Hepatitis Viruses

Question 1

Acute Viral Hepatitis (2)

Answer 1

Sudden

Followed by complete resolution

Question 2

Chronic Viral Hepatitis (2)

Answer 2

Prolonged course of active disease with silent asymptomatic or symptomatic infection

Can transmit virus throughout life

Question 3

Viral Hepatitis Comparison (4)

Answer 3

Source of Virus:
A, E —> Feces
B, C, D —> Blood / body fluids

Transmission route:
A, E —> Fecal-oral
B, C, D —> Percutaneous, Permucosal

Chronic Infection:
A, E —>No
B, C, D —> Yes

Prevention:
A, B —> Vaccine 
C —> Blood donor screening; Behavior modification 
D —> HBV Vaccine
E —> Ensure safe drinking water

Question 4

Why is Chronic Hepatitis difficult to diagnose?

Answer 4

Often ASYMPTOMATIC with only enlarged tender liver and mildly elevated liver enzymes

Question 5

HAV- General Characteristics (2)

Answer 5

ssRNA

Non-enveloped

Question 6

HAV- Clinical Features (3)

Answer 6

Children —> ASYMPTOMATIC
Adults —> MILD
Pregnant —> MORE SEVERE

Question 7

HAV- Pathogenesis (2)

Answer 7

REPLICATES in DIGESTIVE TRACT then spreads to liver

EXCRETED in STOOLS for TWO WEEKS PRECEDING ONSET of SYMPTOMS

Question 8

HAV- Complications

Answer 8

FULMINANT HEPATITIS RARE

Question 9

Where are HAV outbreaks common?

Answer 9

Nurseries

Question 10

HEV- Case to case transmission??

Answer 10

Uncommon

LARGE INOCULUM needed to establish infection

Question 11

HEV- Viremia?

Answer 11

Transient (NOT persistent)

Question 12

HEV- Clinical Features (2)

Answer 12

ACUTE

SELF-LIMITING

Question 13

HEV- Age?

Answer 13

Young adults

Question 14

HEV- Immunity

Answer 14

Short-term memory

Question 15

HEV- Complications

Answer 15

FULMINANT HEPATITIS in PREGNANT

Question 16

HBV- General Characteristics (2)

Answer 16

ENVELOPED

DOUBLE STRANDED DNA

Question 17

HBV- Antigens (3)

Answer 17

HBsAg —> SURFACE (COAT) protein
HBcAg —> INNER CORE protein
HBeAg —> SECRETED protein

Question 18

HBV- Transmission

Answer 18

BODY FLUIDS (blood, semen, vaginal fluids, menstrual blood, saliva)

Question 19

HBV- Complications (3)

Answer 19

FULMINANT HEPATITIS RARE
CIRRHOSIS
HEPATOCELLULAR CARCINOMA

Question 20

HBV- Risk

Answer 20

Males > Females

Question 21

HBV- Window Phase

Answer 21

The period from 24-32 weeks when neither free HBsAg nor its antibody (Anti-HBsAg) can be detected

The failure to detected Anti-HBsAg early in infection is not because of lack of antibodies; instead, they are undetectable because they are complexed with large amount of antigen that is shed from infected cells

Question 22

HBs

Answer 22

HBsAg
- Live virus and infection

HBsAb

• Recovery and immunity to HBV
• Develops in people successfully vaccinated against HBV

Question 23

HBe

Answer 23

HBeAg

• Active infection
• Determines how contagious you are
• Used to monitor effectiveness of treatment

HBeAb
- IgG = old infection

Question 24

HBc

Answer 24

HbcAb

• Appears 1 month after active infection
• Persists for life as they are not protective
• Indicated previous or ongoing infection
• Used by blood banks to screen

IgM = New infection

Question 25

Acute HBV

Answer 25

HBsAg HBeAg Anti-HBcAg (IgM)

Question 26

Chronic HBV High Infectivity

Answer 26

HBsAg HBeAg Anti-HBcAg (igG)

Question 27

Chronic HBV Low Infectivity

Answer 27

HBsAg Anti-HBeAg Anti-HBcAg (IgG)

Question 28

Recovery

Answer 28

Anti-HBsAg Anti-HBeAg Anti-HBcAg (IgG)

Question 29

Immununized

Answer 29

Anti-HBsAg

Question 30

HBV- Active Immunization

Answer 30

Serum derived —> Prepared from HBsAg | Recombinant HBsAg —> By genetic engineering in yeasts

Question 31

HBV- Passive Immunization

Answer 31

Administered to non-immune individuals following exposure to HBV- infected blood E.g. Needle stick injury

Question 32

HCV- General Characteristics (2)

Answer 32

ssRNA | Enveloped

Question 33

HCV- Reservoirs (2)

Answer 33

Humans | Chimpanzees

Question 34

HCV- Progession (4)

Answer 34

Alcohol consumption Males Co-infection with HIV or HBV Older

Question 35

HCV- Pathogenesis (2)

Answer 35

Enters bloodstream | Infects hepatocytes

Question 36

HCV- Clinical Manifestations (3)

Answer 36

Milder than HBV Most ASYMPTOMATIC Most PERSISTENT liver infection leading to CHRONIC ACTIVE HEPATITIS

Question 37

HCV- Diagnosis (2)

Answer 37

IgG —> EXPOSURE NOT INFECTIVITY RNA —> INFECTIVITY

Question 38

HDV- General Characteristics (2)

Answer 38

``` DEFECTIVE virus (can’t replicate on its own) Cannot code for its own surface proteins and so in order to produce more virus particles; it needs a HELPER virus —> HBV ```

Question 39

HDV- Acquired

Answer 39

Along with HBV (CO-INFECTION) or as SUPER-INFECTION of an already HBV-INFECTED individual

Question 40

HDV- Coinfection

Answer 40

- Exacerbates ACUTE disease | - FULMINANT HEPATITIS more likely

Question 41

HDV- Superinfection

Answer 41

- CHRONIC liver disease accompanied by CIRRHOSIS