1.Study on the pretence of Japanese encephalitis virus in nature
Journal of Preventive Medicine 2004;14(1):21-26
Haemagglutination Inhibition Technique was applied to study conversion anti-Japanese encephalitis (JE) virus antibodies in pigs in Hoai Duc, Ha Tay, in 2002. The results showed that antibody conversion in pigs occurs year-round. Vero and C6/36 cells were used to isolate JE virus. From 83 mosquito pools and 30 pig blood samples, 7 JE viruses strains were isolated from mosquito pools, and 4 JE viruses strains were isolated from pig blood samples. These JE viruses strains were isolated either in the epidemic or in the non epidemic season. Sequencing of E gene region of JE virus strains that were isolated from mosquitoes and pigs, circulating of genotype I of JE virus in North Vietnam in 2002
Encephalitis Virus, Japanese
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Encephalitis Viruses
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Encephalitis
;
Viruses
2.Pathological findings in a mouse model of Japanese encephalitis infected via the footpad
Tzeh Long Fu ; Kien Chai Ong ; Kum Thong Wong
Neurology Asia 2015;20(4):349-354
We have developed and characterised a mouse model of Japanese encephalitis virus (JEV) infection via
footpad inoculation in order to better mimic viral transmission by mosquito bites. Two-week-old and
5-week-old mice consistently developed signs of infection such as ruffled fur, weight loss, hunchback
posture, tremors, mask-like facies and occasionally, hindlimb paralysis at 4 days post infection (dpi)
and 11-13 dpi, respectively. Most of the animals died within 24 to 48 hours following the onset of signs
of infection, with mortalities of 100% and 33.3% in 2-week-old and 5-week-old mice, respectively.
Mild meningitis and variable parenchymal inflammation with formation of microglial nodules, focal
necrosis and neuronophagia, and perivascular cuffing by inflammatory cells were observed in the
caudate nucleus, putamen, thalamus, cerebral cortex, brainstem, and spinal cord. Viral antigens/RNA
were demonstrated by immunohistochemisty and in situ hybridization, respectively, in most of these
areas as well as in the hippocampus and cerebellum, albeit more focally. The pathological findings in
this mouse model were generally similar to human Japanese encephalitis (JE) and other established JE
models but perhaps, compared to other JEV mouse models, it demonstrates lethal encephalitic infection
more consistently. We believe that our mouse model should be useful to study the pathogenesis of JE,
and for testing anti-viral drugs and vaccines
Encephalitis, Japanese
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Virus Diseases
3.To purify Japanese encaphalitis virus for vaccine production at semiindustrial scale
Journal of Practical Medicine 2003;445(3):19-20
42 lots of Japaness encaphalitis virus were purified from viral infected rat brain mixture, for obtaining 28 lots of vaccine products. All lots of vaccine were met WHO standard through local and national laboratory qualification ultracentrifugal 126000 g within 5 hours demonstrated that saturated ammonium sulphate precipitated procedure had removed 26.4% to 32% of protein, then ultricentyrifugal sucrose had removed almost the rest. Protein contents in producted vaccine reached 6.53-61.3%
Encephalitis, Japanese
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Encephalitis Virus, Japanese
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Viruses
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Vaccines
4.Japanese encephalitis disease and the efficacy of vaccination in Thai Binh province, 2003 - 2007
Diu Van Pham ; Viet Hong Nguyen ; Trang Thi Dang ; Thom Van Nguyen ; Ninh Kim Do ; Hoang Viet Nguyen ; Loan Phuong Do ; Nga Thi Phan
Journal of Preventive Medicine 2008;0(3):54-59
Background: Japanese Encephalitis (JE) is common in the plains and mountainous areas in Asia \u2013 Pacific. Japanese encephalitis vaccine shows effectiveness in protecting children from JE in some countries such as Japan and Korea. Objective: To evaluate the efficacy of Japanese Encephalitis (JE) vaccination in Thai Binh province during 2003-2007. Subject and Method: Prospective, retrospective and sero-epidemiological methods were carried out on 329 samples collected from viral encephalitis patients and tested by JE MAC-ELISA, the positive average was 41.6% (137/329). Result: It had dramatically dropped from 85.2% in 2003 to 8.5 % in 2007 related to the rate of JE vaccination for children from 1 to 5 years old increasing from 49 % in 2003 to 77 % in 2007. Most of JE confirmed cases were un-vaccinated. Conclusion: JE etiology cause viral encephalitis in children in Thai Binh province was reduced thanks to JE vaccination in EPI program for 1 to 5 year old children. But more than 96% (131/136) of viral encephalitis in 15 years old upward was unknown etiology, the need for further study of the etiology cause viral encephalitis in adults.
Japanese encephalitis
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virus encephalitis
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MAC-ELISA
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Vaccine
5.Applying mac-elisa for etiological surveillance of Japanese encephalitis, West Nile and Nam Dinh viruses cause acute encephalitis syndrome, 2003-2004
Journal of Medical Research 2005;36(3):18-24
During 2003 - 2004, in total 976 sera and cerebrospinal fluid samples from patients with acute encephalitis syndrome (AES) were collected from Pediatric Hospital, several Centers of Preventive Medicine and National Institute of Hygiene and Epidemiology, Tay Nguyen for screening viral pathogens cause AES using MAC-ELISA with Japanese encephalitis (JE), West Nile and Nam Dinh virus antigens. Results: Out of 976 sera and cerebrospinal fluid samples of AES patients were screened using JE virus antigen, 46.1% (454/976) cases were confirmed to be JE virus infection. Out of 239 cerebrospinal fluid samples of AES patients were screened by Nam Dinh virus antigen, 13.4% (32/239) cases were confirmed to be Nam Dinh virus infection. Out of 103 sera and cerebrospinal fluid samples of AES patients were screened by West Nile virus antigen, there were no positive result was confirmed with this antigen. To date, JE virus is leading cause of AES in Vietnam, with over 80% cases in children under 15 years old. It should be intensive JE vaccination for all children under 15 years old in order to control JE soon.
Encephalitis, Japanese, West Nile virus
6.Analysis of the Three Dimensional Structure of Envelope Protein of the Japnes Encephalitis virus Isolated in Korea.
Jae hwan NAM ; Soo Lim CHAE ; Eung Jung KIM ; Kyung Sik YOON ; Ho dong LEE ; Hae Wol CHO ; Hyun Chul KOH
Journal of the Korean Society of Virology 1997;27(2):209-216
Three dimensional structures of envelope protein from Korean isolates and Nakayama-NIH strain of Japanese encephalitis virus (JEV) were deduced by a computer program (HyperChem 4.0 Chemplus 1.0) based on the data of the three dimentional structure of Tick-borne encephalitis virus. In the three dimensional structure of envelope protein, neutralizing epitope and T-helper cell recognition site of C-terminal region of Korean isolates were structually similar to those of Nakayama-NIH but the N-terminal region was not. Korean JE isolates were compared with Nakayama-NIH strain by using cross-neutralization antibody test. Neutralizing activities of Korean isolates derived from guinea pigs were higher than those of Nakayama-NIH strain against Korean isolates, although the polyclonal antibody titers of Nakayama-NIH showed 1:160 to 1:640 against Korean isolates. According to the results from three dimentional structures and cross-neutralization analyses, the antigenic difference between Korean JE isolates and Nakayama-NIH strain may be dependent on structural difference of envelope protein.
Animals
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Encephalitis Virus, Japanese
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Encephalitis Viruses*
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Encephalitis Viruses, Tick-Borne
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Encephalitis*
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Guinea Pigs
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Korea*
7.Serological screening of Tick-borne encephalitis (TBE) among Malaysian encephalitis patients.
Ravindran Thayan ; Nor Shahidah Khairullah ; Ho Tze Ming
Tropical biomedicine 2004;21(2):153-6
Tick-borne encephalitis (TBE) is a viral infection of the central nervous system and is caused by tick bites, usually after travel to rural or forested areas. The disease is prevalent in Scandinavia, Western Europe, Central Europe and the former Soviet Union and East Asia including Japan. In Malaysia, so far there are no reported cases of TBE. In the present time, many illnesses have been attributed to traveling to other parts of the world. Thus it is important to carry out TBE prevalence study to determine whether the virus is present among Malaysian population. Samples (sera and CSF) from patients admitted to major MOH hospitals in Peninsular Malaysia and Sabah with a clinical diagnosis of encephalitis but is IgM negative for JE, were tested for TBEV IgM ELISA and TBEV IgG ELISA (DRG, Germany). Out of the 600 samples screened for TBEV IgG, all were non-reactive. In addition, out of the 100 samples screened for TBEV IgM, all the samples were also non-reactive. Our results indicate that currently TBE is not present in the Malaysian population. Among the reasons for this could be lack of the infection agent, absence of the suitable vector or subjects selected for the study did not fit the criteria of possible exposure to TBE infections. Hence we recommend that for any future study, the selection of subjects should include those who returned from tick-infested forested areas.
Encephalitis
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Ticks
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Tick-Borne Encephalitis Virus
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MALAYSIAN
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Immunoglobulin M measurement
8.Analysis of change in viral titers under different conditions in cultured cells persistently-infected with Japanese encephalitis virus.
Chinese Journal of Experimental and Clinical Virology 2007;21(2):147-149
OBJECTIVETo investigate the change of viral titers under different conditions in cultured cells persistently-infected with different strains of Japanese encephalitis virus (JEV) and find out the factors that influence viral multiplication.
METHODSJEV JaGAr-01 and Nakayama wild strains were used to infect human hepatoma cell line KN73 respectively, and the persistent infection model was established. Viral titers were examined by plaque methods using BHK cells. Human nerve fibroblastoma cell line IMR-32 was infected with the strains of the virus that can cause persistent infection, and the thermal sensitivity of the viral strains was measured at 30 degrees C and 37 degrees C. KN73 cells persistently infected with JEV were infected with two JEV strains respectively, and viral superinfection was studied. To explore the replication of the persistently-infected viruses, KN73 and IMR-32 cells were infected with the viral strains.
RESULTSTwo persistently infected viral strains did not show any thermal difference. The results of superinfection were that the viral titers of JaGAr-01 strains were 1.3 and 8.8 percent of the control, respectively, and the viral titers of Nakayama strain were 80 and 1.7 percent of the control, respectively. JaGAr-01 wild strains, Nakayama wild strains and their persistently-infected strains infected KN73 and IMR-32 respectively. The replication of the persistently-infected strains was obviously lower than the wild strains in KN73 cells, however, in IMR-32 cells their replication was similar.
CONCLUSIONSThe two strains of JEV were not found to be temperature-mutant. It is possible that mutant viruses containing DI particles exist in JEV persistently-infected strains. In different cells there may be different host factors hindering the replication of the persistently-infected strains.
Animals ; Cell Line ; Encephalitis Virus, Japanese ; genetics ; physiology ; Encephalitis, Japanese ; virology ; Humans ; Virus Cultivation ; Virus Replication
9.Detection of Japanese encephalitis genotype 1 in central, southern and highland of Viet Nam
Hoang Viet Nguyen ; Loan Phuong Do ; Trang Minh Bui ; Thu Thi Hien Le ; Nga Thi Phan
Journal of Preventive Medicine 2008;97(5):38-45
Background: In recent year, Japanese Encephalitis Virus (JEV) genotype 1 has been detected among isolates from mosquitoes and pig\u2019s blood samples in northern Viet Nam, but there has been no information on the presence of this genotype in the Central, Southern and Highland regions. Objectives: This study aims to detect the Japanese encephalitis genotype 1 in various different geographic regions of Viet Nam. Material and method: Sequence analysis\u2019s of whole E gene of 18 strains isolated from human, mosquitoes and pig\u2019s blood during 2001-2007. Results: 7 strains isolated from pig\u2019s blood and mosquito samples in the Northern, Central, Southern and Highland fell into genotype 1, but 11 others isolated from humans in the Northern and Central regions belonged to genotype 3. Conclusion: This is the first time that JEV genotype 1 was detected in the central, northern, highland Viet Nam and further studies on genotype 1 causing human diseases needs to be carried out.\r\n', u'\r\n', u'
Virus
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Japanese Encephalitis
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genotype 1
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E gene.
10.Advances in research of interchangeable immunization with live attenuated Japanese encephalitis vaccines and inactivated vaccines.
Xuan DENG ; Han Qing HE ; Yang ZHOU ; Rui YAN ; Xue Wen TANG ; Yao ZHU ; Xiao Ping XU ; Hua Kun LYU
Chinese Journal of Preventive Medicine 2022;56(5):554-560
Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia and the Western Pacific, which mainly invades central nervous system. Vaccination is the most important strategy to prevent JE. Currently, both live attenuated Japanese encephalitis vaccines (JE-L) and inactivated vaccines (JE-I) are in use. Due to the supply of vaccines and the personal choice of recipients, there will be a demand for interchangeable immunization of these two vaccines. However, relevant research is limited. By reviewing domestic and foreign research evidence, this article summarizes the current situation of the interchangeable use of JE-L and JE-I, and makes recommendations when the interchangeable immunization is in urgent need, so as to provide reference for practical vaccination and policymaking in China.
Encephalitis Virus, Japanese
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Encephalitis, Japanese/prevention & control*
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Humans
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Immunization
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Japanese Encephalitis Vaccines
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Vaccination
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Vaccines, Inactivated