1、,Hepatitis viruses 肝 炎 病 毒,Hong Ling, Ph.D. Microbiol Department, Harbin Medical University,第37章,问题,肝炎病毒有哪些？ 简述甲型肝炎病毒的传播方式、致病特点和预防原则 简述乙型肝炎病毒的生物学性状、抗原抗体组成及检出的意义 乙型肝炎病毒的传播方式和致病特点及预防原则 丙型肝炎病毒的生物学特点和致病特点 丁型肝炎病毒（HDV）的概念 简述戊型肝炎病毒传播方式和致病特点,肝炎病毒（Hepatitis virus）,以侵害肝脏为主引起病毒性肝炎的病毒 种类：甲型肝炎病毒（HAV）、乙型肝炎病毒（HBV）
2、、丙型肝炎病毒（HCV）、丁型肝炎病毒（HDV）、戊型肝炎病毒（HEV）、GBV-C/HGV、TTV 其他病毒如黄热病毒、CMV、EBV、风疹病毒等也可引起肝炎，但不列为肝炎病毒,A,“Infectious”,“Serum”,Viral hepatitis,Enterically transmitted,Parenterally transmitted,F, G, TTV ? other,E,NANB,B,D,C,Viral Hepatitis - Historical Perspectives,Hepatitis A virus,1973年Feinstone应用免疫电镜技术从急性肝炎患者粪便
3、悬液中发现 生物学性状与肠道病毒一致，故1982年国际病毒命名委员会将它分类为小核糖核酸病毒科肠道病毒属72型,Anti-HAV Prevalence,High,Intermediate,Low,Very Low,Geographic Distribution of HAV infection,生物学性状,HAV为球形颗粒，直径2732nm，无包膜。基因组为线状单正链RNA,由VP14四种多肽组成，VP1是主要衣壳蛋白和中和抗原，能中和所有HAV 细胞培养：HAV可用猴肾、人胚肾细胞等进行增殖和传代，但不引起CPE 易感动物有黑猩猩、南美洲猴、猕猴等，接种后可出现急性肝炎 抵抗力：较强，对乙醚
4、、酸、热（60oC）稳定。高压、紫外、煮沸等可灭活,致病性,传染源为患者和隐性感染者 传播方式是粪口途径。HAV污染食物、水源、海产品等引起暴发或散发流行 隐性感染率高，成人HAV抗体阳性率高达70%90% 病毒进入机体经过两次病毒血症，到达肝脏，在肝细胞增殖致病,非溶细胞型病毒，不直接杀伤细胞，患者症状高峰是潜伏期末和症状出现初期，与病毒复制高峰时间不相符，说明病毒复制量与症状严重程度不一致，故认为免疫应答参与损伤过程 发病后期粪便中可检出sIgA抗体。出现病毒的特异细胞免疫应答 典型的甲肝是自限过程，大约三个月，无慢性病例,Incubation period: Average 30 day
5、sRange 15-50 days Jaundice by 14 yrs, 70%-80% Complications: Fulminant hepatitis Cholestatic hepatitis Relapsing hepatitis Chronic sequelae: None,Hepatitis A - Clinical Features,Fecal HAV,Symptoms,0,1,2,3,4,5,6,12,24,Hepatitis A Infection,Total anti-HAV,Titre,ALT,IgM anti-HAV,Months after exposure,T
6、ypical Serological Course,Close personal contact (e.g., household contact, sex contact, child day care centers) Contaminated food, water (e.g., infected food handlers, raw shellfish) Blood exposure (rare) (e.g., injecting drug use, transfusion),Hepatitis A Virus Transmission,Sources of HAV Infection
7、 1983-93,Percentage of Cases,Source: CDC, Viral Hepatitis Surveillance Program,Year,Personal contact,Day care center,Foreign travel,Outbreak,Drug use,40,30,20,10,0,1983,1984,1985,1986,1987,1988,1989,1990,1991,1992,1993,Concentration of HAV in Various Body Fluids,Source: Viral Hepatitis and Liver Dis
8、ease 1984;9-22J Infect Dis 1989;160:887-890,Feces,Serum,Saliva,Urine,100,102,104,106,108,1010,Infectious Doses per ml,Age-specific Incidence of Hepatitis A 1983-93,Source: CDC, National Notifiable Diseases Surveillance System,Year,Reported Cases (per 100,000),1983,1984,1985,1986,1987,1988,1989,1990,
9、1991,1992,1993,0,5,10,15,20,25,5-14 years,15-24 years,25-39 years,0-4 years,40+ years,Endemicity,Disease,Rate,Peak Age,of Infection,Transmission Patterns,High,Low to,High,Early,childhood,Person to person;,outbreaks uncommon,Moderate,High,Late,childhood/,young adults,Person to person;,food and waterb
10、orne,outbreaks,Low,Low,Young adults,Person to person;,food and waterborne,outbreaks,Very low,Very low,Adults,Travelers; outbreaks,uncommon,Global Patterns of Hepatitis A Virus Transmission,诊断（Laboratory Diagnosis）,Acute infection is diagnosed by the detection of HAV-IgM in serum by EIA. Past Infecti
11、on i.e. immunity is determined by the detection of HAV-IgG by EIA.,防治原则,加强食品卫生管理，水源保护。但HAV感染以隐性感染和无黄疸型病毒例占多数，故对传染源较难控制 我国已批准将减毒疫苗株H2株和L1株投放市场试用 应急预防可用丙种球蛋白 基因工程疫苗也正在研究之中,Many cases occur in community-wide outbreaks no risk factor identified for most cases highest attack rates in 5-14 year olds child
12、ren serve as reservoir of infection Persons at increased risk of infection travelers homosexual men injecting drug users,Hepatitis A Vaccination Strategies Epidemiologic Considerations,Pre-exposure travelers to intermediate and high HAV-endemic regions Post-exposure (within 14 days) Routine househol
13、d and other intimate contacts Selected situations institutions (e.g., day care centers) common source exposure (e.g., food prepared by infected food handler),Hepatitis A Prevention - Immune Globulin,Group,Age,No.,Doses,EL.U.* (ml),Schedule,(months),Children and,adolescents,2-18 years,3,360 (0.5),0,
14、1, 6-12,Adults,18 years,2,1,440 (1.0),0, 6-12,Doses,HAVRIX,*ELISA units,Recommended Doses & Schedules of HAV Vaccination,Hapatitis B Virus,1963年Blumberg在多次输血的血友病患者中发现澳抗，1968年确与血清型肝炎高度相关，1970年Dane在电镜下看到具有传染性的42nm病毒颗粒 HBV在亚洲广泛流行，在中国约10%人口携带该病毒，全球约3.5亿,1983年将HBV及与其分子结构、生物学特性相似的土拨鼠肝炎病毒(woodchuck hepatit
15、is virus,WHV)、地松鼠肝炎病毒(ground squirrel hepatitis virus,GSHV)及鸭肝炎病毒(duck hepatits virus,DHV)归纳起来独立命名为嗜肝病毒科（Hepadnaviridae）,HBsAg Prevalence,8% - High,2-7% - Intermediate,2% - Low,Geographic Distribution of Chronic HBV Infection,形态与结构,电镜检查血清标本可见小球形颗粒（22nm）、管形颗粒（22nmx50700nm）、大球形颗粒（42nm）,完整的HBV颗粒亦称Dane颗
16、粒，颗粒直径为42nm 具有双层衣壳结构。外壳相当于包膜，由脂质双层和乙肝表面抗原（HBsAg）、多聚人血清白蛋白受体（PHSA-r）和前S抗原（Pre-S）组成。内部有28nm的核心，表面相当于内衣壳，含有乙型肝炎核心抗原（HBcAg）和乙型肝炎e抗原（HBeAg）。内部有HBV的DNA和DNA多聚酶,HBV 基因组,DNA是由3.2KB的长链 L（-）和短链 S（+）（约为L链的50%至85%长）组成的不完全双链环状DNA，长链载有病毒蛋白质的全部密码，有4个开放读码框架(ORF)，分别称为S、C、P和X区,HBV: Replication,HBV,2.4 KB,3.5 KB,Provir
17、us,RT,Replicate,Nuclear,2.1 KB,抗原组成,HBV表面抗原（HBsAg），是机体受HBV感染的标志。226AA，由S基因编码。HBsAg有一个共同抗原决定簇a和二组互相排斥的亚型抗原决定簇d/y和w/r。因此， HBsAg可分为adr、adw、ayr和 ayw4种亚型。我国内地和沿海各省汉族主要为adr型，欧美为adw HBsAg刺激机体产生的抗HBs，能与HBV表面结合,使其失去感染性，具有防御HBV感染的作用,HBV核心抗原（HBcAg），在肝细胞核中才能检出。分子量22KD，由C基因编码，是病毒的内衣壳蛋白。通常被HBsAg或与抗HBc抗体结合成免疫复合物，一
18、般方法在血中检测不到，只能在肝细胞内检出。是致敏CTL作用的靶抗原 抗HBc无中和作用，检出高效价抗HBc，特别是抗HBc IgM表示HBV再肝内处于增殖状态,HBVe抗原（HBeAg），由PreC和C基因共同编码， 15KD，是HBcAg在细胞经蛋白酶降解形成。是HBV复制及血清有传染性的标志 抗HBe对HBV感染有一定保护作用,前S抗原（Pre-S Ag），目前认为，HBsAg由三种蛋白组成。病毒小球颗粒只有主要蛋白，而大球形颗粒和管形颗粒里则有300400分子的主要蛋白和4080分子的中等蛋白和大分子蛋白 主要蛋白：S基因编码，226AA 中等蛋白：S + PreS2编码，226 + 5
19、5=281AA，称前S2蛋白或抗原 大分子蛋白：S + PreS2 + PreS1编码，226 + 55 + 119 = 400AA，称前S1蛋白或抗原,Pre-S2抗原和人肝细胞表面都具有PHSA受体，通过PHSAr搭桥，HBV病毒易吸附于肝细胞表面，这也可以部分解释为什么HBV具有嗜肝细胞性 Pre-S抗原的出现与HBsAg、HBV DNA的检出意义相同，都说明病毒在复制 抗前S1和抗前S2抗体具有中和血循环内的HBV作用，故具有阻止HBV侵入肝细胞的免疫防御作用,易感动物和细胞培养：只有黑猩猩对HBV易感，体外细胞培养尚未成功,抵抗力：认为抵抗力相当强 对低温、干燥、UV、醚、氯仿、酚等
20、均有抵抗性 高压蒸汽灭菌、0.5%过氧乙酸、5%次氯酸钠、3%漂白粉液、0.2%新洁尔灭均可灭活病毒，但处理时间要稍长,Incubation period: Average 60-90 daysRange 45-180 days Clinical illness (jaundice): 5 yrs, 10% 5 yrs, 30%-50% Acute case-fatality rate: 0.5%-1% Chronic infection: 5 yrs, 30%-90% 5 yrs, 2%-10% Premature mortality from chronic liver disease:
21、15%-25%,Hepatitis B - Clinical Features,Spectrum of Chronic Hepatitis B Diseases,Chronic Persistent Hepatitis - asymptomatic Chronic Active Hepatitis - symptomatic exacerbations of hepatitis Cirrhosis of Liver Hepatocellular Carcinoma,High (8%): 45% of global population lifetime risk of infection 60
22、% early childhood infections common Intermediate (2%-7%): 43% of global population lifetime risk of infection 20%-60% infections occur in all age groups Low (2%): 12% of global population lifetime risk of infection 20% most infections occur in adult risk groups,Global Patterns of Chronic HBV Infecti
23、on,High,Moderate,Low/NT,blood,semen,urine,serum,vaginal fluid,feces,wound exudates,saliva,sweat,tears,breastmilk,Concentration of Hepatitis B Virus in Various Body Fluids,Sexual sexual and homosexuals are particular at risk.Parenteral Intravenous drug abuse (IVDA), Health Workers are at increased ri
24、sk.Perinatal Mothers who are HBeAg positive are much more likely to transmit to their offspring than those who are not. Perinatal transmission is the main means of transmission in high prevalence populations.,Modes of Transmission of HBV,传染源：急、慢性乙肝患者及无症状携带者 传播途径：非胃肠道途径 血液、血制品传播：输血、丙种球蛋白 医源性传播：注射（吸毒）
25、、手术、采血、针刺、拨牙、内窥镜检查、纹身等 母婴传播：发生在围产期，通过产道或吞入羊水等因素。宫内感染相对少（10%）。母亲HBeAg阳性婴儿感染机会大（90%），HBeAg阴性、抗HBe阳性婴儿感染机率小（10%15%） 接触传播：公共卫生洁具、剃刀、吸血昆虫,* Includes sexual contact with acute cases, carriers, and multiple partners.Source: CDC Sentinel Counties Study of Viral Hepatitis,Heterosexual*(41%),Homosexual Activi
26、ty (9%),Household Contact (2%),Health Care Employment (1%),Other (1%),Unknown (31%),Injecting Drug Use (15%),Risk factors for Acute Hepatitis B 1992-1993 USA,Source: CDC Viral Hepatitis Surveillance Program,0-14,15-19,20-29,30-39,40+,0,5,10,15,20,25,Rate of Reported Hepatitis B by Age Group USA 1990
27、,Age Group (years),Rate (/100,000),Exposure,Infection,Death 1% Fulminant hepatitis,Recovery 90% - 95% Immune,Asymptomatic Carrier Persistent Infection Chromic hepatitis,Chronic active hepatitis Cirrhosis Hepatocellular carcinoma,致病机理,尚未完全明了。一般认为HBV不直接损害肝细胞，而产通过宿主的免疫应答引起肝细胞的损伤和破坏，出现相应临床表现 细胞免疫损伤：以抗原特
28、异CTL为主。直接杀伤或释放淋巴因子间接杀伤肝细胞。细胞免疫强弱与临床过程轻重与转归密切相关。免疫力过强可出现重症肝炎，过低则是慢性肝炎,体液免疫损伤：并不十分重要，因为先天性无丙种球蛋白血症患者的乙肝仍表现为典型的肝炎病变。抗原抗 体复合物导致的超敏反应，造成了肝外症状表现，如关节炎、皮疹、肾小球肾炎等 自身免疫损伤：HBV感染后，肝细胞自身表面抗原肝特异性脂蛋白抗原（Liver specific protein, LSP）暴露，自身抗体加重肝细胞损伤,HBV与原发性肝细胞癌,乙肝患者原发性肝癌发生率比对照高。原发性肝癌患者血清中，有HBV感染标志者比自然人群多。HBV感染者比阴性者发生原发
29、性肝癌的危险性高217倍 与HBV分子生物学相似的WHV在其宿主土拨鼠中可诱导肝硬化及原发性肝癌。新生土拨鼠感染WHV三年后100%发生肝癌，未感染鼠则无一只发生肝癌 肝癌细胞DNA整合有HBV-DNA,免疫性,体液免疫：有免疫防御作用的有抗HBs和抗Pre-S2，是HBV的中和抗体 细胞免疫：CTL是清除细胞内病毒的主要机制，如细胞免疫处于较低水平则易转为慢性,微生物学检查法,病毒核酸的检测：斑点杂交法，PCR，极敏感的方法，临床常规。对血清病毒DNA浓度可做动态监测 HBV抗原、抗体的检测 最敏感方法是RIA、ELISA 检测的项目主要是HBsAg和抗-HBs、HBeAg和抗-HBe、以及
30、抗-HBcIgM和抗HBc-IgG,Symptoms,HBeAg,anti-HBe,Total anti-HBc,IgM anti-HBc,anti-HBs,HBsAg,0,4,8,12,16,20,24,28,32,36,52,100,Typical Serologic Course,Weeks after Exposure,Titre,Acute Hepatitis B Virus Infection with Recovery,IgM anti-HBc,Total anti-HBc,HBsAg,Acute (6 months),HBeAg,Chronic (Years),anti-HBe
31、,0,4,8,12,16,20,24,28,32,36,52,Years,Weeks after Exposure,Titre,Progression to Chronic Hepatitis B Virus Infection,Typical Serologic Course,HBsA：表示机体感染了HBV。阳性见于 急性乙型肝炎潜伏期和急性期（70%） HBV所致的慢性肝病如慢性乙型肝炎、肝硬化和原发性肝炎 无症状HBsAg携带者 抗HBs：表示机体曾感染过HBV，并获得对HBV的免疫力,HBcAg：常规方法难以检出，临床不做 抗HBc 抗HBc IgM出现于急性乙型肝炎急性期 抗HBc
32、IgG阳性表示过去感染过HBV，少数也可能仍有HBV感染,HBeAg：HBeAg阳性是体内有HBV复制和血液传染性强的标志 急性乙肝HBeAg呈短暂阳性，如持续阳性提示转为慢性，预后不良 孕妇HBeAg阳性，新生儿感染率高 抗Hbe：见于急性乙肝的恢复期，可持续较长时间，表示机体获得一定免疫力,Pre-S1、Pre-S2和PHSA受体：HBV新感染的标志，检出表示HBV正在复制 抗Pre-S1、抗Pre-S2：有中和病毒作用，出现于急性乙肝恢复早期，消失较快,Examples of Serology Test,预防原则,要采取切断传播途径为主的综合性措施 自动免疫：HBsAg疫苗（血源或重组）
33、 被动免疫：乙肝免疫球蛋白(HBIg)。接种者: 医务人员或实验室工作人员 HBsAg、HBeAg阳性母亲的新生儿 发现已误用HBsAg阳性的血液或血制品者 与HBsAg、HBeAg阳性者有密切性接触者,Prevent perinatal HBV transmission Routine vaccination all infants children in high-risk groups adolescents all unvaccinated children at 11-12 years adults in high-risk groups,Strategy,Elimination o
34、f HBV Transmission,Vaccine licensed,HBsAg screening of pregnant women recommended,Infant immunization recommended,Adolescent immunization recommended,Decline among homosexual men & HCWs,Decline among injecting drug users,80,70,60,50,40,30,20,10,0,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95
35、,Year,Cases per 100,000 Population,Estimated Incidence of Acute Hepatitis B, USA 1978-1995,Hepatitis C virus,1978年WHO将非甲非乙型肝炎病毒按传播途径分为肠道传播的非甲非乙型病毒和肠道外传播的非甲非乙型肝炎病毒 1989年进一步将前者命名为戊型肝炎病毒（HEV），将后者命名为丙型肝炎病毒（HCV） 目前拟将HCV和庚型肝炎病毒（HGV）列入黄病毒科（Flavivurus）Hepacivirus属,生物学性状,HCV属于黄病毒科，电镜照片不清晰，似球形，直径5565 nm，有脂蛋白包
36、膜，包膜上有短突起。核酸为+ssRNA，9.4Kb,由于不能培养，故尚不能进行血清分型。据基因序列同源性，现分为I VI六个基因型。中国和亚洲流行多型，欧美为I 型 细胞培养未成功。黑猩猩是唯一易感动物,hypervariable region,capsid,envelope protein,protease/helicase,RNA polymerase,c22,5,core,E1,E2,NS2,NS3,33c,NS4,c-100,NS5,3,Hepatitis C Virus Genome,Hepatitis C - Clinical Features,潜伏期 平均6-7周（2-26周）
37、急性表现（黄疸） 轻微(20%) 急性期死亡率 低 慢性感染率 75%-85% 慢性肝炎 70% 肝硬化 10%-20% 慢性肝脏疾病导致死亡 1%-5%,Chronic Hepatitis C Infection,The spectrum of chronic hepatitis C infection is essentially the same as chronic hepatitis B infection.All the manifestations of chronic hepatitis B infection may be seen, albeit with a lower
38、frequency i.e. chronic persistent hepatitis, chronic active hepatitis, cirrhosis, and hepatocellular carcinoma.,病理,HCV不直接杀伤细胞，故其致病机理被认是病理免疫和细胞凋亡是造成伤害的原因,Transmission of HCV,Percutaneous Intravenous drug abuse Transfusion, transplant Therapeutic (contaminated equipment, unsafe injection practices) Pe
39、rmucosal Perinatal Sexual,Sources of Infection for Persons with Hepatitis C,Sexual 15%,Other* 5%,Unknown 10%,Injecting drug use 60%,Transfusion 10% (before screening),*Nosocomial; Health-care work; Perinatal,Source: Centers for Disease Control and Prevention,HCV Prevalence by Selected Groups, USA,He
40、mophilia,Injecting drug users,Surgeons, PSWs,Hemodialysis,Average Percent Anti-HCV Positive,Gen population adults,Military personnel,STD clients,Pregnant women,Prevalence of HCV Infection by Age & Gender, 1988-1994 USA,Males,Females,Source: CDC, NHANES III,Total,Perinatal Transmission of HCV,Transmi
41、ssion only from women HCV-RNA positive at delivery Average rate of infection 6% Higher (17%) if woman co-infected with HIV No association with Delivery method Breastfeeding Infected infants do well Severe hepatitis is rare,*Reported in U.S.,Household Transmission of HCV,Rare but not absent Could occ
42、ur through percutaneous/mucosal exposures to blood Theoretically through sharing of contaminated personal articles (razors, toothbrushes) Contaminated equipment used for home therapies Injections* Folk remedies,Serologic Pattern of Acute HCV Infection with Recovery,Symptoms +/-,Time after Exposure,Titer,anti-HCV,ALT,Normal,0,1,2,3,4,5,6,1,2,
