Characterization of the Complete Genome of Chikungunya in Zhejiang, China, Using a Modified Virus Discovery Method Based on cDNA-AFLP

BACKGROUND Chikungunya (CHIK) virus is a mosquito-borne emerging pathogen presenting great health challenges worldwide, particularly in tropical zones. Here we report a newly detected strain of CHIK, Zhejiang/chik-sy/2012, in China, a nonindigenous region for CHIK, using a modified approach based on the classic cDNA-AFLP. We then performed etiological and phylogenetic analyses to better understand its molecular characterization and phylogenetic pattern, and also to aid in further evaluating its persistence in Southeast Asia. METHODS By using this modified procedure, we determined for the first time the complete genome sequence of the chikungunya virus strain, Zhejiang/chik-sy/2012, isolated in 2012 from a patient in Zhejiang, China. Sequence analyses revealed that this positive single strand of RNA is 12,017 bp long. We found no single amino acid mutation in A226V, D284E and A316V. Phylogenetic analysis showed that our strain shared the greatest homology with a strain isolated in Taiwan, which was derived from a strain from Indonesia. Chik-sy/2012 is in a different clade from other CHIK viruses found in China previously. CONCLUSIONS A modified cDNA-AFLP in virus discovery was used to isolate the first CHIK and the first complete genome sequence of virus strain chik-sy/2012 in 2012 from a patient with CHIK fever in Zhejiang, China. The infection displayed great phylogenetic distance from viruses detected in Guangdong, China, in 2008 and 2010, since they were derived from another evolutionary lineage. Additional molecular epidemiology data are needed to further understand, monitor and evaluate CHIK in China.