Epidemiological Characteristics Of Hepatitis E Virus And Human T-lymphocyte Virus In Blood Donors

BackgroundThrough strict blood screening strategies,the risk of transfusion transmission of traditional infectious diseases such as hepatitis B virus,hepatitis C virus and human immunodeficiency virus has dropped to an extremely low level.However,since 1970,new infectious diseases related to blood transfusion have been jeopardizing human health and life.Most of the pathogens are viruses,such as West Nile virus,Zika virus,Hepatitis E virus(HEV),Human T-cell lymphocyte virus(HTLV),etc.[1]Among them,HEV is the causative agent of hepatitis E,which has caused outbreak in many areas[2];HTLV subtype 1 can cause serious diseases such as leukemia and lower limb paralysis after infecting human body[3-5].Both HEV and HTLV can be transmitted through the bloodstream[2,6].The positive rates of anti-HEV IgG antibodies(HEV IgG)were significantly different among blood donors in different countries[7-9];the prevalence of HTLV among blood donors was relatively low[10,11].In order to ensure the safety of blood transfusion,some foreign countries have included HEV and HTLV in the routine screening programs for blood donors,and the screening of HEV and HTLV for blood donors has not yet been implemented in China.ObjectiveGuangzhou is the largest city in the southeastern coastal region of China,with large population mobility and complex population structure.The annual blood collection in Guangzhou is the second in the country,and because of the good medical resources,the clinical blood demand is large,so there is a risk of transfusion transmitted HEV and HTLV.Urgently,investigating the infection status of HEV and HTLV in unpaid blood donors in Guangzhou provides scientific data for the blood screening of HEV and HTLV,which is of great significance for the safety of blood transfusion.Methods1.Blood screening by enzyme linked immunosorbent assay(ELISA):Plasma samples of blood donors were tested for HEV IgG,HEV IgM and HEV antigen by enzyme-linked immunosorbent assay,and HTLV-1/2 antibody was detected by HTLV antibody diagnostic ELISA kit.2.Electrochemiluminescence immunoassay(ECLIA)retest:For HTLV antibody-detected ELISA-positive samples,ECLIA was used as repeat detection assay.3.Western blot(WB)and nucleic acid detection(NAT)confirmation experiments:Both ELISA and ECLIA-positive HTLV samples were confirmed by WB and NAT experiments.The two experiments have any one positive,that is,the sample is HTLV positive.4.Nested Polymerase Chain Reaction(PCR)amplification:NAT positive samples were sequenced after amplification.Results1.The positive rates of ELISA for the three serological markers HEV IgG,HEY IgM,and HEV Ag were 20.05%,0.76%,and 0.04%,respectively.The positive rates of both IgG and IgM(IgG/IgM)positive samples,single IgG and single IgM positive samples were 0.58%,19.47%and 0.18%,respectively.2.Statistical analysis showed that the independent risk factors affecting the positive rates of HEV IgG and HEV IgM included age and ethnicity.As the age of blood donors growing,the positive rate of HEV increase gradually(IgG OR=1.089,P<0.001;IgM OR=1.055,P<0.001).Compared with Han ethnicity,the positive rates of HEV IgG and IgM were higher in Zhuang minority.3.The HTLV antibody screening results showed that the ELISA positive rate was 0.024%.The ELISA positive samples were re-examined by ECLIA,and only 22.67%of the samples were positive,with a positive rate of 0.005%.4.The samples with positive ELISA and ECLIA results were confirmed by WB and NAT experiments.The overall positive rate of HTLV was 0.002%.According to the results of WB experiments,it was found that the genotypes of HTLV-positive samples were all HTLV-1.5.The genotypes of NAT positive samples after sequencing were all worldwide subtypes la.ConclusionHEV and HTLV,the pathogens of new infectious disease,which can be transmitted by blood transfusion,have different positive rates among unpaid blood donors in Guangzhou.HEV antibodies show a high positive rate,and the infection status of each population is different;the HTLV positive rate is low.The prevalent HTLV genotype among blood donors in Guangzhou is mainly HTLV-1aA.