HBV

Question 1

What viral family is HBV?

Answer 1

HBV is in the hepadnaviridae family

Question 2

What kind of genome does HBV have?

Answer 2

Partially dsDNA

Question 3

What does the HBV genome encode for?

Answer 3

HBV encodes for lots of different proteins

Question 4

What is the outermost layer of HBV?

Answer 4

Envelop

Question 5

What is the significance of HBV having an envelope instead of a protein shell?

Answer 5

Envelopes are less stable and require direct contact to spread (blood/sexual contact)

Question 6

HBV encodes for two particles…what are they?

Answer 6

Dane particle (infectious particle)
Surface antigen particle...HBsAg (decoy)

Question 7

Since HBV is spread by blood/sexual contact, what are some risk factors for contracting the infection?

Answer 7

Multiple sexual partners without protection…but hey…yolo

Question 8

HBV infects liver cells expressing a variety of receptors (including transferrin receptor)…what happens after HBV enters a liver cell?

Answer 8

HBV completes its dsDNA genome (via the viral polymerase packed inside the Dane particle)

Question 9

After the genome is completed, it is transcribed into viral mRNA. What is done with the viral mRNA?

Answer 9

Viral mRNA is used to make viral proteins AND is used as a template to make the partial dsDNA HBV genome

Question 10

What is the typical incubation period of HBV?

Answer 10

Long…2-24 weeks

Virus starts replicating within 3 days of exposure

Question 11

What is the infection duration of HBV?

Answer 11

HBV can be acute OR chronic…not like HAV or HEV

Question 12

What causes an acute HBV infection?

Answer 12

Effective cell-mediated response

Question 13

What are the typical symptoms of an HBV infection? When do they typically occur?

Answer 13

Jaundice
Dark urine
Release of enzymes
Malaise
Anorexia
RUQ pain
Itching

May take up to 45 days

Question 14

What causes the chronic HBV infection?

Answer 14

Limited cell-mediated immune response (mild symptoms)

Question 15

What are some possible complications of a chronic HBV infection?

Answer 15

Fulminant hepatitis
Primary hepatocellular carcinoma
Cirrhosis
Extrahepatic disease (polyarteritis nodosum, GN)

Question 16

How is HBV diagnosed?

Answer 16

Multiple serological markers

Question 17

What are some treatment options for HBV infections?

Answer 17

Alpha-interferon (4 months)
Lamivudine...reverse transcriptase inhib (1 year)
Nucleoside analogues (1 year)

Question 18

What can be given to newborns of HBsAg mothers or individuals within a week of exposure for prophylactic treatment?

Answer 18

Hepatitis B immun globulin

Question 19

Who should get the HBV vaccine?

Answer 19

Infants
Children
People in high risk groups

Question 20

How many people in the US have been infected with HBV? How many people die every year from HBV infections?

Answer 20

12 million have been infected

5000 people die every year from HBV infection

Question 21

What percentage of people worldwide have been infected by HBV? How many have chronic HBV infections? How many die per year?

Answer 21

1/3 of the worlds population has been infected by HBV

> 350million people have chronic HBV infections

1million people die of HBV infection every year