Medicine had the greatest number of articles (27) and citations (12,266) in the top 100. Articles were mainly published after the late 1980s. Bacteria were the most discussed agents (72 articles and 26,362 citations), but Cryptococcus sp represented the most-discussed single agent (16 articles and 6,617 citations). Primary research represented 70 articles and 25,754 citations. Among them, the most discussed topic was Clinical Features and Diagnosis/Outcomes (22 articles and 8,325 citations). Among the 27 secondary research articles, the most common type of study was Narrative Review (18 articles and 5,685 citations). The United States was the country with the greatest number of articles (56) and citations (21,388). Centers for Disease Control and Prevention (CDC) and Yale University had the greatest number of articles (six each), being CDC the most cited (3,559).

Conclusions

The most cited articles within meningitis research are primary research studies, more frequently published in high IF journals and by North American institutions. Bacterial meningitis comprises the majority of publications. The articles were mainly published after the AIDS pandemic and after the implementation of the main vaccines for meningitis.

Real evidence to assess clinical testing interference risk (REACTIR): A strategy using real world data to assess the prevalence of interfering substances in patients undergoing clinical laboratory testing

INTRODUCTION

Laboratory test interferences can cause spurious test results and patient harm. Knowing the frequency of various interfering substances in patient populations likely to be tested with a particular laboratory assay may inform test development, test utilization and strategies to mitigate interference risk.

METHODS

We developed REACTIR (Real Evidence to Assess Clinical Testing Interference Risk), an approach using real world data to assess the prevalence of various interfering substances in patients tested with a particular type of assay. REACTIR uses administrative real world data to identify and subgroup patient cohorts tested with a particular laboratory test and evaluate interference risk.

RESULTS

We demonstrate the application REACTIR to point of care (POC) blood glucose testing. We found that exposure to several substances with the potential to interfere in POC blood glucose tests, including N-acetyl cysteine (NAC) and high dose vitamin C was uncommon in most patients undergoing POC glucose tests with several key exceptions, such as burn patients receiving high dose IV-vitamin C or acetaminophen overdose patients receiving NAC.

CONCLUSIONS

Findings from REACTIR may support risk mitigation strategies including targeted clinician education and clinical decision support. Likewise, adaptations of REACTIR to premarket assay development may inform optimal assay design and assessment.

Dealing with MDR bacteria and biofilm in the post-antibiotic era: Application of antimicrobial peptides-based nano-formulation

The rapid development of multidrug-resistant (MDR) bacteria due to the improper and overuse of antibiotics and the ineffective performance of antibiotics against the difficult-to-treat biofilm-related infections (BRIs) have urgently called for alternative antimicrobial agents and strategies in combating bacterial infections. Antimicrobial peptides (AMPs), owing to their compelling antimicrobial activity against MDR bacteria and BRIs without causing bacteria resistance, have attracted extensive attention in the research field. With the development of nanomaterial-based drug delivery strategies, AMPs-based nano-formulations have significantly improved the therapeutic effects of AMPs by ameliorating their hydrolytic stability, half-life in vivo, and solubility as well as reducing the cytotoxicity and hemolysis, etc. This review has comprehensively summarized the application AMPs-based nano-formulation in various bacterial infections models, including bloodstream infections (specifically sepsis), pulmonary infections, chronic wound infections, gastrointestinal infections, among others. The design of the nanomaterial-based drug delivery systems and the therapeutic effects of the AMPs-based nano-formulations in literature have been categorized and in details discussed. Overall, this review provides insights into the advantages and disadvantages of the current developed AMPs-based nano-formulations in literature for the treatment of bacterial infections, bringing inspirations and suggestions for their future design in the way towards clinical translation.

Epidemiology of patients with central nervous system infections, mainly neurosurgical patients: a retrospective study from 2012 to 2019 in a teaching hospital in China

BACKGROUND

Central nervous system (CNS) infections are relatively rare but are associated with high mortality worldwide. Empirical antimicrobial therapy is crucial for the survival of patients with CNS infections, and should be based on the knowledge of the pathogen distribution and antibiotic sensitivities. The aim of this study was to investigate the features of pathogens in patients with CNS infections in North China and evaluate the risk factors for mortality and multi-drug-resistant (MDR) bacterial infections.

METHODS

A retrospective study was conducted with patients with positive cerebrospinal fluid (CSF) cultures in a teaching hospital from January 2012 to December 2019. The following data were collected: demographic characteristics, laboratory data, causative organisms and antimicrobial sensitivity results. Data were analyzed with SPSS 16.0. Univariate analysis and binary logistic regression analyses were performed to identify the risk factors for mortality and MDR bacterial infections.

RESULTS

A total of 72 patients were diagnosed with CNS infections, and 86 isolates were identified. The proportions of Gram-positive bacteria, Gram-negative bacteria and fungi were 59.3, 30.2 and 10.5%, respectively. The predominant Gram-positive bacteria was Coagulase-negative Staphylococci. Acinetobacter baumannii, Escherichia coli and Klebsiella spp. were the predominant Gram-negative bacteria. Compared to 2012-2015 years, the proportion of Gram-negative bacteria increased markedly during 2016-2019 years. Coagulase-negative Staphylococci, Streptococcus pneumoniae and Enterococcus faecium had 100% sensitivity to vancomycin, teicoplanin and linezolid. Acinetobacter baumannii and Klebsiella pneumoniae were 100% sensitive to tigecycline. Escherichia coli had 100% sensitivity to amikacin, meropenem and imipenem. The overall mortality rate in the 72 patients was 30.6%. In multivariate analysis, age > 50 years, pulmonary infections and CSF glucose level < the normal value were associated with poor outcomes. CSF adenosine deaminase level > the normal value and the presence of external ventricular drainage/lumbar cistern drainage were associated with MDR bacterial infections.

CONCLUSIONS

The mortality rate due to CNS infections reached 30.6% in our study. The proportion of Gram-negative bacteria has increased markedly in recent years. We should give particular attention to patients with risk factors for mortality and MDR bacterial infections mentioned above.

Distinguishing cytomegalovirus meningoencephalitis from other viral central nervous system infections

BACKGROUND

Hallmarks of cytomegalovirus (CMV) meningoencephalitis include fever, altered mental status, or meningismus with pleocytosis, elevated protein and hypoglycorrhachia on cerebrospinal fluid (CSF) analysis. Magnetic resonance imaging may show ventriculitis, ependymitis or periventricular enhancement. Studies are limited comparing clinical and laboratory characteristics to other viral etiologies.

OBJECTIVES

This multi-center, retrospective cohort analysis reviewed patients with CMV meningitis or encephalitis and compared clinical features, laboratory findings and outcomes to the most common viral causes of meningoencephalitis.

STUDY DESIGN

Patients with encephalitis or aseptic meningitis and detectable genetic material by polymerase chain reaction were identified. Clinical characteristics, laboratory findings and neuroimaging were collected from the electronic medical record. Data analysis was performed comparing CMV to other viral etiologies.

RESULTS

485 patients were evaluated and included cases of CMV (n = 36) which were compared with herpes simplex virus (n = 114), enterovirus (n = 207), varicella zoster virus (n = 41) and West Nile virus (n = 81). Human immunodeficiency virus (HIV) infection was seen more frequently in CMV infection compared with all other viral etiologies. Clinical presentations and CSF findings of other viral etiologies differ compared with CMV. Hypoglycorrhacia occurred more often with CMV compared with other viral pathogens. Outcomes were significantly worse compared with enterovirus, herpes simplex virus and varicella zoster virus but not West Nile virus.

CONCLUSIONS

CMV meningoencephalitis occurs most often in patients with HIV and encephalitis occurs more frequently than meningitis. Clinical and laboratory findings differ compared with other viral etiologies and can support consideration of CMV in the differential diagnosis of patients with meningoencephalitis.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

Encephalitis in Thailand: A Neglected Disease Increasingly Caused by Enterovirus

From 2013 to 2018, the Thai Red Cross Emerging Infectious Disease–Health Science Center (TRC-EID-HS), in collaboration with the Department of Disease Control (DDC) and the Ministry of Public Health (MOPH) Thailand, conducted encephalitis surveillance. A total of 1700 cerebrospinal fluid (CSF) samples from patients with encephalitis were tested by a predesigned multiplex PCR. Diagnosis was made in 318 cases (18.7%), 86 (27%) of which were caused by Epstein–Barr virus (EBV), 55 (17.3%) by enteroviruses (EV), 36 (11.3%) by varicella–zoster virus (VZV), 31 (9.7%) by cytomegalovirus (CMV), 25 (7.8%) by herpes simplex virus type 1 (HSV-1), and 20 (6.3%) by human herpesvirus 6 (HHV-6). Results were compared with 3099 CSF samples from patients with encephalitis collected between 2002 to 2012, which were tested by specific PCR assays. Diagnosis was made in 337 (10.9%) of these cases, and 91 (27%) were CMV, 79 (23.4%) were VZV, 72 (21.4%) were EBV, 39 (11.6%) were EVs, 39 (11.6%) were HSV-1, 33 (9.8%) were HSV-2, and 2 (0.6%) were Dengue virus (DENV). The change in the pattern toward EVs as a major cause of viral encephalitis was unexpected, and a change in viral neurotropism may be responsible.

Volatile Organic Compounds to Identify Infectious (Bacteria/Viruses) Diseases of the Central Nervous System: A Pilot Study

BACKGROUND

Central nervous system (CNS) infectious diseases are common diseases in emergency rooms and neurology departments. CNS pathogen identification methods are time consuming and expensive and have low sensitivity and poor specificity. Some studies have shown that bacteria and viruses can produce specific volatile organic compounds (VOCs). The aim of this study is to find potential biomarkers by VOC analysis of cerebrospinal fluid (CSF) in patients with bacterial and viral meningitis/encephalitis (ME).

METHODS

CSF samples from 16 patients with bacterial ME and 42 patients with viral ME were collected, and solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze the metabolites in the CSF.

RESULTS

There are 2 substances (ethylene oxide and phenol) that were found to be different between the 2 groups. Ethylene oxide was significantly greater in the group of bacterial ME patients than in the viral ME group of patients (p < 0.05). In addition, phenol was remarkably increased in the group of ME patients compared with the bacterial ME patients (p < 0.05).

CONCLUSIONS

Ethylene oxide and phenol may be potential biomarkers to distinguish bacterial ME and viral ME. VOC analysis of CSF may be used as a supporting tool for clinical diagnosis.

Potential Virus Involvement in Alzheimer's Disease: Results from a Phase IIa Trial Evaluating Apovir, an Antiviral Drug Combination

Background:

Accumulating data suggest infectious agents are involved in Alzheimer’s disease (AD). The two primary aims of this trial were to assess safety and efficacy of an antiviral drug combination on AD progression.

Objective:

The trial evaluated whether Apovir, a combination of two antiviral agents, pleconaril (active on enteroviruses) and ribavirin (active on several viruses), could slow AD progression.

Methods:

Sixty-nine patients 60–85 years were treated with Apovir or placebo for 9 months and followed until 12 months after end of treatment. Cognitive tests, safety, biomarkers, drug plasma, and cerebrospinal fluid concentrations were assessed.

Results:

The tolerability of Apovir was compromised as demonstrated by the large drop-out rate and increased frequency and severity of adverse events. The primary endpoint, demonstrating a difference in change from baseline to 9 months between groups in ADAS-cog total score, was not met (p = 0.1809). However, there were observations indicating potential effects on both ADAS-cog and CDR-SB but these effects need to be verified. Also, there was a decrease in cerebrospinal fluid amyloid-β in Apovir at 9 months (p = 0.0330) but no change in placebo.

Conclusion:

This was the first randomized, placebo controlled clinical trial exploring antiviral treatment on AD progression. The trial is considered inconclusive due to the large drop-out rate. New trials are needed to verify if the indications of effect observed can be confirmed and which component(s) in Apovir contributed to such effects. Pleconaril alone may be studied to improve the tolerability and to verify if enterovirus is involved in the disease process.

Anti-Alpha-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor Encephalitis: A Review

Anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis, a rare subtype of autoimmune encephalitis, was first reported by Lai et al. The AMPAR antibodies target against extracellular epitopes of the GluA1 or GluA2 subunits of the receptor. AMPARs are expressed throughout the central nervous system, especially in the hippocampus and other limbic regions. Anti-AMPAR encephalitis was more common in middle-aged women and most patients had an acute or subacute onset. Limbic encephalitis, a classic syndrome of anti-AMPAR encephalitis, was clinically characterized by a subacute disturbance of short-term memory loss, confusion, abnormal behavior and seizure. Magnetic resonance imaging often showed T2/fluid-attenuated inversion-recovery hyperintensities in the bilateral medial temporal lobe. For suspected patients, paired serum and cerebrospinal fluid (CSF) testing with cell-based assay were recommended. CSF specimen was preferred given its higher sensitivity. Most patients with anti-AMPAR encephalitis were complicated with tumors, such as thymoma, small cell lung cancer, breast cancer, and ovarian cancer. First-line treatments included high-dose steroids, intravenous immunoglobulin and plasma exchange. Second-line treatments, including rituximab and cyclophosphamide, can be initiated in patients who were non-reactive to first-line treatment. Most patients with anti-AMPAR encephalitis showed a partial neurologic response to immunotherapy.

Molecular characterisation and epidemiology of enterovirus-associated aseptic meningitis in the Western and Eastern Cape Provinces, South Africa 2018-2019

BACKGROUND

Enteroviruses are amongst the most common causes of aseptic meningitis. Between November 2018 and May 2019, an outbreak of enterovirus-associated aseptic meningitis cases was noted in the Western and Eastern Cape Provinces, South Africa.

OBJECTIVES

To describe the epidemiology and phylogeography of enterovirus infections during an aseptic meningitis outbreak in the Western and Eastern Cape Provinces of South Africa.

METHODS

Cerebrospinal fluid samples from suspected cases were screened using a polymerase chain reaction targeting the 5'UTR. Confirmed enterovirus-associated meningitis samples underwent molecular typing through species-specific VP1/VP2 primers and pan-species VP1 primers.

RESULTS

Between November 2018 and May 2019, 3497 suspected cases of aseptic meningitis were documented in the Western and Eastern Cape Provinces. Median age was 8 years (range 0-61), interquartile range (IQR=4-13 years), 405/735 (55%) male. 742/3497 (21%) cases were laboratory - confirmed enterovirus positive by routine diagnostic PCR targeting the 5'UTR. 128/742 (17%) underwent molecular typing by VP1 gene sequencing. Echovirus 4 (E4) was detected in 102/128 (80%) cases. Echovirus 9 was found in 7%, Coxsackievirus A13 in 3%. 10 genotypes contributed to the remaining 10% of cases. Synonymous mutations were found in most cases, with sporadic amino acid changes in 13 (12.7%) cases.

CONCLUSION

The aseptic meningitis outbreak was associated with echovirus 4. Stool samples are valuable for molecular typing in CSF confirmed EV-associated aseptic meningitis.

Cerebrospinal Fluid Analysis for Viruses by Metagenomic Next-Generation Sequencing in Pediatric Encephalitis: Not Yet Ready for Prime Time?

BACKGROUND

Metagenomic next-generation sequencing offers an unbiased approach to identifying viral pathogens in cerebrospinal fluid of patients with meningoencephalitis of unknown etiology.

METHODS

In an 11-month case series, we investigated the use of cerebrospinal fluid metagenomic next-generation sequencing to diagnose viral infections among pediatric hospitalized patients presenting with encephalitis or meningoencephalitis of unknown etiology. Cerebrospinal fluid from patients with known enterovirus meningitis were included as positive controls. Cerebrospinal fluid from patients with primary intracranial hypertension were included to serve as controls without known infections.

RESULTS

Cerebrospinal fluid metagenomic next-generation sequencing was performed for 37 patients. Among 27 patients with encephalitis or meningoencephalitis, 4 were later diagnosed with viral encephalitis, 6 had non-central nervous system infections with central nervous system manifestations, 6 had no positive diagnostic tests, and 11 were found to have a noninfectious diagnosis. Metagenomic next-generation sequencing identified West Nile virus (WNV) in the cerebrospinal fluid of 1 immunocompromised patient. Among the 4 patients with known enterovirus meningitis, metagenomic next-generation sequencing correctly identified enteroviruses and characterized the viral genotype. No viral sequences were detected in the cerebrospinal fluid of patients with primary intracranial hypertension. Metagenomic next-generation sequencing also identified sequences of nonpathogenic torque Teno virus in cerebrospinal fluid specimens from 13 patients.

CONCLUSIONS

Our results showed viral detection by cerebrospinal fluid metagenomic next-generation sequencing only in 1 immunocompromised patient and did not offer a diagnostic advantage over conventional testing. Viral phylogenetic characterization by metagenomic next-generation sequencing could be used in epidemiologic investigations of some viral pathogens, such as enteroviruses. The finding of torque Teno viruses in cerebrospinal fluid by metagenomic next-generation sequencing is of unknown significance but may merit further exploration for a possible association with noninfectious central nervous system disorders.

Acute bacterial meningitis

Purpose of review

Community-acquired bacterial meningitis is a continually changing disease. This review summarises both dynamic epidemiology and emerging data on pathogenesis. Updated clinical guidelines are discussed, new agents undergoing clinical trials intended to reduce secondary brain damage are presented.

Recent findings

Conjugate vaccines are effective against serotype/serogroup-specific meningitis but vaccine escape variants are rising in prevalence. Meningitis occurs when bacteria evade mucosal and circulating immune responses and invade the brain: directly, or across the blood–brain barrier. Tissue damage is caused when host genetic susceptibility is exploited by bacterial virulence. The classical clinical triad of fever, neck stiffness and headache has poor diagnostic sensitivity, all guidelines reflect the necessity for a low index of suspicion and early Lumbar puncture. Unnecessary cranial imaging causes diagnostic delays. cerebrospinal fluid (CSF) culture and PCR are diagnostic, direct next-generation sequencing of CSF may revolutionise diagnostics. Administration of early antibiotics is essential to improve survival. Dexamethasone partially mitigates central nervous system inflammation in high-income settings. New agents in clinical trials include C5 inhibitors and daptomycin, data are expected in 2025.

Summary

Clinicians must remain vigilant for bacterial meningitis. Constantly changing epidemiology and emerging pathogenesis data are increasing the understanding of meningitis. Prospects for better treatments are forthcoming.

Viral Etiologies of Meningitis in Patients with Presumed Pyogenic Meningitis at University Hospitals in Ethiopia

Introduction

Viral meningitis is common in most resource-limited settings, posing a challenge for the management and prognosis of suspected patients. No study has been done on the detection of either viral or viral-bacterial co-infection among presumed pyogenic meningitis cases in Ethiopia. We, therefore, aimed to determine the distribution of cytomegalovirus (CMV) and human enteroviruses (HEVs) among patients with presumptive pyogenic meningitis at University hospitals in Ethiopia.

Methods

Viral nucleic acid was extracted from 86 repository CSF samples, which were collected from patients presumptively diagnosed with pyogenic meningitis between 2012 and 2013. PCR was done consecutively to investigate the possible viral etiologic agents of meningitis.

Results

HEVs were detected in 11 (12.8%) of the analyzed samples while none of the 86 samples were tested positive for CMV. Viral-bacterial co-infections were found among 4/11 (36.4%) confirmed cases. The majority of the patients (10/11) with HEVs were younger aged ≤ 19 years old.

Conclusions

In this study, the magnitude of HEVs was shown to have a significant role in presumed pyogenic meningitis cases. Therefore, we recommend presumed pyogenic meningitis cases to be inspected for viral etiologies and improve meningeal symptoms interpretations.