HAV and HEV在线视频

Hello everyone.
大家好

We will discuss Hepatitis viruses today.
今天我们学习肝炎病毒

I'm Gang XIN from the Department
我是辛岗

of Microbiology and Immunology,
来自中国

Shantou University Medical College,
汕头大学医学院

China.
微生物与免疫教研室

Learning Objectives:
学习目标

At the end of this chapter,
在这章结束时

you should be able to
你应该能够

List the six hepatitis viruses.
列举六种肝炎病毒

Describe the structure
描述HAV和HBV

of HAV and HBV virions.
的病毒体结构

Describe the pathogenicity
描述HAV,HBV,HCV,HDV以及HEV

(source of the infection,
的致病性

transmission routes, pathogenesis)
（传染源，传播途径，致病机制）

of HAV, HBV, HCV, HDV and HEV.

Compare and contrast
比较和对比

the clinical findings of HAV,
HAV,HBV,HDV以及HEV感染

HBV, HCV, HDV and HEV infections.
的临床发现

Compare the lab diagnoses of HAV,
比较HAV，HBV和HCV

HBV and HCV.
的实验室诊断

Describe the treatment
描述HAV，HBV和HCV

and prevention of HAV, HBV and HCV.
的治疗与预防措施

The hepatitis viruses
肝炎病毒

include at least 6 viruses:
包括最少六种病毒：

A through E and G
甲型到戊型和庚型

Hepatitis A
甲型肝炎病毒（HAV）

and hepatitis B viruses (HAV, HBV)
和乙型肝炎病毒（HBV）

are the traditional hepatitis viruses,
是传统的肝炎病毒

and hepatitis C, D, E,
而丙型，丁型，戊型和庚型病毒

and G viruses (HCV, HDV, HEV, HGV)
(HCV, HDV, HEV, HGV)

are called non-A,
被称为

non-B hepatitis (NANBH) viruses.
非甲非乙型肝炎（NANBH）病毒

They belong to different families.
它们属于不同的科

HAV (Picornaviridae)
HAV（小RNA病毒科）

HBV (Hepadnaviridae)
HBV(正嗜肝DNA病毒科)

HCV, HGV (Flaviviridae)
HCV,HGV（黄病毒科）

HDV
HDV

(the delta agent, viroid, unclassified)
（δ因子，类病毒，未分类）

HEV (resembles the caliciviruses)
HEV（类人类杯状病毒）

Other viruses
其他病毒

can also cause hepatitis, e.g.
也可以引起肝炎

CMV, EBV, yellow fever virus.
例如CMV,EBV，黄热病病毒

I will show you two cases.
请比较以下两个案例

Please compare and contrast them.

Case 1
案例1

A 30-year-old man developed anorexia,
男，30岁。4周前

vomiting, and right upper abdominal
在一家小餐馆吃饭

pain after eating in a small
之后出现厌食

restaurant 4 weeks ago,
呕吐以及上腹部疼痛的症状

followed by jaundice,
近2周出现黄疸

and abnormal liver enzymes for 2 weeks.
以及肝酶异常

Then symptoms subsided.
随后他的症状就消退了

Case 2
第二个案例

Elevated liver enzymes were found
常规体检发现

in an individual during a routine checkup.
肝酶升高

Ten years later,
十年后

cirrhosis and liver failure developed,
发展为肝硬化和肝功能衰竭

requiring a liver transplant.
需要进行肝移植

Both individuals developed liver
两个案例中的患者都患有肝病

disease with elevated liver enzymes.
肝酶水平升高

But the person in case 1 had a short
但案例1的患者只是短暂地患病

illness and recovered,
并已痊愈

while the one in case 2 developed
而第二个案例

a chronic infection.
患者得的是慢性病

Although the target organ
尽管所有肝炎病毒的靶器官

for all hepatitis viruses
都是肝脏

is the liver eliciting similar symptoms,
都出现类似的症状

these viruses differ greatly
但这些病毒在其

in their structure,
结构

mode of replication,
复制

mode of transmission,
传播

as well as the clinical course
临床病程以及预后

and sequelae of the disease they cause.
会有很大的不同

Hepatitis viruses infect
肝炎病毒

and damage the liver,
感染并破坏肝脏

causing jaundice and the release
引起黄疸和

of liver cell enzymes.
肝细胞酶的释放

Hepatitis can be self-limiting
肝炎可以是自限性的疾病

or can progress to fibrosis (scarring),
也可以发展成肝纤维化（形成瘢痕）

cirrhosis or liver cancer.
肝硬化甚至是肝癌

Acute infection may occur with mild
急性感染

or no symptoms,
也许只出现轻微或者没有症状

or may cause jaundice
或者引起黄疸

(yellowing of the skin and eyes)
（皮肤和眼睛的黄染）

dark urine, extreme fatigue, nausea,
深色尿液，极度疲乏，恶心

vomiting and abdominal pain.
呕吐和腹痛

Hepatitis B and C can become chronic.
乙型肝炎和丙型肝炎可以发展出慢性肝炎

They may be asymptomatic for years.
无症状的装填可以持续多年

However,
然而

by the time warning signs appear,
当有明显体征出现时

the liver may already be damaged.
肝脏其实已经受损

HBV and HCV can cause primary
HBV和HCV可以引起

hepatocellular carcinoma (HCC).
原发性肝细胞性肝癌（HCC）

Chronic hepatitis, then cirrhosis,
慢性肝炎，接着肝硬化

and hepatocellular carcinoma.
和肝细胞癌

Key words of hepatitis viruses:
肝炎病毒的关键词

HAV, HEV: fecal-oral transmission,
HAV,HEV：粪口传播

acute/sudden onset, hygiene
急性/突发起病，卫生

Hepatitis A: vaccine
甲型肝炎：疫苗

Hepatitis E: pregnant women
戊型肝炎：怀孕女性

HBV, HCV, HDV spread in blood,
HBC,HCV,HDV在血液，组织和精液中传播

tissue, and semen; STDs
STDs

Hepatitis B: reverse transcriptase,
乙型肝炎：逆转录酶

chronic, Dane particle, HBsAg,
慢性，Dane颗粒，HBsAg（HBV表面抗原）

vaccine, antiviral drugs
疫苗，抗病毒药物

Hepatitis C: chronic
丙型肝炎：慢性

Hepatitis D: defective,
丁型肝炎：缺陷病毒

hepatitis B helper virus,
乙型肝炎辅助病毒

fulminant disease, HBV immunization
爆发性疾病，HBV免疫

Let’s start from hepatitis A virus, HAV.
从甲型肝炎病毒HAV开始学习

Structure of HAV.
HAV的结构

HAV is a picornavirus and was
HAV是小RNA病毒

formerly called enterovirus 72,
从前被称为肠道病毒72型

but it has been placed into
但由于其独特的基因组

a new genus, Heparnavirus,
现在被归为新的病毒属

on the basis of its unique genome.
嗜肝病毒属

HAV has a 27 nm, naked,
HAV直径27nm，无包膜

icosahedral capsid
二十面体的衣壳

surrounding a +ssRNA genome.
包裹着一条正单链RNA基因组

There is only one serotype of HAV.
HAV只有一种血清型

The capsid is even more resistant
比起其他的小RNA病毒

than other picornaviruses to acid
HAV的衣壳更加耐酸

and other treatments.
和耐受其他的处理

It is stable to acid at pH 1,
HAV在pH为1的酸性条件，

ether, detergents,
乙醚，洗涤剂，

salt water/groundwater, drying,
盐水/地下水，干燥

and heating at 56℃ for 30 min.
和加热的环境中都很稳定

It can be inactivated by chlorine
饮用水可以用氯处理

treatment of drinking water,
从而灭活HAV

formalin,
福尔马林

ultraviolet radiation
紫外线照射

and heating at 100℃ for 5 min.
和100°C加热5分钟的方式都可以灭活HAV

HAV is transmitted through ingestion
HAV传播途径

of contaminated food
食用或饮用被污染的食物和水

and water or through direct
直接接触患者

contact with an infected person.

HAV does not cause
HAV不引起

chronic liver disease,
慢性肝病

and rarely causes fatal disease.
并很少出现死亡病例

Virus is shed in large quantity into
在黄疸出现

the stool approximately 10 days
或者抗体可以被检测到的约10天前

before jaundice appear
病毒就会大量地

or antibody can be detected.
随粪便排出

The source of the infection is patients
传染源是患者

and asymptomatic carriers.
以及无症状携带者

HAV is spread by the fecal-oral route.
HAV通过粪口途径传播

The clinical disease caused
HAV引起的临床疾病

by HAV is acute hepatitis.
是急性肝炎

Approximately 40% of acute cases
大约40%的急性肝炎案例

of hepatitis are caused by HAV.
是由HAV引起

The incubation period
潜伏期

is usually 14–28 days.
通常是14到28天

Symptoms of hepatitis A range
甲型肝炎的症状

from mild to severe,
严重程度从轻微到严重不等

and can include fever,
还可以引起发热

malaise, and loss of appetite,
不适，以及无食欲

diarrhea, nausea, abdominal discomfort,
腹泻，恶心，腹部不适

dark-colored urine and jaundice.
深色尿以及黄疸

Not everyone who is infected
不是每个感染者

will have all of the symptoms.
都会有所有这些症状

Complete recovery occurs
99%的患者在发病后2到4周

in 99% within 2 to 4 weeks of onset.
痊愈

This table shows you
这个表格展示了

the clinical outcomes of HAV infection.
HAV感染的临床结果

90% of children and 25-50% of
90%的儿童以及25到50%的成年人

adults have subclinical infections
出现亚临床的感染

Jaundice is found in 70% to 80%
黄疸会出现在70到80%的成年患者上

of adults but in only 10%
但只有10%儿童患者（年龄小于6岁）

of children (<6 years of age).
会出现黄疸

Almost everyone recovers fully from
基本上所有患甲型肝炎的患者

hepatitis A with a lifelong immunity.
痊愈后都可获得终身免疫

Unlike hepatitis B and C,
不像乙型和丙型肝炎

hepatitis A does not cause chronic
甲型肝炎不引起慢性肝病

liver disease and is rarely fatal,
也极少是致命性的

but it can cause debilitating symptoms
但它可以导致令人衰弱的症状

and fulminant hepatitis
以及急性重型肝炎

(acute liver failure).
（急性肝衰竭）

Immunity:
免疫

The person is contagious prior
患者在出现症状前

to symptom onset and appearance of
就具有传染性

symptoms correlate with
并且症状的出现

the development of immune responses.
与免疫反应的发展相关

HAV-specific IgM rises in acute phase.
HAV-特异的IgM在急性期升高

HAV-specific IgG is produced later
HAV-特异的IgG随后产生

and may be lifelong.
并且可以终生存在

Lab diagnosis:
实验室检查：

Cases of hepatitis A are not clinically
甲型肝炎

distinguishable from other types
仅通过临床表现

of acute viral hepatitis.
与其他急性病毒性肝炎很难区分

Specific diagnosis is made by
特异性诊断依赖

the detection of HAV-specific IgM
检测血液中

antibodies in the blood,
HAV-特异性的IgM抗体

indicating an acute infection.
表明有急性感染

Additional tests include RT-PCR
其他的实验室检查包括RT-PCR

to detect the hepatitis A virus RNA.
可以用于检测甲型肝炎病毒RNA

Viral isolation is not performed.
一般不进行病毒的分离

Prevention and Treatment:
预防以及治疗措施：

There is no specific
没有特异性

treatment for hepatitis A.
治疗措施

Recovery may be slow and may
痊愈过程可能

take several weeks or months.
需要几周甚至几个月

The spread of HAV is reduced
降低HAV的传播

by interrupting the fecal-oral route.
可通过切断干预粪口传播途径来实现

Improved sanitation,
改善公众卫生条件

food safety and immunization are
食品安全和疫苗接种

the most effective ways
是最有效的

to combat hepatitis A.
对抗甲型肝炎的方法

Prophylaxis with immunoglobulin
免疫球蛋白可以

given before or early in
在疾病潜伏期或潜伏期前使用

the incubation period is 80-90%
可以有效预防临床疾病的发生

effective in preventing
有效率80-90%

clinical illness.

Killed HAV vaccine or live
疫苗有灭活的HAV疫苗

attenuated vaccine are recommended
和活的减毒疫苗

for all children.
都可以用于儿童预防接种

Another hepatitis virus that
另一种

can be transmitted
可以通过粪口途径传播的肝炎病毒

by fecal-oral route is HEV.
是HEV

HEV resembles calicivirus.
戊型肝炎病毒类似于杯状病毒

It is a spherical,
它是球形的

non-enveloped, ssRNA virus,
没有包膜的，单链RNA病毒

which is approximately 27 to 34 nm
直径约

in diameter.
27到34nm之间

HEV
HEV

(the E stands for enteric or epidemic)
（这个E表示肠的或者流行的）

is predominantly spread
主要通过污染的水

by contaminated water.
来传播

The symptoms and course of HEV disease
戊型肝炎的症状和病程

are similar to those of HAV disease;
与甲型肝炎的类似

it causes only acute disease.
它只引起急性肝炎

In rare cases,
严重的急性戊肝

acute hepatitis E can be severe,
很少见

and result in fulminant hepatitis;
可导致急性重型肝炎

these patients are at risk of death.
这些患者面临着死亡的危险

Fulminant hepatitis occurs more
急性重型肝炎

frequently when hepatitis E
更多发生在得了戊型肝炎的

occurs during pregnancy.
怀孕女性身上

The mortality rate is up to 20–25%
孕妇在妊娠晚期

if the pregnant women get hepatitis E
感染戊型肝炎

in third trimester.
致死率会高达20%到25%

Definitive diagnosis is usually based on
确诊通常

the detection of specific IgM in serum.
基于血清中特异性IgM的检测

A vaccine to prevent HEV infection has
HEV疫苗

been developed
已在中国获批上市

and is licensed in China,

but is not yet available elsewhere.
但其他国家尚未上市

Now back to the two cases.
现在回到开头的两个案例

Which one may be caused by HAV?
哪一个是由HAV引起的？

Yes, case 1.
是的，案例1

The patient developed acute hepatitis,
患者得了急性肝炎

and recovered.
后来痊愈了

Thank you for joining us.
感谢你的参与

See you in the next session.
下节课再见