The Genotype/subtype Distribution And Phylogenetic Analysis Of HCV Among Blood Donors In Five Regions Of China

Objective To investigate the genotype/subtype distribution and phylogeny of HCV among blood donors in five regions of China as well as population genetic characteristics of HCV with different genotypes.Methods A total of 802 plasma sample,positive to anti-HCV confirmatory testing,from Chongqing,Urumqi,Luoyang,Mianyang and Guangxi blood centers are collected,and demographic information such as gender,age,ethnicity and occupation from these blood donors were acquired;HCV Core gene fragment is amplified using reverse transcription nested PCR and sequenced;To build HCV molecular evolutionary tree using MEGA 6.0,and determine HCV genotype and perform phylogenetic analysis;To discuss various HCV genotypes expansion in these regions with population genetics analysis using Arlequin,DNAsp and BEAST;To analyze the correlation between HCV genotype and demographics using SPSS Statistics 17.0.Results A total of 419 HCV plasma samples from five regions with Chongqing(116),Urumqi(104),Miangyang(74),Luo yang(67)and Guangxi(58)were amplified successfully.HCV-1a,1b,2a,3a,3b,6a,6e and 6n were found,and the proportion of above subtypes were 0.72%(3/419),59.90%(251/419),16.95%(71/419),4.53%(19/419),3.82%(16/419),12.41%(52/419),0.95%(4/419)and 0.72%(3/419),respectively.The top two HCV genotypes among blood donors in Mianyang,Urumqi and Luoyang are lb and 2a,yet Chongqing and Guangxi are lb and 6a.The Tajima’s D and Fu’s Fs values of HCV lb and 6a are both negative,and P value is less than 0.05 which indicate that the corresponding HCV populations were under expansion.Significant statistical difference(P<0.05)is found between HCV genotype distribution and age,ethnicity but not and gender,occupation,educational level and marital status.Conclusion China has an abundance of HCV subtypes among blood donors with mainly lb and partially 2a,6a,3a,3b,6e and 6n being found.The dominant genotype of Mianyang,Urumqi and Luoyang blood centers was lb and 2a,and yet Chongqing and Guangxi was 1b and 6a.HCV 6a has a significant trend of expansion,and subtypes 1b,3a and 3b show different degree of expansion.There was a significant statistical correlation between HCV genotype distribution and age and ethnicity.