OBJECTIVETo understand the hereditary and variant characteristics of rubella virus(RV), especially the strains isolated from China, investigating the epidemical trend and variation principle of RV.

METHODSThe envelope glycoprotein E1 gene was amplified from rubella virus by RT-PCR. After sequencing, the gene sequence was handled by the software DNASTAR and the phylogenetic tree was drawn to analyze the molecular epidemiological characteristics of RV.

RESULTSThe sequence of RV strain JR23 was sequenced, the phylogenetic tree was drawn taking 30 strains isolated at different times and locations in GenBank, including three strains from China as reference. The regions that encode the peptides which react with the HI antibody and the neutralization antibody were compared to show if there was any amino acid mutation in the sequence. (1) In general, the nucleotide and amino acid sequences of RV were highly conserved. The four strains isolated from China had relatively large variations. Strain 379 and strain BRD constituted genotype II, which is different from the other 29 strains. Further study is needed to understand their heritable resources and biological characteristics. (2) Strain JR23 showed little difference from the strains that were epidemic during 1960s in UK, USA and Japan, so maybe it is the derivative strain of that in epidemic 1960s. But the accurate epidemic time is not known.

CONCLUSIONThere are differences among areas and time in epidemics of rubella. The mobility and the region difference seem to be the key factors that affect the epidemic characteristics of RV.