Viral Hepatitis Flashcards
HAV
Duration: Acute, self limited
Route of infection: Fecal-oral. (usually)
Outcome: asymptomatic in young, acute hepatitis in later ages
NO Chronic liver failure.
Rare acute liver failure
Immunization is available.
Immunity is lifelong.
No therapy.
No cancer
HAV
ssRNA Picornavirus.
40% of all acute viral hepatitis is HAV
Mortality <0.5%
Incubation: 15-50 days.
Virus secreted into bile and stool
11 days prior to formation of anti-HAV IgM (patients are infectious before they know they are ill).
HAV Diagnosis
HAV IgM: Acute or recent infection
HAV IgG: past infection or immunization.
Can be detected in stool: not performed.
PCR HAV: not performed.
HAV typical serologic course
HAV Prevention
Sanitation and hygiene, handwashing.
Inactivated HAV vaccine
Live, attenuated HAV vaccine
95% protective, >25 years duration
Vaccination in US at 1-2 years of age
First dose: protection by 2-4 weeks after vaccination
US incidence has dropped 90% since 1990
Verify titers in all liver disease patients: revaccinate.
HBV DNA Hepadnavirus
Duration: Acute, Chronic, Lifelong
Route of Infection: Blood, Sexual, Vertical
Usual outcome: Asymptomatic, Chronic, Fulminant
Chronic infection: Occasional (adults), common (infants).
Cirrhosis and Liver failure: common.
Acute liver failure: Occasional.
Immunization: Mandated, Available.
Therapy: Indirect, Direct, Variable success.
Malignancy: HBV is major cause of HCC.
HBV Epidemiology
240-350 million chronic infections worldwide.
750,000 die from HBV annually.
300,000 cases of liver cancer annually.
Sub-Saharan Africa, East Asian infection rates in adults: 5-10%.
Hep B The Details
Exposure to blood/body fluid, or at birth.
Endemic areas: infection at birth or in infancy.
Epidemic areas: IV drug use, sex, blood, other.
Incubation: 30-180 days.
Detection in blood: 30 days post infection.
Infection at birth: >90% develop chronic HBV.
Infection >5 years old <10% chronic HBV.
Most chronic carriers are asymptomatic.
In chronic disease: cirrhosis and liver CA can occur. Early mortality: 15-25%
Hep B Clinical
- Acute hepatitis: typically self resolve, some are asymptomatic/unrecognized.
- Chronic infection may be symptomatic or asymptomatic
- Cirrhosis
- HBV and HCV together account for 50% of HCC
- Extra intestinal features: Membranous GN, Serum sickness, Cryoglobulinemia, Aplastic anemia
Hep B markers
- HBsAg: surface antigen: first viral detectable antigen.
- HBcAg: core antigen
- Anti-HBc IgM: early serological evidence of infection.
- “Window” HBsAg cleared, but anti-HBS still negative.
- HBeAg: presence is associated with decline in replication.
- Anti-HBs IgM: early clearance
- Anti-HBs IgG: clearance of infection.
- HBV PCR: quantitative assay of viral load.
- ALT: evidence of chronic “hepatitis”
How to tell if a patient is immune to HBV due to vaccination:
anti HBS is positive
anti E antibody is absent
anti core antibody is absent
HBV Transmission
Highly infectious.
Vertical transmission: HBsAg+ mother: 20% transmission to infant.
HBeAg+: 90% infective.
Natural history: ultimately 1/4 die of HBV complications.
Can be transmitted within households.
Parenteral transmission
Sexual transmission.
Hep B prevention
Education
Screening of blood donors.
Screening of mothers
Vaccination.
HEP B therapy
Acute HBV is self resolving by definition: supportive care.
Chronic infections: candidates for therapy:
- persistently elevated ALT, appropriate levels of HB DNA
therapies vary by medication/dosage and genotype.
HEP B therapy meds
Antiviral drugs
Immune system modulators.
HCV
Duration: Chronic, lifelong
ROI: blood (rarely sexual, some vertical).
Common route: Parenteral blood exposure
Usual outcome: Asymptomatic, chronic
Chronic infection: typical
Cirrhosis and liver failure: common
Acute liver failure: rare
Immunization: not available.
Therapy: indirect, direct, excellent recent success.
Malignancy: Yes. Major cause of HCC
HCV
ss RNA. 7 major genotypes. Genotype correlated with treatment success, particularly with IFN.
200 million people infected: 3% of the world.
11 million new cases per year.
HCV
75-85% of infections become chronic.
Risk factors: IV drug use, medical equipment, needlestick, tattooing, incarceration.
vertical transmission occurs (rate is <10%, higher if mother is HIV+)
Sexual transmission rate low or very low for monogamous heterosexual couples.
HCV Clinical
Acute HCV: symptomatic in 15%, fatigue, nausea, anorexia, weight loss, mostly anicteric. HCV infection resolves in 10-50%.
Chronic HCV >6 months.
Can be asymptomatic for decades.
ALT/AST can be normal in up to 50%.
10-30% develop cirrhosis by 3 decades.
Alcohol increases risk 100 fold.
other risk factors: male, HBV, HH (iron)
Many extraintestinal manifestations
HCV Prevention
No vaccine
Education
Blood screening
Needle sharing/needle exchanges
HCV Detection
HCV Ab EIA or ELISA
Qualitative and Quantitative HCV PCR.
Antibodies can take weeks to be detectable.
PCR detection at 1-2 weeks.
antibody is not protective.
HCV Therapy
Direct Acting Antivirals (DAAs). Cure rates as high as 93-99%.
Immune Enhancing Regimens.
Liver transplantation
HCV in children
incidence in pregnant mothers: 1-8%
Vertical transmission: 3-5 % (higher if mother is HIV+)
spontaneous clearance in 25-50%
Hep D
ssRNA virus.
Can only replicate in presence of HBV.
Simulatneous infection of HDV
Superinfection of HDV in patients with HBV: results in more severe complications, increased liver failure.
HEV
ssRNA
Fecal-oral transmission.
Incubation: 3-8 weeks
Short prodromal phase, virus is cleared early from blood, may persist in stool for weeks.
in pregnancy is associated with fulminant liver failure, 20% mortality if infected in 3rd trimester.
Hep E prevention
Sanitation, personal hygiene
Vaccine, not yet licensed.
TORCHES
Toxoplasma
“Others”
Rubella
Cytomegalovirus
Herpes
Enterovirus
Syphilis
Hepatitis B: Acute Infection with recovery
Hepatitis B: Acute Infection: “Window:
Hepatitis B Chronic Infection
Hepatitis B Vaccination Results
Hepatitis C Acute HCV Infection
Hepatitis C Chronic Infection
Hepatitis C Testing Sequence
Hep D on Hep B Super-Infection
Hep D and Hep B Confection
Hepatitis E- HEV
