Consensus guidelines on evaluation and management of suspected acute viral encephalitis in children in India

The emergence of parvovirus B19 as a pathogen in acute encephalitis syndrome

Despite scarcity of data, in recent years, human parvovirus B19 (PVB19) has been emerging as an important pathogen in acute encephalitis syndrome (AES). But, PVB19 virus is mostly looked for only after the exclusion of other common pathogens implicated in AES. Hence, this study was conducted to correlate clinical, radiological, and sequencing data to establish the crucial role of PVB19 in AES. Cerebrospinal fluid and/or serum samples were collected from AES patients as per WHO criteria and tested by ELISA, real-time PCR and bacterial culture sensitivity for various pathogens. PVB19 positive samples were subjected to sequencing. PVB19 attributed to 5% of total AES cases in the present study with fatalities in two of eight cases. Two isolates of PVB19 belonged to Genotype 1 A whereas one belonged to Genotype 3B. On multivariate analysis of predictive symptoms of PVB19 AES cases, blurring of vision (odds ratio [OR] 20.67; p = 0.001) was found to be significant independent predictor of PVB19 AES. Six of eight patients (two encephalitis specific and four nonspecific) had abnormal radiological findings. Hence, being an emerging viral pathogen, PVB19 should be included in the diagnostic algorithm of AES for prompt diagnosis and definitive management to prevent undesired neurological sequelae.

Retrospective analysis of clinico-laboratory parameters, outcome and predictors of scrub typhus co- infection in covid-19 affected children

The objective of this study was to describe clinico-laboratory parameters, outcome and predictors of scrub typhus co- infection in COVID-19 affected children. Ours was a retrospective analysis done in a tertiary care pediatric COVID facility. COVID-19 positive children in the age group of 1 month to 12 years who were tested for scrub typhus co-infection between May to August 2020 were included in the study. In all positive cases, clinical, laboratory, treatment and outcome data were analyzed. Relevant data were compared between scrub typhus confirmed, and suspected but negative patients. All six patients with co-infection had fever for >5 days and four had features of cerebral involvement. These had lymphocytic pleocytosis in cerebrospinal fluid (CSF) analysis and two had eschar. Screening for scrub typhus in persistently febrile children residing in highly endemic areas is highly recommended.

Prevalence, clinico-laboratory features, and the functional outcome of children with scrub typhus meningoencephalitis-a cohort study

Scrub typhus is being reported as the most common cause of childhood meningoencephalitis (ME) in India. Hence, we planned to estimate the proportion of scrub typhus infection among children aged 1 month to 12 years with the clinical diagnosis of ME and to evaluate their demographic, clinical and laboratory characteristics. This cohort study was conducted in the Department of Pediatrics of a tertiary care teaching hospital in south India. One hundred and twenty-seven consecutive children aged 1 month to 12 years with the clinical diagnosis of ME were the participants. Their socio-demographic factors, clinical details, laboratory reports and outcomes were analyzed. The etiological agent was identified in 71 (56%) children. Orientia tsutsugamushi (Scrub typhus) was the most common infection (24.4%), of all children with ME. Children aged ≥5 years were frequently affected by scrub typhus ME. Eschar, capillary leak, hepatomegaly and splenomegaly were the predominant clinical features of scrub typhus ME. Thrombocytopenia and deranged liver function tests were common in scrub typhus ME. To conclude, Orientia tsutsugamushi was the most common organism identified in our study. Prompt recognition of some tell-tale clinical signs of scrub typhus (such as eschar, thrombocytopenia and hepatosplenomegaly), and timely initiation of antibiotics would lead to better outcomes as evident from the study.

Metabolic Disorders among Children Presenting with Acute Encephalopathy

OBJECTIVE

To study the clinicoetiological profile of children presenting with acute noninfectious encephalopathy (NIE) and identify the proportion of children having inborn errors of metabolism (IEM).

METHOD

This descriptive cross sectional study was conducted in a tertiary care centre in Northern India. Consecutive children, aged more than 28 d and less than 12 y, with acute encephalopathy were enrolled after ruling out CNS infection. All children were evaluated on an internally validated structured proforma. A sequential pre-decided battery of tests was applied to determine the cause of encephalopathy. IEM suspects were subjected to TMS/GCMS followed by mutation analysis for confirmation.

RESULTS

Fifty children with noninfectious encephalopathy (NIE) were recruited and metabolic causes were detected in 9 of these children (18%), aged 3 to 42 mo, with female preponderance. The IEMs included lactic acidosis (4), glutaric aciduria (3), isovaleric academia (1), and hyperhomocysteinemia (1). History of previously affected siblings and consanguinity between the parents were important indicators of IEM. MS/MS and mutation analysis were the mainstay of diagnosis in these patients. IEMs contributed to the most common cause amongst cases of NIE.

CONCLUSION

IEMs constitute a significant proportion of NIE in India and a high index of suspicion is required to make the diagnosis.

A systematic review of brain imaging findings in neurological infection with Japanese encephalitis virus compared with Dengue virus

OBJECTIVES

Japanese encephalitis virus (JEV) and dengue virus (DENV) represent important causes of encephalitis in Asia. Brain imaging may provide diagnostic clues about the etiology of infectious encephalitis. We performed a systematic review of brain imaging findings in Japanese encephalitis (JE) and DENV neurological infection (dengue) to identify characteristic lesions.

METHODOLOGY

Five databases were searched. We included all study types and imaging techniques. Laboratory methods were categorized using diagnostic confidence levels. Imaging data were synthesized, and focal findings are presented as proportions for JE and dengue and for subgroups based on diagnostic confidence.

PRINCIPAL FINDINGS

Thalamic lesions were the most reported magnetic resonance imaging finding in both diseases but appeared to occur more often in JE (74% in 23 studies) than dengue (29.4% in 58 studies). In cases diagnosed with antigen or nucleic acid tests, thalamic lesions were reported frequently in both JE (76.5% in 17 studies) and dengue (65.2% in 23 studies).

SIGNIFICANCE

The results suggest that thalamic lesions frequently occur in both JE and dengue encephalitis. No radiological findings were found to be pathognomonic of either disease. Although brain imaging may support a diagnosis, laboratory confirmation with highly specific tests remains crucial.

Is Ambient Weather a Risk Factor for Acute Encephalopathy Outbreaks in Children in Muzaffarpur, Bihar, India? Insight from a 9-Year Analysis

OBJECTIVES

Despite periodic outbreaks, the causes and risk factors of acute encephalitis syndrome (AES) in children of Muzaffarpur, Bihar, India, remain unknown. We explored the correlation between AES caseload and the climate parameters.

METHODS

Data for 1318 hospitalized children with AES during 2012-20 were used. The correlation between AES cases and daily climate parameters (temperature, sunshine, rainfall, humidity and wind speed) for the previous 24, 48 and 72 h were examined using Pearson's and Spearman's rank-order correlation and Poisson regression or negative binomial regression analyses.

RESULTS

Most (91.8%) of the AES cases occurred during the summer season (May-July months), especially June month. Pearson's and Spearman's rank-order correlation analyses revealed that AES caseload had positive correlations with maximum (r = 0.275, ρ = 0.293) and minimum (r = 0.306, ρ = 0.306) temperatures during past 24 h and heat index (r = 0.325, ρ = 0.325) and negative correlation with humidity (r = -0.222, ρ = -0.222) and rainfall (r = -0.183, ρ = -0.183) (all p < 0.05). The correlation was consistent for the climate parameters for the past 24, 48 and 72 h. Regression analysis also documented a significant association of AES cases with daily maximum (β: 0.32-0.36) and minimum (β: 0.53-0.62) temperatures and heat index (β: 0.92-1.03) over past 24, 48 and 72 h (all p < 0.01). The number of AES cases exponentially increased when the daily maximum and minimum temperatures crossed 40°C and 31°C, respectively.

CONCLUSIONS

The climate parameters, especially temperature appears to be a risk factor for AES in children. The definite aetiological role of heat for AES in children needs further exploration.

Utility of the END-IT Score to Predict the outcome of Childhood Status Epilepticus: A Retrospective Cohort Study

Introduction:

Scoring systems to predict outcomes in pediatric status epilepticus (SE) are limited. We sought to assess usefulness of the END-IT score in pediatric SE.

Methodology:

We conducted a retrospective study at a tertiary hospital in New Delhi, India. Children aged 1 month–18 years who presented with seizure for ≥5 min/actively convulsing to emergency were enrolled. END-IT score was calculated and correlated with outcome at discharge using Pediatric Overall Performance Category (POPC) scale, in-hospital mortality, and progression to refractory and super-refractory SE (SRSE).

Results:

We enrolled 140 children (mean age 5.8 years; 67.1% males). Seven children died and 15 had unfavorable outcomes. The predictive accuracy of END-IT at a cutoff of > 2: for unfavorable outcome (POPC score ≥3) was: sensitivity 0.73 (95% CI: 0.45–0.92), specificity 0.94 (95% CI: 0.89–0.98), PPV 0.61 (95% CI: 0.36–0.83), NPV 0.97 (95% CI: 0.92–0.99), positive likelihood ratio (13.09), F1 score (0.666); for death: sensitivity 0.86 (95% CI: 0.42–0.99), specificity 0.91 (95% CI: 0.85–0.95), PPV 0.33 (95% CI: 0.13–0.59), NPV 0.99 (95% CI: 0.96–1.00), F1 score (0.48); for RSE: sensitivity 0.80 (95%CI: 0.28–0.99), specificity 0.90 (95% CI: 0.83–0.94), PPV 0.22 (95% CI: 0.06–0.48) NPV 0.99 (95% CI: 0.96–1.00), F1 score (0.35); for SRSE: sensitivity 0.67 (95% CI: 0.22–0.96) specificity 0.75 (95% CI: 0.66–0.82), PPV 0.22 (95% CI: 0.06–0.48) NPV 0.98 (95% CI: 0.94–0.99), F1 score (0.33).

Conclusion:

We demonstrate utility of the END-IT score to predict short-term outcomes as well as progression to refractory and SRSE for the first time among children with SE.

Cerebrospinal Fluid and Serum C-Reactive Protein among Children with Acute Encephalitis Syndrome

Objectives This study aimed to evaluate the positivity of C-reactive protein (CRP) in cerebrospinal fluid (CSF) and serum in children presented with clinical diagnosis of acute encephalitis syndrome (AES).

Methods A total of 164 children between 6 months and 14 years with clinical diagnosis of AES were investigated. Qualitative CRP (slide agglutination) was determined in CSF and serum sample of each patient. On the basis of clinical examination and investigations, all the patients were divided into four groups as pyogenic meningitis, viral encephalitis, tuberculous meningitis, and cerebral malaria. The positivity of CRP in CSF and serum were compared in these groups.

Results CSF CRP was found to be positive in the majority of patients with pyogenic meningitis and a statistically significant (p ≤ 0.001) association was found between CSF CRP and final diagnosis of AES, while this association was nonsignificant (p = 0.141) in case of serum CRP. When we compared the CSF and serum CRP, serum CRP was found to be more suggestive of tuberculous meningitis, viral encephalitis, and cerebral malaria while CSF CRP was more sensitive and specific for the diagnosis of pyogenic meningitis.

Conclusion The sensitivity and specificity of CSF CRP for pyogenic meningitis was quite high. Serum CRP with a high sensitivity can be used as a screening test for different types of meningitis and cerebral malaria; however, its diagnostic accuracy has yet to be established.

"Rationalization of Empiric Antibiotic Therapy" - A Move Towards Preventing Emergence of Resistant Infections

Antimicrobial resistance is a key factor leading to emerging/ re-emerging infections. Rational antimicrobial therapy or antimicrobial stewardship is one of the important interventions to prevent emergence of resistance. Choosing correct empiric therapy is crucial not only to prevent antimicrobial resistance but also to achieve good treatment outcomes. Antimicrobial therapy can be broadly classified as empiric, definitive/ targeted and preventive. It is in choice of empiric therapy that the largest margin of error exists. Paradoxically, empiric therapy is the most commonly employed therapy since microbiologic results are either not available at initiation of treatment or cannot be sent due to logistic reasons or are negative. In the Indian setting, where penetration of microbiologic diagnostic methods in small cities, towns and rural areas is still fairly low, therapy is largely empiric. Choice of empiric therapy is governed by various factors including likely pathogens, antimicrobial resistance, degree of sickness, site of infection and host co-morbidities. These principles can be applied to any clinical syndrome whether it is fever without focus, infections of the respiratory tract, gastrointestinal tract, abdomen, central nervous system, bone and joint, skin and soft tissue, urinary tract as well as neonatal sepsis and healthcare associated infections. Adherence to published guidelines for syndromic management such as that by the Indian Academy of Pediatrics and Indian Council of Medical Research is strongly recommended. One can tailor these guidelines and suggestions made in this article to an individual setting.

Coronaviruses and the central nervous system

Seven coronavirus (CoV) species are known human pathogens: the epidemic viruses SARS-CoV, SARS-CoV-2, and MERS-CoV and those continuously circulating in human populations since initial isolation: HCoV-OC43, HCoV-229E, HCoV-HKU1, and HCoV-NL63. All have associations with human central nervous system (CNS) dysfunction. In infants and young children, the most common CNS phenomena are febrile seizures; in adults, non-focal abnormalities that may be either neurologic or constitutional. Neurotropism and neurovirulence are dependent in part on CNS expression of cell surface receptors mediating viral entry, and host immune response. In adults, CNS receptors for epidemic viruses are largely expressed on brain vasculature, whereas receptors for less pathogenic viruses are present in vasculature, brain parenchyma, and olfactory neuroepithelium, dependent upon viral species. Human coronaviruses can infect circulating mononuclear cells, but meningoencephalitis is rare. Well-documented human neuropathologies are infrequent and, for SARS, MERS, and COVID-19, can entail cerebrovascular accidents originating extrinsically to brain. There is evidence of neuronal infection in the absence of inflammatory infiltrates with SARS-CoV, and CSF studies of rare patients with seizures have demonstrated virus but no pleocytosis. In contrast to human disease, animal models of neuropathogenesis are well developed, and pathologies including demyelination, neuronal necrosis, and meningoencephalitis are seen with both native CoVs as well as human CoVs inoculated into nasal cavities or brain. This review covers basic CoV biology pertinent to CNS disease; the spectrum of clinical abnormalities encountered in infants, children, and adults; and the evidence for CoV infection of human brain, with reference to pertinent animal models of neuropathogenesis.

Clinico-epidemiological Study of Viral Acute Encephalitis Syndrome Cases and Comparison to Nonviral Cases in Children from Eastern India

Objectives:

The objective is to study the clinico-epidemiological features of viral acute encephalitis syndrome (AES) cases and compare them with nonviral AES cases in children from Eastern India.

Methods:

This prospective observational study was conducted in the department of pediatrics of a tertiary care teaching hospital in Eastern India over 18-month period. Children (6 months to 15 years) with acute onset of fever (≥37.5°C) and a change in mental status (including symptoms such as confusion, disorientation, coma, or inability to talk) and/or new onset of seizures (excluding simple febrile seizures) were included in the study. The main outcome measures were the etiology and proportion attributed to viruses causing AES with clinical correlation.

Results:

Of 834 of clinically suspected AES cases, viral etiology could be confirmed in 136 (16.3%) cases (herpes simplex virus-1 [HSV-I] was most common). The 5–15 years' age group was most commonly affected (boys > girls). More cases occurred from July to November. The presence of rash and Glasgow Coma Scale <8 at admission was significantly higher in viral AES. During hospitalization, development of shock, ventilatory requirement, duration of stay, and mortality was significantly higher in viral AES. On neuroimaging, global cerebral injury was common in HSV, Japanese encephalitis, and varicella-virus AES.

Conclusions:

Viral etiology forms a significant proportion of pediatric AES. Morbidity and mortality are high in viral compared to nonviral AES. Herpes encephalitis (HSV-I) is the most common cause of pediatric AES in Eastern India. Viral AES has poor prognosis compared to nonviral AES.

Diagnosis and Management of Acute Encephalitis in Children

Acute encephalitis is a common cause of death and neurodevelopmental problems in children. The causative agents are numerous including infectious agents such as viruses, bacteria, mycobacteria and protozoa; para-infectious and immune mediated disorders such as acute disseminated encephalomyelitis (ADEM) and autoimmune encephalitis, especially the recently described anti-NMDA receptor encephalitis. Also, many viral associated encephalopathies such as acute necrotizing encephalopathy can mimic the presentation of acute encephalitis. In this article, authors describe the approach to the diagnosis and management of acute encephalitis in children.

NMR metabolomics of cerebrospinal fluid differentiates inflammatory diseases of the central nervous system

BACKGROUND

Myriad infectious and noninfectious causes of encephalomyelitis (EM) have similar clinical manifestations, presenting serious challenges to diagnosis and treatment. Metabolomics of cerebrospinal fluid (CSF) was explored as a method of differentiating among neurological diseases causing EM using a single CSF sample.

METHODOLOGY/PRINCIPAL FINDINGS

1H NMR metabolomics was applied to CSF samples from 27 patients with a laboratory-confirmed disease, including Lyme disease or West Nile Virus meningoencephalitis, multiple sclerosis, rabies, or Histoplasma meningitis, and 25 controls. Cluster analyses distinguished samples by infection status and moderately by pathogen, with shared and differentiating metabolite patterns observed among diseases. CART analysis predicted infection status with 100% sensitivity and 93% specificity.

CONCLUSIONS/SIGNIFICANCE

These preliminary results suggest the potential utility of CSF metabolomics as a rapid screening test to enhance diagnostic accuracies and improve patient outcomes.

Emergence of Orientia tsutsugamushi as an important cause of Acute Encephalitis Syndrome in India

Background

Acute Encephalitis Syndrome (AES) is a major seasonal public health problem in Bihar, India. Despite efforts of the Bihar health department and the Government of India, burden and mortality of AES cases have not decreased, and definitive etiologies for the illness have yet to be identified.

Objectives

The present study was undertaken to study the specific etiology of AES in Bihar.

Methods

Cerebrospinal fluid and/or serum samples from AES patients were collected and tested for various pathogens, including viruses and bacteria by ELISA and/or Real Time PCR.

Findings

Of 540 enrolled patients, 33.3% (180) tested positive for at least one pathogen of which 23.3% were co-positive for more than one pathogen. Most samples were positive for scrub typhus IgM or PCR (25%), followed by IgM positivity for JEV (8.1%), WNV (6.8%), DV (6.1%), and ChikV (4.5%).M. tuberculosis and S. pneumoniae each was detected in ~ 1% cases. H. influenzae, adenovirus, Herpes Simplex Virus -1, enterovirus, and measles virus, each was detected occasionally. The presence of Scrub typhus was confirmed by PCR and sequencing. Bihar strains resembled Gilliam-like strains from Thailand, Combodia and Vietnam.

Conclusion

The highlights of this pilot AES study were detection of an infectious etiology in one third of the AES cases, multiple etiologies, and emergence of O. tsutsugamushi infection as an important causative agent of AES in India.

Acute encephalitis syndrome (AES) is a dreaded disease in India including the state of Bihar. Every year several people specially children, succumb to this disease and often the survivors are left with permanent residual disorders. The present research throws light on specific etiological agents that may cause AES and have found scrub typhus to be an important etiology. Knowing the specific etiology would help in definitive management of the patients that may improve the outcome both in terms of morbidity and mortality, as well as help the policy makers to take specific action for prevention and control of the disease.

Critical Illness Scoring Systems: Sequential Organ Failure Assessment, Acute Physiology and Chronic Health Evaluation II, and Quick Sequential Organ Failure Assessment to Predict the Clinical Outcomes in Scrub Typhus Patients with Organ Dysfunctions

Background and Aim

Scrub typhus (ST) is an acute infectious disease of variable severity caused by Orientia (formerly Rickettsia) tsutsugamushi. The disease can be complicated by organ dysfunctions and the case fatality rate (CFR) is approximately 15%, which further rises with the development of severe complications. We studied the clinical features of the ST and the performance of critical illness scoring systems (CISSs) - Acute Physiology and Chronic Health Evaluation (APACHE) II, sequential organ failure assessment (SOFA), and quick SOFA (qSOFA) in predicting the clinical outcomes in complicated ST (cST) patients admitted to the emergency department.

Study Design and Methods

A prospective observational study was done in 50 patients diagnosed to have cST with one or more organ dysfunctions. Clinical features and laboratory parameters were recorded and the patients were followed up until the end of their stay in the hospital. APACHE II, SOFA, and qSOFA scores at admission were calculated and were analyzed in predicting the clinical outcomes.

Results

The median SOFA, APACHE II, and qSOFA scores of the cohort were 7 (interquartile range [IQR] = 13-22), 8 (IQR = 5-11), and 2 (IQR = 1-3), respectively. The median duration of in-hospital stay was 9 (IQR 5-11) days and overall CFR was 8%. On bivariate analysis, both SOFA (P = 0.031) and qSOFA (P = 0.001) predicted mortality. However, only SOFA score correlated with the in-hospital stay duration (Pearson's correlation = 0.311, P = 0.028).

Conclusion

Among the three CISSs studied, the SOFA score correlated with in-hospital stay duration and mortality, whereas the qSOFA score formed a simple as well as a convenient tool in predicting the mortality in patients of cST with organ dysfunction.

Wernicke's encephalopathy in exclusive breastfed infants

BACKGROUND

Kashmir has a population that largely consumes polished rice which is deficient in thiamine. Furthermore, lactating women in this region are prone to severe thiamine deficiency because of their traditional food avoidance practices. Infantile beriberi is common in exclusively breastfed infants of thiamine deficient mothers in Kashmir.

METHODS

This was a one year prospective hospital-based study. We included 50 exclusively breastfed infants in our study. All patients were evaluated as per unit protocol including complete septic workup and metabolic workup. Most of our patients belonged to low and middle income group families, and mothers were on customary dietary restriction. Demographic and anthropometric data were collected from all the study participants. In addition, data regarding the treatments received by the study population and overall mortality were collected.

RESULTS

The mean age, male:female ratio, and mean weight of the study population were 3.15±0.97 months, 1.5:1, and 5.1±1.1 kg, respectively. Traditional food avoidance practices were followed by 80% of the mothers. Irritability was observed in 40 (80%) patients. Blepharoptosis was observed in 30 (60%). Septic workup including cerebro spinal fluid analysis was normal in all patients. Predominant magnetic resonance imaging finding was bilateral basal ganglia hyperintensity. Whole blood thiamine diphosphate levels showed a drastic decrease (10-49 nmol/L). Ten percent of the study infants died.

CONCLUSION

In exclusively breastfed infants, we observed acute infantile encephalopathy with epidemiological, clinical, biochemical, and radiological features suggestive of infantile Wernicke's encephalopathy and a favourable therapeutic response to thiamine supplementation during the acute stage.

Cytokines Interleukin 4 (IL-4) and Interleukin 10 (IL-10) Gene Polymorphisms as Potential Host Susceptibility Factors in Virus-Induced Encephalitis

Background

This study aimed to analyze and explore the relationship between the cytokines IL-4 and IL-10 in relation to gene polymorphism and their respective effects on the susceptibility to virus-induced encephalitis.

Material/Methods

From January 2012 to June 2013, 112 patients with virus-induced encephalitis (the case group and 109 healthy individuals (the control group) were recruited for the purposes of this study. The functional variations that IL-4 and IL-10 genes exhibit were detected through the use of a function analysis and selection tool for single-nucleotide polymorphisms (FASTSNP). The genotypes of IL-4 were rs2227283 and IL-4 rs2227288, and the genotypes of IL-10 were rs1800871 and IL-10 rs1800872. These genotypes were respectively assessed using direct sequencing.

Results

IL-4 rs2227283 and IL-10 rs1800871 have no correlation in with risk of virus-induced encephalitis (both P>0.05)

GA and AA genotypes were related to IL-4 rs2227288 and GT, while TT and GT + TT genotypes were related to IL-10 rs1800872. These were highlighted as being risk factors in virus-induced encephalitis (all P<0.05). However, the duration of fever, white blood cell (WBC) count, C-reactive protein (CRP), neutrophils, and lymphocytes and monocytes of virus-induced encephalitis patients with IL-4 rs2227288 and IL-10 rs1800872 all displayed significant differences (all P<0.05). Frequencies of GAGT and CAGT haplotypes were evaluated and deemed to be of statistical significance and subsequently were highlighted as being risk factors in virus-induced encephalitis (all P<0.05).

Conclusions

IL-4 rs2227288 and IL-10 rs1800872 may contribute to an increased risk for virus-induced encephalitis. Through use of direct sequencing, we showed that genotypes of IL-4 rs2227288 and IL-10 rs1800872 may have particular host susceptibility to virus-induced encephalitis.

Diagnostic Approach to Viral Acute Encephalitis Syndrome (AES) in Paediatric Age Group: A Study from New Delhi

Introduction

Acute Encephalitis Syndrome has heralded the emergence of multiple virulent pathogens, which may result in severe morbidity and mortality. In India, encephalitis is not notified and there has been a dearth of analysis for trends in encephalitis death rates and causation. A downward trend has been observed in encephalitis deaths, due to 'known' causes, which can be largely explained by improvement in diagnostic, treatment, and prevention methods. There is still a very high proportion of encephalitis deaths in developing countries, where the aetiological diagnosis of the pathogen is not established and thus, lies the importance of monitoring encephalitis morbidity and mortality with a view to improve pathogen diagnosis and identify emerging infectious diseases.

Aim

To formulate a diagnostic approach to viral acute encephalitis syndrome in paediatric age group.

Materials and Methods

A cross-sectional study including 50 paediatric patients, clinically diagnosed with acute encephalitis syndrome using WHO criteria was conducted. The CSF of all the patients was evaluated to diagnose the aetiology for viral pathogens. ELISA was used for diagnosing Japanese encephalitis and dengue encephalitis; and multiplex real time PCR was used for detecting HSV-1, HSV-2, Varicella zoster virus, Mumps virus, Enterovirus and Parechovirus.

Results

Confirmed diagnosis was established in 11 (22%) of 50 cases. A confirmed or probable viral agent of encephalitis was found in 7 (14%), bacterial agent was found in 2 (4%), non-infectious aetiology was found in 2 (4%). Fatal outcome was independently associated with patient age.

Conclusion

Despite extensive testing, the aetiologies of more than three fourth of the cases remains elusive. Nevertheless the result from the present study may be useful for future design of early diagnosis and treatment of the disease. New strategies for pathogen identification and continued analysis of clinical features and case histories should help us improve our ability to diagnose, treat and prevent encephalitis.

Update and new insights in encephalitis

Infectious encephalitis is a rare but severe medical condition resulting from direct invasion of the brain by viruses, bacteria, fungi or parasites, or indirect post-infectious immune or inflammatory disorders when the infectious agent does not cross the blood-brain barrier. Infectious encephalitis cases represent an interesting and accurate sentinel to follow up on trends in infectious diseases or to detect emerging infections. Using Pubmed and Embase, we searched the most relevant publications over the last years. We present here an update on the important findings and new data recently published about infectious encephalitis.

Development of a novel rapid micro-neutralization ELISA for the detection of neutralizing antibodies against Chandipura virus

BACKGROUND

Chandipura virus (CHPV) is a leading cause of acute encephalitis with high mortality in paediatric population in India. A micro-neutralization ELISA (MN-ELISA) assay was developed for the detection of neutralizing antibodies (Nab) against CHPV. This novel method gives read-out in the form of ELISA optical density (OD) values and has a shorter turn-around time (TAT) as compared to the conventional cytopathic effect (CPE)-based neutralization assay (MN-CPE). The assay was developed using an Indian strain of CHPV. During the development of the assay different parameters such as cell count, dilution of primary and secondary antibodies and time point for the test termination were optimized. The new and conventional assays were run in parallel where known positive and negative human serum samples were used as test controls. The conventional MN-CPE was terminated at 48h post-infection (p.i.) and stained with Amido black, while in the new assay, MN-ELISA was terminated at pre-determined 18h p.i. and the infected cells were fixed with acetone, followed by in-situ ELISA. Results of both the assays were compared. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the new test was 100% when compared with the conventional MN-CPE method as a 'gold standard'. The MN-ELISA showed two-fold higher antibody titer in one sample and one sample was additionally positive than MN-CPE ELISA.

CONCLUSION

The MN-ELISA is rapid, more sensitive and read-out of results is by measurement of OD, which could be more accurate than manual observation of reduction in CPE. This novel test could be used as an alternative to the conventional MN-CPE based assay in sero-surveillance and in future vaccine studies.

Virus and Immune-Mediated Encephalitides: Epidemiology, Diagnosis, Treatment, and Prevention

Virus encephalitis remains a major cause of acute neurological dysfunction and permanent disability among children worldwide. Although some disorders, such as measles encephalomyelitis, subacute sclerosing panencephalitis, and varicella-zoster virus-associated neurological conditions, have largely disappeared in resource-rich regions because of widespread immunization programs, other disorders, such as herpes simplex virus encephalitis, West Nile virus-associated neuroinvasive disease, and nonpolio enterovirus-induced disorders of the nervous system, cannot be prevented. Moreover, emerging viral disorders pose new, potential threats to the child's nervous system. This review summarizes current information regarding the epidemiology of virus encephalitis, the diagnostic methods available to detect central nervous system infection and identify viral pathogens, and the available treatments. The review also describes immune-mediated disorders, including acute disseminated encephalomyelitis and N-methyl-D-aspartate receptor antibody encephalitis, conditions that mimic virus encephalitis and account for a substantial proportion of childhood encephalitis.