154. Viral Hepatitis Clinical Features

Question 1

HAV

• epidemiology: where do outbreaks occur
• chronicity
• genome
• transmission
• pathogenesis
• sx
• dx
• tx

Answer 1

Epi: in US and world, due to imported food, drug use, homelessness, low mortality
Chronicity: NONE (acute only)
genome: ssRNA
trans: fecal-oral (poor sanitation, food/water, day care)
PGen: hepatotrophic: enteric = bloodstream = liver (immune-related hepatotoxicity)
Sx: weeks incubation, weeks-months infected, jaundice, fatigue, fever, low appetite (adults more sx due to more immune response than kids)
Dx: HAV +IgM = Acute; HAV +IgG = Resolved

Tx: Acute: supportive/hygienic care, exposure prophylaxis/close contacts (vaccine/IVIG)
Prophylaxis: excellent vaccine universal for children

Question 2

HBV
- epidemiology
- chronicity
- genome
- transmission
- pathogenesis
- sx
- tx
(dx panel next card)

Answer 2

Epi: 1mil in US, 250mil worldwide (2/3 unaware)
Chronicity: YES >6mo (most chronic infections acquired perinatally/young; most adult infections acute due to immune response)
dsDNA
trans: vertical (mom-child at birth), parenteral, sexual, IDU, hemodialysis
PGen: hepatotrophic: cccDNA in hepatocyte nucleus (immune and cytotoxic hepatotoxicity)
Sx: months incubation, duration depends on chronicity, jaundice, fatigue, abd discomfort
Tx:
MONITOR: acute, chronic + immune tolerant (normal LFT), chronic + inactive carrier
TREAT: chronic + immune-active (liver damage)
Acute: supportive/hygienic, exposure prophylaxis (vaccine/IVIG)
Chronic: reverse transcriptase inhibitor (Tenofovir - good in pregnancy, Entecavir) - manages does not cure (viral load suppressing); immune-stimulant (IM Interferon - very low cure rate with side effects)
Prophylaxis: excellent vaccine
Screening: high risk of HCC w/o cirrhosis (need imaging and AFP every 6 mo)

Question 3

Dx panel for HBV:
Healthy unexposed
Resolved Acute
Vaccinated
Acute
Chronic

What does HBeAg show?

Answer 3

Healthy unexposed: (-) for all
Resolved Acute: +HBsAb, +HBcAb, -HBsAg
Vaccinated: +HBsAb, -HBcAb, -HBsAg
Acute: +HBsAg, +HBcAb, +IgM HBsAb
Chronic: +HBsAg, +IgG HBcAb, -HBsAb

HBeAg: virus in highly replicable state

Question 4

HCV

• epidemiology
• chronicity
• genome
• transmission
• screening
• pathogenesis
• sx
• dx
• tx

Answer 4

Epi: 2 mil US, 70mil Global
Chronic: YES
ssRNA w/ identified protein targets (7 genotypes- 1 most common, then 2-3)
Trans: IDU, tattoos, blood transfusions pre-1992
Screening: EVERYONE 18+yo (+Pregnant women) due to increasing prevalence in younger people (opioid epidemic)
Pgen: targets hepatocytes, immune/cytotoxic hepatotoxicity
Sx: months incubation, lasts months/years (acute/chronic), 80% ASX, jaundice, fatigue, abd discomfort
Dx: HCV Ab + RNA Viral Load! (resolved when undetectable RNA)
Tx: Treat ALL patients: benefits public health
Specific viral protein inhibitors to diff parts of HCV (>95% curative!)
Pregnancy: therapies not approved, but low transmission risk
No vaccine
Cancer screen: only in cirrhotic pts, even if cured

Question 5

HDV

• epidemiology
• chronicity
• genome
• transmission
• screening
• pathogenesis
• sx
• dx
• tx

Answer 5

Epi: 12.5 mil global (5% HBV pts)
Chronicity: depends on HBV
circular ssRNA
Trans: parenteral, sexual, IDU
Screen: check HDV in all HBV pts!
PGen: requires HBsAg for virion assembly/infectivity (immune + cytotoxic hepatotoxicity)
Sx: wks-mo incubation, duration depends on HBV status, jaundice, flu-like sx, abd discomfort
Dx:
Co-infection: acquire HBV/HDV together: +HDV IgM + viral load
Superinfection: HDV on chronic HBV: +HDV IgM/IgG +viral load
Cured: undetectable RNA (cured HBV = cured HDV)
Tx: Immune stimulant: IM IFN - low cure rates but high SEs - try to cure HBV to cure HDV
Prophylaxis: HBV vaccine to prevent HDV!

Question 6

HEV

• epidemiology
• chronicity
• genome
• transmission
• pathogenesis
• sx
• dx
• tx

Answer 6

Epi: 20mil globally/year
Chronicity: NONE (acute only except organ tx)
ssRNA (4 genotypes: 1/2 - human-human trans, waterborne, younger pts; 3/4 - zoonotic, foodborne, older pts)
Trans: fecal-oral, poor sanitation/food/water
PGen: enteric = bloodstream = liver (immune mediated hepatotoxicity)
Sx: incubation - wks, duration - wks, jaundice, fever, fatigue, poor appetite (adults more sx than kids due to more immune response)
Dx: Acute: +/-HEV IgM and high RNA viral load, IMPORTANT TO SCREEN IN PREGNACY (20-30% mortality in 3rd trimester), resolved has no detectable RNA and +HEV IgG

TX: Acute - supportive/hygienic (most pts)
Chronic (rare tx): immune stimulant (Ribavirin) and lower immunosuppressant meds
Prophylaxis: VACCINE - good but developed recently, unsure durability