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Chapter 21  Human enterovirus  Viruses of causing acute gastroenteritis.

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Presentation on theme: "Chapter 21  Human enterovirus  Viruses of causing acute gastroenteritis."— Presentation transcript:

1 Chapter 21  Human enterovirus  Viruses of causing acute gastroenteritis

2 Poliovirus Coxsackievirus group A : types 1~22, 24 group B : types 1~6 Enteric cytopathogenic human orphan(ECHO) virus orphan(ECHO) virus New enteroviruses (types 1~3) (31 types) (types 68~71)

3 of enterovirus of enterovirus  Shape and structure d=24~30 nm, spherical and naked virus with icosahedral nucleocapsid polyprotein ↓ VP1~VP4 and functional protein ↓ VP1~VP4 and functional protein 衣壳蛋白 (VP1 与受体结合 ) genome:+ssRNA 1.Biological properties

4   Cultivation  Rresistance (stronger) (pH3~9 稳定, 污水和粪便中可存活数月 )  Type-specific antigen D(density)/N(native) antigen C (coreless) antigen primary cell culture----CPE animal inoculation (A1,A19,A22)

5 2.Pathogenicity of enteroviruses  Replicate in the intestinal tract and spread through bloodstream to target organs  Via fecal-oral route cause a variety of diseases or syndromes of diseases or syndromes ( 夏秋季为主要流行季节 ) 不同肠道病毒可引起相同的临床症状, 同一种 病毒可引起几种不同的临床疾病 P275~276 表 ( 通常有二次病毒血症 ) ---from subclinical infection to severe infection of CNS

6 source of infection source of infection (patients and carrier) cause poliomyelitis by fecal-oral route clinical findings of poliomyelitis clinical findings of poliomyelitis ⑴ ⑴ Poliovirus (neurotropic virus) *subclinical infection(90%) *abortive infection (5%) *nonparalytic poliomyelitis/aseptic meningitis(1-2%) *paralytic poliomyelitis(0.1%-2%) nonparalytic : paralytic=100~1000 : 1 ---pathogen of poliomyelitis ---pathogen of poliomyelitis ( 脊髓灰质炎或小儿麻痹症 )

7 ⑵ Coxsackievirus and ECHO virus ⑵ Coxsackievirus and ECHO virus ⑶ Enterovirus 71 ---cause a variety of diseases or syndromes P275~276 表 ) ---cause a variety of diseases or syndromes (such as aseptic meningitis and encephalitis and so.on) (P275~276 表 ) initial site of infection and route of transmission E70,CA24 and Ad3,7→AHC ( 急性出血性结膜炎 ) ----The main cause of acute hemorrhagic conjunctivitis (AHC)

8 ⑷ Enterovirus 71 --- lifelong type-specific immunity ( neutralizing antibody ) cause viral CNS disease ---cause viral CNS disease (such as aseptic meningitis and encephalitis and so.on) and HFMD HFMD (hand-foot-and-mouth disease, 手足口病 ) 3. Immunity of enteroviruses (neurotropic virus)

9 4. Laboratory diagnosis of enteroviruses äIsolation and identification of virus  Detection of viral antibody and RNA 5. Specific prevention of 5. Specific prevention of poliovirus   Artificial active immunity   Artificial passive immunity IPV ( Salk vaccine)OPV(Sabin vaccine )IPV ( Salk vaccine)OPV(Sabin vaccine ) 均为三价混合疫苗;但 OPV 与疫苗相关麻痹型脊髓 灰质炎 (VAPP) 发生有关 均为三价混合疫苗;但 OPV 与疫苗相关麻痹型脊髓 灰质炎 (VAPP) 发生有关 (CPE)

10 ---Viruses of causing acute gastroenteritis acute gastroenteritis  Rotavirus (RV)  Other acute gastroenteritis virus

11 1.Shape of virion ---d=60-80nm, spheric and naked virus with double-shelled capsid 2.Genome appearance of a “wheel” appearance of a “wheel” ( 轮状病毒 ) ( 轮状病毒 )   consists of 11 segments of ds-RNA   code for 6 structural proteins(VP1-4,6,7) and 5 non-structural proteins (NSP1~NSP5)

12 3.Pathogenicity  Source of infection  Route of transmission  The main viral cause of acute gastroenteritis of acute gastroenteritis group A: main pathogen of acute gastroenteritis in infants group B cause epidemic diarrhea in adult group C: cause human or animal sporadic diarrhea (or ADRV) (6 个月 ~2 岁 )

13 4. Diagnosis of infection  Detection of viral particle and viral antigen and viral antigen (EM,ELISA)  PAGE & RT-PCR ( 聚丙烯酰胺凝胶电泳 )

14  Including: Enteric adenovirusEnteric adenovirus CalicivirusCalicivirus  Cause viral gastroenteritis by fecal- oral route oral route * SRSV (small round structured virus) * “classic” calicivirus (Classified as HuCV) ٭ 其原型病毒为 Norwalk 病毒 ٭ 无菌性胃肠炎暴发流行最重要病原体 ٭ 流行季节 : 冬季 ٭ 可累及任何年龄组 →5 岁以下小儿腹泻 ٭ 主要引起 5 岁以下小儿腹泻 (5%~20% 为隐性感染 ) ٭ 冬季流行 2.Other acute gastroenteritis virus EAd-40, 41 and 42 型是引起 EAd-40, 41 and 42 型是引起婴 儿病毒性腹泻的第二位病原体 Astrovirus Astrovirus


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