Viral encephalitis in England, 1989-1998: what did we miss?

Clinical epidemiology, determinants, and outcomes of viral encephalitis in Ghana; a cross-sectional study

Viral encephalitis is a rare, yet severe neurological disorder. It poses a significant public health threat due to its high morbidity and mortality. Despite the disproportionate burden of the disease in impoverished African countries, the true extent of the problem remains elusive due to the scarcity of accurate diagnostic methods. The absence of timely and effective diagnostic tools, particularly Real-time Polymerase Chain Reaction, has led to misguided treatment, and an underestimation of the disease burden in Ghana. We conducted a prospective cross-sectional study to determine the viral aetiologies of encephalitis among patients presenting to a major referral hospital in Ghana from May 2019 and August 2022. The study aimed at providing a comprehensive information on the clinical epidemiology, and outcomes of viral encephalitis in Ghana. Clinical samples were collected from patients presenting with signs and symptoms of encephalitis and tested for viral agents using real-time polymerase chain reaction. We assessed the clinical epidemiology, risk factors and outcome of individuals using descriptive and logistic regression analysis. Seventy-seven (77) patients were enrolled unto the study. The participants frequently presented with fever (85.7%), seizures (80.5%), lethargy (64.9%) and headache (50.6%). Viruses were detected in 40.3% of the study participants in either cerebrospinal fluid, rectal or oral swab samples. The most frequently detected viruses were cytomegalovirus (48.4%), enteroviruses (38.7%) and HSV (29.0%). Twenty-one (27.3%) of the patients died while on hospital admission. Gender (OR = 5.70 (1.536-1.172), p = 0.01), and negative polymerase chain reaction test results were identified as significant factors associated with death. Antiviral treatment increased the chance of survival of viral encephalitis patients by 21.8%. Our results validate the crucial role of molecular tools as essential for the rapid diagnosis of viral encephalitis, enabling effective treatment and improved patient outcomes. This study contributes valuable epidemiological and clinical insight into viral encephalitis in Ghana.

Magnetic resonance imaging in acute meningoencephalitis of viral and unknown origin: frequent findings and prognostic potential

Background

Magnetic resonance imaging (MRI) findings in meningoencephalitis have mainly been described in terms of their diagnostic value rather than their prognostic potential, except for herpes simplex virus (HSV) encephalitis. The aims of our study were to describe frequency and anatomic locations of MRI abnormalities specific to limbic, circadian and motor systems in a cohort of meningoencephalitis patients, as well as to investigate the prognostic value of these MRI findings.

Methods

A secondary, selective analysis of a retrospective database including all meningitis, meningoencephalitis and encephalitis cases treated between 2016 and 2018 in the University hospital of Bern, Switzerland was performed. Patients with meningitis of any cause, bacterial or autoimmune causes of encephalitis were excluded.

Results

MRI scans and clinical data from 129 meningoencephalitis cases found that the most frequent causes were tick-borne encephalitis (TBE, 42%), unknown pathogens (40%), VZV (7%), and HSV1 (5%). At discharge, median modified Rankin Score (mRS) was 3 (interquartile range, IQR, 1), 88% of patients had persisting signs and symptoms. After a median of 17 months, median Glasgow Outcome Score (GOS) was 5 (IQR 1), 39% of patients still had residual signs or symptoms. All patients with HSV, 27% with TBE and 31% of those with meningoencephalitis of unknown etiology had fluid-attenuated inversion recovery (FLAIR) and to a lesser extent diffusion-weighted imaging (DWI) lesions in their initial MRI, with highly overlapping anatomical distribution. In one fifth of TBE patients the limbic system was affected. Worse outcome was associated with presence of DWI and/or FLAIR lesions and lower normalized apparent diffusion coefficient (ADC) signal intensities.

Conclusion

Presence of FLAIR lesions, restricted diffusion as well as the extent of ADC hypointensity in initial MRI are parameters which might be of prognostic value regarding the longterm clinical outcome for patients with meningoencephalitis of viral and of unknown origin. Although not described before, affection of limbic structures by TBE is possible as shown by our results: A substantial proportion of our TBE patients had FLAIR signal abnormalities in these regions.

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.

Global Landscape of Encephalitis: Key Priorities to Reduce Future Disease Burden

Encephalitis affects people across the lifespan, has high rates of mortality and morbidity, and results in significant neurological sequelae with long-term consequences to quality of life and wider society. The true incidence is currently unknown due to inaccurate reporting systems. The disease burden of encephalitis is unequally distributed across the globe being highest in low- and middle-income countries where resources are limited. Here countries often lack diagnostic testing, with poor access to essential treatments and neurological services, and limited surveillance and vaccination programs. Many types of encephalitis are vaccine preventable, whereas others are treatable with early diagnosis and appropriate management. In this viewpoint, we provide a narrative review of key aspects of diagnosis, surveillance, treatment, and prevention of encephalitis and highlight priorities for public health, clinical management, and research, to reduce the disease burden.

Severe encephalitis: aetiology, management and outcomes over 10 years in a paediatric intensive care unit

OBJECTIVE

To describe the characteristics, differential diagnoses, management and outcomes of severe encephalitis in children.

DESIGN

A 10-year retrospective cohort study in children admitted to a tertiary paediatric intensive care unit (PICU) with suspected encephalitis. One to 6 months' follow-up data were compared between different categories.

PARTICIPANTS

Patients from 0 to 17 years of age with acute encephalopathy and one or more of fever, seizure, focal neurological findings, cerebrospinal fluid abnormalities, EEG/neuroimaging consistent with encephalitis.

MAIN OUTCOME MEASURES

Epidemiology, clinical features, outcomes and risk factor analysis.

RESULTS

175 children with encephalitis required intensive care unit (ICU) admission over 10 years. The median age was 4.5 months (IQR 1.6-54.8). The leading cause was enterovirus (n=49, 28%), followed by parechovirus, influenza, herpes simplex virus (HSV), human herpesvirus-6 (HHV-6), Streptococcus pneumoniae, acute-disseminated encephalomyelitis and anti-N-methyl-D-aspartate-receptor-associated encephalitis. Immune-mediated encephalitis had higher prevalence in females, older age and longer duration of encephalopathy. Mechanical ventilation was required by 74 children (42%); haemodynamic support by 28 children (16%), 3 received extracorporeal membrane oxygenation (ECMO) support. Eleven patients died (case fatality rate 6.3%): five with HHV-6, two enterovirus, two influenza, one HSV, one human-metapneumovirus. At follow-up, 34 children had mild or moderate disability, and six severe disability. In a multivariable logistic regression model, three factors were associated with severe disability or death: age <2 years old (OR 8.2, CI 1.0 to 67.2), Herpesviridae aetiology (OR 14.5, CI 1.2 to 177.3) and length of intubation (OR 1.005, CI 1.00 to 1.01).

CONCLUSIONS

Encephalitis has a varied aetiology and causes death or severe disability in 1 in every 10 children requiring intensive care.

A decrease in the incidence of encephalitis in South Korea during the COVID-19 pandemic: A nationwide study between 2010 and 2021

Limited data are available on the impact of the coronavirus disease (COVID-19) pandemic on encephalitis. Therefore, we evaluated trends in encephalitis in South Korea between 2010 and 2021 using data from the National Health Insurance Service. During the pandemic (February 2020 to 2021), the monthly incidence of encephalitis declined by 0.027 per 100 000 population (95% confidence interval [CI]: -0.055 to 0.001, p = 0.062) compared to that before the pandemic. In subgroup analysis, the estimated coefficient for level change during the pandemic in the 0-4 and 5-9 years age groups were -2.050 (95% CI: -2.972 to -1.128, p < 0.001) and -0.813 (95% CI: -1.399 to -0.227, p = 0.008), respectively. The annual incidence of encephalitis during the pandemic period significantly decreased in the 0-4 and 5-9 years age groups (incidence rate ratio: 0.34 [p = 0.007] and 0.28 [p = 0.024], respectively). The intensive care unit admission rate (39.1% vs. 58.9%, p  < 0.001) and cases of death (8.9% vs. 11.1%, p < 0.001) decreased significantly during the pandemic compared to the prepandemic. During the pandemic, the incidence of encephalitis decreased markedly in South Korea, particularly in children aged ≤9 years. In addition, there were changes in the clinical outcome of encephalitis during the COVID-19 pandemic.

LTBP1 Gene Expression in the Cerebral Cortex and its Neuroprotective Mechanism in Mice with Postischemic Stroke Epilepsy

OBJECTIVE

This study aimed at exploring the expression level of LTBP1 in the mouse model of epilepsy. The mechanism of LTBP1 in epileptic cerebral neural stem cells was deeply investigated to control the occurrence of epilepsy with neuroprotection.

METHODS

qRT-PCR was conducted for the expression levels of LTBP1 in clinical human epileptic tissues and neural stem cells, as well as normal cerebral tissues and neural stem cells. The mouse model of postischemic stroke epilepsy (PSE) was established by the middle cerebral artery occlusion (MCAO). Then, qRT-PCR was conducted again for the expression levels of LTBP1 in mouse epileptic tissues and neural stem cells as well as normal cerebral tissues and neural stem cells. The activation and inhibitory vectors of LTBP1 were constructed to detect the effects of LTBP1 on the proliferation of cerebral neural stem cells in the PSE model combined with CCK-8. Finally, Western blot was conducted for the specific mechanism of LTBP1 affecting the development of epileptic cells.

RESULTS

Racine score and epilepsy index of 15 mice showed epilepsy symptoms after the determination with MCAO, showing a successful establishment of the PSE model. LTBP1 expression in both diseased epileptic tissues and cells was higher than that in normal clinical epileptic tissues and cells. Meanwhile, qRT-PCR showed higher LTBP1 expression in both mouse epileptic tissues and their neural stem cells compared to that in normal tissues and cells. CCK-8 showed that the activation of LTBP1 stimulated the increased proliferative capacity of epileptic cells, while the inhibition of LTBP1 expression controlled the proliferation of epileptic cells. Western blot showed an elevated expression of TGFβ/SMAD signaling pathway-associated protein SMAD1/5/8 after activating LTBP1. The expression of molecular MMP-13 associated with the occurrence of inflammation was also activated.

CONCLUSION

LTBP1 can affect the changes in inflammation-related pathways by activating the TGFβ/SMAD signaling pathway and stimulate the development of epilepsy, and the inhibition of LTBP1 expression can control the occurrence of epilepsy with neuroprotection.

Viral aetiology of acute central nervous system infections in children, Iran

Introduction. Viral infections are increasingly an important cause of central nervous system (CNS) complications.

Hypothesis/Gap Statement. There is no comprehensive insight about CNS infections due to viral agents among Iranian children.

Aim. This study aimed to investigate the viral aetiology, clinical and epidemiological profile of children with acute infections of the CNS.

Methodology. A prospective study was conducted on children at the referral hospital in Isfahan, Iran, from June 2019 to June 2020. A multiplex PCR assay was used to detect the viral causative agent in cerebrospinal fluid and throat/rectal swab samples.

Results. Among 103 patients with eligible criteria, a confirmed or probable viral aetiology was detected in 41 (39.8 %) patients, including enteroviruses – 56.1 %, herpes simplex virus 1/2 (HSV-1/2) – 31.7 %, Epstein-Barr virus – 17.1 %, varicella-zoster virus (VZV) – 9.7 %, influenza A virus (H1N1) –4.9 % and mumps – 2.4 %. There was a higher proportion of PCR-positive samples in infants than in other age groups. Encephalitis and meningoencephalitis were diagnosed in 68.3 % (28/41) and 22 % (9/41) PCR-positive cases, respectively.

Conclusion. The findings of this research provide insights into the clinical and viral aetiological patterns of acute CNS infections in Iran, and the importance of molecular methods to identify CNS viruses. HSV and VZV were identified as important causes of encephalitis in young children.

Infectious encephalitis in elderly patients: a prospective multicentre observational study in France 2016-2019

PURPOSE

Data on encephalitis in elderly patients are scarce. We aimed to describe the characteristics, aetiologies, management, and outcome of encephalitis in patients older than 65 years.

METHODS

We performed an ancillary study of ENCEIF, a prospective cohort that enrolled all cases of encephalitis managed in 46 clinical sites in France during years 2016-2019. Cases were categorized in three age groups: (1) 18-64; (2) 65-79; (3) ≥ 80 years.

RESULTS

Of the 494 adults with encephalitis enrolled, 258 (52%) were ≥ 65 years, including 74 (15%) ≥ 80 years. Patients ≥ 65 years were more likely to present with coma, impaired consciousness, confusion, aphasia, and rash, but less likely to present with fever, and headache (P < 0.05 for each). Median cerebrospinal fluid (CSF) white cells count was 61/mm³[13-220] in 65-79 years, 62 [17-180] in ≥ 80 years, vs. 114 [34-302] in < 65 years (P = 0.01). The proportion of cases due to Listeria monocytogenes and VZV increased after 65 years (P < 0.001), while the proportion of tick-borne encephalitis and Mycobacterium tuberculosis decreased with age (P < 0.05 for each). In-hospital mortality was 6/234 (3%) in < 65 years, 18/183 (10%) in 65-79 years, and 13/73 (18%) in ≥ 80 years (P < 0.001). Age ≥ 80 years, coma on admission, CSF protein ≥ 0.8 g/L and viral encephalitis were independently predictive of 6 month mortality.

CONCLUSION

Elderly patients represent > 50% of adults with encephalitis in France, with higher proportion of L. monocytogenes and VZV encephalitis, increased risk of death, and sequels. The empirical treatment currently recommended, aciclovir and amoxicillin, is appropriate for this age group.

Evaluation of human bocavirus as well as other well-known viral etiologic agents by PCR in the cerebrospinal fluid of children with clinical impression of viral meningoencephalitis referred to the Children's Medical Center in Tehran, Iran, from 2019 to 2020

Viral meningoencephalitis is one of the most important diseases that most commonly affect children. In many cases of viral meningoencephalitis, the underlying cause of the disease is not identified, raising the possibility of a variety of pathogens that are not routinely tested. Bocaviruses belong to a newly identified class of viruses that have been reported in some studies to be associated with viral encephalitis. In the present study, we investigated the prevalence of bocaviruses and other viruses in the patients suspected of having viral encephalitis and their associations with various demographic and clinical variables. Two hundred patients with suspected viral meningoencephalitis referred to Children's Medical Center were studied from 2019 to 2020. Age, sex, length of hospitalization, and course of the disease were gathered. Cerebrospinal fluid (CSF) samples were taken from the patients and subjected to biochemical examinations and PCR to identify the underlying cause. Bocaviruses were detected in none of the DNA samples extracted from the CSF specimens. The most identified organisms were mumps and enteroviruses. In 92% of cases, the underlying cause was not identified. PCR-based identification of the underlying causes of viral meningoencephalitis in CSF specimens was not successful in most cases. Bocavirus was not found in any of the collected CSF samples. Further studies are required for drawing more accurate conclusions.

Repetitive seizures after febrile period exclusively involving bilateral claustrum

The purpose of this study is to demonstrate the relationship between acute repetitive seizures and claustrum damage, and to provide basis for the treatment of repetitive seizures exclusively involved the bilateral claustrum.Between August 2014 and October 2015, 5 patients with repetitive seizures after a febrile period were admitted to our hospital, showing exclusive involvement of bilateral claustrum on magnetic resonance images (MRI). All patients underwent serum virology testing, autoimmune antibody test, MRI, and electroencephalograph examination.All patients were young women (16-29 years) with an unremarkable previous medical history, and 2 of them were pregnant. Similar clinical symptoms like antecedent febrile illness in the 3 to 7 days preceding seizures, psychiatric disorder, or dysautonomia occurred in 5 patients. Abnormal MRI signals exclusively confined to the bilateral claustrum appeared in 4 patients during the acute phase and in 1 patient during the chronic phase. All patients accepted empirical treatment with anti-viral and anti-seizure drugs and had good outcomes (seizure-free, though with some residual short-term memory loss) at the 3rd year follow-up.Although the clinical and associated brain imaging findings were characteristic, the etiology was still unclear. Contrary to previous studies, the patients presented here have all received a good prognosis.

Protocol for DexEnceph: a randomised controlled trial of dexamethasone therapy in adults with herpes simplex virus encephalitis

INTRODUCTION

Herpes simplex virus (HSV) encephalitis is a rare severe form of brain inflammation that commonly leaves survivors and their families with devastating long-term consequences. The virus particularly targets the temporal lobe of the brain causing debilitating problems in memory, especially verbal memory. It is postulated that immunomodulation with the corticosteroid, dexamethasone, could improve outcomes by reducing brain swelling. However, there are concerns (so far not observed) that such immunosuppression might facilitate increased viral replication with resultant worsening of disease. A previous trail closed early because of slow recruitment.

METHOD

DexEnceph is a pragmatic multicentre, randomised, controlled, open-label, observer-blind trial to determine whether adults with HSV encephalitis who receive dexamethasone alongside standard antiviral treatment with aciclovir for have improved clinical outcomes compared with those who receive standard treatment alone. Overall, 90 patients with HSV encephalitis are being recruited from a target of 45 recruiting sites; patients are randomised 1:1 to the dexamethasone or control arms of the study. The primary outcome measured is verbal memory as assessed by the Weschler Memory Scale fourth edition Auditory Memory Index at 26 weeks after randomisation. Secondary outcomes are measured up to 72 weeks include additional neuropsychological, clinical and functional outcomes as well as comparison of neuroimaging findings. Patient safety monitoring occurs throughout and includes the detection of HSV DNA in cerebrospinal fluid 2 weeks after randomisation, which is indicative of ongoing viral replication. Innovative methods are being used to ensure recrutiment targets are met for this rare disease.

DISCUSSION

DexEnceph aims to be the first completed randomised controlled trial of corticosteroid therapy in HSV encephalitis. The results will provide evidence for future practice in managing adults with the condition and has the potential to improve outcomes .

ETHICS AND DISSEMINATION

The trial has ethical approval from the UK National Research Ethics Committee (Liverpool Central, REF: 15/NW/0545, 10 August 2015). Protocol V.2.1, July 2019. The results will be published and presented as soon as possible on completion.

TRIAL REGISTRATION NUMBERS

ISRCTN11774734, EUDRACT 2015-001609-16.

Pediatric auto-immune encephalitis

Pediatric Auto-Immune Encephalitis (PAE) is a neuro-inflammatory disorder with a varied presentation. The discovery of the Anti NMDA receptor and other antibodies as the causative agents of PAE, has led to an increased need for guidelines for diagnosis and management of these disorders. PAE remains a challenging group of disorders due to their varying presentations and etiology with a prolonged clinical course. The wide spectrum of clinical symptoms involves altered mental status, movement disorders, acute behavioral changes, psychosis, delirium, seizures, and insomnia. This group of disorders was recently recognized in the children. This review provides clinicians with information on the most common PAE disorders, the spectrum of their clinical presentation, diagnostic tests and treatment protocols based on the current literature.

Multicenter prospective surveillance study of viral agents causing meningoencephalitis

The frequency of bacterial factors causing central nervous system infections has decreased as a result of the development of our national immunization program. In this study, it is aimed to obtain the data of our local surveillance by defining the viral etiology in cases diagnosed with meningoencephalitis for 1 year. Previously healhty 186 children, who applied with findings suggesting viral meningoencephalitis to 8 different tertiary health centers between August 2018 and August 2019, in Istanbul, were included. The cerebrospinal fluid (CSF) sample was evaluated by polymerase chain reaction. The M:F ratio was 1.24 in the patient group, whose age ranged from 1 to 216 months (mean 40.2 ± 48.7). Viral factor was detected in 26.8%. Enterovirus was the most common agent (24%) and followed by Adenovirus (22%) and HHV type 6 (22%). In the rest of the samples revealed HHV type 7 (10%), EBV (6%), CMV (6%), HSV type 1 (6%), Parvovirus (4%) and VZV (2%). The most common symptoms were fever (79%) and convulsions (45.7%). Antibiotherapy and antiviral therapy was started 48.6% and 4% respectively. Mortality and sequela rate resulted 0.53% and 3.7%, respectively. This highlights the importance of monitoring trends in encephalitis in Turkey with aview to improving pathogen diagnosis for encephalitis and rapidly identifying novel emerging encephalitis-causing pathogens that demand public health action especially in national immunisation programme.

Acute Childhood Viral Encephalitis in Southern Brazil

BACKGROUND

Viral meningoencephalitis is highly heterogeneous, varying by geographic location. The aim of this study was to characterize the etiology and reporting the clinical findings and outcome of viral encephalitis in children in southern Brazil.

METHODS

A cross-Sectional study was conducted at Hospital Pequeno Príncipe, Curitiba, Brazil, between January 2013 and December 2017. It included patients younger than 18 years, who fulfilled the criteria: altered mental status as a major criteria and 2 or more minor criteria (1) fever, (2) seizures, (3) focal neurologic findings, (4) central system fluid white cell count of ≥5 cells/mm, (5) abnormal brain imaging, and/or (6) electroencephalogram abnormalities.

RESULTS

Viral meningoencephalitis was diagnosed in 270 children, with median age of 2 years (interquartile range: 0-4), The etiology of viral meningoencephalitis was confirmed in 47% of patients. Enterovirus (18%) was the major cause of encephalitis in Southern Brazilian children, and a high prevalence of Epstein-Barr virus (6%) was demonstrated. Most patients presented with fever (81%), followed by vomiting (50%), focal neurologic findings (46%), seizures (31%) and headache (30%). Few abnormalities were detected on electroencephalograms and brain magnetic resonance images. On discharge from hospital, symptoms resolved completely in 87% of children. Sequelae were mainly observed in patients with focal neurologic symptoms (P<0.001), presence of seizures (P<0.001) and electroencephalogram abnormalities (P=0.024).

CONCLUSIONS

Enterovirus was the major cause of encephalitis. Etiologic agent of encephalitis seems to be influenced by the local virologic pattern. A poor outcome was identified in patients with seizures, focal neurologic findings and electroencephalogram abnormalities.

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

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

Infectious and Autoimmune Causes of Encephalitis in Children

BACKGROUND AND OBJECTIVES

Encephalitis can result in neurologic morbidity and mortality in children. Newly recognized infectious and noninfectious causes of encephalitis have become increasingly important over the past decade.

METHODS

We retrospectively reviewed medical records from pediatric patients in Houston diagnosed with encephalitis in both an urban and rural catchment area between 2010 and 2017. We conducted an investigation to understand the etiology, clinical characteristics, and diagnostic testing practices in this population.

RESULTS

We evaluated 231 patients who met the case definition of encephalitis, among which 42% had no recognized etiology. Among those with an identified etiology, the most common were infectious (73; 31%), including viral (n = 51; 22%), with the most frequent being West Nile virus (WNV; n = 12), and bacterial (n = 19; 8%), with the most frequent being Bartonella henselae (n = 7). Among cases of autoimmune encephalitis (n = 60; 26%), the most frequent cause was anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis (n = 31). Autoimmune causes were seen more commonly in female (P < .01) patients. Testing for herpes simplex virus and enterovirus was nearly universal; testing for anti-NMDAR encephalitis, WNV, and Bartonella was less common.

CONCLUSIONS

WNV was the most common infectious cause of encephalitis in our pediatric population despite lower testing frequency for WNV than herpes simplex virus or enterovirus. Increasing testing for anti-NMDAR encephalitis resulted in frequent identification of cases. Increased awareness and testing for WNV and Bartonella would likely result in more identified causes of pediatric encephalitis. Earlier etiologic diagnosis of encephalitides may lead to improve clinical outcomes.

The longitudinal health economic impact of viral encephalitis in the United States

Introduction. Previous studies of viral encephalitis have focused on acute costs, estimating incidence at 7.3 per 100 000 and total US annual charges at $2 billion in 2010.Aim. We aim to quantify the most updated longitudinal health economic impact of viral encephalitis in the USA from 2008 to 2015.Methodology. Data on patients diagnosed with viral encephalitis were obtained from the Truven Health Analytics MarketScan database. Patients with a primary diagnosis of viral encephalitis, from herpetic viruses and other viral aetiologies (e.g. West Nile fever) were included in the analysis. Data concerning healthcare resource utilization, inpatient mortality, length of stay and accrued healthcare costs were collected for up to 5 years.Results. Among 3985 patients with continuous enrolment for 13 months prior to the encephalitis diagnosis, more non-herpes simplex encephalitis (61.7 %) than herpes simplex encephalitis (HSE; 38.3 %) cases were recorded, with the majority concentrated in the southern USA (29.2 %). One-year inpatient mortality was 6.2 %, which over a 5-year period rose to 8.9 % for HSE and 5.8 % for all other viral encephalitides. HSE resulted in longer cumulative stays in the hospital (11 days vs. 4 days; P=0.0025), and accrued 37 % higher first-year costs, after adjusting for known confounders [P<0.001, cost ratio=1.37, 95 % confidence interval (1.20, 1.57)]. Additionally, HSE was associated with greater 5-year cumulative median charges ($125 338 vs. $82 317, P=0.0015).Conclusion. The health economic impact and long-term morbidity of viral encephalitis in the USA are substantial.

Clinical features and surgical treatment of epilepsy after viral encephalitis

Encephalitis is an acute inflammatory process of the brain parenchyma, which is often caused by viral infection. It is an vital cause of acute symptomatic seizures and subsequent epilepsy. The incidence of unprovoked and recurrent seizures after previous infections of the central nervous system is high and accounts for 1%~5% of the cases of epilepsy. Viral encephalitis (VE) is directly caused by viral infection. The occurrence of seizures after VE is associated with poor prognosis. In survivors of VE, among other neurological sequelae, the risk of developing epilepsy is increased 10-fold. The risk of severe neurological sequelae after VE is particularly high in very young children. Studies on seizure occurrence, possible underlying mechanisms, clinical characteristics, and clinical treatment (especially surgical treatment) of VE have yielded only limited detailed data. We reviewed the most recent literature on the clinical features and surgical treatment of post-VE epilepsy.

Varicella zoster virus infection of the central nervous system in a tertiary care center in Lebanon

OBJECTIVE

To describe the clinical manifestations and treatment outcomes of patients with VZV meningitis and encephalitis consulting at two medical centers in Lebanon.

METHODS

Retrospective study of patients with VZV meningitis and/or encephalitis confirmed by positive cerebrospinal fluid (CSF) VZV PCR.

RESULTS

Twenty patients were identified (13 males). The average age was 49.7±22.2 years. The most common complaint was headache (n=17/20). Common comorbidities included hypertension (n=7/20) and diabetes mellitus (n=5/20). Immunosuppression was reported in two patients. Vesicles were only observed in eight patients. Altered mental status, focal neurological deficits, and fever were documented in six, two, and four patients respectively. All patients had CSF leukocytosis with lymphocytic predominance, normal CSF/serum glucose ratio, and high CSF protein. Eighteen patients had brain CT scans showing no relevant findings. Two of 12 patients with brain MRI had focal abnormalities. Unilateral temporal slow waves were observed in three of four patients who underwent electroencephalograms. Four patients had encephalitis and 16 had meningitis. Eighteen patients received an antiviral therapy. Treatment either included intravenous acyclovir or oral valacyclovir. The encephalitis and meningitis groups had comparable mean duration of treatment (13.5±6.6 vs. 12.2±5.4, respectively). All admitted patients showed clinical cure with no reported neurological sequelae.

CONCLUSION

VZV infection should be suspected in any patient with signs and symptoms of viral meningitis or encephalitis, irrespective of age, immune status, presence or absence of vesicles, fever, or neck stiffness.

Exploring the knowledge, attitudes and practices (KAP) of health care professionals on viral hepatitis notification in Gauteng, South Africa, 2015

Background

Data on viral hepatitis in South Africa is scarce. Although viral hepatitis A, B and C are notifiable conditions in South Africa, discrepancies have been noted in the number of viral hepatitis cases notified by the National Department of Health (NDOH) compared with laboratory confirmed cases from the National Institute for Communicable Diseases (NICD). The aim of the study was to assess the knowledge, attitudes and practices of health care professionals on the notification of viral hepatitis A, B and C.

Methods

A descriptive, cross-sectional study on 385 health care professionals was conducted at Charlotte Maxeke Johannesburg Academic and Tshwane District hospitals in Gauteng province, South Africa, between March and May 2015. A pre-tested, structured questionnaire with 21 (6 demographic and 15 knowledge, attitudes, and practice (KAP)) questions was used to collect information from invited participants. A score was assigned to each KAP question and a mean (SD) score was calculated for each section. Data were analyzed using descriptive statistics in STATA version 13.

Results

Of the total 385 respondents, 65% (n = 250) were nurses and 35% (n = 135) were doctors. The overall mean knowledge score for health care professionals was 2.0 ± 1.6 (mean ± SD) out of a score of 6 regarding viral hepatitis notification. Overall mean scores of practice and attitude towards notification were higher at 2.9 ± 0.4 and 3.3 ± 0.7, out of a score of 4 and 5, respectively. Lack of training, poor knowledge, a complex process and excessive workload were some of the reasons for poor notification of viral hepatitis.

Conclusions

Overall, knowledge on notification of viral hepatitis was poor among health care professionals. Adequate training on viral hepatitis, notification process, roles and responsibilities of health care professionals to notify and the implication of viral hepatitis notifications is recommended to improve reporting rate of notifiable diseases and referrals to increase linkage to care.

Electronic supplementary material

The online version of this article (10.1186/s13690-018-0319-8) contains supplementary material, which is available to authorized users.

Community-acquired acute meningitis and encephalitis: a narrative review

Meningitis and encephalitis are medical emergencies. Patients need prompt evaluation and immediate empiric therapy to reduce the likelihood of fatal outcomes and chronic neurological sequelae. Conjugate bacterial vaccines have significantly reduced the incidence of bacterial meningitis, especially in children. As the results of changes in patterns of bacterial drug sensitivity, ceftriaxone is now part of the recommended empiric treatment for bacterial meningitis and should be administered as early as possible. Neuroimaging delays the treatment of meningitis and is not needed in most cases. Adjunctive corticosteroid therapy is of benefit for many patients with meningitis and should be initiated in most adults before antibiotic therapy. Molecular testing can assist the specific diagnosis of encephalitis and should be based on the exposure history and geographic risk factors relevant to the patient, but non-infectious causes of encephalitis are also common. Empiric therapy for encephalitis should be directed at the most frequently identified infectious pathogen, herpes simplex virus type 1 (ie, intravenous aciclovir). Vaccines can protect against the major pathogens of childhood infections (measles, mumps, rubella, polio, varicella viruses), influenza viruses, and exotic pathogens that cause meningitis and encephalitis (rabies, Japanese encephalitis, dengue, yellow fever, tick-borne encephalitis viruses, Mycobacterium tuberculosis).

Multimodal Predictions of Super-Refractory Status Epilepticus and Outcome in Status Epilepticus Due to Acute Encephalitis

Objective: Status epilepticus (SE) is one of the most critical symptoms of encephalitis. Studies on early predictions of progression to super-refractory status epilepticus (SRSE) and poor outcome in SE due to acute encephalitis are scarce. We aimed to investigate the values of neuroimaging and continuous electroencephalogram (EEG) in the multimodal prediction. Methods: Consecutive patients with convulsive SE due to acute encephalitis were included in this study. Demographics, clinical features, neuro-imaging characteristics, medical interventions, and anti-epileptic treatment responses were collected. All the patients had EEG monitoring for at least 24 h. We determined the early predictors of SRSE and prognostic factors of 3-month outcome using multivariate logistic regression analyses. Results: From March 2008 to February 2018, 570 patients with acute encephalitis were admitted to neurological intensive care unit (N-ICU) of Xijing hospital. Among them, a total of 94 patients with SE were included in this study. The percentage of non-SRSE and SRSE were 76.6 and 23.4%. Cortical or hippocampal abnormality on neuroimaging (p = 0.002, OR 20.55, 95% CI 3.16-133.46) and END-IT score (p < 0.001, OR 4.07, 95% CI 1.91-8.67) were independent predictors of the progression to SRSE. At 3 months after N-ICU discharge, 56 (59.6%) patients attained good outcomes, and 38 (40.4%) patients had poor outcomes. The recurrence of clinical or EEG seizures within 2 h after the infusion rate of a single anesthetic drug >50% proposed maximal dose (p = 0.044, OR 4.52, 95% CI 1.04-19.68), tracheal intubation (p = 0.011, OR 4.99, 95% CI 1.37-11.69) and emergency resuscitation (p = 0.040, OR 9.80, 95% 1.11-86.47) predicted poor functional outcome. Interpretation: Initial neuro-imaging findings assist early identification of the progression to SRSE. Continuous EEG monitoring contributes to outcome prediction in SE due to acute encephalitis.

A Rare Case of Concurrent Herpes Simplex Encephalitis and Glioblastoma Multiforme

Herpes encephalitis superimposed on an intracranial malignancy has previously been described mainly in the context of malignancy imitating infection or in the postoperative setting after neurosurgical intervention. We report a rare case of de novo presentation of concurrent herpes encephalitis and glioblastoma. A 63-year-old man presented with status epilepticus and subsequent magnetic resonance imaging (MRI) brain showed a right temporal enhancing lesion with mass effect. He underwent a craniotomy and debulking of this lesion, which on subsequent histology was positive for herpes simplex virus (HSV) antigens and HSV DNA was confirmed by polymerase chain reaction analysis. The sample however also had some hypercellular areas with atypical astrocytes. Our patient recovered well from surgery and was eventually commenced on acyclovir albeit with a delay of 3 weeks due to the initial diagnostic dilemma. However, he re-presented with lethargy and confusion a further 3 weeks later and an MRI scan showed recurrence of the temporal lesion with MR spectroscopy more suggestive of high-grade glioma. He, therefore, underwent a further debulking surgery and the histology revealed a WHO Grade 4 glioblastoma with some residual areas of inflammation. A diagnosis of 2 co-existing pathologies namely HSV encephalitis and glioblastoma was thus reached. Unfortunately, due to poor performance status, he could not undergo chemo-radiotherapy and died 8 months after presentation. Immuno-modulators, expressed locally and globally in glioma patients, are likely to render them susceptible to infections. There are an increasing number of reports of HSV encephalitis in the glioma setting postoperatively. However, we report a de novo presentation which has only been recognized once before in the 1970s. Recognition of HSV encephalitis in glioma patients in the de novo and also the postoperative context is important for commencing early treatment and preventing poor outcomes.

Intravenous immunoglobulin for the treatment of childhood encephalitis

BACKGROUND

Encephalitis is a syndrome of neurological dysfunction due to inflammation of the brain parenchyma, caused by an infection or an exaggerated host immune response, or both. Attenuation of brain inflammation through modulation of the immune response could improve patient outcomes. Biological agents such as immunoglobulin that have both anti-inflammatory and immunomodulatory properties may therefore be useful as adjunctive therapies for people with encephalitis.

OBJECTIVES

To assess the efficacy and safety of intravenous immunoglobulin (IVIG) as add-on treatment for children with encephalitis.

SEARCH METHODS

The Cochrane Multiple Sclerosis and Rare Diseases of the CNS group's Information Specialist searched the following databases up to 30 September 2016: CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and the WHO ICTRP Search Portal. In addition, two review authors searched Science Citation Index Expanded (SCI-EXPANDED) & Conference Proceedings Citation Index - Science (CPCI-S) (Web of Science Core Collection, Thomson Reuters) (1945 to January 2016), Global Health Library (Virtual Health Library), and Database of Abstracts of Reviews of Effects (DARE).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing IVIG in addition to standard care versus standard care alone or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected articles for inclusion, extracted relevant data, and assessed quality of trials. We resolved disagreements by discussion among the review authors. Where possible, we contacted authors of included studies for additional information. We presented results as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI).

MAIN RESULTS

The search identified three RCTs with 138 participants. All three trials included only children with viral encephalitis, one of these included only children with Japanese encephalitis, a specific form of viral encephalitis. Only the trial of Japanese encephalitis (22 children) contributed to the primary outcome of this review and follow-up in that study was for three to six months after hospital discharge. There was no follow-up of participants in the other two studies. We identified one ongoing trial.For the primary outcomes, the results showed no significant difference between IVIG and placebo when used in the treatment of children with Japanese encephalitis: significant disability (RR 0.75, 95% CI 0.22 to 2.60; P = 0.65) and serious adverse events (RR 1.00, 95% CI 0.07 to 14.05; P = 1.00).For the secondary outcomes, the study of Japanese encephalitis showed no significant difference between IVIG and placebo when assessing significant disability at hospital discharge (RR 1.00, 95% CI 0.60 to 1.67). There was no significant difference (P = 0.53) in Glasgow Coma Score at discharge between IVIG (median score 14; range 3 to 15) and placebo (median 14 score; range 7 to 15) in the Japanese encephalitis study. The median length of hospital stay in the Japanese encephalitis study was similar for IVIG-treated (median 13 days; range 9 to 21) and placebo-treated (median 12 days; range 6 to 18) children (P = 0.59).Pooled analysis of the results of the other two studies resulted in a significantly lower mean length of hospital stay (MD -4.54 days, 95% CI -7.47 to -1.61; P = 0.002), time to resolution of fever (MD -0.97 days, 95% CI -1.25 to -0.69; P < 0.00001), time to stop spasms (MD -1.49 days, 95% CI -1.97 to -1.01; P < 0.00001), time to regain consciousness (MD -1.10 days, 95% CI -1.48 to -0.72; P < 0.00001), and time to resolution of neuropathic symptoms (MD -3.20 days, 95% CI -3.34 to -3.06; P < 0.00001) in favour of IVIG when compared with standard care.None of the included studies reported other outcomes of interest in this review including need for invasive ventilation, duration of invasive ventilation, cognitive impairment, poor adaptive functioning, quality of life, number of seizures, and new diagnosis of epilepsy.The quality of evidence was very low for all outcomes of this review.

AUTHORS' CONCLUSIONS

The findings suggest a clinical benefit of adjunctive IVIG treatment for children with viral encephalitis for some clinical measures (i.e. mean length of hospital stay, time (days) to stop spasms, time to regain consciousness, and time to resolution of neuropathic symptoms and fever. For children with Japanese encephalitis, IVIG had a similar effect to placebo when assessing significant disability and serious adverse events.Despite these findings, the risk of bias in the included studies and quality of the evidence make it impossible to reach any firm conclusions on the efficacy and safety of IVIG as add-on treatment for children with encephalitis. Furthermore, the included studies involved only children with viral encephalitis, therefore findings of this review cannot be generalised to all forms of encephalitis. Future well-designed RCTs are needed to assess the efficacy and safety of IVIG in the management of children with all forms of encephalitis. There is a need for internationally agreed core outcome measures for clinical trials in childhood encephalitis.

Viral Encephalitis of Unknown Cause: Current Perspective and Recent Advances

Viral encephalitis causes acute inflammation of the brain parenchyma and is a significant cause of human morbidity and mortality. Although Herpes Simplex encephalitis is the most frequent known cause of fatal sporadic encephalitis in humans, an increasingly wide range of viruses and other microbial pathogens are implicated. Up to 60% of cases of presumed viral encephalitis remain unexplained due to the failure of conventional laboratory techniques to detect an infectious agent. High-throughput DNA sequencing technologies have the potential to detect any microbial nucleic acid present in a biological specimen without any prior knowledge of the target sequence. While there remain challenges intrinsic to these technologies, they have great promise in virus discovery in unexplained encephalitis.

Epidemiology of infectious encephalitis causes in 2016

We performed a literature search in the Medline database, using the PubMed website. The incidence of presumably infectious encephalitis is estimated at 1.5-7 cases/100,000 inhabitants/year, excluding epidemics. Infectious encephalitis and immune-mediated encephalitis share similar clinical signs and symptoms. The latter accounts for a significant proportion of presumably infectious encephalitis cases without any established etiological diagnosis; as shown from a prospective cohort study where 21% of cases were due to an immune cause. Several infectious agents are frequently reported in all studies: Herpes simplex virus (HSV) is the most frequent pathogen in 65% of studies, followed by Varicella-zoster virus (VZV) in several studies. Enteroviruses are also reported; being the most frequent viruses in two studies, and the 2nd or 3rd viruses in five other studies. There are important regional differences, especially in case of vector-borne transmission: Asia and the Japanese encephalitis virus, Eastern and Northern Europe/Eastern Russia and the tick-borne encephalitis virus, Northern America and Flavivirus or Alphavirus. Bacteria can also be incriminated: Mycobacterium tuberculosis and Listeria monocytogenes are the most frequent, after HSV and VZV, in a French prospective study. The epidemiology of encephalitis is constantly evolving. Epidemiological data may indicate the emergence and/or dissemination of new causative agents. The dissemination and emergence of causative agents are fostered by environmental, social, and economical changes, but prevention programs (vaccination, vector controls) help reduce the incidence of other infectious diseases and associated encephalitis (e.g., measles).

30-year trends in admission rates for encephalitis in children in England and effect of improved diagnostics and measles-mumps-rubella vaccination: a population-based observational study

BACKGROUND

Encephalitis is a serious neurological disorder, yet data on admission rates for all-cause childhood encephalitis in England are scarce. We aimed to estimate admission rates for childhood encephalitis in England over 33 years (1979-2011), to describe trends in admission rates, and to observe how these rates have varied with the introduction of vaccines and improved diagnostics.

METHODS

We did a retrospective analysis of hospital admission statistics for encephalitis for individuals aged 0-19 years using national data from the Hospital Inpatient Enquiry (HIPE, 1979-85) and Hospital Episode Statistics (HES, 1990-2011). We analysed annual age-specific and age-standardised admission rates in single calendar years and admission rate trends for specified aetiologies in relation to introduction of PCR testing and measles-mumps-rubella (MMR) vaccination. We compared admission rates between the two International Classification of Diseases (ICD) periods, ICD9 (1979-94) and ICD10 (1995-2011).

FINDINGS

We found 16 571 encephalitis hospital admissions in the period 1979-2011, with a mean hospital admission rate of 5·97 per 100 000 per year (95% CI 5·52-6·41). Hospital admission rates declined from 1979 to 1994 (ICD9; annual percentage change [APC] -3·30%; 95% CI -2·88 to -3·66; p<0·0001) and increased between 1995 and 2011 (ICD10; APC 3·30%; 2·75-3·85; p<0·0001). Admissions for measles decreased by 97% (from 0·32 to 0·009) and admissions for mumps encephalitis decreased by 98% (from 0·60 to 0·01) after the introduction of the two-dose MMR vaccine. Hospital admission rates for encephalitis of unknown aetiology have increased by 37% since the introduction of PCR testing.

INTERPRETATION

Hospital admission rates for all-cause childhood encephalitis in England are increasing. Admissions for measles and mumps encephalitis have decreased substantially. The numbers of encephalitis admissions without a specific diagnosis are increasing despite availability of PCR testing, indicating the need for strategies to improve aetiological diagnosis in children with encephalitis.

FUNDING

None.

Pro-epileptogenic effects of viral-like inflammation in both mature and immature brains

BACKGROUND

Infectious encephalitides are most often associated with acute seizures during the infection period and are risk factors for the development of epilepsy at later times. Mechanisms of viral encephalitis-induced epileptogenesis are poorly understood. Here, we evaluated the contribution of viral encephalitis-associated inflammation to ictogenesis and epileptogenesis using a rapid kindling protocol in rats. In addition, we examined whether minocycline can improve outcomes of viral-like brain inflammation.

METHODS

To produce viral-like inflammation, polyinosinic-polycytidylic acid (PIC), a toll-like receptor 3 (TLR3) agonist, was applied to microglial/macrophage cell cultures and to the hippocampus of postnatal day 13 (P13) and postnatal day 74 (P74) rats. Cell cultures permit the examination of the inflammation induced by PIC, while the in vivo setting better suits the analysis of cytokine production and the effects of inflammation on epileptogenesis. Minocycline (50 mg/kg) was injected intraperitoneally for 3 consecutive days prior to the kindling procedure to evaluate its effects on inflammation and epileptogenesis.

RESULTS

PIC injection facilitated kindling epileptogenesis, which was evident as an increase in the number of full limbic seizures at both ages. Furthermore, in P14 rats, we observed a faster seizure onset and prolonged retention of the kindling state. PIC administration also led to an increase in interleukin 1β (IL-1β) levels in the hippocampus in P14 and P75 rats. Treatment with minocycline reversed neither the pro-epileptogenic effects of PIC nor the increase of IL-1β in the hippocampus in both P14 and P75 rats.

CONCLUSIONS

Hippocampal injection of PIC facilitates rapid kindling epileptogenesis at both P14 and P75, suggesting that viral-induced inflammation increases epileptogenesis irrespective of brain maturation. Minocycline, however, was unable to reverse the increase of epileptogenesis, which might be linked to its absence of effect on hippocampal IL-1β levels at both ages.

ImmunoglobuliN in the Treatment of Encephalitis (IgNiTE): protocol for a multicentre randomised controlled trial

INTRODUCTION

Infectious and immune-mediated encephalitides are important but under-recognised causes of morbidity and mortality in childhood, with a 7% death rate and up to 50% morbidity after prolonged follow-up. There is a theoretical basis for ameliorating the immune response with intravenous immunoglobulin (IVIG), which is supported by empirical evidence of a beneficial response following its use in the treatment of viral and autoimmune encephalitis. In immune-mediated encephalitis, IVIG is often used after a delay (by weeks in some cases), while diagnosis is confirmed. Wider use of IVIG in infectious encephalitis and earlier use in immune-mediated encephalitis could improve outcomes for these conditions. We describe the protocol for the first ever randomised control trial of IVIG treatment for children with all-cause encephalitis.

METHODS AND ANALYSIS

308 children (6 months to 16 years) with a diagnosis of acute/subacute encephalitis will be recruited in ∼30 UK hospitals and randomised to receive 2 doses (1 g/kg/dose) of either IVIG or matching placebo, in addition to standard treatment. Recruitment will be over a 42-month period and follow-up of each participant will be for 12 months post randomisation. The primary outcome is 'good recovery' (score of 2 or lower on the Glasgow Outcome Score Extended-paediatric version), at 12 months after randomisation. Additional secondary neurological measures will be collected at 4-6 weeks after discharge from acute care and at 6 and 12 months after randomisation. Safety, radiological, other autoimmune and tertiary outcomes will also be assessed.

ETHICS AND DISSEMINATION

This trial has been approved by the UK National Research Ethics committee (South Central-Oxford A; REC 14/SC/1416). Current protocol: V4.0 (10/03/2016). The findings will be presented at national and international meetings and conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

NCT02308982, EudraCT201400299735 and ISRCTN15791925; Pre-results.

Encephalitis, Ontario, Canada, 2002-2013

The epidemiology of encephalitis in Ontario is remarkably similar to that in England.

Encephalitis, a brain inflammation leading to severe illness and often death, is caused by >100 pathogens. To assess the incidence and trends of encephalitis in Ontario, Canada, we obtained data on 6,463 Ontario encephalitis hospitalizations from the hospital Discharge Abstract Database for April 2002–December 2013 and analyzed these data using multiple negative binomial regression. The estimated crude incidence of all-cause encephalitis in Ontario was ≈4.3 cases/100,000 persons/year. Incidence rates for infants <1 year of age and adults >65 years were 3.9 and 3.0 times that of adults 20–44 years of age, respectively. Incidence peaks during August–September in 2002 and 2012 resulted primarily from encephalitis of unknown cause and viral encephalitis. Encephalitis occurred more frequently in older age groups and less frequently in women in Ontario when compared to England, but despite differences in population, vector-borne diseases, climate, and geography, the epidemiology was overall remarkably similar in the two regions.

Long-term outcomes of infective encephalitis in children: a systematic review and meta-analysis

AIM

The long-term outcomes of childhood infective encephalitis are variable and not well quantified. We aimed to systematically review the literature and undertake meta-analyses on predetermined outcomes to address this knowledge gap and identify areas for future research.

METHOD

We searched electronic databases, performed complementary reviews of references of fully extracted articles, and made contact with experts on infective encephalitis. Articles published up until April 2016 were selected for screening.

RESULTS

We evaluated sequelae of 1018 survivors of childhood infective encephalitis (934 with complete follow-up) from 16 studies. Mean age during acute encephalitis episodes was 5 years 3.6 months (range 1.2mo-17y), 57.6% were male (500/868), and mean follow-up period was 4 years 1.2 months (range 1-12y). Incomplete recovery was reported in 312 children (42.0%; 95% confidence interval [CI] 31.6-53.1% in pooled estimate). Among the other sequelae, developmental delay, abnormal behaviour, motor impairment, and seizures were reported among 35.0% (95% CI 10.0-65.0%), 18.0% (95% CI 8.0-31.0%), 17.0% (95% CI 10.0-26.0%), and 10.0% (95% CI 6.0-14.0%) respectively.

INTERPRETATION

Almost half of childhood infective encephalitis survivors report incomplete recovery in the long-term; most commonly developmental delay, behavioural abnormality, and neurological impairments (i.e. seizure). Well designed, large-scale prospective studies are needed to better quantify neurodevelopmental sequelae among childhood encephalitis survivors.

Seasonality of Viral Encephalitis and Associated Environmental Risk Factors in Son La and Thai Binh Provinces in Vietnam from 2004 to 2013

In Vietnam, Japanese encephalitis virus accounts for 12-71% of viral encephalitis (VE) cases followed by enteroviruses and dengue virus among identified pathogens. This study is the first attempt to evaluate the seasonality of VE and associated environmental risk factors in two provinces from 2004 to 2013 using a seasonal trend-decomposition procedure based on loess regression and negative binomial regression models. We found seasonality with a peak of VE in August and June in Son La and Thai Binh, respectively. In Son La, the model showed that for every 1°C increase in average monthly temperature, there was a 4.0% increase in monthly VE incidence. There was a gradual decline in incidence rates as the relative humidity rose to its mean value (80%) and a dramatic rise in incidence rate as the relative humidity rose past 80%. Another model found that a 100 mm rise in precipitation in the preceding and same months corresponded to an increase in VE incidence of 23% and 21%, respectively. In Thai Binh, our model showed that a 1°C increase in temperature corresponded with a 9% increase in VE incidence. Another model found that VE incidence increased as monthly precipitation rose to its mean value of 130 mm but declined gradually as precipitation levels rose beyond that. The last model showed that a monthly increase in duration of sunshine of 1 hour corresponded to a 0.6% increase in VE incidence. The findings may assist clinicians by improving the evidence for diagnosis.

Diagnostics and Discovery in Viral Central Nervous System Infections

The range of viruses implicated in central nervous system disease continues to grow with globalization of travel and trade, emergence and reemergence of zoonoses and investments in discovery science. Diagnosis of viral central nervous system infections is challenging in that brain tissue, where the pathogen concentration is likely to be highest, is not readily obtained and sensitive methods for molecular and serological detection of infection are not available in most clinical microbiology laboratories. Here we review these challenges and discuss how they may be addressed using advances in molecular, proteomic and immunological methods.

Consensus guidelines for the investigation and management of encephalitis in adults and children in Australia and New Zealand

Encephalitis is a complex neurological syndrome caused by inflammation of the brain parenchyma. The management of encephalitis is challenging because: the differential diagnosis of encephalopathy is broad; there is often rapid disease progression; it often requires intensive supportive management; and there are many aetiologic agents for which there is no definitive treatment. Patients with possible meningoencephalitis are often encountered in the emergency care environment where clinicians must consider differential diagnoses, perform appropriate investigations and initiate empiric antimicrobials. For patients who require admission to hospital and in whom encephalitis is likely, a staged approach to investigation and management is preferred with the potential involvement of multiple medical specialties. Key considerations in the investigation and management of patients with encephalitis addressed in this guideline include: Which first-line investigations should be performed?; Which aetiologies should be considered possible based on clinical features, risk factors and radiological features?; What tests should be arranged in order to diagnose the common causes of encephalitis?; When to consider empiric antimicrobials and immune modulatory therapies?; and What is the role of brain biopsy?

Encephalitis in Australian children: contemporary trends in hospitalisation

OBJECTIVE

The clinical epidemiology of childhood encephalitis in Australia is inadequately understood. We aimed to describe recent trends in childhood encephalitis-related hospitalisation.

STUDY DESIGN

We identified encephalitis-related hospital admissions (2000-2012) in national datasets among children ≤14 years using ICD encephalitis codes. We calculated hospitalisation rates and analysed trends by year, age, gender, location, indigenous status and aetiology.

RESULTS

Rates of childhood encephalitis hospitalisations significantly declined over an 11-year period (2000-2012; average hospitalisation rate 3.2/100 000). Varicella encephalitis hospitalisations decreased significantly, associated with high levels of varicella vaccine coverage since 2006. Acute disseminated encephalomyelitis (ADEM) was the most common 'specified' cause of encephalitis hospitalisation (15%-17%), and its rate has significantly increased. The highest hospitalisation rates occurred in the <1 year age group (5.8/100 000) and varied by location (highest in Northern Territory). The majority (58.9%) of hospitalised encephalitis had no cause identified; this proportion was highest in the <1 year age group (77%). The most common specified infectious causes included: herpes simplex virus, enterovirus, bacterial meningoencephalitis and varicella. When aggregated, the proportion of childhood encephalitis coded as viral was 21.2%.

CONCLUSION

Hospitalisation of childhood encephalitis has slightly decreased in Australia. High rates of childhood immunisation have been associated with a reduction of varicella-associated encephalitis in Australian children. ADEM, an immune-mediated encephalitis, is the most common recognised cause of encephalitis in children. Young children (<1 year) have the highest admission rates. The high proportion of 'unspecified' encephalitis deaths and hospitalisations is an ongoing challenge.

A Population-Based Acute Meningitis and Encephalitis Syndromes Surveillance in Guangxi, China, May 2007-June 2012

Objectives

Acute meningitis and encephalitis (AME) are common diseases with the main pathogens being viruses and bacteria. As specific treatments are different, it is important to develop clinical prediction rules to distinguish aseptic from bacterial or fungal infection. In this study we evaluated the incidence rates, seasonal variety and the main etiologic agents of AME, and identified factors that could be used to predict the etiologic agents.

Methods

A population-based AME syndrome surveillance system was set up in Guigang City, Guangxi, involving 12 hospitals serving the study communities. All patients meeting the case definition were investigated. Blood and/or cerebrospinal fluid were tested for bacterial pathogens using culture or RT-PCR and serological tests for viruses using enzyme-linked immunosorbent assays. Laboratory testing variables were grouped using factor analysis. Multinomial logistic regression was used to predict the etiology of AME.

Results

From May 2007 to June 2012, the annual incidence rate of AME syndrome, and disease specifically caused by Japanese encephalitis (JE), other viruses, bacteria and fungi were 12.55, 0.58, 4.57, 0.45 and 0.14 per 100,000 population, respectively. The top three identified viral etiologic agents were enterovirus, mumps virus, and JE virus, and for bacteria/fungi were Streptococcus sp., Cryptococcus neoformans and Staphylococcus sp. The incidence of JE and other viruses affected younger populations and peaked from April to August. Alteration of consciousness and leukocytosis were more likely to be caused by JE, bacteria and fungi whereas CSF inflammation was associated with bacterial/fungal infection.

Conclusions

With limited predictive validity of symptoms and signs and routine laboratory tests, specific tests for JE virus, mumps virus and enteroviruses are required to evaluate the immunization impact and plan for further intervention. CSF bacterial culture cannot be omitted in guiding clinical decisions regarding patient treatment.

Clinical characteristics and outcome of clinically diagnosed viral encephalitis in southwest China

Patients with viral encephalitis have a high incidence of morbidity and mortality. We analyze the clinical characteristics and outcome of patients with clinically diagnosed viral encephalitis to investigate possible predictors of prognosis. We retrospectively evaluated 1107 patients diagnosed with viral encephalitis in southwest China from 2009 to 2012 by evaluating their outcomes using the Glasgow Outcome Scale. We compared patient outcome at hospital discharge with long-term follow-up visits, and evaluated the prognostic indicators of the outcome. At hospital discharge, 375 (33.9 %) of the 1107 patients who survived made a full recovery, while 399 (36.0 %), 160 (14.5 %), and 145 (13.1 %) had mild, moderate or severe neurologic sequelae, respectively. Twenty-eight (2.5 %) of the patients died prior to discharge from the hospital. Of the 1027 patients who had follow-up assessments, 658 (64.1 %) made a full recovery, while 213 (20.7 %), 103 (10.0 %), and 19 (1.8 %) had mild, moderate or severe neurologic sequelae, respectively. Six (0.6 %) of the patients died after discharge from the hospital. Use of mechanical ventilation, lower Glasgow coma score, and concurrent seizures are predictors for a poor outcome in patients both at hospital discharge and at long-term follow-up visits.

Acute encephalitis in children: Progress and priorities from an Australasian perspective

Encephalitis is a complex neurological syndrome caused by inflammation of the brain that occurs with highest incidence in children. It is challenging to diagnose and manage due to the variety of aetiologies and non-specific clinical presentations. We discuss the recent progress in clinical case definitions; review recent, large, prospective epidemiological studies; and describe aetiologies. We emphasise infectious causes relevant to children in Australasia but also consider emerging immune-mediated syndromes responsive to immune therapies. We identify priorities for future research in children, given the potential for climate change and international travel to influence the emergence of infectious agents in our region.

Inflammation and epilepsy in the developing brain: clinical and experimental evidence

There is an increasing evidence to support a role of inflammatory processes in epilepsy. However, most clinical and experimental studies have been conducted in adult patients or using adult rodents. The pediatric epilepsies constitute a varied group of diseases that are most frequently age specific. In this review, we will focus on the possible role of inflammation in pediatric epilepsy syndromes. We will first describe the clinical data available and provide an overview of our current understanding of the role of inflammation in these clinical situations. We will then review experimental data regarding the role of inflammation in epilepsy in the developing brain. To summarize, inflammation contributes to seizure precipitation, and reciprocally, prolonged seizures induce inflammation. There is also a relationship between inflammation and cell injury following status epilepticus, which differs according to the developmental stage. Finally, inflammation seems to contribute to epileptogenesis even in the developing brain. Based on the available data, we highlight the need for further studies dissecting the exact role of inflammation in epilepsy during development.

Encephalitis hospitalization rates and inpatient mortality in the United States, 2000-2010

Background

Encephalitis rates by etiology and acute-phase outcomes for encephalitis in the 21^st century are largely unknown. We sought to evaluate cause-specific rates of encephalitis hospitalizations and predictors of inpatient mortality in the United States.

Methods

Using the Nationwide Inpatient Sample (NIS) from 2000 to 2010, a retrospective observational study of 238,567 patients (mean [SD] age, 44.8 [24.0] years) hospitalized within non-federal, acute care hospitals in the U.S. with a diagnosis of encephalitis was conducted. Hospitalization rates were calculated using population-level estimates of disease from the NIS and population estimates from the United States Census Bureau. Adjusted odds of mortality were calculated for patients included in the study.

Results

In the U.S. from 2000–2010, there were 7.3±0.2 encephalitis hospitalizations per 100,000 population (95% CI: 7.1–7.6). Encephalitis hospitalization rates were highest among females (7.6±0.2 per 100,000) and those <1 year and >65 years of age with rates of 13.5±0.9 and 14.1±0.4 per 100,000, respectively. Etiology was unknown for approximately 50% of cases. Among patients with identified etiology, viral causes were most common (48.2%), followed by Other Specified causes (32.5%), which included predominantly autoimmune conditions. The most common infectious agents were herpes simplex virus, toxoplasma, and West Nile virus. Comorbid HIV infection was present in 7.7% of hospitalizations. Average length of stay was 11.2 days with mortality of 5.6%. In regression analysis, patients with comorbid HIV/AIDS or cancer had increased odds of mortality (odds ratio [OR]  = 1.70; 95% CI: 1.30–2.22 and OR = 2.26; 95% CI: 1.88–2.71, respectively). Enteroviral, postinfectious, toxic, and Other Specified causes were associated with lower odds vs. herpes simplex encephalitis.

Conclusions

While encephalitis and encephalitis-related mortality impose a considerable burden in the U.S. in the 21^st Century, the reported demographics of hospitalized encephalitis patients may be changing.

Quality of life and associated socio-clinical factors after encephalitis in children and adults in England: a population-based, prospective cohort study

OBJECTIVE

We sought to measure HRQoL in all-cause encephalitis survivors and assess the impact of various socio-clinical factors on outcome.

METHODS

We used a prospective cohort study design, using the short-form 36 (SF-36) to measure the HRQoL in patients 15 years and older, and the short-form 10 (SF-10) for patients less than 15 years old. We posted questionnaires to individuals six months after discharge from hospital. All scores were normalised to the age- and sex-matched general population. We used multivariate statistical analysis to assess the relative association of clinical and socio-demographic variables on HRQoL in adults.

RESULTS

Of 109 individuals followed-up, we received 61 SF-36 and twenty SF-10 questionnaires (response rate 74%). Patients scored consistently worse than the general population in all domains of the SF-36 and SF-10, although there was variation in individual scores. Infectious encephalitis was associated with the worst HRQoL in those aged 15 years and over, scoring on average 5.64 points less than immune-mediated encephalitis (95% CI -8.77- -2.89). In those aged less than 15 years the worst quality of life followed encephalitis of unknown cause. Immuno compromise, unemployment, and the 35-44 age group all had an independent negative association with HRQoL. A poor Glasgow Outcome Score was most strongly associated with a poor HRQoL. Less than half of those who had made a 'good' recovery on the score reported a HRQoL equivalent to the general population.

CONCLUSIONS

Encephalitis has adverse effects on the majority of survivors' wellbeing and quality of life. Many of these adverse consequences could be minimised by prompt identification and treatment, and with better rehabilitation and support for survivors.