Hepatitis

Question 1

what types of hepatitis are there

Answer 1

• bacteria
• viral
• noninfectious etiologic agents

Question 2

how is hepatitis transmitted

Answer 2

via blood and sex while others via fecal-oral route

Question 3

what is the pathogenesis of viral hepatitis

Answer 3

• liver damage due mostly to host cell-mediated immune response
• mainly CTL (immunopathology)
• hepatitis viruses are not cytolytic

Question 4

what are the three viral pathogens of hepatitis

Answer 4

• hepatitis A virus (HAV)
• hepatitis B virus (HBV)
• hepatitis C virus (HCV)

Question 5

describe the pathogenesis of acute viral hepatitis

Answer 5

• robust immune response
• lots of CTLs activated
• CTL-mediated apoptosis of hepatocytes
  
  • signs/symptoms; jaundice
• virus cleared

Question 6

describe the pathogenesis of chronic viral hepatitis

Answer 6

• insufficient immune response
• few CTLs activated
• little damage to hepatocytes
  
  • no or mild symptoms
• virus persists
• scar tissue accumulates
• sequelae

Question 7

describe hepatitis disease

Answer 7

• inflammation of the liver
• hepatocytes are destroyed
• acute symptoms:
  
  • bilirubinemia -> jaundice -> yellow skin and
    yellow skin and eyes; dark urine
• abdominal pain
• vomiting, nausea, anorexia
• fatigue

Question 8

describe hep A

Answer 8

• HAV is a naked virus
• acute disease, usually mild and self-limiting
• fecal-oral route

Question 9

describe hep C

Answer 9

• HCV is enveloped
• usually chronic asymptomatic disease but causes serious problems many years later
• no vaccine

Question 10

how is HCV transmitted

Answer 10

blood, sexual contact, and vertical transmission; “blood-borne pathogen”

Question 11

what are some complications of chronic hepatitis

Answer 11

• can lead to: cirrhosis, liver failure, liver cancer
• increases risk for liver cancer by 10-fold

Question 12

describe hep B

Answer 12

• HBV is enveloped
• acute and chronic infections possible

Question 13

how is HBV transmitted

Answer 13

blood, sexual contact, and vertical transmission; “blood-borne pathogen”

Question 14

studies show that age of infection is the single most important factor associated with chronicity of HBV infection. hosts that mount a robust CTL response tend to have acute hepatitis infections whereas hosts who mount an insufficient CTL response, have chronic infections. which age group would you predict to be more likely to develop chronic HBV infections?
- newborns
- children > 5 years
- young adults (18-35 years)
- adults (36-64 years)

Answer 14

newborns

Question 15

how is HBV in adults, infants, and young children

Answer 15

• HBV in adults -> usually acute disease, occasionally severe
• HBV in infants and young children -> chronic disease
• infants born to HBV+ mothers are given HB immune globulin
• all pregnant women are routinely screened for HBV

Question 16

HBV vaccine is routinely offered to all newborns within how many hours of birth

Answer 16

48

Question 17

describe HDV

Answer 17

• aka “delta agent”
• uncommon in the U.S.
• causes severe fulminant hepatitis in hosts already infected with HBV

Question 18

what does HDV require for replication

Answer 18

HBV

Question 19

vaccination against HBV is also protective against

Answer 19

HDV infection

Question 20

what is the prevention for HAV, HBV, and HCV

Answer 20

• HAV = inactivated virus vaccine
• HBV = subunit vaccine
• HCV = no HCV vaccine; avoid high risk behavior; screen high risk individuals
  
  • treatment: interferon and antiviral drugs
    for people born between 1945-1965

Question 21

what is the diagnosis of viral hepatitis

Answer 21

• initial diagnosis made by observation of jaundice, enlarged liver, or fluid in the abdomen
• serological testing can identify viral antigens or antibodies
• molecules tests (ie PCR) to detect viral genomes