Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Infection and Immunity > Hepatitis C Virus > Flashcards

Hepatitis C Virus Flashcards

1
Q

What is viral hepatitis?

A 
Inflammation of liver
Non-specific symptoms
Malaise, fever, headaches
Anorexia, nausea and vomiting 
Right upper quadrant abdominal pain
Dark urine and clay coloured faeces
Jaundice
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the spectrum of viral hepatitis?

A

Wide spread

Asymptomatic, acute, chronic, fulminant (death)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is acute viral hepatitis?

A

Mild or severe
Fulminant (A, B, C, D or E)
Usually severe primary, high mortality
Encephalopathy, coagulopathy, multi organ failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is chronic hepatitis?

A

B,C,D and rarely E

Presence of virus for more than 6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the routes of transmission of viral hepatitis?

A

Faecal oral

Parenteral- contact with body fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Hepatitis A virus (HAV)?

A

Infectious hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Hepatitis B virus (HBV)?

A

Homologous serum hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the causative agents for Hepatitis A and B

A

non-A, non-B hepatitis virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Are all cases of Hepatitis caused by A and B?

A

No, not many cases caused by A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is transmitted parenterally?

A

HCV (not via the alimentary tract)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is known to cause chronic infections?

A

NANBH

Non A Non B hep Virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is most common to occur in Hepatitis C virus?

A

Cirrohsis and chronic liver disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What was the experiment to test for Hepatitis C in chimpanzees?

A

Infection passed experimentally to chimpanzees
Infectious agent passed through 50nm filter
Agent inactivated by solvents
Probably a small, enveloped virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is HAV?

A

Positive
RNA
Picornaviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Hep B?

A

Partly ds DNA positive sense RNA

Hepadnaviri dae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Hep C?

A

Partly ds DNA positive sense RNA

Flaviviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Hep D?

A

Circular RNA

Deltaviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Hep E?

A

Positive sense RNA

Calciviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the clinical features of acute hep C?

A

Most asymptomatic

<1% fulminant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the clinical features chronic hep C?

A

50-70%
20% cirrhosis
3-7% HCC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does HCV account for?

A

Around 30% liver transplants

22
Q

How was HCV cloning initially?

A

It was difficult to characterises due to inability to grow in culture
Eventually cloned in 1989

23
Q

What is HCV derived from?

A

Derived from roughly 10kb ssRNA, expressed proteins that react with patient antisera

24
Q

What family does HCV belong to?

A

Flavivirus

25
Why is HCV virion difficult to detect?
Low levels of virus in plasma
26
What is the morphology the HCV virion?
Roughly 50nm spherical particles Enveloped React with antibodies
27
What is the classification of HCV?
Flavivirus family hepacivirus genus
28
What is the HCV genome structure?
Enveloped RNA genome Positive sense (same as mRNA) 10Kb genome encodes structural (s) and non structural proteins (NS) flanked by regulatory elements S- env, core and p7 NS- viral enzymes and cofactors One large open reading frame translated into a 3010aa polyprotein Processed/cleaved by viral and cellular proteases
29
What are structural proteins composition?
``` Core (C) Envelope glycoproteins (E1, E2), p7 protein ```
30
What are non-structural proteins (translated into polyprotein then cleaved by viral proteases)?
Serine protease/helicase/NTPase (NS2/3), RNA-dependent RNA polymerase (NS5b), protease cofactor (NS4a), less well characterised or not known (NS4b, NS5a)
31
What is the HCV replication cycle?
1. Receptor binding (CD81, SRB1, Claudin, Occludin) 2. Endocytosis 3. Uncoating 4. Translation/processing 5. RNA replication 6. Virion morphogenesis 7. Virion transport 8. Fusion and release
32
What is the HCV protein function?
S Env- receptor binding P7- ion channel Core- maintenance of the genome NS Enzymes and cofactors HCV core protein binds to the p53 promoter This blocks expression of p53 HCV therefore inhibits the ‘Guardian of the genome’ & allows proliferation of cells with DNA damage Can lead to Hepatocellular carcinoma (HCC)
33
What is the viral family closely related to?
Dengue and yellow fever viruses (flavivirus)
34
What do isolates of HCV from different sources fall into?
Separate genotypes (1 & 2 a & b, & 3, 4, 5 & 6a)
35
What are HCV strains characterised by?
DNA sequencing
36
What is the nucleotide homology between most divergent HCV strains?
65% nucleotide homology | 80% between a and b
37
What new genus has HCV been placed in?
Flaviviruse family called Hepacivirus
38
What is the prevalence and incidence of falviviridae?
170 m people ww/roughly 3% of the population
39
How many Americans are chronically infected with falviviridae?
2.7M Americans chronically infected
40
What age group is typically infected with falviviridae?
Most common in 30-49 years | • Illegal drug use in/around Vietnam war?
41
What is the differences in falviviridae epidemiology across countries?
``` Reflects routes of infection and origin Italy A disease of the elderly Egypt- 15-20% seropositive: Bilharzia treatment with dirty needles Highest levels in the world ```
42
What are the 6 different HCV genotypes and their distributions?
1. Is the most common (46%) and is distributed worldwide. World wars 2. Mediterranean countries and the far East 3. Europe 4. Middle East, Bilharzia treatment 5. South Africa 6. Hong Kong, Injecting drug user (IDU)
43
What is the source of HCV infection in the western world?
1. Sharing needles and syringes (60%) 2. Having sex without condoms with someone who has hepatitis C <5-15% i.e. rare 3. Being born to a mother who has hepatitis C <5% i.e. rare 4. In past, blood transfusion, blood products
44
What is the result of Hepatitis C virus infection?
Chronic infection Ab and cytotoxic T-cell production exacerbates liver inflammation Liver cirrhosis occurs Hepatocellular carcinoma (HCC) can eventually occur
45
How many HCCs are viral?
80%
46
How many of the HCCs are HBV?
60%
47
How many of the HCCs are HCV?
40%
48
What factors promote progression or severity?
``` Alcohol Age > 40 years at time of infection HIV co-infection Other o Male gender o Chronic HBV co-infection ```
49
What is the new Hep C vaccine?
Shown promising results in an early clinical trial at Oxford University, generating strong and broad immune responses against the virus causing the disease The vaccine was found to be very safe and well tolerated in the 15 healthy human volunteers who took part in the phase 1 safety trial A trial to test the efficacy of the vaccine is now underway among intravenous drug users in two sites in the USA. It is the first hepatitis C vaccine to reach this stage of clinical trials
50
What is the prime boost approach of the Hep C vaccine?
Stimulate a T cell response

Infection and Immunity (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions