浙江省农村自然人群隐匿性乙型肝炎病毒感染（OBI）情况及进化特征分析

 【摘要】目的 了解浙江省德清县农村一般人群隐匿性及实际乙型肝炎病毒(hepatitis B virus,HBV)感染情况及病毒株S基因的分子特征。方法 采用多级抽样方法进行横断面调查,在取得调查对象知情同意的基础上采集调查表信息并采血。采用Epidata 3.2软件录入调查表信息,双录入并核对;采用SPSS 18.0软件进行数据分析;对所有样品进行乙型肝炎表面抗原（hepatitis B surface antigen,HBsAg) ELISA检测及病毒载量real time PCR测定,并对HBsAg检测阳性或病毒载量测定阳性的标本进行后续HBV S基因PCR扩增和测序;采用MEGA 5.0软件对测得序列进行进化分析。结果 共调查对象1 720例,调查人群中HBsAg阳性者共162例,隐匿性乙型肝炎病毒感染(occult hepatitis B virus infection,OBI)者共4例,实际HBV感染率为9.65% (166/1 720),OBI感染率为2.57‰ (4/1 558)。显性和隐匿性病毒株病毒载量中位数及四分位数范围分别为866 (425,12 500)IU/mL和314 (216,677.5)IU/mL,前者显著高于后者。HBsAg阳性血清样本扩增得到71株显性病毒株S基因序列,HBsAg阴性血清样本扩增得到4株OBI病毒株S基因序列。OBI病毒株均为C基因型,adrq+血清型。显性HBV病毒株54株为B基因型,其中有2例标本为adw3血清型,其余52例均为adw2血清型;余17株为C基因型,adrq+血清型。OBI病毒株中C基因型的比例显著高于显性HBV病毒株中C基因型的比例。B基因型显性病毒株发生I104F、L109V、I110L、S113T、T126I、P127T、Q129R、M133L、F134L、P135A、T140A、K141I、T143M/S、V159A、Y161F、A166G和R169P突变,C基因型显性病毒株发生I126S、I126T及F158S突变。OBI病毒株发生Q129R、I126T、 M133T及F161Y突变。结论 浙江省德清县一般人群存在一定比例的OBI感染,OBI感染病毒载量较低,OBI病毒株存在氨基酸突变,C基因型为其可能的优势基因型,需重视OBI预防问题。

Prevalence of occult hepatitis B virus infection (OBI) and its phylogenetic analysis among a rural general population in Zhejiang Province, China

【Abstract】Objective To investigate the prevalence and molecular characteristics of both overt and occult hepatitis B virus (HBV) infection in a general rural population in Deqing county,Zhejiang Province. Methods We performed a cross-sectional study based on multi-stage sampling.Questionnaires and blood samples were collected after informed consent.Questionnaire database was built using Epidata 3.2.ELISA detection of hepatitis B surface antigen （HBsAg） and real-time PCR detection of HBV viral load were performed in all blood samples.PCR amplification and sequencing of HBV S gene were further performed in HBsAg-positive or HBV viral loadpositive samples.Phylogenetic analysis was performed using MEGA5.0 software.Data analysis was done using SPSS 18.0 software. Results Questionnaires and parallel blood samples of 1 720 subjects were collected.HBV prevalence was 9.65% (166/1 720),with 162 HBsAg positive cases and 4 occult HBV infection (OBI) cases.OBI prevalence was 2.57‰ (4/1 558).HBV viral load in overt HBV strains was significantly higher than that in OBI strains with the medians and inter-quatile ranges 866 (425,12 500) IU/mL and 314 (216,677.5) IU/mL respectively.All of the OBI strains were genotype C and serotype adrq+.While 54 of 71 overt HBV strains were genotype B,of which 2 were serotype adw3 and 52 were serotype adw2,and the other 17 were genotype C and serotype adrq+.The proportion of genotype C was significantly higher in OBI strains than in overt HBV strains.I104F,L109V,I110L,S113T,T126I,P127T,Q129R,M133L,F134L,P135A,T140A,K141I,T143M/S,V159A,Y161F,A166G,and R169P mutations were found in genotype B overt HBV strains,while I126S,I126T and F158S mutations were found in genotype C overt HBV strains.I126T,Q129R,M133T and F161Y mutations were found in OBI strains. Conclusions A certain proportion of OBI cases occurs in general population of Deqing county in Zhejiang Province.Viral load of OBI strains is probably lower.Genotype C is probably the prior genotype in OBI strains.More attention should be paid to OBI prevention issue.