1. Chapter 22 pathogen of viral hepatitis

2. Introduction 1. Human hepatitis viruses   HAV (+ssRNA), HBV (dsDNA), HCV (+ssRNA), HDV (–ssRNA) and HEV (+ssRNA)   HGV (+ssRNA) and TTV (–ssDNA) 2.Other viruses of causing viral hepatitis viral hepatitis (CMV,EBV,Rubella virus,VZV,Yellow fever virus,etc.)

3. * * pathogen of hepatitis type A * *classified as Hepatornaviridae ( 肝 RNA 病毒属 )

4. 1. Shape and structure spherical particle (d=27nm)icosahedral nucleocapsid ssRNA (positive stranded)can code for polyprotein,RNA polymerase and proteinase VP1-4  Genome  Naked virus ↓ Cleave 4 polypeptide (VP1 to VP4) ↓ capsomere→capsid capsomere Ⅰ.Biological Properties

5.  ( 黑猩猩、狨猴、红面猴 )  infective model ( 黑猩猩、狨猴、红面猴 )  ( 原代肝细胞或恒河猴胚肾传代细胞 )  cell culture ( 原代肝细胞或恒河猴胚肾传代细胞 )   stable to treatment with ether ( 乙醚 ), (60 ℃ for 1 hour) acid (PH3) and heat (60 ℃ for 1 hour)   tolerate boiling for 5 minutes 2.Resistance 3.Cultivation (multiply slowly, non-CPE)  Antigenicity of capsid protein:HAV-Ag (only one serotype)

6. 1.Pathogenicity  Source of infection  Route of transmission asymptomatic or only mildly ill acute hepatitis of short incubation f ulminant hepatitis and favorable prognosis  Feature of HAV-infection by fecal-oral route ( 通过粪 - 口途径传播 ) 罕见暴发性肝炎, 预后良好 很常见 罕见慢肝和携带者 Ⅱ.Pathogenicity and Immunity

7. 2.Pathogenesis   Immunopathogenesis   Damage caused by HAV ? Virus Virus in feces in feces Intestine and local lymphoid tissue blood (replication) liver by fecal-oral route ( 污染食物和水 ) 通过日常生活接触 → 散发性肝炎 通过污染食物和水 → 肝炎的暴发流行

8. 3.Immunity3.Immunity  IgM anti-HAV + ---recent infection  antibody to HAV  antibody to HAV (IgG---lifetime persistence) --- long-lasting immunity virus in blood

9. Ⅲ.Laboratory Diagnosis 1.Detection of viral antibody 2.Detection of virus particles in feces 2.Detection of virus particles in feces (IEM)   IgM anti-HAV （ ELISA, 早期诊断）   IgG anti-HAV （ ELISA ，既往感染 / 流调） 3.Detection of viral RNA Ⅳ.Specific Prevention 1.Artificial active immunity 2.Artificial passive immunity (vaccine---strain H2 ) (gamma globulin ）

10. Pathogen of hepatitis B

11.  Shape larger spherical particle small spherical particle tubular particle/filaments virion of HBV, i.e. Dane particle 1.Shape and structure 1:1730:120 in the blood of patients with HB ---three viral particle in the blood of infected persons 42 nm Ⅰ.Biological Properties

12.  Structure of virion ---Spherical particle with double-shelled capsid ⑵ viral core---nucleocapsid ⑵ viral core---nucleocapsid surface---inner shell core HBcAg dsDNA DNA polymerase (d=27nm) (contains HBsAg, Pre-S1 and Pre-S2 Ag) (contain HBcAg and HBeAg) *ds-DNA *DNA polymerase *Protein kinase ⑴ outer shell d=42nm core 27nm protein kinase HBsAg

13. -DNA +DNA DR2 DR1 X Pre-C C S Pre-S2 Pre-S1 P  Circular ds-DNA  Circular ds-DNA (has a single-chain region) –DNA +DNA  Sticky end & direct repeat (DR1,2) 2. Genome structure 2. Genome structure 5‘ long chain---complete 4 ORF (open reading frames)long chain---complete4 ORF (open reading frames) (short chain ---variable length) (DNA 成环和病毒复制的关键序列 )

14.  Unique mode of replication 3.Replication of HBV 3.Replication of HBV ---retrovirus-like pathway of replication  Replicative cycle (p287 Figure 22-5) dsDNA cccDNA 3.5kbRNA 外衣壳蛋白 （ HBsAg ） 内衣壳蛋白 （ HBcAg ） 2.1kbRNA 转录 RNAP 作为 mRNA 转译 前基因组 与 DNAP 进入内衣壳 逆转录 -DNA 复制 +DNA dsDNA 子代 HBV DNA 多聚酶 与负链结合 完整的环状 ds-DNA

15. 4.Compositions of antigen äHepatitis B surface antigen äHepatitis B surface antigen (HBsAg) äHepatitis B core antigen äHepatitis B core antigen (HBcAg) äHepatitis B e antigen äHepatitis B e antigen (HBeAg) äOther antigen (Pre-S1, Pre-S2 antigen, HBxAg)

16. ⑴ Exist in blood from infected person ⑴ Exist in blood from infected person with HBV with HBV outer shell of Dane particle small spherical particle tubular particle  HBsAg HBsAg

17. ⑵ Subtypes of HBsAg ⑶ HBsAg + ---marker of HBV infection ⑷ Anti-HBs:neutralizing antibody contains common epitope a, subtype epitope d/y and w/r subtypes 4 major subtypes ---- adr, adw, ayr, ayw 具有免疫保护作用 抗 -HBs + 表示感染过 / 患病已恢复 / 接种过疫苗获得免疫力

18.  HBcAg ⑴ Locate in surface of viral core ⑴ Locate in surface of viral core ⑵ Anti-HBc + ---marker of viral infection and replication + IgM anti-HBc + ---active replication of HBV + IgG anti-HBc + ---past infection (cann’t find in serum) *marker of recent infection * high titers---marker of acute hepatitis B (non-neutralizing Ab)

19.  HBeAg ⑴ Exist in HBsAg-positive serum ⑵ Associated with presence of Dane particles and DNAP ⑶ HBeAg + ---marker of virus replication and high infectivity of serum ⑷ Anti- HBe + ----marker of lower infectivity

20. 5.Animal model and cell culture 6.Resistance of HBV (60 ℃ for 4 hour) ) stable to heat (60 ℃ for 4 hour) disinfectant ( 常用 0.5% 过氧乙酸和 5% 次氯酸钠 ) 高压灭菌法、 100 ℃加热 10 分钟和环氧乙烷可灭活病毒

21.  Source of infection patients with hepatitis B asymptomatic HBsAg carrier ( 无症状 HBsAg 携带者,ASC) 1.Pathogenicity  Route of transmission via infected blood or blood products vertical transmission 杜绝医源性传播 ! Ⅱ.Pathogenicity and Immunity

22.  Feature of HBV-infection Diversity of clinical finding prognosis * progress toward choronic (10%) * leading to hepatocirrhosis * often associated with primary hepatocellular carcinoma hepatocellular carcinoma Long incubation hepatitis ---ASC, acute/chronic or fulminant hepatitis Liver damage is caused by the host immunologic response （肝硬化） （原发性肝细胞癌）

23.  Pathogenesis ---liver damage is caused by the host immunologic response ⑴ immunopathogenic damage mediated by cellular immunity ⑵ pathogenic damage caused by IC ⑵ pathogenic damage caused by IC ⑶ pathogenic damage caused by autoimmunity ⑶ pathogenic damage caused by autoimmunity ⑷ immune tolerance & chronic hepatitis ⑸ viral variation & immune escape (CTL,CD4 + T;CKs→→→ 急性、慢性、重症肝炎和肝硬化 ) （重症肝炎以及肝外症状） (LSP→ 慢迁肝和慢活肝 )

24. 2.Immunity äSpecific humoral immunity  Specific cellular immunity ---neutralization of anti-HBs ( 清除血中的游离病毒 ) ---double effects mediated by CTL 免疫保护作用 --- 清除细胞内病毒 免疫损伤作用 --- 参与致病作用 抗 -PreS1 、抗 Pre-S2 也有保护作用 也有保护作用 3.HBV & primary hepatocellular carcinoma

25. Ⅲ.Laboratory Diagnosis 1.Detection of viral antigens and antibodys antibodys (“ 二对半 ” 的检测 )   Including : HBsAg, anti-HBs, anti-HBc, HBeAg and anti-Hbe  ELISA or RIA  Methods : ELISA or RIA   Clinical analysis and signification

26. 二对半检测结果的临床分析 HBsAg HBeAg anti-HBs anti-HBe anti-HBc 结果分析 + – – – – HBV 感染者或 ASC + + – – – 急性 / 慢性肝炎或 ASC ( 传染性强 ) + + – – + 急性 / 慢性肝炎或 ASC ( 传染性强 ) + – – + + 急性感染趋向恢复 – – + + + 既往感染恢复期 – – + + – 既往感染恢复期 – – – – + 既往感染 / 窗口期 – – + – – 对再感染有免疫力 ( 恢复期、既往感染或接种过疫苗 ) p291 “ 小三阳 ” “ 大三阳 ”

27. “ 二对半 ” 的检测的实际应用 ⑴特异性诊断 ⑵筛选供血者 ⑶判断病人、 ASC 和孕妇的 传染性 ⑷估计病人的转归和预后 ⑸流行病学调查与追踪传染 源 ⑹确定母婴传播阻断对象 “ 大三阳 ”, IgM 抗 -HBc + ; HBsAg 单项阳性 (ASC) 筛去 HBsAg +, 抗 -HBc + HBsAg + 伴 HBeAg + HBsAg + 与 HBeAg + 在 2 个月内阴转 — 好“ 大三阳 ” 持续 6 个月以 上 --- 慢性转化 慢活肝 HBeAg 一旦 消 失示病情好转 ( 抗 -HBs 和 HBsAg 及其亚型的检测 ) 2.Detection of HBV-DNA HBV-DNA + ---- 病毒正在复制, 其血清传染性强

28. Ⅳ.Principle of prevention 1.General prevention 2.Specific prevention  Artificial active immunity  Artificial passive immunity  Passive-active immunity (HBIg) (HBIg+vaccine) vaccine

29. 1.General properties  30-60nm spherical particle, enveloped virus  Genome structure ( p297) ---linear ss-RNA (positive strand) 2.Pathogenicity  Souse of infection  Route of transmission  Cause hepatitis C 血源性传播为主 非经血传播 → 散发性丙肝 血源性传播 → 输血后丙肝 患者或慢性携带者

30.  Feature of HCV-infection asymptomatic, acute hepatitis and chronic hepatitis cause extrahepatic damage prognosis *progress to hepatocirrhosis (20%) *often associated with primary cellular carcinoma (40% ~ 50%) 肾小球肾炎 3.Diagnosis4.Prevention --- detection of HCV-RNA and anti-HCV 抗 -HCV+ 表示已感染 HCV ( 不可献血 ) Stop iatrogenic transmission!!! 严格筛选供血者, 使用灭活的血制品

31. 1.Shape & structure  Shape  structure 35-37 nm HDAg RNAHBsAg *genome: circular –ssRNA circular –ssRNA *HDAg ( P24,P27) capsid:HBsAgviral core (helper virus: HBV) HDV--- defective virus

32. 2.Pathogenicity  Hematogenic transmission  Cause acute hepatitis D ( 联合感染或共同感染 )coinfection ( 联合感染或共同感染 ) ( 重叠感染 )superinfection ( 重叠感染 ) 3.Diagnosis detection of anti-HD, HD-Ag (detection of anti-HD, HD-Ag and HDV-RNA) and HDV-RNA)

33. 1.Shape & structure  Shape  Shape 32-34nm spherical particle naked virus with appearance of a calicine  Genome  Genome --- +ssRNA (p301 Figure 29-11) 形似杯状

34. 2.Pathogenicity  Route of transmission   Cause acute hepatitis E 3.Diagnosis (detection of HEV-RNA and anti-HEV) 水源污染 → 暴发流行 流行及临床似甲肝 (by fecal-oral route)