Viral Hepatitis Flashcards Preview

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Flashcards in Viral Hepatitis Deck (41):
1

Hepatitis A - Transmission

Faecal-oral
Poor hygiene/overcrowding
Some imported cases
Clusters = gay men, injecting drug users

2

Hepatitis A - Clinical

Acute hepatitis, no chronic infection
Peak incidence of symptomatic disease in children/younger adults
Usually ill for a few weeks then get better

3

Hepatitis A - Lab Conformation fo Acute Infection

Clotted blood for serology
Hepatitis A IgM (usually detectable from onset of disease)

4

Hepatitis A - Control

Hygiene
Vaccine prophylaxis

5

Hepatitis E - Clinical

Acute hepatitis, no chronic infection
Peak incidence of symptomatic disease in children/younger adults
Usually ill for a few weeks then get better
Some immunocompromised humans can become chronically infected

6

Hepatitis E - Incidence

More common in tropics
Has become more common than Hep A in UK

7

Hepatitis E - Transmission

Faecal-oral
UK cases are thought to be through zoonoses (esp. pigs, deer and rabbits)

8

Hepatitis E - Tropical Genotypes

In pregnant women, causes severe disease and likely death

9

Hepatitis E - Control

No vaccine available yet

10

Hepatitis D - Incidence

Can only infect those with Hep B
Exacerbates Hep B infection

11

Hepatitis D - Co Infection

Have Hep B and Hep D at the same time

12

Hepatitis D - Superinfection

Have Hep B, then go on to develop Hep D

13

Hepatitis B - Transmission

Sex
Mother to child
Blood

14

Hepatitis B - Higher Risk

People born in intermediate/high prevalence areas
Multiple sex partners
People who inject drugs
Children of infected mothers

15

Hepatitis B - HBsAg

Hepatitis B Surface Antigen
Present in the blood of all infected individuals
Chronic infection = present for >6 months

16

Hepatitis B - Clinical

Risk of chronic infection decreases with increasing age of exposure
Risk of acute hepatitis increases with age at exposure
Death is more likely to result from a chronic infection than an acute infection

17

Hepatitis B - HBeAG

Hepatitis B e Antigen
Usually present in highly infectious individuals

18

Hepatitis B - Hep B DNA

Always present in highly infectious individuals
Used to predict risk of chronic liver disease and monitor therapy
More sensitive than HBeAG

19

Hepatitis B - Hep B IgM

Most likely to be present in recently infected cases

20

Hepatitis B - Control

Safe blood
Safe sex
Needle exchange
Prevention of needlesticks
Screening of pregnant women
Pre-exposure vaccination
Post-exposure prophylaxis (vaccine + HBIG)

21

Hepatitis C - Transmission

Less easily transmitted by sex than Hep B
Mother to child
Blood

22

Hepatitis C - Clinical

75% of cases result in chronic infection
Natural history not dependent on age at time of infection

23

Hepatitis C - Lab Conformation

Test for antibody to Hep C
+ve = Past or active infection
-ve = Not infected
Test for Hep C RNA by PCR
+ve = Active infection
-ve = Past infection

24

Hepatitis C - Control

No vaccine
Must minimise exposure

25

Hepatitis A - Natural History

Infection
Mostly asymptomatic/acute hepatitis -> resolution
Rarely (e.g. elderly) acute liver failure -> death or resolution

26

Natural History of Chronic Infection - Hep B

Spontaneous cure not uncommon, eve after many years of infection

27

Natural History of Chronic Infection - Hep C

Once chronic infection is established, spontaneous cure is not seen

28

Hepatitis C - Natural History

Infection
Mostly asymptomatic -> chronic infection -> chronic hepatitis -> cirrhosis -> chronic liver failure/cancer -> death
25% resolution from asymptomatic disease

29

Hepatitis B - Natural History, Adult Infection

Infection
Most asymptomatic/acute hepatitis -> resolution
Less than 5% develop chronic infection/chronic hepatitis (some of these cases still resolve)
Few result in cirrhosis -> chronic liver failure/cancer -> death

30

Hepatitis B - Natural History, Infection at Birth

Similar to Hep C
high levels of chronic infection and complications

31

Management of Acute Viral Hepatitis

Symptomatic
No antivirals given
Monitor for encephalopathy
Monitor for resolution
Notify Public Health
Immunise contacts
Test/vaccinate for other at risk infections

32

Management of Chronic Viral Hepatitis

Antivirals
Vaccination
Infection control
Decrease alcohol intake
Hepatocellular carcinoma awareness/screening

33

Antiviral Treatment - Who?

Chronic infection
Risk of complications = inflammation present
Fit for treatment = liver cancer contraindicates, cirrhosis and HIV make treatment more difficult
Patient issues = side effects, lifestyle issues, attitude to treatment

34

Antiviral Treatment - When?

Before complications
Evidence of inflammation
Patient is ready
Clinical priority (e.g. HIV may be treated an controlled first)

35

Antiviral Treatment - Interferon Alpha

Human protein
Injected
Genetically engineered

36

Antiviral Treatment - Interferon Alpha - Side Effects

Common =
Flu like
Chills
Sore muscles
Malaise

Rarer but severe =
Thyroid disease
Autoimmune disease
Psychiatric disease

37

Therapy for Chronic Hepatitis B

Option 1
Interferon only
Sustained cure possible, but only minority gain benefit and serious side effects

Option 2
Suppressive antiviral drug
Safer, but only suppression so no cure and possible resistance

38

Aims of Chronic Hepatitis B Therapy

Reduce HBV DNA, lose HBeAg, lose HBsAg
Improve liver biochemistry
Improve histopathology
Reduce infectivity
Reduce progression
Reduce mortality

39

Aims of Chronic Hepatitis C Therapy

Response defied by loss of HCV RNA in blood sustained 6 moths after therapy (aka SVR)
Improve liver biochemistry
Improve histopathology
Reduce infectivity
Reduce progression
Reduce mortality

40

Principles of Hepatitis C Therapy

Choice of antiviral based on =
Genotype of virus, viral load
Genotype of patient's interferon response genes
Stage of disease
Past treatment experience
Likelihood of side effects
Cost effectiveness

41

Hepatitis C Therapy - Newer Antivirals

Simeprevir, Ledipasvir, Daclatasvir =
Used in certain genotypes in combo with other drugs
Safe and well tolerated

Sofosbuvir =
Active against all genotypes in combo with other drugs
Safe and well tolerated