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 ; Encephalitis Viruses ; Encephalitis ; Viruses

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 ; Encephalitis Virus, Japanese ; Viruses ; Vaccines

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 ; Encephalitis Virus, Japanese ; Encephalitis Viruses* ; Encephalitis Viruses, Tick-Borne ; Encephalitis* ; Guinea Pigs ; Korea*

During the 1997-2000, 62 children patients with Japanese encephalitis were treated at the Pediatric Department, Vietnam Institute of Traditional Medicine for motor sequelae. The age range was from 8 months to 15 years, and 27 of them were girls. All of them had motor disorders as follows:-52 cases with tetraplegia.-43 cases with severe and complete paralysis (according to Henry degree)- 57 cases with spastic paralysis, and 5 cases with flaccid paralysis.-34 cases with extrapyramidal contracture, and 32 cases with marked axial dystonia
Encephalitis, Japanese ; Encephalitis Viruses, Japanese

The Japanese encephalitis Circulated in Vietnam, especially in the delta provinces of Northern Vietnam. The yearly morbidity rate was 3-5 /100.000 rehabitants. The disease occurred mainly in ages of 1-15, highest in ages of 5-9 and followed by ages of 1-4 and in the summer (May, June, July). Vietnam manufactured the vaccine of encephalitis. It should strengthen the health communication and education and expanded immunization for susceptible ages
Encephalitis, Japanese ; Encephalitis Viruses, Japanese

The analysis of evolutionary of JE virus in the North Vietnam was examined through 1,000 nucleotides of the envelope gene region encoded the E protein. 9 JE virus strains isolated from Vietnamese patients were sequenced and compared with previous published JE virus strains. The results showed that the Vietnamese strains isolated from human brain between 1986 and 1989 clustered in genotype 3. The strains isolated from mosquitoes and pigs between 2001 and 2002 clustered in genotype 1. The emerging JE virus genotype 1 in the North Vietnam among isolates from mosquitoes and pigs in the last few years was recorded for the first time. But JE virus genotype 1 was not detected among isolates from Vietnamese JE patients so far
Encephalitis, Japanese ; epidemiology ; Viruses

In 2004, 13 mosquito samples and 31 pig blood samples were collected at reveral districts, Gia Lai province for virus isolating. Isolating virus was carried out by Aedes albopictus clone C6/36 cells. Identifying virus was implemented by RT-PCR with generate primers of Alpha, Bunya, Flavi viruses and specific primers of Japanese encephalitis and Nam dinh virus. Result: one Japanese encephalitis virus strain was isolated from pig blood samples at Ia Grai, Gialai and six Nam dinh virus strains were isolated from Clux tritaeniorhynchus, Culex vishnui and Culex gelidus at Chu se, Gia Lai.
Encephalitis, Japanese ; Viruses

57 school children were immunized with the Japanese encephalitis (JE) veccine produced at NIHE, Hanoi (Nakayama vaccine strain). One year after the third dose, their sera were examined for the presence of antibodies against a JE virus clinical isolate (HNH 693, isolated in North VietNam). The results showed that 100% of the serum samples had high antibody titers against both HNH 693 and Nakayama strains. the antibody titer against 693 was significantly higher than thatagainst Nakayama. Potency testing of 11 batches of NIHE-JE vaccine were carried out using parallely HNH 693 and Nakayama as challenge strains. It showed that all these 11 vaccine batches had high potency against both challenge strains (2.62 with HNH 693 and 2.38 with Nakayama).
Encephalitis, Japanese ; Encephalitis Viruses, Japanese ; ; child

During the 1998 Japanese Encephalitis epidemic in Northern Vietnam the authors have examined 402 patients which were clinically diagnosed as "acute encephalitis syndrome". The IgM anti JE was evidenced in only 132 cases. The seropositivity is patients under 5 years of age was 33.0 - 42.1% in 1998, compared with 64.2 - 75.7% during the period of 1989 - 1995.
Encephalitis, Japanese ; Encephalitis Viruses, Japanese ; Serologic Tests

Particle agglutination assay (PA) was developed and applied for detecting specific IgM antibodies to Japanese encephalitis virus in recent years. In this study, the sensitivity of PA and MAC-ELISA were 91.11 and 97.77%, respectively
Encephalitis, Japanese ; Encephalitis Viruses, Japanese ; diagnosis