Temporal and spatial dynamics of Listeria monocytogenes central nervous system infection in mice

Listeria monocytogenes is a bacterial pathogen that can cause life-threatening central nervous system (CNS) infections. While mechanisms by which L. monocytogenes and other pathogens traffic to the brain have been studied, a quantitative understanding of the underlying dynamics of colonization and replication within the brain is still lacking. In this study, we used barcoded L. monocytogenes to quantify the bottlenecks and dissemination patterns that lead to cerebral infection. Following intravenous (IV) inoculation, multiple independent invasion events seeded all parts of the CNS from the blood, however, only one clone usually became dominant in the brain. Sequential IV inoculations and intracranial inoculations suggested that clones that had a temporal advantage (i.e., seeded the CNS first), rather than a spatial advantage (i.e., invaded a particular brain region), were the main drivers of clonal dominance. In a foodborne model of cerebral infection with immunocompromised mice, rare invasion events instead led to a highly infected yet monoclonal CNS. This restrictive bottleneck likely arose from pathogen transit into the blood, rather than directly from the blood to the brain. Collectively, our findings provide a detailed quantitative understanding of the L. monocytogenes population dynamics that lead to CNS infection and a framework for studying the dynamics of other cerebral infections.

Cerebrospinal fluid metagenomics has greatest added value as a test for Powassan virus among patients in New England with suspected central nervous system infection

Cerebrospinal fluid (CSF) metagenomic next generation sequencing (mNGS) can detect diverse pathogens in patients with central nervous system infection. Due to its high cost and unclear clinical utility, it is typically reserved for patients with unrevealing routine workups. A multi-center retrospective analysis of real-world CSF mNGS was performed involving orders between 2017 and 2022 at a large New England healthcare system. CSF mNGS was performed 64 times with 17 positive results (27 %). In 11/17 positive samples (65 %), the infectious agent had not been previously detected using routine methods. Arboviruses (n = 8) were the most frequently detected agents, particularly Powassan virus (n = 6). Results changed therapy in 3/64 cases (5 %). Positive results were associated with immunodeficiency (p = 0.06), especially anti-B-cell therapy (p = 0.02), and earlier sample collection (p = 0.06). The association with compromised humoral immunity was stronger in the arbovirus and Powassan virus subgroups (p = 0.001), whose constituents were older than the overall cohort and had higher mortality rates.

Nomogram for Predicting Central Nervous System Infection Following Traumatic Brain Injury in the Elderly

OBJECTIVE

This study aims to identify risk factors for central nervous system (CNS) infection in elderly patients hospitalized with traumatic brain injury (TBI) and to develop a reliable predictive tool for assessing the likelihood of CNS infection in this population.

METHOD

We conducted a retrospective study on 742 elderly TBI patients treated at Tangdu Hospital, China. Clinical data was randomly split into training and validation sets (7:3 ratio). By conducting univariate and multivariate logistic regression analysis in the training set, we identified a list of variables to develop a nomogram for predicting the risk of CNS infection. We evaluated the performance of the predictive model in both cohorts respectively, using receiver operating characteristics curves, calibration curves, and decision curve analysis.

RESULTS

Results of the logistic analysis in the training set indicated that surgical intervention (P = 0.007), red blood cell count (P = 0.019), C-reactive protein concentration (P < 0.001), and cerebrospinal fluid leakage (P < 0.001) significantly predicted the occurrence of CNS infection in elderly TBI patients. The model constructed based on these variables had high predictive capability (area under the curve-training = 0.832; area under the curve-validation = 0.824) as well as clinical utility.

CONCLUSIONS

A nomogram constructed based on several key predictors reasonably predicts the risk of CNS infection in elderly TBI patients upon hospital admission. The model of the nanogram may contribute to timely interventions and improve health outcomes among affected individuals.

Characterization and diagnosis spectrum of patients with cerebrospinal fluid pleocytosis

PURPOSE

There is an overlap in the cerebrospinal fluid (CSF) characteristics of patients presenting with different etiologies of CSF pleocytosis. Here, we characterized patients with CSF pleocytosis treated in a large hospital.

METHODS

A retrospective cohort study of 1150 patients with an elevated CSF leukocyte count > 5 cells/µl treated at a university hospital in Germany from January 2015 to December 2017 was performed. Information on clinical presentation, laboratory parameters, diagnosis and outcome was collected. Clinical and laboratory features were tested for their potential to differentiate between bacterial meningitis (BM) and other causes of CSF pleocytosis.

RESULTS

The most common etiologies of CSF pleocytosis were CNS infections (34%: 20% with detected pathogen, 14% without), autoimmune (21%) and neoplastic diseases (16%). CSF cell count was higher in CNS infections with detected pathogen (median 82 cells/µl) compared to autoimmune (11 cells/µl, p = 0.001), neoplastic diseases (19 cells/µl, p = 0.01) and other causes (11 cells/µl, p < 0.001). The CHANCE score was developed to differentiate BM from other causes of CSF pleocytosis: Multivariate regression revealed that CSF cell count > 100 cells/µl, CSF protein > 100 mg/dl, CRP > 5 mg/dl, elevated white blood cell count, abnormal mental status and nuchal rigidity are important indicators. The CHANCE score identified patients with BM with high sensitivity (92.1%) and specificity (90.9%) (derivation cohort: AUC: 0.955, validation cohort: AUC: 0.956).

CONCLUSION

Overall, the most common causes for CSF pleocytosis include infectious, neoplastic or autoimmune CNS diseases in ~ 70% of patients. The CHANCE score could be of help to identify patients with high likelihood of BM and support clinical decision making.

Economic impact of metagenomic next-generation sequencing versus traditional bacterial culture for postoperative central nervous system infections using a decision analysis mode: study protocol for a randomized controlled trial

IMPORTANCE

Diagnosing and treating postoperative central nervous system infections (PCNSIs) remains challenging due to the low detection rate and time-consuming nature of traditional methods for identifying microorganisms in cerebrospinal fluid. Metagenomic next-generation sequencing (mNGS) technology provides a rapid and comprehensive understanding of microbial composition in PCNSIs by swiftly sequencing and analyzing the microbial genome. The current study aimed to assess the economic impact of using mNGS versus traditional bacterial culture-directed PCNSIs diagnosis and therapy in post-neurosurgical patients from Beijing Tiantan Hospital. mNGS is a relatively expensive test item, and whether it has the corresponding health-economic significance in the clinical application of diagnosing intracranial infection has not been studied clearly. Therefore, the investigators hope to explore the clinical application value of mNGS detection in PCNSIs after neurosurgery.

Pathogen quantitative efficacy of different spike-in internal controls and clinical application in central nervous system infection with metagenomic sequencing

IMPORTANCE

Metagenomic next-generation sequencing (mNGS) has been used broadly for pathogens detection of infectious diseases. However, there is a lack of method for the absolute quantitation of pathogens by mNGS. We compared the quantitative efficiency of three mNGS internal controls (ICs) Thermus thermophilus, T1 phages, and artificial DNA sequence and developed the most applicable strategies for pathogen quantitation via mNGS in central nervous system infection. The IC application strategy we developed will enable mNGS analysis to assess the pathogen load simultaneously with the detection of pathogens, which should provide critical information for quick decision-making of treatment as well as clinical prognosis.

Potential infection foci in the oral cavity and their impact on the formation of central nervous system abscesses: A literature review

Despite advancements in preventive, diagnostic, and therapeutic activities in medicine, inflammatory processes of the central nervous system remain a significant problem, posing a serious threat to life and health. Purulent central nervous system infections are unique, including abscesses of the brain and spine, which are severe infections occurring in 0.4% to 0.9% of 1000 patients worldwide. Central nervous system abscesses have varying etiology. For example, organized, encapsulated abscesses of the brain are a unique group of inflammatory processes in the central nervous system caused by inflammation around the teeth in 3% to 10% of cases. Sometimes, the condition of patients with brain abscesses is severe and life-threatening. Therefore, detecting and eliminating all causes early, including those potentially resulting from odontogenic infections, is important; accurate and early diagnosis enables appropriate treatment. This paper presents a review of the information available in the literature on brain abscesses and their relationship with odontogenic foci of infection in the oral cavity.

Enteroviral central nervous system infections in patients with Lyme neuroborreliosis

Patients with Lyme neuroborreliosis (LNB) are rarely tested for the presence of neurovirulent viruses other than tick-borne encephalitis virus (TBEV); however, such coinfections could be of clinical importance. The aim of the study was to search for the presence of neurotropic viruses in a LNB patients. Fourteen patients admitted with signs and symptoms of neuroinfection who were eventually diagnosed to have LNB (according to the guidelines of the European Federation of Neurological Societies) were subjects of the study. Sera and cerebrospinal fluid (CSF) collected at the time of initial presentation were tested for viral pathogens most common in our geographical area: human enteroviruses (EV), herpes simplex virus type 1 and 2, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, human herpesvirus type 6, human adenoviruses, and TBEV using PCR/RT-PCR and serological assays. RNA and DNA-based metagenomic next-generation sequencing (mNGS) was used to detect other viral pathogens. EV was detected in CSF from two (14 %) LNB patients and viral loads were similar (220 and 270 copies/ml). The mMGS analysis were performed on CSFs from 10 patients and generated a total 213,750,885 NGS reads, 0.05 % of which were viral. However, none of potential pathogens fulfilled the criteria for positive viral detection by mNGS. Using a number of PCR/RT-PCR assays and mNGS we identified EV infection in two out of 14 LNB patients. The possible co-occurrence of enterovirus and Lyme neuroborreliosis infections may warrant further research.

mAb therapy controls CNS-resident lyssavirus infection via a CD4 T cell-dependent mechanism

Infections with rabies virus (RABV) and related lyssaviruses are uniformly fatal once virus accesses the central nervous system (CNS) and causes disease signs. Current immunotherapies are thus focused on the early, pre-symptomatic stage of disease, with the goal of peripheral neutralization of virus to prevent CNS infection. Here, we evaluated the therapeutic efficacy of F11, an anti-lyssavirus human monoclonal antibody (mAb), on established lyssavirus infections. We show that a single dose of F11 limits viral load in the brain and reverses disease signs following infection with a lethal dose of lyssavirus, even when administered after initiation of robust virus replication in the CNS. Importantly, we found that F11-dependent neutralization is not sufficient to protect animals from mortality, and a CD4 T cell-dependent adaptive immune response is required for successful control of infection. F11 significantly changes the spectrum of leukocyte populations in the brain, and the FcRγ-binding function of F11 contributes to therapeutic efficacy. Thus, mAb therapy can drive potent neutralization-independent T cell-mediated effects, even against an established CNS infection by a lethal neurotropic virus.

Metagenomic search of viral coinfections in herpes simplex encephalitis patients

Little is known about concomitant central nervous system (CNS) infections by more than one virus. Current diagnostics are based on molecular tests for particular pathogens making it difficult to identify multi-viral infections. In the present study, we applied DNA- and RNA-based next-generation sequencing metagenomics (mNGS) to detect viruses in cerebrospinal fluids from 20 patients with herpes simplex encephalitis. Coinfection was detected in one patient: sequences in cerebrospinal fluids matched enterovirus A (2.660 reads; 4% of recovered genome) and enterovirus B (1.571 reads; 13% of recovered genome). Subsequent PCR combined with serotyping allowed to identify human echovirus 6, a representative of enterovirus B. Several other mNGS hits (human pegivirus, Merkel cell polyomavirus, human papillomavirus type 5) were not considered to represent a genuine signal as they could not be confirmed by specific RT-PCR/PCR. HSV DNA, while being detectable by PCR in every patient, was detected by mNGS in only one. In conclusion, contaminations and false signals may complicate mNGS interpretation; however, the method can be useful in diagnostics of viral coinfections in CNS, particularly in the case of rare pathogens.

Metabolic response to CNS infection with flaviviruses

Flaviviruses are arthropod-borne RNA viruses found worldwide that, when introduced into the human body, cause diseases, including neuroinfections, that can lead to serious metabolic consequences and even death. Some of the diseases caused by flaviviruses occur continuously in certain regions, while others occur intermittently or sporadically, causing epidemics. Some of the most common flaviviruses are West Nile virus, dengue virus, tick-borne encephalitis virus, Zika virus and Japanese encephalitis virus. Since all the above-mentioned viruses are capable of penetrating the blood-brain barrier through different mechanisms, their actions also affect the central nervous system (CNS). Like other viruses, flaviviruses, after entering the human body, contribute to redox imbalance and, consequently, to oxidative stress, which promotes inflammation in skin cells, in the blood and in CNS. This review focuses on discussing the effects of oxidative stress and inflammation resulting from pathogen invasion on the metabolic antiviral response of the host, and the ability of viruses to evade the consequences of metabolic changes or exploit them for increased replication and further progression of infection, which affects the development of sequelae and difficulties in therapy.

Case report: A toxoplasmic encephalitis in an immunocompromised child detected through metagenomic next-generation sequencing

There exist numerous pathogens that are capable of causing infections within the central nervous system (CNS); however, conventional detection and analysis methods prove to be challenging. Clinical diagnosis of CNS infections often depends on clinical characteristics, cerebrospinal fluid (CSF) analysis, imaging, and molecular detection assays. Unfortunately, these methods can be both insensitive and time consuming, which can lead to missed diagnoses and catastrophic outcomes, especially in the case of infrequent diseases. Despite the application of appropriate prophylactic regimens and evidence-based antimicrobial agents, CNS infections continue to result in significant morbidity and mortality in hospital settings. Metagenomic next-generation sequencing (mNGS) is a novel tool that enables the identification of thousands of pathogens in a target-independent manner in a single run. The role of this innovative detection method in clinical pathogen diagnostics has matured over time. In this particular research, clinicians employed mNGS to investigate a suspected CNS infection in a child with leukemia, and unexpectedly detected Toxoplasma gondii.

Case

A 3-year-old child diagnosed with T-cell lymphoblastic lymphoma was admitted to our hospital due to a 2-day history of fever and headache, along with 1 day of altered consciousness. Upon admission, the patient's Glasgow Coma Scale score was 14. Brain magnetic resonance imaging revealed multiple abnormal signals. Due to the patient's atypical clinical symptoms and laboratory test results, determining the etiology and treatment plan was difficulty.Subsequently, the patient underwent next-generation sequencing examination of cerebrospinal fluid. The following day, the results indicated the presence of Toxoplasma gondii. The patient received treatment with a combination of sulfamethoxazole (SMZ) and azithromycin. After approximately 7 days, the patient's symptoms significantly improved, and they were discharged from the hospital with oral medication to continue at home. A follow-up polymerase chain reaction (PCR) testing after about 6 weeks revealed the absence of Toxoplasma.

Conclusion

This case highlights the potential of mNGS as an effective method for detecting toxoplasmic encephalitis (TE). Since mNGS can identify thousands of pathogens in a single run, it may be a promising detection method for investigating the causative pathogens of central nervous system infections with atypical features.

Prevalence of dementia and its association with central nervous system infections among older persons in northern Uganda: cross-sectional community-based study

BACKGROUND

Dementia is a condition in which there is deterioration in cognitive function beyond what might be expected from the usual consequence of biological aging. Few studies have been conducted on the prevalence of dementia and its association with central nervous system (CNS) infections among older persons in African settings, particularly in Uganda. Therefore, this study assessed the prevalence of dementia and its association with CNS infections among older persons in Lira District, northern Uganda.

METHODS

This was a cross-sectional community-based study in Lira district northern Uganda. The study was conducted in March 2022 among 434 older persons aged 50 and above years who were selected by multistage sampling. Data were collected using an interviewer-administered questionnaire supplemented with information from participant's medical records and a brief community screening instrument for dementia. The instrument classifies dementia into unlikely, probable or possible dementia. Data were entered in duplicate into EpiData version 3.0, then transferred to Statistical Package for Social Sciences (SPSS) version 23 for statistical analysis.

RESULTS

Our study found almost one in four (23%) of the older persons in Lira district northern Uganda were suffering from probable or possible dementia. Our study further found that older persons in Lira district northern Uganda with a positive history of central nervous system infections (CNS) had nearly five times higher odds of having probable or possible dementia compared to their counterparts (cOR: 4.5; 2.76-7.23; p ≤ 0.001). Being in advanced age of 70 + years (aOR: 2.6; 1.6-4.3; p ≤ 0.001), positive history of CNS infection particularly Herpes simplex virus-1 (aOR: 5.4; 1.4-20.5; p = 0.013), and chronic headache (aOR: 1.9; 1.1-3.1; p = 0.019) were independent predictors of probable or possible dementia among participants in this study.

CONCLUSION AND RECOMMENDATIONS

Dementia is a common condition among older persons in Lira district northern Uganda with a prevalence of 23% in our study. Older persons with a positive history of CNS infection had higher odd of developing dementia compared to their counterparts. Having advanced age, cerebral malaria, Herpes simplex virus - 1 (HSV-1) infections, and chronic headache were independent predictors for dementia. These results imply that health assessment for the risk of dementia should include screening for history of CNS conditions particularly cerebral malaria, HSV-1 and chronic headache.

Meningeal regulation of infections: A double-edged sword

In the past 10 years, important discoveries have been made in the field of neuroimmunology, especially regarding brain borders. Indeed, meninges are protective envelopes surrounding the CNS and are currently in the spotlight, with multiple studies showing their involvement in brain infection and cognitive disorders. In this review, we describe the meningeal layers and their protective role in the CNS against bacterial, viral, fungal, and parasitic infections, by immune and nonimmune cells. Moreover, we discuss the neurological and cognitive consequences resulting from meningeal infections in neonates (e.g. infection with group B Streptococcus, cytomegalovirus, …) or adults (e.g. infection with Trypanosoma brucei, Streptococcus pneumoniae, …). We hope that this review will bring to light an integrated view of meningeal immune regulations during CNS infections and their neurological consequences.

Parental Attitudes About Lumbar Puncture in Children With Suspected Central Nervous System Infection

OBJECTIVES

This study aimed to evaluate parents' attitudes toward lumbar puncture (LP) for their children with suspected central nervous system infection to determine the reasons for rejection and related factors.

METHODS

The survey was provided to parents of children (1 month to 18 years old) for whom LP was recommended because of a concern for central nervous system infection. Sociodemographic characteristics and other related factors of parents who did and did not approve of LP were compared statistically. The reasons for the disapproval of parents who refused LP were revealed.

RESULTS

A total of 100 parents were included in the study. Eighty-two percent of the participating parents were mothers, and the median age of the mothers was 31 years (min: 17 years; max: 70 years). The median age of the fathers was 37 years (min: 22 years; max: 60 years). Among the parents, 34% did not give consent for LP. The most common reason for the participants to refuse LP was fear of paralysis of their children due to the procedure (82.3%). There was a statistical difference between the approval of the LP procedure and the person who informed the parents about the LP procedure and read the informed consent form ( P = 0.004 and P = 0.038, respectively).As a result of the binary logistic regression analysis, it was seen that the rate of acceptance of the LP procedure by the parents informed by the specialist doctors was 7.1-fold ( P = 0.02; 95% confidence interval, 1.3-37.6) higher than the parents informed by the resident physicians.

CONCLUSION

The informed consent process mainly influenced parents' attitudes toward LP. To increase the acceptance rates of LP, we should standardize the informed consent process so that it is not affected by factors such as seniority of the physician.

Analysis of tigecycline in the cerebrospinal fluid and serum of patients with Acinetobacter baumannii central nervous system infection

Aim: This study aimed to establish a method to determine tigecycline (TGC) in the cerebrospinal fluid (CSF) and serum of 12 patients with multidrug-resistant Acinetobacter baumannii (MDRAB) central nervous system infection (CNSI) and evaluate the correlation of TGC in CSF and serum samples. Materials & methods: TGC in CSF and serum was detected by high-performance liquid chromatography with tandem mass spectrometry. Results: In all 12 patients, the CSF-to-serum ratio of TGC at a steady-state trough concentration ranged from 21.46 to 44.46%, and the mean value was 31.61 ± 8.13%. The correlation of TGC in CSF and serum was 0.5065. Conclusion: CNSI might have no potential to increase the penetration ability of TGC into the CSF. The correlation between the concentrations of TGC in CSF and serum at steady state was demonstrated to be positive.

The role of STING signaling in central nervous system infection and neuroinflammatory disease

The cyclic guanosine monophosphate-adenosine monophosphate (GMP-AMP) synthase-Stimulator of Interferon Genes (cGAS-STING) pathway is a critical innate immune mechanism for detecting the presence of double-stranded DNA (dsDNA) and prompting a robust immune response. Canonical cGAS-STING activation occurs when cGAS, a predominantly cytosolic pattern recognition receptor, binds microbial DNA to promote STING activation. Upon STING activation, transcription factors enter the nucleus to cause the production of Type I interferons, inflammatory cytokines whose primary function is to prime the host for viral infection by producing a number of antiviral interferon-stimulated genes. While the pathway was originally described in viral infection, more recent studies have implicated cGAS-STING signaling in a number of different contexts, including autoimmune disease, cancer, injury, and neuroinflammatory disease. This review focuses on how our understanding of the cGAS-STING pathway has evolved over time with an emphasis on the role of STING-mediated neuroinflammation and infection in the nervous system. We discuss recent findings on how STING signaling contributes to the pathology of pain, traumatic brain injury, and stroke, as well as how mitochondrial DNA may promote STING activation in common neurodegenerative diseases. We conclude by commenting on the current knowledge gaps that should be filled before STING can be an effective therapeutic target in neuroinflammatory disease. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology Infectious Diseases > Molecular and Cellular Physiology Immune System Diseases > Molecular and Cellular Physiology.

CSF-contacting neurons respond to Streptococcus pneumoniae and promote host survival during central nervous system infection

The pathogenic bacterium Streptococcus pneumoniae (S. pneumoniae) can invade the cerebrospinal fluid (CSF) and cause meningitis with devastating consequences. Whether and how sensory cells in the central nervous system (CNS) become activated during bacterial infection, as recently reported for the peripheral nervous system, is not known. We find that CSF infection by S. pneumoniae in larval zebrafish leads to changes in posture and behavior that are reminiscent of pneumococcal meningitis, including dorsal arching and epileptic-like seizures. We show that during infection, invasion of the CSF by S. pneumoniae massively activates in vivo sensory neurons contacting the CSF, referred to as "CSF-cNs" and previously shown to detect spinal curvature and to control posture, locomotion, and spine morphogenesis. We find that CSF-cNs express orphan bitter taste receptors and respond in vitro to bacterial supernatant and metabolites via massive calcium transients, similar to the ones observed in vivo during infection. Upon infection, CSF-cNs also upregulate the expression of numerous cytokines and complement components involved in innate immunity. Accordingly, we demonstrate, using cell-specific ablation and blockade of neurotransmission, that CSF-cN neurosecretion enhances survival of the host during S. pneumoniae infection. Finally, we show that CSF-cNs respond to various pathogenic bacteria causing meningitis in humans, as well as to the supernatant of cells infected by a neurotropic virus. Altogether, our work uncovers that central sensory neurons in the spinal cord, previously involved in postural control and morphogenesis, contribute as well to host survival by responding to the invasion of the CSF by pathogenic bacteria during meningitis.

Pentraxin 3 in the cerebrospinal fluid during central nervous system infections: A retrospective cohort study

The present study describes diagnostic and prognostic abilities of Cerebrospinal fluid (CSF) Pentraxin 3 (PTX3) in central nervous system (CNS) infections. CSF PTX3 was measured retrospectively from 174 patients admitted under suspicion of CNS infection. Medians, ROC curves and Youdens index was calculated. CSF PTX3 was significantly higher among all CNS infections and undetectable in most of the patients in the control group, and significantly higher in bacterial infections compared to viral and Lyme infections. No association was found between CSF PTX3 and Glasgow Outcome Score. PTX3 in the CSF can distinguish bacterial infection from viral and Lyme infections and non-CNS infections. Highest levels were found in bacterial meningitis. No prognostic abilities were found.

Aetiology and Potential Animal Exposure in Central Nervous System Infections in Vietnam

An estimated 73% of emerging infections are zoonotic in origin, with animal contact and encroachment on their habitats increasing the risk of spill-over events. In Vietnam, close exposure to a wide range of animals and animal products can lead to acquisition of zoonotic pathogens, a number of which cause central nervous system (CNS) infections. However, studies show the aetiology of CNS infections remains unknown in around half of cases. We used samples and data from hospitalised patients with CNS infections, enrolled into the Vietnam Initiative on Zoonotic Infections multicentre study, to determine the association between aetiology and animal contact including those in whom the cause was unknown. Among 933 patients, a pathogen or an antibody response to it was identified in 291 (31.2%, 95% CI 28.3-34.3%). The most common pathogens were Streptococcus suis (n = 91 (9.8%, 8.0-11.9%)) and Japanese encephalitis virus (JEV) (n = 72 (7.7%, 6.1-9.7%)). Commonly reported animal contact included keeping, raising or handling (n = 364 (39.0%, 35.9-42.2%)) and handling, cooking or consuming raw meat, blood or viscera in the 2 weeks prior to symptom onset (n = 371 (39.8%, 36.6-43.0%)), with the latter most commonly from pigs (n = 343 (36.9%, 33.8-40.1%). There was no association between an unknown aetiology and exposure to animals in a multivariate logistic regression. Further testing for unknown or undetected pathogens may increase diagnostic yield, however, given the high proportion of zoonotic pathogens and the presence of risk factors, increasing public awareness about zoonoses and preventive measures can be considered.

Comparisons in the changes of clinical characteristics and cerebrospinal fluid cytokine profiles between varicella-zoster virus meningitis/encephalitis and other central nervous system infections

OBJECTIVES

Varicella-zoster virus (VZV) is one of the most common etiologies of viral meningitis/encephalitis. The early clinical manifestations and cerebrospinal fluid (CSF) changes of VZV meningitis/encephalitis lack specificity, and it is easy to be misdiagnosed as other viral encephalitides or tuberculous meningitis. This study aims to investigate whether the clinical characteristics, CSF analysis findings, and CSF cytokine levels could distinguish VZV meningitis/encephalitis from central nervous system (CNS) herpes simplex virus (HSV) and Mycobacterium tuberculosis (MTB) infections.

METHODS

The medical records from 157 CNS infections, including 49 HSV (45 HSV-1, 4 HSV-2), 55 VZV, and 53 MTB infections between January 2018 and June 2021 in the Cytology Laboratory, Department of Neurology, Third Xiangya Hospital of Central South University were retrospectively reviewed. The data of 3 groups included demographic characteristics, laboratory results, radiographic findings, and outcomes. The levels of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, IFN-γ, IFN-α, and TNF-α) in the CSF of 68 patients (13 HSV, 22 VZV, and 33 MTB infection cases) were quantified. Clinical and laboratory data were compared among the 3 groups.

RESULTS

The most common clinical manifestations in the 3 groups were fever, headache, vomiting, and neck stiffness. The clinical manifestations of HSV and VZV CNS disease were similar, although fever and altered consciousness were less common in the VZV group than those in the HSV and MTB groups (63.6% vs 87.8% vs 96.2%, P<0.001, and 14.5% vs 26.5% vs 47.2%, P=0.004, respectively). Seven patients (7/55, 12.7%) presented cutaneous zoster in the VZV group. CSF leukocyte count was significantly higher in the VZV group (230×106 cells/mL) and MTB groups (276×106 cells/mL) than that in the HSV group (87×106 cells/mL, P=0.002). CSF protein level was significantly higher in the VZV than that in the HSV group (1 034 mg/L vs 694 mg/L, P=0.011) but lower than that in the MTB group (1 744 mg/L, P<0.001). IL-6 (VZV vs HSV vs MTB: 2 855.93 pg/mL vs 2 128.26 pg/mL vs 354.77 pg/mL, P=0.029) and IL-8 (VZV vs HSV vs MTB: 4 001.46 pg/mL vs 1 578.11 pg/mL vs 1 023.25 pg/mL, P=0.046) levels were significantly different among the 3 groups and were elevated in the VZV group.Post hoc analysis revealed that IL-6 and IL-8 were significantly higher in the VZV group than those in the MTB group (P=0.002 and P=0.035, respectively), but not in the HSV group (P>0.05).

CONCLUSIONS

VZV meningitis/encephalitis presents with CSF hypercellularity and proteinemia, challenging the classical view of CSF profiles in viral encephalitis. CSF IL-6 and IL-8 levels are elevated in patients with VZV meningitis/encephalitis, indicating a more intense inflammatory response in these patients.

Risk factors for hospitalization at the pediatric intensive care unit among infants and children younger than 5 years of age diagnosed with infectious diseases

BACKGROUND

Children hospitalized with infectious diseases may develop severe, life-threatening conditions, often requiring admission to pediatric intensive care unit (PICU). The objectives of this study were to identify independent risk factors for PICU hospitalization with an infectious disease in children <5 years of age.

METHODS

In southern Israel, two populations live side by side: the middle-high income Jewish population and the low-income Bedouin population, both receiving equal and free medical care at the only tertiary medical center in the area. The study population included all children born in southern Israel and hospitalized at PICU with an infectious disease during 1991-2012. Risk factors for PICU hospitalizations were retrospectively studied by Kaplan-Meier and Cox proportional hazard survival analyses.

RESULTS

9951 Jewish children and 18,002 Bedouin children were enrolled; overall, 1135 episodes of PICU hospitalizations with an infectious disease were recorded (879, 77.4% Bedouin and 256, 22.6% Jewish patients). Bedouin children had a higher risk for PICU hospitalization with an infectious disease compared with Jewish children (adjusted Hazard Ratio [adj. HR] 1.7, 95% CI 1.5-2.0); maternal multiparity and low-birth weight (<2500 g) were additional risk factors for PICU hospitalization with an infectious disease compared to firstborns (adj. HR = 1.2, 95% CI 1.0-1.5) or to children with a birth weight ≥2500 g (adj. HR = 1.5, 95% 1.2-1.9). Older age was a protective factor for PICU hospitalization (adj. HR = 0.98, 95% CI 0.97-0.99). Children hospitalized with a central nervous system infection had the highest risk of PICU hospitalization (adj. HR 6.8, 95% CI 5.5-8.4), followed by those with urinary tract infections (UTI, adj. HR 3.1, 95% CI 2.5-3.8) and those with lower respiratory tract infections (LRTI, adj. HR 2.9, 95% CI 2.4-3.4).

CONCLUSION

Bedouin ethnicity, low birth weight, maternal multiparity and younger age were significant risk factors for PICU hospitalizations with an infectious disease. Among the infectious diseases analyzed, CNS infection had the highest risk for PICU hospitalization, followed by UTI and LRTI.

[Meningitis, Encephalitis, and Myelitis]

Infections of the central nervous system such as meningitis, encephalitis, and myelitis are a life-threatening neurological emergences. Early recognition, efficient decision-making, and rapid initiation of therapy can be lifesaving. Adequate clinical management of central nervous system infections is important for neurosurgeons during neurological emergences. This article describes recent trends in central nervous system infections and the pitfalls faced by neurosurgeons.

Analysis of Coxsackievirus B5 Infections in the Central Nervous System in Brazil: Insights into Molecular Epidemiology and Genetic Diversity

Coxsackievirus B5 (CVB5) is one of the most prevalent enteroviruses types in humans and causes annual epidemics worldwide. In the present study, we explored viral genetic diversity, molecular and epidemiological aspects of CVB5 obtained from cerebrospinal fluid and stool samples of patients with aseptic meningitis or acute flaccid paralysis, information that is still scarce in Brazil. From 2005 to 2018, 57 isolates of CVB5 were identified in the scope of the Brazilian Poliomyelitis Surveillance Program. Phylogenetic analyses of VP1 sequences revealed the circulation of two CVB5 genogroups, with genogroup B circulating until 2017, further replaced by genogroup A. Network analysis based on deduced amino acid sequences showed important substitutions in residues known to play critical roles in viral host tropism, cell entry, and viral antigenicity. Amino acid substitutions were investigated by the Protein Variation Effect Analyzer (PROVEAN) tool, which revealed two deleterious substitutions: T130N and T130A. To the best of our knowledge, this is the first report to use in silico approaches to determine the putative impact of amino acid substitutions on the CVB5 capsid structure. This work provides valuable information on CVB5 diversity associated with central nervous system (CNS) infections, highlighting the importance of evaluating the biological impact of certain amino acids substitutions associated with epidemiological and structural analyses.

[Pathogenic spectrum and laboratory indicators of fungal infections in the central nervous system]

Central nervous system (CNS) fungal infections are challenging and difficult to diagnose and treat. This article introduces the high risk factors, pathogen spectrum and laboratory indicators that cause CNS fungal infection. As patients with CNS fungal infections are often accompanied by immunodeficiency, it is especially necessary for clinical early detection, early prevention, and early diagnosis, and timely and effective implementation of optimized diagnosis and treatment programs to prevent further deterioration of the disease.

Metagenomic Next-Generation Sequencing vs. Traditional Microbiological Tests for Diagnosing Varicella-Zoster Virus Central Nervous System Infection

Background

Unbiased metagenomic next-generation sequencing (mNGS) detects pathogens in a target-independent manner. It is not well-understood whether mNGS has comparable sensitivity to target-dependent nucleic acid test for pathogen identification.

Methods

This study included 31 patients with chickenpox and neurological symptoms for screening of possible varicella-zoster virus (VZV) central nervous system (CNS) infection. Microbiological diagnosing of VZV cerebrospinal fluid (CSF) infection was performed on stored CSF samples using mNGS, quantitative and qualitative VZV-specific PCR assays, and VZV IgM antibodies test.

Results

The median age was 30.0 [interquartile range (IQR), 24.3–33.3] years. 51.6% of the patients were men. About 80.6% of the patients had normal CSF white blood cell counts (≤ 5 × 10⁶/L). VZV IgM antibodies presented in 16.1% of the CSF samples, and nucleic acids were detectable in 16.1 and 9.7% using two different VZV-specific real-time PCR protocols. Intriguingly, maximal identification of VZV elements was achieved by CSF mNGS (p = 0.001 and p = 007; compared with qualitative PCR and VZV IgM antibody test, respectively), with sequence reads of VZV being reported in 51.6% (16/31) of the CSF samples. All VZV PCR positive samples were positive when analyzed by mNGS. Of note, human betaherpesvirus 6A with clinical significance was unexpectedly detected in one CSF sample.

Conclusions

Our study suggests that CSF mNGS may have higher sensitivity for VZV detection than CSF VZV PCR and antibody tests, and has the advantage of identifying unexpected pathogens.

Recurrent Aseptic Meningitis Associated with Kikuchi's Disease (Histiocytic Necrotizing Lymphadenitis): A Case Report and Literature Review

We herein report a 31-year-old man with recurrent aseptic meningitis associated with Kikuchi's disease. Although aseptic meningitis is the most common neurological complication of Kikuchi's disease, its characteristics remain unclear, especially in recurrent cases. A literature review revealed that aseptic meningitis associated with Kikuchi's disease was more likely to occur in men and was associated with a low cerebrospinal fluid (CSF)/serum glucose ratio. Lymphadenopathy tended to occur simultaneously or after the onset of meningitis. When encountering a patient with aseptic meningitis of unknown etiology, it may be worthwhile to focus on the CSF/serum glucose ratio and lymphadenopathy with a careful examination.

Central Nervous System Infections in Immunocompromised Patients

PURPOSE OF REVIEW

This article reviews current epidemiologic trends, clinical presentations, and diagnostic strategies for central nervous system (CNS) infections in human immunodeficiency virus-negative (HIV) patients immunocompromised by their underlying disease or by receipt of immunosuppressive or immunomodulating therapies. Three patient groups are considered: (1) cancer patients; (2) hematopoietic or solid organ transplantation recipients; and (3) patients with autoimmune or inflammatory conditions requiring therapies that alter the host immune response.

RECENT FINDINGS

Clinical presentations, associated neuroimaging, and cerebrospinal fluid (CSF) abnormalities differ between immunocompromised and immunocompetent patients. Infections can trigger the emergence of neurotropic antibodies or inflammatory conditions due to treatment with cancer immunotherapies. Unbiased metagenomic assays to identify obscure pathogens help clinicians navigate the increasing range of conditions affecting the growing population of patients with altered immunity. Awareness of clinical presentations and disease and drug-specific risks is important for early diagnosis and intervention in these often life-threatening infections and their noninfectious mimes.

Bibliometric analysis of bacterial central nervous system infection research in Southeast Asia

BACKGROUND

The status of research and scientific outputs with regards to bacterial central nervous system (CNS) infection in southeast Asia (SEA) is unknown. This study aimed to analyze and compare bacterial CNS infection research output of SEA countries in terms of bibliometric indices.

METHODS

The major electronic databases (MEDLINE, Scopus, Embase, CENTRAL, Clinicaltrials.gov and WPRIM) were searched for studies on bacterial CNS infection in SEA until August 31, 2020. Frequencies, percentages and Spearman's rho correlations were used.

RESULTS

There was a total of 648 unique studies on bacterial CNS infection in SEA and it was 657 when double-counted (collaborative studies between SEA countries). Thailand (n=148, 22.5%) and Vietnam (n=142, 21.6%) had the highest number of publications. The most common type of research publication was the case report / case series (n=160, 24.7%). Tuberculous meningitis/tuberculoma (n=176, 26.7%) was the most common topic. This study showed that the %GDP for research and development (R&D) was associated with a higher number of research output. However, the GDP per capita was not associated with any of the bibliometric indices. The total number of neurologists was associated with all of the bibliometric analysis.

CONCLUSION

Bacterial CNS infection research output in SEA countries was low in terms of quantity. The %GDP for R&D was associated with the number of research publications. The total number of neurologists was associated with all of the bibliometric indices.

CNS infection with a history of recurrent epistaxis: Streptococcal meningitis as a first presentation of juvenile nasopharyngeal angiofibroma

An adolescent male with a history of recurrent epistaxis presented with headache and vomiting. Investigations revealed concurrent meningitis as well as the presence of a subarachnoid haemorrhage. Subsequent imaging identified a Juvenile Nasopharyngeal Angiofibroma; a rare but important cause of meningitis that should be considered in the young adult population.

Neurologic Complications in Patients With Cancer

PURPOSE OF REVIEW

Neurologic complications in patients with cancer can significantly impact morbidity and mortality. Although these complications can be seen in patients without cancer as well, the purpose of this review is to highlight how the presentation, etiology, and management of delirium, seizures, cerebrovascular disease, and central nervous system infections may be different in patients with cancer.

RECENT FINDINGS

Some of the newer anticancer therapies are associated with neurologic complications. Delirium and seizures have been described in patients receiving chimeric antigen receptor (CAR) T-cell therapy and other immune effector cell therapies. Angiogenesis inhibitors can increase the risk of bleeding and clotting, including intracranial hemorrhage and stroke. The risk of opportunistic fungal infections, including aspergillosis, is elevated with the Bruton tyrosine kinase inhibitor ibrutinib.

SUMMARY

Providers should familiarize themselves with neurologic complications in patients with cancer because early diagnosis and intervention can improve outcomes. The differential diagnosis should be broad, including conventional causes as seen in patients who do not have cancer, with special consideration of etiologies specific to patients with cancer.

Outcomes measures in children after acute central nervous system infections and malaria

PURPOSE OF REVIEW

Acute central nervous system (CNS) infections in children result in significant mortality and neurologic morbidity worldwide. This article summarizes the recent pediatric literature published on outcomes measures used after acute infectious meningitis, encephalitis, and cerebral malaria, and highlights ongoing research efforts to standardize outcomes measurements. Search terms were geared toward functional, cognitive, behavioral, and other outcome assessments.

RECENT FINDINGS

Recent data suggest that, depending on microbiological cause, there are differences in currently used outcome measures following acute CNS infections. Outcomes assessments include a variety of formal psychological tests (structured interviews and neuropsychological tests of cognitive and motor functioning) and dichotomized or ordinal scales. Standardization of outcome measures, however, is lacking. Global efforts to standardize outcomes that encompass both the child and family are ongoing.

SUMMARY

Centers worldwide can track and measure a variety of cognitive, behavioral, and functional outcomes after acute CNS infections. Standardized documentation and coding of clinically important outcomes is needed. Further research to evaluate effective practices using acute adjunctive and rehabilitation therapies will be aided by outcome measure standardization.

[The neurologic diseases]

Neurologic diseases have important social and economic repercussions. The economic cost related to medications, caretakers, and therapists is evident, as well as the impact the disease may cause on the family. Epilepsy is the most frequent cause of medical care at the out-patient service of the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (NINN), in Mexico City and the estimated annual prevalence of this disease is 5.9 per 1,000 inhabitants. Parkinson's disease, the most representative of movement disorders, affects 20% of the populating aged > 65 years. Depression and dementia are complex and heterogeneous neuropsychiatry disorders, representing the fifth cause of morbility after accidents, cardiovascular disease, liver cirrhosis and diabetes mellitus. During the last decades, encephalic trauma has been the first cause of mortality: among brain tumors, glioblastomas have the greatest impact. Among infectious disease of the central nervous system (CNS), which are relatively infrequent as compared to gastrointestinal or respiratory infections; viral encephalitis, AIDS-associated toxoplasmosis, and tuberculous meningitis are the most frequent discharge diagnoses at the NINN. The need for a national registration system of neurologic diseases is unquestionable. Such a system would provide accurate data regarding the magnitude of problems related with such disease and help design adequate care and prevention programs.

Tick-borne diseases

Tick-transmitted infectious agents have assumed increased importance as causes of human disease in the United States. During the past two decades, Lyme borreliosis, ehrlichiosis, and babesiosis have emerged as newly described tick-borne infectious diseases of significance for pediatricians and pediatric neurologists. In fact, the highest rates of infection for Lyme disease and Rocky Mountain spotted fever (RMSF), by decade of age, are in childhood. As such, tick-borne infectious disease are of considerable public health concern, particularly for children residing in endemic regions. RMSF and human ehrlichioses can be life-threatening but are also eminently treatable when recognized early. Delays in diagnosis and treatment can lead to adverse outcomes. This article reviews the clinical and epidemiological features of Lyme borreliosis, RMSF, and ehrlichiosis, important causes of neurological illness among children, and summarizes current therapeutic and preventive strategies.

Measles virus infections of the central nervous system

Acute measles is a classic infectious disease of childhood with worldwide distribution. Its causative agent, measles virus (MV), is an efficient pathogen, persisting in nature in populations large enough to support it, even though it is able to cause an acute infection in any individual only once in his lifetime. The characteristic clinical hallmarks of measles, fever and rash, coincide with antiviral immune response. MV-specific T lymphocyte and antibody responses contribute to virus clearance and protection from reinfection, respectively. Concomitant with immune activation immunologic abnormalities arise during MV infection. The ensuing suppression of cellular immune responses is presumably responsible for increased susceptibility to other infections. Additionally, central nervous system (CNS) complications of MV infection with different pathogenesis occur. Autoimmune disease may appear in the form of acute measles encephalomyelitis. Furthermore, MV may persist in the CNS in rare cases without periodic shedding of infectious virus. Measles inclusion body encephalitis can develop on the basis of inadequate virus-specific cell-mediated immune responses and subacute sclerosing panencephalitis occurs many years after primary measles as a slow virus infection. Host cell factors operating in cells of the CNS together with mutations particularly in genes coding for viral envelope proteins initiate and maintain the persistent state of infection with a viral replication cycle that is attenuated at the transcriptional and translational level.