A prospective multicenter study of childhood encephalitis in Greece

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children's hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Assessment of a multiplex RT-PCR for Simultaneous, Rapid Screening of Common Viral Infections of Central Nervous System: A Prospective Study for Enteroviruses and Herpesviruses

Introduction

Acute meningitis is a common neurological disorder that affects both children and adults and has a high mortality rate. This study aimed to create a multiplex reverse transcriptase PCR system for screening clinical samples for the presence of the two viruses currently considered to be the most common causes of acute meningitis in Asia.

Materials and Methods

A single-tube RT multiplex PCR assay was developed and tested for sensitivity and specificity using primers that have been commonly used to screen for herpes simplex viruses 1 and 2 (HSV-1/2) and enterovirus (EV) in clinical samples. The procedure was then used to screen 303 clinical samples for the target viruses, which included 101 feces samples, 101 throat swabs, and 101 cerebrospinal fluid (CSF) samples obtained from 101 hospitalized Iranian children with suspected viral meningitis/meningoencephalitis, and the findings were compared to those of an RT monoplex PCR method.

Results

The RT-PCR approach demonstrated high precision, with no non-target virus amplification. The results of using this assay to screen clinical samples revealed that RT monoplex PCR had the same sensitivity as RT multiplex PCR for the three different types of specimens.

Conclusions

This newly developed multiplex RT-PCR method is a simple, fast diagnostic tool that can be used to screen clinical samples for viruses that cause acute meningitis/meningoencephalitis in children.

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children's hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Diagnosis and Therapy of Infectious Encephalitis in Children: A Ten-Years Retrospective Study

BACKGROUND

Infectious encephalitis represents a rare but potentially severe clinical condition. However, limited international data are available in pediatric age.

METHODS

We conducted a retrospective study to review (a) the clinical presentation; (b) laboratory, radiology, and neurophysiology findings; (c) the correlations between these exams and outcome; and (d) the therapy performed.

RESULTS

Fifty-six patients were enrolled [22 female (39.6%), mean age 4.7 years, IQR 0.7-8.7 years], 19.6% presented neurologic sequelae. HSV was the single most frequently isolated pathogen (19.6%), although in most cases, the etiology remained undefined. 41.1% children presented prodromal before the development of neurologic signs. Fever was the most frequent constitutional symptom (83.9% of cases). Cerebrospinal fluid was normal in 48.5% of cases and electroencephalograpy in 24.5% cases. Brain computed tomography scans was normal in 33 (91.7%) cases, while cerebral magnetic resonance imaging (MRI) showed pathologic findings in 62.5% of cases. MRI was the only parameter associated with neurologic sequalae [P = 0.01; OR, 8.1 (95% CI: 1.52-42.84)].

CONCLUSIONS

Pediatric encephalitis is a heterogeneous entity with nonspecific clinical and laboratory findings, with undefined etiologies in most times. MRI can play a primary role, both on a diagnostic and prognostic point-of-view, and its role should be implemented and made more accessible. Further studies are needed to define the exact role and timing of steroids.

Study protocol: The clinical features, epidemiology, and causes of paediatric encephalitis in southern Vietnam

Encephalitis is a major cause of morbidity and mortality worldwide. The clinical syndrome of encephalitis consists of altered mental status, seizures, neurologic signs, and is often accompanied by fever, headache, nausea, and vomiting. The encephalitis in children has been known that more common than in adult, with the incidence rate of infants was 3.9 times higher than that of people 20-44 years of age. The reported incidence of hospitalization attributed to paediatric encephalitis ranged from 3 to 13 admissions per 100,000 children per year with the overall mortality ranging from 0 to 7%. There are however more than 100 pathogens that can cause encephalitis and accurate diagnosis is challenging. Over 50% of patients with encephalitis are left undiagnosed despite extensive laboratory investigations. Furthermore, recent studies in high-income settings have suggested autoimmune encephalitis has now surpassed infectious aetiologies, mainly due to increased awareness and diagnostic capacity, which further challenges routine diagnosis and clinical management, especially in developing countries. There are limited contemporary data on the causes of encephalitis in children in Vietnam. Improving our knowledge of the causative agents of encephalitis in this resource-constrained setting remains critical to informing case management, resource distribution and vaccination strategy. Therefore, we conduct a prospective observational study to characterise the clinical, microbiological, and epidemiological features of encephalitis in a major children's hospital in southern Vietnam. Admission clinical samples will be collected alongside meta clinical data and from each study participants. A combination of classical assays (serology and PCR) and metagenomic next-generation sequencing will used to identify the causative agents. Undiagnosed patients with clinical presentations compatible with autoimmune encephalitis will then be tested for common forms of the disease. Finally, using direct- and indirect costs, we will estimate the economic burden of hospitalization and seven days post hospital discharge of paediatric encephalitis in our setting.

Epidemiology, Etiology and Clinical Aspects of Childhood Acute Encephalitis in a Tertiary Pediatric Hospital in Costa Rica

BACKGROUND

Limited data are available on childhood encephalitis in Latin America. Our study aimed to increase insight on clinical presentation, etiology and outcome of children with acute encephalitis in Costa Rica.

METHODS

We conducted a prospective, observational study during an 8-month period at the Hospital Nacional de Niños "Dr. Carlos Sáenz Herrera" in Costa Rica. Case definition was according to "International Encephalitis Consortium" in children <13 years. We analyzed demographic characteristics, clinical symptoms, neurologic imaging, etiology, treatment and mortality.

RESULTS

Forty patients were identified. Mean age was 5 years and 57.5% were male. Most frequently neurologic symptoms were altered mental status (100.0%), headache (57.5%) and seizures (52.5%). Etiology was determined in 52.5% of cases. Probable or confirmed viral etiology was identified in 6 cases (15.0%) and bacterial etiology in also 6 cases (15.0%). A possible etiology was identified in 7 cases (17.5%). Autoimmune encephalitis was diagnosed in 2 patients (5.0%). Enterovirus and Streptococcus pneumoniae were the most common confirmed agents. No cases of herpes simplex virus were found. Etiology of 19 cases (47.5%) remained unknown. Sequelae were reported in 45.0% of patients. Mortality rate was 15.0% (6 cases), 3 caused by virus (adenovirus, human herpesvirus 6, enterovirus), 2 by bacteria (S. pneumoniae, Haemophilus influenzae type b) and 1 of unknown etiology. Diffuse cerebral edema was the most important mortality predictor (P < 0.001).

CONCLUSIONS

Acute encephalitis in our study was associated with significant morbidity and mortality. Early and aggressive antiviral, antibiotic and anticerebral edema treatment is necessary when acute encephalitis is suspected.

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.

Epidemiological Profile of Acute Viral Encephalitis in a Sample of Egyptian Children

INTRODUCTION

Acute encephalitis syndrome (AES) is a considerable public health problem.

AIM

This study was designed to describe the aetiology, demographic features, clinical picture, short-term outcome and risk factors of mortality of children with viral encephalitis in Egyptian children.

METHODS

PCR detection of viruses in the CSF of pediatric patients admitted to the pediatric unit or ICU Cairo University Pediatric hospital presenting with encephalitis syndrome.

RESULTS

Of the 96 patients included in the study, viral etiological agents were detected in 20 cases (20.8%), while 76 patients (79.2%) had no definite viral aetiology. The most abundant virus detected was Enterovirus (EV) in fourteen (14.5%), two (2.1%) were positive for human herpes simplex virus 6 (HSV-6), one (1.0%), human herpes simplex virus1 (HSV-1), one (1.0%) Epstein Barr virus (EBV), one (1.0%), cytomegalovirus (CMV) and one (1.0%) with varicella-zoster virus (VZV). On the short term outcome, 22 (22.9) patients died, and 74 (77.1%) survived. Severity outcome among survival was vegetative in three cases (4%) severe in 9 (12.16%), moderate in 14 (18.9%), mild in 29 (39.2%) and full recovery in 19 (25.6%). Mortality risk factors for younger age, the presence of apnea, the need for mechanical ventilation and the presence of abnormal CT findings were all significantly associated with fatal outcome (p < 0.05).

CONCLUSION

Enterovirus was the most common cause of encephalitis among Egyptian children. Mortality was correlated with younger age and disease severity at admission. Sequelae were high among infected children.

Etiology and prognosis of acute viral encephalitis and meningitis in Chinese children: a multicentre prospective study

BACKGROUND

In China, there were few studies about the pathogens of acute viral encephalitis and meningitis in children in recent years. The aims of this study were to characterize the etiology and prognosis of acute viral encephalitis and meningitis in Chinese children.

METHODS

This was a multicentre prospective study. Two hundred and sixty one viral encephalitis patients and 285 viral meningitis patients were enrolled. The mean age of viral encephalitis and meningitis were 5.88 ± 3.60 years and 6.39 ± 3.57 years, respectively. Real-time reverse transcription PCR and multiplex PCR were used to detect human enteroviruses and herpes viruses in cerebrospinal fluid (CSF) of patients with encephalitis or meningitis. The enzyme-linked immune absorbent assay (ELISA) was used for detecting IgM antibody against Japanese encephalitis virus (JEV) in CSF and against mumps virus, tick-borne encephalitis virus (TBEV), dengue virus and rubella virus in acute serum. The clinical and outcome data were collected during patients' hospitalization.

RESULTS

The etiology of viral encephalitis was confirmed in 52.5% patients. The primary pathogen was human enteroviruses (27.7%) in viral encephalitis. The incidence of sequelae and the fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The etiology of viral meningitis was identified in 42.8% cases. The leading pathogen was also human enteroviruses (37.7%) in viral meningitis. The prognosis of viral meningitis was favorable with only 0.7% patients had neurological sequelae.

CONCLUSIONS

Human enteroviruses were the leading cause both in acute viral encephalitis and viral meningitis in children. The incidence of sequelae and fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The prognosis of viral meningitis was favorable compared to viral encephalitis.

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.

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.

Outcome of children with acute encephalitis and refractory status epilepticus

Acute encephalitis in children is a life-threatening neurological emergency. However, little is reported about the outcome of this devastating illness in the United States. The authors retrospectively reviewed the charts of patients admitted to a regional pediatric intensive care unit with the diagnosis of acute encephalitis between 2006 and 2011. In 41 cases that met the inclusion criteria, the most common presenting symptoms were fever (65.9%), altered mental status (61%), and seizures (58.5%). Eight patients (19.5%) who presented with refractory status epilepticus had a longer median length of stay in the pediatric intensive care unit (46 vs. 4 days; P < .0001) and a significant worsening of Pediatric Cerebral Performance Category score on discharge by 2 or more points (odds ratio 20.38; 95% confidence interval, 2.89-143.52). All children survived to hospital discharge. In conclusion, children with acute encephalitis who present with refractory status epilepticus have a worse neurological outcome and a longer stay in the pediatric intensive care unit.

VGKC complex antibodies in pediatric severe acute encephalitis: a study and literature review

BACKGROUND

Antibodies to surface proteins like voltage-gated potassium channel (VGKC) complexes are increasingly found in different neurologic diseases and encephalitis in adults and recently, in children. Detecting such antibodies can help identify forms of encephalitis that may respond to immuno-therapies. However, there are few reports on VGKC complex antibodies in pediatric severe acute encephalitis.

METHODS

This study retrospectively reviewed antibodies to VGKC, leucine-rich glioma-inactivated 1 (Lgi1), and contactin-associated protein-like 2 (Caspr2) in 46 children with severe acute encephalitis. Published cases of VGKC complex antibodies in pediatric encephalitis in the period of 2000-2012 were also reviewed.

RESULTS

Elevated VGKC complex antibodies (>100pM) were detected in one of the 46 children with severe acute encephalitis. The 4-year and 6-month-old girl presented with seizure and disturbed consciousness. Viral PCR/culture and serologic evidence of influenza A infection was noted. She also had complications of epilepsy, impaired cognition, and altered behavior and psychology. Antibodies to Lgi1 and Caspr2 were not detected. Ten previously published reports revealed that VGKC complex antibodies can occur in children with limbic encephalitis and acute or sub-acute encephalitis.

CONCLUSION

The incidence of VGKC complex antibodies in pediatric severe acute encephalitis is not high with only one (2.2%) of 46 children in this study. And, this is the first report on the association of VGKC complex antibodies and patients with influenza A-related severe acute encephalitis. The mechanism of VGKC complex antibodies in pediatric severe acute encephalitis warrants further study.

Epidemiology of viral encephalitis in 2011

Encephalitis is an inflammation of the brain structures: neurons, vessels or glial cells. However, a consensual definition of the syndrome is difficult to obtain, and it is even more difficult to define encephalitis due a specific agent. Most viruses can be responsible for infectious encephalitis, but the number of encephalitis cases is very limited with regards of the incidence of benign infections from these pathogens. Viruses responsible for encephalitis can be animal-borne, vector-borne or human-to-human transmitted, they can infect preferentially immunocompetent or immunosuppressed patients, and some of them have demonstrated their epidemic potential. Herpes simplex encephalitis is recognized worldwide as the most frequent infectious encephalitis, and the only one with a validated specific treatment. Encephalitis following some viral infections such as measles or rabies can be prevented by vaccination. Unfortunately, effective treatment currently lacks for most encephalitic viral agents identified so far.