viral hepatitis part 1 W5

Question 1

viral hepatitis types?

Answer 1

Hepatitis A/B/C/D/E
Hepatitis non-A/E

Question 2

what do viruses need to replicate

Answer 2

require host cells and its cellular biochemical machinery to replicate

Question 3

what do viruses consist of

Answer 3

DNA/RNA enclosed in a protein coat (nucleocapsid) and sometimes a host cell derived envelope

Question 4

how do viruses attach to host cells

Answer 4

viruses attach to host cell using receptor-binding proteins targeting host cell surface molecules that also serve as virus-specific receptors

Question 5

clinical symptoms of hepatitis?

Answer 5

jaundice
dark urine
clay-coloured stool
nausea and vomiting
loss of appetite
fever
abdominal pain
weakness

Question 6

biochemical blood tests for hepatitis?

Answer 6

liver enzymes (ALT, AST, ALP, GGT)
other liver proteins (albumin, prothrombin)
bilirubin (indirect, direct)

Question 7

serological and molecular tests for viral hepatitis?

Answer 7

enzymes immunosorbent assays (EIA)
molecular assays

Question 8

serological and molecular tests for viral hepatitis - enzyme immunosorbent assays?

Answer 8

viral antigen
anti-viral antibody

Question 9

serological and molecular tests for viral hepatitis - molecular assays?

Answer 9

PCR (viral load)
sequencing (genotype, antiviral resistance)

Question 10

transmission of hepatitis?

Answer 10

B/C/D - transmitted parentally
A/E - transmitted faecal-orally

Question 11

parenteral transmission meaning?

Answer 11

transmitted outside of GI tract (eg sexual contact and blood)

Question 12

acute/chronic hepatitis types?

Answer 12

B/C/D - chronic
A/C/E - acute

Question 13

who can hep D infect

Answer 13

only those who are already hep B positive

Question 14

which types of hepatitis are more stable and why

Answer 14

types transmitted faecal-orally, as must survive for a longer time outside the body

Question 15

hepatitis A - family?

Answer 15

picornavirus (same as viruses causing meningitis, encephalitis)

Question 16

hepatitis A - incubation time?

Answer 16

10-50 days

Question 17

who does hepatitis A mainly affect?

Answer 17

children and young adults

Question 18

hepatitis A - seasonality?

Answer 18

no seasonality

Question 19

hepatitis A - onset, resolution, fatality?

Answer 19

onset = abrupt with pyrexia
resolves spontaneously followed by life long immunity
fatality rate <0.5%

Question 20

hepatitis A - treatment?

Answer 20

supportive

Question 21

hepatitis A - test results

Answer 21

dramatic increase in liver enzymes

Question 22

hepatitis A - vaccine?

Answer 22

inactivated virus vaccine and immunoglobulin available

Question 23

HAV transmission?

Answer 23

transmitted via stool, contaminates water, infecting eg shellfish and vegetables

Question 24

HAV diagnosis?

Answer 24

diagnosed with antibodies in blood
IgM and IgG antibodies

Question 25

HAV outcome - children?

Answer 25

subclinical infection: 80-90% icteric disease (jaundice): 5-20% complete recovery: >98% no chronic disease fatality rate: 0.1%

Question 26

HAV outcome - adults?

Answer 26

subclinical infection: 10-25% icteric disease: 75-90% complete recovery: >98% no chronic disease fatality rate: 0.3-2.1%

Question 27

HBV - family and structure?

Answer 27

enveloped partially dsDNA hepadnavirus

Question 28

HBV incubation time?

Answer 28

40-180 days

Question 29

HBV mainly affects?

Answer 29

babies, young adults

Question 30

HBV seasonality?

Answer 30

no seasonality

Question 31

HBV onset?

Answer 31

insidious, sometimes apyrexia

Question 32

HBV outcome

Answer 32

remains in hepatocytes for life, may re-activate under immunosuppression chronic infection develops in 5-10% of adults, associated with hepatocellular cancer

Question 33

HBV fatality rate?

Answer 33

up to 2% in icteric cases

Question 34

HBV vaccine?

Answer 34

recombinant HBV surface antigen vaccine and immunoglobulin avaliable

Question 35

HBV treatment?

Answer 35

interferon alpha or antivirals

Question 36

HBV transmission?

Answer 36

parenteral, vertical, sexual

Question 37

hepatitis B antigens?

Answer 37

surface antigen (envelope - active infection) core antigen (nucleocapsid) - antibodies indicate recent infection) E antigen (nucleocapsid) - active infection

Question 38

HBV prevalence in europe/north america/australia?

Answer 38

HBsAg 0.2-0.5% Anti-HBs 4-6% neonatal infection rare childhood infection rate

Question 39

HBV prevalence in eastern europe, Mediterranean, former USSR, central and south america, south-west asia?

Answer 39

HBsAg 2-7% Anti-HBs 20-55% neonatal infection frequent childhood infection frequent

Question 40

HBV prevalence in south-east asia, parts of china, sub-saharan africa?

Answer 40

HBsAg 8-20% anti-HBs 70-95% neonatal infection very frequent childhood infection very frequent

Question 41

HBV infection outcomes in different age groups?

Answer 41

newborns have severe infections and high chances of chronic infections compared to older children and adults