Transfusion transmitted virus infection in patients on maintenance haemodialysis and in hospital workers

A newly discovered DNA virus, transfusion transmitted virus (TTV), was isolated from a post-transfusional hepatitis patient in Japan. A high prevalence (32-46%) of TTV infections in patients receiving maintenance haemodialysis (HD) has been reported but the occupational risk of TTV on HD units has not yet been determined. We determined the prevalence of TTV in workers in the same HD unit and the risk factors for TTV infection in HD patients, using logistic regression analysis. The prevalence of TTV DNA was 59.6% in 198 HD patients, significantly higher than that in the HD unit (13 of 39, 33.3%;P= 0.002) and non-HD healthcare workers (20 of 75, 26.7%; P= 0.001). A logistic regression analysis showed that male gender and negative test results for hepatitis G virus RNA were risk factors for TTV infection, but prior blood transfusion and duration of HD were not. Stepwise selection of multiple regression analysis showed that the presence of hepatitis C virus RNA was the only significant predictor for high serum ALT activity, and that the presence of TTV DNA was not. These results indicate that TTV is one of the prevalent human viruses transmissible either parenterally or nonparenterally in HD patients, but the occupational risk of TTV infection in HD unit workers is as low as in other healthcare workers. The pathogenic effects of TTV on the liver appear to be limited.     

深圳市一般人群输血传播病毒感染的现况研究

目的　探讨深圳市一般人群中输血传播病毒 (TTV)感染情况及其影响因素。方法采用多阶段随机抽样抽取研究对象 ,并用套式聚合酶链反应法 (nPCR)检测该人群血清中TTVDNA。结果　深圳市一般人群中TTVDNA总阳性率为 11.86% ,男女阳性率分别为 14 .67%和9.41% ;年龄组间TTVDNA阳性率差异无显著性 ,单因素和logistic回归分析未显示肝病史、近期手术史、注射史、拔牙史及乙型肝炎疫苗接种等因素与TTVDNA感染有关 ;HBsAg、抗 -HBs和抗 -HBc与TTV感染无统计学意义。但不同职业人群TTVDNA阳性率差异有显著性 ,地税干部和中小学教师TTVDNA阳性率高于其他人群。结论　深圳市一般人群中TTV感染率较高 ,尤其是地税干部和中小学教师 ,但其流行因素尚需进一步研究     

河北地区TT病毒感染与不同型别病毒性肝病的关系

目的分析健康人群及肝病患者TTV感染状况。方法采用TTV（N22）区核苷酸序列设计引物，建立半巢式聚合酶链反应（Semi—nested PCR）方法，对309例7种不同人群血清检测TTV DNA。结果TTV在非甲一非戊型肝炎、肝硬化患者、丙型肝炎、急性甲型肝炎、急性乙型肝炎、慢性乙型肝炎和健康人群中感染率分别为75．00％（15／20）、75．00％（27／36）、61．90％（13/21）、58．06％（18／31）、52．78％（38／72）、45．61％（26／57）和38．89％（28／72）。肝硬化患者及非甲非戊型肝炎感染率明显高于健康人群（P〈0．01），也明显高于急、慢性乙型肝炎患者（P〈0．05）。21～30岁年龄组TTV感染率（39．06％）显著低于51～60岁年龄组感染率（68．75％）（P〈0．01），其他年龄间无差异。急性甲型肝炎、急性乙型肝炎和慢性乙型肝炎与丙型肝炎之间无统计学意义，性别之间亦无统计学意义。结论TTV在河北地区健康人群及肝病患者中有较高的感染率，TTV感染与不明原因ALT升高有一定的关系。     

中国部分地区新型肝炎病毒TTV感染的分子流行病学

目的了解我国部分地区新型肝炎病毒ＴＴＶ感染的分子流行病学、ＴＴＶ在人群中的感染分布状况,探讨ＴＴＶ在肝炎发病中的作用和地位。方法采用ＰＣＲ方法检测血清标本中ＴＴＶＤＮＡ,克隆测定不同地理株ＴＴＶ的部分基因序列,分析其基因变异情况。结果检测了南方（广东深圳和江苏南京）和北方（北京和辽宁沈阳）的１１２例非甲～非庚型肝炎病人,其中ＴＴＶＤＮＡ阳性者４８例,阳性率４２．９％,而１０２例甲～庚型肝炎病人中阳性率为２．９％（χ２＝４２．８,Ｐ＜０．０１）。ＡＬＴ异常而无甲～庚型肝炎病毒感染标志的献血员中,ＴＴＶＤＮＡ阳性率（３４６％）明显高于ＡＬＴ正常献血员的阳性率（１６．８％,χ２＝４．５,Ｐ＜０．０１）。南方株（广东深圳ＴＴＶＣＨＮ００２、南京ＴＴＶＮＡＮ００１）和北方株（北京ＴＴＶＳＨＢ０１５）病毒间同源性在９８％以上,日本发表的序列同源性也高于９７％。结论我国北方和南方地区均存在ＴＴＶ感染。ＴＴＶ感染与ＡＬＴ异常有极为密切的关系,可能是导致非甲～非庚型肝炎的重要病原。正常人群中存在ＴＴＶ感染者,类似于ＨＢｓＡｇ的所谓“慢性携带状态”。     

不同人群TTV检测及阳性标本核苷酸序列分析

目的了解不同人群TTV感染状况及基因型别，探讨TTV传播途径。方法设计合成引物采用半套式聚合酶链反应方法，对献血者、肝炎病人、幼儿及母婴配对等4组人群血清进行TTV DNA的PCR检测并对部分阳性株进行序列测定及分析。结果(1)在457份被检血清中检测出TTV DNA阳性111份，总阳性率24．29％。在血清转氨酶(ALT)正常的96份献血者血清标本中TTV DNA阳性检出率为16．6％，而在ALT异常、HBsAg及抗HCV阴性的99份献血者血清标本中，TTV DNA的阳性检出率为36．3％，明显高于ALT正常献血者。(2)在72例不同肝炎病人血清中，TTV DNA阳性检出率为54．16％；在非甲一庚型肝炎病人中TTV DNA阳性率为87．5％，高于甲一庚型肝炎的病人中TTV DNA阳性率。(3)110份体检幼儿血清中，共检出TTV DNA阳性14份，总检出率为12．73％。(4)一对母婴配对血清的TTV DNA同时阳性且序列相同。(5)12个阳性株序列分析结果显示：11株分属于G1、G2 2个基因型的5个亚型，而另1株与Gla、Glb的同源性为74．8％～80．2％。结论(1)献血者人群中存在TTV感染，TTV可以导致感染个体的肝功能异常。(2)TTV感染与肝炎有关，可能是非甲一庚型肝炎的病原之一。(3)TTV可能存在血源途径外的其它传播选径；TTV存在母婴垂直传播途径。     

STD患者血清抗TTV IgG及性传播途径研究

目的：探讨输血传播病毒（TTV）在STD患者中的感染状况及经性传播的可能性。方法：应用ELISA法检测237例STD患者和80例健康体检正常人的血清抗TTV IgG。结果：STD患者抗TTV IgG的阳性率明显高于正常人群（P＜0．005）；不同STD病种患者中以梅毒、生殖器疱疹以及梅毒合并NGU和CA、生殖器疱疹合并NGU的患者的抗TTV IgG的阳性率较高，而非淋菌性尿道炎患者的抗TTV IgG阳性率较低；STD患者男性与女性抗TTV IgG的阳性率两者无显著性差异（P＞0．05）；STD患者配偶抗TTV IgG阳性率为30．36％，正常人配偶抗TTV IgG的阳性率为4．55％，两者存在显著性差异（P＜0．05）；抗TTV IgG阳性组和抗TTV IgG阴性组的STD患者冶游史大于半年以上者的人数分别为23，7（P＜0．005），性伴侣平均个数分别16．80，7．53（P＜0．001）。结论：STD患者中存在严重的TTV感染；冶游史的时间越长，性伴侣个数越多感染TTV可能性越大，提示性传播可能是TTV感染途径之一。     

TT virus among blood donors in Alexandria

TTV is a non enveloped, single-stranded, circular- DNA virus that has been assigned to the Family Circiniviridae. The primary mode of TTV transmission was proposed to be transfusion (and hence its name). Little is known about the clinical significance and the natural history of TTV infection. Hence, responsibility of the virus for specific liver disease is still debated. In our study, we tested ninety five blood donors attending Kom EL-Decka regional blood bank in Alexandria for the presence of TTV DNA in their sera by PCR technique. The same samples were tested for ALT and AST levels by colorimetric technique and for HBsAg and anti-HCV by the ELISA technique. Out of the 95 blood donors, 46 (48.4%) had TTV DNA in their sera. None of the 95 blood donors included in this study was positive for HBsAg, while 22 (23.2%) were anti-HCV positive. Out of the 22 anti-HCV positive blood donors, 13 (59.1%) were TTV DNA positive, while out of the 73 anti-HCV negative blood donors, 33 (45.2%) had TTV DNA in their sera. There was no statistically significant difference between the prevalence of TTV DNA and anti-HCV in blood donors. No biochemical evidence of liver disease potentially linked to the TTV infection was observed in our blood donors who were TTV DNA positive. Furthermore, the occurrence of elevated serum AST and ALT was most often linked to HCV rather than TTV.     

熔点曲线法研究TTV肝炎患者中TTV准种与其临床分型的关系

目的研究TTV肝炎患者中TTV准种及其与患者不同临床分型的关系。方法采用巢式荧光实时多聚酶链式反应(PCR)扩增TTVDNA,收集TTV DNA阳性的慢性肝炎病例52例,其中轻度、中度、重度分别为15例、17例、20例;慢性重型肝炎患者18例;献血员15例。采用熔点曲线方法进行TTV准种检测。结果TTV肝炎患者中度、重度和重型组中熔点曲线波峰数量显著多于献血员和慢性TTV肝炎轻度组(P<0.05),重度和重型组熔点曲线波峰数量显著多于中度组患者(P<0.05)。但重度组患者TTVDNA熔点曲线波峰数量与重型组相比较无显著差异(P>0.05)。结论TTV存在病毒准种,TTV准种感染的复杂性可能是TTV肝炎患者病情严重程度有关,准种越复杂病情越严重。     

泉州地区肝炎患者TTV感染状况调查

「目的」了解泉州地区各型肝炎患者ＴＴＶ感染情况。「方法」设计特异性引物采用巢式ＰＣＲ方法对５７例肝炎患者及２０例健康献血员的血清标本进行ＴＴＶＤＮＡ检测。「结果」肝炎患者ＴＴＶＤＮＡ阳性率为１５．８％,其中乙型肝炎（或重叠丁型肝炎）患者ＴＴＶＤＮＡ阳性率为２５．０％（６／２４）,非Ａ－Ｇ型肝炎患者ＴＴＶＤＮＡ阳性率为１３．６４％（３／２２）,甲、戊型肝炎患者未检出;健康献血员为３５．０％。ＴＴＶＤ     

海南地区不同人群TTV感染的流行病学研究

「目的」研究海南地区不同人群ＴＴＶ感染情况。「方法」对１６２例城市一般人群、１５３例农村少数民族、１２０例献血员、９６例丙氨酸氨基转移酶异常者、６８例血透析者、９２例非甲～庚型肝炎病人、１０２例甲～庚型肝炎病海南地区以上８种人群中的阳性率依次为１０．５％、８．５％、９．２％、１１．５％、１７．６％、４０．２％、２６．５％、３８．７％,各类人员之间差异非常显著（Ｐ〈０．０１）;ＴＴＶ阳性甲～庚型肝炎     

Viral co-infections in hepatitis C: HBV, HBV-C/HGV and TTV studies

BACKGROUND/AIMS: The prevalence of co-infections with hepatitis B virus (HBV) and novel hepatitis viruses GBV-C (Hepatitis G virus, HGV) and TT virus (TTV) in chronic hepatitis C (HCV) infection has been studied. In patients with chronic hepatitis C and in asymptomatic healthy HCV carriers, the influence of these agents on the course of HCV infection was assessed. METHODS: a total of 110 HCV-positive individuals, among them 77 patients with chronic hepatitis C--50 of them treated with interferon (IFN)--and 33 HCV carriers with normal alanine aminotransferase have been investigated. HBV-DNA, HGV RNA and TTV DNA were detected by PCR, to determine HBsAg and anti-HBc ELISA technic has been used. RESULTS: In the healthy population, the prevalence of anti-HCV was 0.3%, HBsAg 0.09%, anti-HBc 2.5%, HGV RNA 8.0% and TTV DNA 18.5%, respectively. In chronic hepatitis C HBsAg (accompanied with HBV-DNA) occurred in 1.29%, anti-HBc 25.97%, HGV RNA in 9.09% and TTV DNA in 40.25% of cases. In IFN-treated patients with sustained remission, the frequency of TTV was 20% vs. 45.7% found in non-responders. Among asymptomatic HCV-carriers, the prevalence of anti-HBc was 27.27%, HGV RNA 9.09% and TTV DNA 75.7% respectively. CONCLUSIONS: Neither previous HBV infection, nor HGV RNA and TTV DNA had apparent effect on the course of chronic HCV infection. TTV was detected with the lowest frequency in persons with sustained remission due to IFN, suggesting antiviral effect of IFN on TTV.     

溶脲脲原体感染者中输血传播病毒DNA的检测

目的：调查输血传播病毒（TTV）在溶脲脲原体感染者中的感染状况，探讨TTV的传播途径。方法：在TTV，ORF1保守区设计引物，建立套式聚合酶链反应（NPCR），检测52例溶脲脲原体感染者和34例普通体检人群分泌物中TTV—DNA。结果：在52例溶脲脲原体感染者中检出19例TTV-DNA阳性，检出率为36．5％，而普通体检人群TTV-DNA阳性率为2．9％，两组差异有统计学意义（χ^2=13．0 P〈0．01）。结论：溶脲脲原体感染者是TTV感染的高危人群，性接触是TTV传播的重要途径之一。     

TT virus--characteristics,occurrence and routes of transmission

Recent discovery of a novel DNA virus from the serum of a Japanese patient (T.T.) has prompted further studies directed on possible role of TT virus in the development of cryptogenic hepatitis. The TT is an unenveloped and circular DNA virus. TTV possesses single stranded DNA genome and comprises 3537 to 3853 nucleotides. TTV is similar to the Circoviridae and possesses three open reading frames. Phylogenetic analysis revealed up to 30% nucleotide sequence divergence in the 16 virus genotypes. TTV infection can be detected by polymerase chain reactions, in situ hybridization and by specific antibodies to TTV. TTV DNA has been identified in the serum of patients with cryptogenic hepatitis, hepatitis B and C, hepatocellular carcinoma as well as in healthy individuals. TTV has been found also in the peripheral blood leukocytes, bone marrow cells, liver biopsies as well as in feces and breast milk. Some animals including cattle, sheep, pigs and chicken appeared to have TTV viremia. Recent detection of TTV in nonblood products, such as saliva and feces suggest in addition to parenteral also nonparenteral routes of TTV transmissions including sexual and fecal-oral.     

2例TTV感染者中TTV DNA的基因变异分析

目的探讨TTV的基因变异情况。方法PCR扩增BD与CSH血清中的TTV DNA后进行分子克隆,每例挑选10个不同TTV DNA克隆进行测序。不同克隆之间及其与G1 a亚型TA278之间进行序列比较并进行进化树分析。结果BD存在2种不同的TTV病毒株,都为G1 a亚型。CSH中存在7种不同的TTV病毒株,分别属于G1 a和G1b亚型。结论CSH中TTV的基因变异比BD中的复杂得多。     

输血传播病毒对妊娠结局的影响

目的:探讨TTV感染对妊娠结局的影响。方法:应用半巢式聚合酶链反应技术检测113例孕产妇血清及其新生儿脐血的TTV—DNA。结果:孕产妇TTV阳性率13.3%(15/113),新生儿TTV阳性率7.8%(9/113)。孕产妇TTV阳性者及阴性者的分娩结局比较,无显著性差异。结论:孕产妇及新生儿间存在母婴垂直传播,孕妇感染TTV后未见不良妊娠结局,远期影响尚需观察。     

某部新兵TT病毒感染情况的研究

目的：了解部队１９９９年入伍新兵ＴＴ病毒（ＴＴＶ）感染情况。为部队做好ＴＴＶ感染的防治工作提供依据。方法：采用巢式ＰＣＲ方法,对驻闽南某部２５１名１９９９年入伍新兵血清进行ＴＴＶ－ＤＮＡ检测,同时做抗ＨＡＶ－ｌｇＭ、ＨＢＶ－Ｍ、ＨＣＶ－ＲＮＡ、抗ＨＥＶ－ＩｇＧ和肝功能检查。对ＴＴＶ感染者和肝功能异常者进行重点体栓和流行病学调查。结果：在２５１名被检的新兵中,发现ＴＴＶ感染者１９例（７．５％）。其中     

The prevalence of TT virus and GB virus C/hepatitis G virus infection in individuals with raised liver enzymes but without HBV or HCV infection in Taiwan

The prevalence of TT virus (TTV) and GB virus-C/hepatitis G virus (GBV-C/HGV) infection and the association with raised liver function tests in 546 Taiwanese with negative HBsAg, anti-HCV and HCV RNA was elucidated. They were tested for serum alanine aminotransferase (ALT), GBV-C/HGV RNA, anti-envelope protein 2 antibody (anti-E2) and TTV DNA. Direct sequencing and phylogenetic analyses were performed on 58 isolates for TTV genotype determination. The prevalence of TTV DNA, GBV-C/HGV RNA, anti-E2 and over all GBV-C/HGV exposure was 24.9, 3.4, 8.2 and 11.1%, respectively. Using uni- and multi-variate analyses, male gender and TTV viremia were associated significantly with raised ALT values. Sixty-nine percent of TTV isolates were deduced to be TTV genotype 1 and they had significantly lower mean age than genotype non-1 isolates. In the population, raised ALT may be related to male gender and be attributable to TTV infection but not to GBV-C/HGV among individuals with no evidence of current HBV and HCV infection. TTV genotype 1 is the most prevalent genotype and associated with younger age.     

TT virus. A review of the literature

In 1997, a new DNA virus was cloned by a Japanese team and designated TT virus (TTV). This virus seemed to be associated with non-A, non-G post-transfusion hepatitis. It was isolated by polymerase chain reaction (PCR) and was presumed to be human Circoviridae. The virus is heterogenous; 16 different genotypes are currently registered, and it can be classified as a "swarm" of at least 5 different viruses. Depending on the PCR technique used, the prevalence of infection ranges from 1.9 to 36% among blood donors, from 11.5 to 71% in hemodialysis patients, from 47 to 82% among patients with non-A, non-B or non-C fulminant hepatic failure, and the most elevated percentage is found in hemophiliacs. Epidemiological studies have established that the routes of TTV infection might be parenteral, oral-fecal, and possibly salivary. Mother-to-infant transmission is controversial. TTV may play a role in the pathogenesis of non-A, non-B or non-C fulminant hepatic failure. Patients co-infected with hepatitis C virus (HCV) and TTV have a significantly higher histological grade score than patients with isolated HCV infection. Treatment with interferon seems to decrease TT viremia, according to results obtained outside the context of clinical trials. TTV seems to be a light pathogenic virus. Its widespread presence in the blood of infected subjects contrasts with the apparent absence of pathological symptoms. PCR standardization is needed to clearly establish its real prevalence worldwide.     

健康人群TTV第1、4、5基因群感染检测分析

目的　对九江市健康婴儿及志愿献血员血清中TT病毒(TTVirus,TTV)第1、4、5基因群感染情况进行检测,以期阐明3种不同TTV基因群在该地区人群中的感染情况。方法　分别用UTRPCR以及N2 2PCR、G4PCR、G5PCR等3种群特异性PCR ,检测九江市86例健康婴儿和12 9例健康献血员血清中总TTVDNA以及3种不同基因群TTVDNA。结果　婴儿和献血员血清中TTV总检出率分别为5 3. 5 % (46 / 86 )和98. 5 % (12 7/ 12 9) ,其中第1基因群TTVDNA检出率分别为16 . 3% (14 / 86 )和35 .7% (46 / 12 9) ,第4基因群TTVDNA检出率分别为4 0 . 7%(35 / 86 )和82. 9% (10 7/ 12 9) ,第5基因群TTVDNA检出率分别为2 4. 4 % (2 1/ 86 )和4 6 .5 % (6 0 / 12 9)。结论　TTV在该地区健康婴儿和成人中有很高的感染率,但不同的基因群感染率各不相同,其中TTV第4基因群可能是该地区人群中TTV感染的优势株。此外,6个月以内的婴儿大多数尚未感染TTV ,受感染的7～12个月龄婴儿中以感染1种TTV基因群为主,但婴儿中不同基因群的混合感染随着年龄的增加而逐渐增多,但同时感染3种基因群者明显少于当地成人水平(P <0 .0 0 1)。而当地健康成人则以混合感染3种不同基因群者多见。     

老年肝炎患者中输血传播病毒感染状况的研究

目的了解输血传播病毒(TTV)在老年病毒性肝炎患者中的感染状况,探讨TTV感染与老年病毒性肝炎的关系。方法取老年病毒性肝炎患者血清作TTV-DNA扩增,微板核酸杂交-ELISA技术作TTV检测及TTV基因分型。结果135例老年病毒性肝炎患者中TTV-DNA阳性者21例,阳性率为15.6%;TTV基因型主要为Ⅰ型(76.2%),TTV单独感染仅2例(9.5%),重叠感染率达90.5%,两者差异具显著性(P<0.01)。结论老年病毒性肝炎患者中TTV感染率较高,TTV可能是老年急性病毒性肝炎的主要病因之一。感染TTV基因型主要为Ⅰ型。可单独或混合感染,多与其他肝炎病毒感染同时存在,尤其是HBV、HEV。