[Surveillance on the etiology and genetic characteristics of rabies in Hunan province, from 2008 to 2009].

OBJECTIVE: To analyze the etiology of rabies in Hunan province and the genetic characteristics of rabies N gene isolated from 2008 to 2009.

METHODS: Direct immunofluorescence assay (DFA) and nested PCR were employed to detect the monitoring samples including brain tissues of dogs and saliva, serum or urine which were collected in 2008 to 2009, from the rabies patients. Positive samples were sequenced by ABI3730 gene analyzer for the full length of the N gene target. The homology and hpylogeography of the rabies virus were analyzed after the phylogenetic tree was constructed by Blast, Clustal W and Mega 4.0 software.

RESULTS: Of the 1451 tissue samples from the dogs' brain, 31 were positive under DFA and the positive rate was 2.14%. The DFA positive samples were redetected by RT-PCR and the positive rate was 1.17%. 56 samples of saliva, serum and urine samples were detected by RT-PCR from the rabies patients, with 3 positives and the positive rate was 5.36%. The length of nest PCR products were 255 bp. The rates of homology to the nucleotide and the amino acid of rabies N gene were 87.2% - 87.9% after compared to the pasture strain. The phylogenetic tree was successfully built and 20 strains isolated lately belonged to the rabies gene type I.

CONCLUSION: The epidemic situation of human and dogs rabies in Human were relatively stable, with all the isolated rabies virus belonging to genotype I, without any variation.