Molecular characterization of full-length genome of Japanese encephalitis virus (KV1899) isolated from pigs in Korea

We have determined the complete nucleotide and deduced amino acid sequences of the Japanese encephalitis virus (JEV) strain KV1899, isolated from a fattening pig in Korea. In comparison with 22 fully sequenced JEV genomes currently available, we found that the 10,963-nucleotide RNA genome of KV1899 has a 13-nucelotide deletion in the 3' non-translated variable region and 53 unique nucleotide sequences including 3' non-translated region (NTR). Its single open reading frame has a total of 28 amino acid substitutions. Comparison of the KV1899 genomic sequence with those of the 21 fully sequenced JEV strains in published databases showed nucleotide homology ranging from 97.4% (Ishikawa strain) to 87.0% (CH2195 strain). Amino acid homology with KV1899 strain ranged from 96.4% (K94P05) to 91.0% (GP78). The KV1899 showed the highest nucleotide homology with Ishikawa strain and the highest amino acid homology with K94P05. We performed an extensive E gene based phylogenetic analysis on a selection of 41 JEV isolates available from the GenBank. Compared with Anyang strain, isolated from a pig in 1969, that is current live vaccine strain for swine in Korea, the homology of nucleotide sequence in envelope gene was only 87.1%. The prM gene of the isolate was closely related with those of Ishikawa and K94P05 strains, which were grouped into genotype I of JEV.

Sero-positivity of domestic animals against Japanese encephalitis in Bareilly area, U.P.

A study on seroprevalence of Japanese Encephalitis (JE), West Nile (WN) and Dengue-2 (DN-2) was undertaken in and around Bareilly, Uttar Pradesh to explore the role of non-human hosts in the natural cycle of these infections. A total of 1449 animal sera samples collected from 104 dogs, 170 pigs, 170 horses, 333 buffaloes, 252 cattle, 168 sheep and 252 goats were screened for antibodies against JE, WN and DN-2 by Micro-haemagglutination inhibition (HI) test employing 4 to 16 HA units of JE, WN and DN-2 antigens. The HI positivity against JE was found in dogs (55.77%) followed by pigs (40%), horses (37.65%), buffaloes (21.92%), goats (17.86%), sheep (2.38%) and cattle (1.98%). The seropositivity against WN was relatively lower with 24.04% in dogs, pigs (27.65%) horses (25.88%) buffaloes (13.81%), goats (6.75%), cattle (1.19%) and nil in sheep. The seropositivity against DN-2 was lowest among all the three infections with 15.88% in horses, in dogs (15.38), pigs (11.76%) buffaloes (7.81%) and 3.97% in goats. All the cattle and sheep sera gave negative results against DN-2 antigen. The study showed endemicity of the infections in this area.

Seroepidemiological survey on dengue and Japanese encephalitis virus infections in Asian monkeys.

To investigate the ecology of dengue and Japanese encephalitis (JE) viruses in the forest in Asia, a seroepidemiological survey was carried out on 358 Southeast Asian cynomolgus (Macaca iris), 33 Indian bonnet (Macaca radiata) and 37 Japanese (Macaca fuscata) monkey sera by a plaque reduction neutralization test. The results indicated that Southeast Asian monkeys were naturally infected with these viruses but the frequency of antibody to them varied considerably according to the geographical origin of the monkeys. The frequency of antibody to one or more types of dengue virus were 87.2, 49.5, 34.3, 34.2 and 14.9% in Malaysian, Vietnamese, Cambodian, Indonesian and Filipino cynomolgus monkey sera, respectively. None of the Indian bonnet monkey sera neutralized type 1 dengue virus which was the only virus type examined with this monkey species. Monkey sera collected in Japan where dengue virus infection had not been known since 1944 did not significantly neutralize dengue viruses. JE virus antibody was detected at 29.7, 9.0, 8.6, 2.7, 1.4 and 0% in Japanese, Cambodian, Vietnamese, Indonesian, Filipino and Malaysian monkey sera respectively.