Study on the complete sequence of CA24 variant isolated during the acute hemorrhagic conjunctivitis outbreaks in Zhejiang province during 2002 to 2010 / 中华流行病学杂志

ABSTRACT

Objective To analyze the genetic characteristics of the complete sequence of coxsackievirus A24 variant(CA24v) isolated from acute hemorrhagic conjunctivitis (AHC) outbreaks in Zhejiang province during 2002 to 2010.Methods Complete sequences of CA24v epidemic strains isolated in different years were amplified under the RT-PCR assay,while the sequences of whole genome,VP1,and 3C region of Zhejiang strains were compared with epidemic strains isolated in other areas of China and abroad.Results The whole genome of Zhejiang CA24v strains isolated in 2002 and 2010 was 7456-7458 bp in length,encoding a polyglutamine protein which containing 2214 amino acid residues.There was a insertion with T on site 97 and 119 within 5' non-coding region between epidemic strain Zhejiang/08/10 and strains isolated in 2002.The rates of amino acid homology among Zhejiang/08/10 and other strains isolated since 2002 were between 94.7％ and 100.0％.Compared with the representative strains circulated within the recent 60 years,the largest average amino acid variations had been occurred on region 2A and 3A,with the ratios as 8.4％ and 7.3％ respectively.The smallest variation happened in region 3D,with the ratio only as 1.9％.The rates of stable amino acid variation on the whole genome between strains isolated since 1987 and 2002 were 38 and 20.P-distance within groups appeared that region 3C was more stable than VP1 of strains isolated in 2002-2010,and the 3D of early strain Jamaica/10628/87 might have had a nature of recombination but not observed on those epidemic strains in recent years.Conclusion Within the evolution of CA24v strains,the time course was more significant than the geographical differences.There had been sporadic epidemics of AHC caused by CA24v in Zhejiang province since 2002.