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An outbreak of viral encephalitis occurred in northern India in 2006. Attempts to identify an etiologic agent in cerebrospinal fluid by using reverse transcription-PCR showed positivity to enterovirus (EV) in [...]

To the Editor: Seasonal outbreaks of fatal acute encephalitis syndrome (AES) occur regularly in several parts of India. Japanese encephalitis virus (JEV) has been the major and consistent cause of [...]

Abstract Background Fast, specific identification and surveillance of pathogens is the cornerstone of any outbreak response system, especially in the case of emerging infectious diseases and viral epidemics. This process is generally tedious and time-consuming thus making it ineffective in traditional settings. The added complexity in these situations is the non-availability of pure isolates of pathogens as they are present as mixed genomes or hologenomes. Next-generation sequencing approaches offer an attractive solution in this scenario as it provides adequate depth of sequencing at fast and affordable costs, apart from making it possible to decipher complex interactions between genomes at a scale that was not possible before. The widespread application of next-generation sequencing in this field has been limited by the non-availability of an efficient computational pipeline to systematically analyze data to delineate pathogen genomes from mixed population of genomes or hologenomes. Findings We applied next-generation sequencing on a sample containing mixed population of genomes from an epidemic with appropriate processing and enrichment. The data was analyzed using an extensive computational pipeline involving mapping to reference genome sets and de-novo assembly. In depth analysis of the data generated revealed the presence of sequences corresponding to Japanese encephalitis virus. The genome of the virus was also independently de-novo assembled. The presence of the virus was in addition, verified using standard molecular biology techniques. Conclusions Our approach can accurately identify causative pathogens from cell culture hologenome samples containing mixed population of genomes and in principle can be applied to patient hologenome samples without any background information. This methodology could be widely applied to identify and isolate pathogen genomes and understand their genomic variability during outbreaks.

Abstract Background Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis, with ~50,000 cases reported annually worldwide. Vaccination is the only measure for prevention. Recombinant vaccines are an efficient and safe alternative for formalin inactivated or live attenuated vaccines. Nowadays, incorporation of molecular adjuvants has been the main strategy for melioration of vaccines. Our attempt of immunomodulation is based on targeting antigen presenting cells (APC) "majorly macrophages" by using macrosialin promoter. We have compared the immune response of the constructed plasmids expressing JEV envelope (E) protein under the control of aforesaid promoter and cytomegalovirus (CMV) immediate early promoter in mouse model. Protection of immunized mice from lethal challenge with JEV was also studied. Results The E protein was successfully expressed in the macrophage cell line and was detected using immunofluorescence assay (IFA) and Western blotting. APC expressing promoter showed comparable expression to CMV promoter. Immunization of mice with either of the plasmids exhibited induction of variable JEV neutralizing antibody titres and provided protection from challenge with a lethal dose of JEV. Immune splenocytes showed proliferative response after stimulation with the JEV antigen (Ag), however, it was higher for CMV promoter. The magnitude of immunity provided by APC dominant promoter was non-significantly lower in comparison to CMV promoter. More importantly, immune response directed by APC promoter was skewed towards Th1 type in comparison to CMV promoter, this was evaluated by cytokine secretion profile of immune splenocytes stimulated with JEV Ag. Conclusions Thus, our APC-expressing DNA vaccination approach induces comparable immunity in comparison to ubiquitous promoter construct. The predominant Th1 type immune responses provide opportunities to further test its potency suitable for response in antiviral or anticancer vaccines.

To the Editor: Kakkar et al. recently concluded that the low-quality surveillance data on acute encephalitis syndrome (AES)/Japanese encephalitis (JE) in Kushinagar District, India, provide little evidence to support development [...]

Abstract: Japanese encephalitis virus (JEV) remains one of the major causative agents of pediatric encephalitis. Interaction of dendritic cells (DCs) with innate lymphocytes (NK and NKT) represents a crucial event during anti-viral innate immune response. In the current study, we have tried to understand the interaction between JEV, human monocyte derived DCs (MDDCs), and CD56+ cells (NK+NKT) in-vitro. We have used two JEV strains (i) JE057434 (neurovirulent, wild-type) and (ii) SA14-14-2 (non-neurovirulent, live-attenuated vaccine) to investigate the effect of viral virulence on the functional status of primary human MDDCs. Our preliminary results indicate that replicating JEV induces MDDCs maturation via PI3K and p38 pathways. We also show that the presence of IL2-activated CD56+ cells impart both immunomodulatory and anti-viral effects on DCs infected with JEV. Mechanistic studies illustrate that, IL2-activated CD56+ lymphocytes mediated immunomodulation occurs through direct cell-to-cell contact and TNFα, while the anti-viral effect is dependent on direct cell-to-cell contact. [Copyright &y& Elsevier]

Background & objectives: Japanese encephalitis (JE) is an important aetiology of acute encephalitis syndrome in Gorakhpur division, Uttar Pradesh, India. Two doses of JE vaccine (first during 9-12 months and second during 16-24 months of age) are administered under the Universal Immunization Programme. We conducted surveys to estimate the coverage of JE vaccine and magnitude of missed opportunity for vaccination (MoV) for JE in Gorakhpur division. Methods: To estimate the JE vaccine coverage, cluster surveys were conducted in four districts of Gorakhpur division by selecting 30 clusters by probability proportional to size method in each district, seven children aged 25-36 months were selected from each cluster and their mothers were interviewed about JE vaccination. To estimate the magnitude of MoV, exit surveys were conducted in vaccination clinics in selected health facilities, mothers were interviewed about the vaccination status of their children and vaccines administered to the child on the day of interview. Results: A total of 840 children were surveyed, 210 from each district. The coverages of one and two doses of JE vaccine in Gorakhpur division were 75 per cent [95% confidence interval (CI): 71.0-78.9] and 42.3 per cent (95% CI: 37.8-46.8), respectively. Facility-based exit survey indicated that 32.7 per cent of the eligible children missed JE vaccine. Interpretation & conclusions: The survey results showed that three of the four children aged 25-36 months in Gorakhpur division had received at least one dose of JE vaccine. The coverage of second dose of JE vaccine, however, was low. Failure to administer vaccination simultaneously was the most common reason for MoV for JE vaccine. Training vaccinators about correct vaccination schedule and removing their misconception about administering vaccines simultaneously would substantially improve JE vaccine coverage in Gorakhpur. [ABSTRACT FROM AUTHOR]

Virus neutralizing MAb binding and T helper cell stimulating peptide epitopes from structural and non-structural proteins of Japanese encephalitis virus were delineated. It was observed that priming by T helper peptides potentiated neutralizing antibody response against JE virus. Immunization with chimeric T helper - B cell peptides could thus protect mice from lethal challenge with JE virus.