HAV

Question 1

HAV is what kind of virus?

Answer 1

Picornaviridae…enterovirus (like coxsackie or polio)

Question 2

What kind of genome does HAV have?

Answer 2

+ssRNA with a VPg protein cap and a polyA tail

Question 3

What kind of proteins are encoded for in the HAV genome?

Answer 3

Structural and non-structural

Question 4

What is the outermost layer of the HAV virus?

Answer 4

Protein shell…NOT an envelope

Question 5

What is a benefit of having a protein shell INSTEAD of an envelope?

Answer 5

Protein shell is more stable and can withstand harsher conditions…like the stomach

Question 6

Why is it important that the HAV can survive past the stomach?

Answer 6

HAV originally infects mucosal epithelial cells

Question 7

What happens after HAV infects mucosal epithelial cells?

Answer 7

HAV replicates and releases into the bloodstream

Question 8

What cells have the HAV cell receptor 1 glycoprotein (HAVR-1) necessary for HAV infection?

Answer 8

Liver and T cells

Question 9

Does viral entry/replication directly harm liver cells?

Answer 9

HAV is NOT cytolytic…just causes the cells to display MHC class I

Question 10

Since HAV is not cytolytic, what damages the liver cells?

Answer 10

Cytotoxic T cells kill the liver cells…after the virus is already pooped out

Question 11

How long before becoming jaundice is the virus excreted?

Answer 11

Roughly 10 days

Question 12

Since HAV enters circulation in the intestine, what kind of transmission is it? What are risk factors?

Answer 12

HAV is fecally-orally transmitted (contagious 10-14 days BEFORE symptoms)

Contaminated seafood or imported berries
Summer camps, schools, etc.

Question 13

What are some methods of inactivation of HAV?

Answer 13

Chlorine treatment of drinking water
Formalin treatment
UV radiation

Question 14

Does HAV have a short or long incubation period?

Answer 14

Short…2-8 weeks

Question 15

When does an HAV typically present? How long do the symptoms usually last?

Answer 15

HAV usually presents 15-50 days post exposure

HAV infection intensifies for 4-6 days

Question 16

What are the symptoms of an HAV infection

Answer 16

Often asymptomatic (90% of kids; 25-50% of adults)

Fever
Fatigue
Nausea
Anorexia
Abdominal pain
Dark urine
Jaundice (70-80% of adults...10% of kids)

Question 17

What percentage of people with HAV infection do NOT recover and develop a fulminant infection? What percentage of those who develop the fulminant infection die of the infection?

Answer 17

1%

80% of that 1% die due to the infection

Question 18

How is HAV diagnosed?

Answer 18

ELISA (anti-HAV IgM)

IgG indicates a prior infection

Question 19

How is HAV treated? What prophylactic treatment is available?

Answer 19

HAV infection is treated supportively

Pooled immune globulins can be given to contacts of people who are infected

Question 20

What kind of vaccine is available for HAV?

Answer 20

Killed HAV infection

Given to children and adults at high risk of infection; travelers to endemic regions

Administered to children at 2yo and adults in conjuncture with HBV vaccie

Question 21

What percentage of all acute hepatitis cases are caused by HAV?

Answer 21

40% of acute hepatitis cases are HAV