| BackgroundHepatitis B virus(HBV)infection remains a serious disease burden in China,causing acute or chronic hepatitis B,cirrhosis,hepatic decompensation,and hepatocellular carcinoma(HCC).The infection rate of HBV is high in Hainan province,which is higher in minority,than Han,especially.This study was to analysis the prevalence and infection,the distribution of genotypes and the characteristics of genetic evolution of HBV among Li minority in Hainan province.ObjectFrom July 2014 to October 2015,a total of 1682 were randomly selected among Li minority in Baisha county,Hainan province.MethodsBaseline data of the population were obtained using a questionnaire survey.HBsAg was detected using two different immunological reagents(EIAs).And the HBsAb and HBcAb were detected by chemiluminescence.The samples of HBsAg+were detected by fluorescence quantitative and the DNA of those was amplified.The genotypes and genetic evolution of the samples of DNA+were analyzed.Categorical variables were analyzed using Pearson Chi-Square test or Fisher’s exact test,and quantitative data were analyzed using Mann-Whitney’s or t-test using SPSS(20.0)statistical analysis software.P<0.05 considered the difference was statistically significant.Results1.The number of HBsAg+was 171 among 1682 samples tested by EIAs,and the number of HBsAb+and HBcAb+was 825 and 1145,respectively.The positive rates of HBsAg+、HBsAb+and HBcAb+were 10.2%,51.7%and 71.8%respectively.The positive rate of HBsAg was significantly higher in males than in females(13.6%vs 8.0%).The positive rate of HBsAb in females was significantly higher than that in males(54.8%vs 46.9%),while the positive rate of HBcAb was no significant difference between males and females(72.3%vs 71.5%).Analysis conducted every 10 years showed that the positive rate of HBsAg was the highest in the 30-39 age(36.7%),which was significantly different from other age groups(P<0.001).The positive rates in the 10-19y,60-69y,70-79y and>80y groups were all lower(5.8%,5.2%,3.2%and 3.0%,respectively).The difference of the positive rate among the four age groups was not statistically significant(P>0.05),but was statistically significant with other age groups(P<0.001).The positive rate of HBsAb was higher in the 10-19y and 20-29y groups(59.9%,62.1%),and there were significant differences compared with other age groups(P<0.001).The lowest positive rate of HBcAb was in the 10-19y group(19.2%),followed by the 20-29y group(42.8%),and they were statistically significant difference compared with other groups(P<0.001),respectively.The analysis also showed that the risk factors of HBV prevalence and infection were gender,alcohol consumption and tattooing.2.A total of 141 cases of HBV-DNA were amplified by different PCR primers.The analysis showed that the predominant genotype is D genotype,a total of 91 cases,all of which were D3 subtype.Followed by is the C genotype,a total of 40 cases,including 13 cases of C1 subtype,25 cases of C5 subtype and 2 cases of unknown.The least is B genotype,a total of 10 cases,all of which were B2 subtype.The proportions of D,C and B genotypes were 64.5%,28.4%and 7.1%,respectively.Genetic evolution analysis showed that the D3 genotype was a single branch(except for only four isolates),not associated with D3 sequences elsewhere.The tMRCA of the D3 genotype of the Li minority in Baisha is about in 1962(95%CI:1924-1992).The C genotype sequence is more associated with other parts of the sequence branches and the tMRCA is about in 1820(95%CI:1646-1939).The evolutionary trends of D3 and C genotypes were relatively flat among Li minority in Baisha county.ConclusionThe prevalence and infection rate of HBV among Li minority in Baisha are both high.The positive rate of HBsAg in males was significantly higher than that in females.The positive rate of HBsAb in females was significantly higher than that in males.The difference in positive rates of HBcAb between males and females was not statistically significant.The positive rate of HBsAg was lower in people aged 10-19 and>60 years,and highest among people aged 30-39.The positive rate of HBsAb was highest among people aged 10-29.The positive rate of HBcAb was lowest among people aged 10-19.Besides,the risk factors of HBV prevalence and infection were gender,alcohol consumption and tattooing.In addition,the distribution of HBV genotypes among Li minority is rather special,mainly in the subtype D3,followed by the C5 and C1 subtypes,and the least in the subtype B2.The HBV genetic evolution of the D3 subtype is more independent.The evolutionary trends of the D and C genotypes are relatively flat.Innovation1.The selected subjects were Li minority in Baisha county who communicate less with the outside world relatively.Therefore the crowd characteristics,living customs,and environmental factors were relatively long-term and fixed,which were appropriate to investigate the related risk factors,genotypes,and genetic evolution characteristics of HBV of the crowd.2.Our study of HBV among Li minority in Baisha county is currently the most comprehensive.The research content mainly includes:analysis the rate of HBV prevalence and infection,analysis of risk factors of HBV in this crowd,the analysis of the genotypes/subtypes and genetic evolution of HBV in this crowd.3.It was first discovered that the distribution of HBV genotype was unique,through the analysis of HBV genotypes/subtypes and genetic evolution of Li minority in Baisha county.The D3 subtype was predominant genotype,followed by C5 and C1 subtypes,and the least subtype B2.The number of D3 subtypes and C5 subtypes are the largest,and their proportions are also the highest in China.In addition,the HBV genetic evolution of the D3 subtype is more independent.The evolutionary trends of the D and C genotypes are relatively flat,and no bottleneck period appears. |
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