Microbiology

Question 1

What type of virus is HAV?

Answer 1

+ssRNA naked icosahedral picornavirus

Question 2

Transmission of HAV?

Answer 2

fecal oral

• acid stable
• found in contaminated water in developing countries

Question 3

How to inactivate HAV?

Answer 3

1. Chlorinate
2. Bleach
3. UV irradiation
4. Boil

Question 4

HAV transmission in USA?

Answer 4

• shellfish

- travelers to endemic areas

Question 5

HAV symptoms in children?

Answer 5

No jaundice with vomit

• often asymptomatic
• shed virus to family

Question 6

HAV symptoms in adults?

Answer 6

Jaundice and vomit

-smokers acquire an aversion to smoking

Question 7

Duration of HAV?

Answer 7

• one month
• self limiting
• no chronic state

Question 8

Who should get the HAV vaccine?

Answer 8

• high risk endemic areas
• liver disease
• homosexuals

Question 9

Type of virus HBV?

Answer 9

partially dsDNA covalently closed circular hepadnavirus with envelope (cccDNA)

• replicates in and out of nucleus through RNA intermediate
• fully ds during replication

Question 10

Key enzyme in HBV?

Answer 10

reverse transcriptase

-doesnt integrate into host

Question 11

HBV transmission?

Answer 11

• sex
• needles
• vertical transmission from mother

Question 12

Who is at high risk of Chronic HBV?

Answer 12

Newborns (90%)

Question 13

Extrahepatic manifestations of HBV?

Answer 13

• arthralgias
• PAN: beads on a string (decreased GFR)
• MGN

Question 14

HBV liver enzymes?

Answer 14

Elevated ALT>AST and then fall after infection

-normal ALT early in neonatal hepatitis

Question 15

HBsAg+?

Answer 15

active infection

Question 16

HBeAg+?

Answer 16

High infectivity

Question 17

Anti-HBc?

Answer 17

• positive in window period
• Ab started to bind Ag, neither Ag nor Ab detected
• false reassurance

Question 18

Anti-HBe?

Answer 18

low infectivity

Question 19

Anti-HBsAg?

Answer 19

Immunity

Question 20

Immunized serology?

Answer 20

-Anti-HBc and Anti-HBe

Question 21

Long term complications of HBV?

Answer 21

• cirrhosis

- HCC

Question 22

HDV virus type?

Answer 22

-ssRNA circular enveloped

Question 23

What does HDV require to be infectious?

Answer 23

HBsAg

Question 24

Coinfection?

Answer 24

HBV and HDV simultaneously

-low risk of chronic

Question 25

Superinfection?

Answer 25

HDV infection on top of preexisting HBV - worse outcome, high risk of severe chronic - HDV uses HBV surface Ag to form envelope and spread

Question 26

Treatment for HBV?

Answer 26

- NRTI (Lamivudine) that inhibits reverse transcriptase - Tenofovir - Entecavir - IFN-gamma - give to pregnant women prior to delivery - give baby IgG + HBV vaccine for active and passive immunity

Question 27

HCV type of virus?

Answer 27

+ssRNA enveloped Flavivirus

Question 28

HCV transmission?

Answer 28

- Transfusions - IVDA - Sex (more common in HBV)

Question 29

Why is HCV very infectious?

Answer 29

antigenic variability - polymerase lacks 3' to 5' exonuclease activity leading to mutations - more infectious than HIV

Question 30

How much HCV becomes chronic?

Answer 30

60-80%

Question 31

Long term complications of HCV?

Answer 31

- Cirrhosis | - HCC

Question 32

ALT levels in HCV?

Answer 32

rise and falls by 6 months indicates acute hepatitis

Question 33

Anti-HCV Ab and immunity?

Answer 33

antibodies may be present but not confer immunity due to HCV ability to mutate

Question 34

Chronic HCV requirements?

Answer 34

viral RNA persists for 6 months

Question 35

Cryoglobulins associated with what?

Answer 35

HCV | -precipitate with cool temp containing IgM

Question 36

Treatment of HCV?

Answer 36

- Ribaviron - IFN alpha - protease inhibitor (NS5B)

Question 37

Leading cause of liver transplant?

Answer 37

HCV

Question 38

HEV type of virus?

Answer 38

Naked icosahedral RNA hepevirus

Question 39

Pregnant woman with acute liver disease dies?

Answer 39

HEV

Question 40

Marker for higher HBV infectivity?

Answer 40

HBeAg | -secreted by infected cells

Question 41

HCV and HIV confections?

Answer 41

shorter time to cirrhosis

Question 42

Keys to HCV replication?

Answer 42

- forms membranous web | - Lipo viral particle forms with HCV and VLDL

Question 43

Most common risk factors for HAV transmission?

Answer 43

- international travel | - IVDA

Question 44

Most common risk factors for HBV and HCV transmission?

Answer 44

- IVDA | - multiple sex partners

Question 45

Major risk factor for HDV transmission?

Answer 45

IVDA

Question 46

Incubation period for HAV?

Answer 46

2-8 weeks

Question 47

Incubation period for HCV, HBV, HDV?

Answer 47

6 weeks to 6 months

Question 48

Chronic hepatitis?

Answer 48

viral Ag > 6 months

Question 49

Immune tolerant HBV?

Answer 49

- normal ALT - high HBeAg and HBV DNA - infected as infant

Question 50

HBeAg+ immune active HBV?

Answer 50

- HBsAg+ longer than 6 months - HBeAg+ - anti-HBe negative - high serum HBV DNA

Question 51

Inactive carrier of HBV?

Answer 51

- HBsAg+ > 6 months - HBeAg negative - Anti-HBe+ - low HBV DNA

Question 52

HBeAg-, immune active HBV?

Answer 52

- HBsAg+ > 6 months - HBeAg- - Anti-HBe+ - low HBV DNA

Question 53

Diagnosis of HAV?

Answer 53

- HAV IgM for acute - HAV IgG for prior exposure - increased ALT

Question 54

Diagnosis of HEV?

Answer 54

- HEV IgM for acute | - HEV IgG past infection

Question 55

Diagnosis of HDV confection?

Answer 55

IgM and IgG both detected

Question 56

Acute HCV and ALT levels?

Answer 56

elevated >7x normal