Liver (Hepatitis) Flashcards
viral hepatitis
Hepatitis A and E: spread feco-orally
Hepatitis B, C, and D: spread parenterally
extremely contagious RNA enterovirus
hepatitis A
spreads through contaminated food and water or through direct contact with infected individuals
hepatitis A
at-risk individuals include MSM (men who have sex with men) and PWID (persons who inject drugs)
hepatitis A
low- and middle-income populations at risk due to poor sanitary conditions and hygienic practices
hepatitis A
does not lead to chronic infection
hepatitis A
incubation period of 1-4 weeks
hepatitis A
clinical symptoms of fever and malaise begin about 4 weeks post-infection with jaundice occurring around weeks 5 to 6
hepatitis A
infected persons usually make full recovery following course of illness
hepatitis A
virus present in stool 2 weeks before and 1 week after onset of jaundice, individuals still infected despite absence and resolution of symptoms
hepatitis A
immunity via anti-HAV antibodies
hepatitis A
Two-dose vaccination
First dose typically administered at 12-23 months of age with second dose given 6 moths later
hepatitis A
Vaccine recommended for the following people:
• All children aged 12-23 months
• Unvaccinated children and adolescents aged 2-18 years
• International travelers
• At-risk populations (MSM, PWID, occupational hazards)
• People experiencing homelessness
• People with HIV
• People with chronic liver disease
hepatitis A
similar to hepatitis A
hepatitis E
single-stranded RNA virus
hepatitis E
incubation period 15-60 days
hepatitis E
Many infected individuals are asymptomatic or mildly symptomatic • Jaundice • Nausea • Vomiting • Anorexia • Hepatomegaly
hepatitis E
usually self-limited course of virus, but immunocompromised populations can develop chronic infection
hepatitis E
diagnosis = IgM and anti-HEV antibodies
hepatitis E
globally, liver disease caused by this is a serious problem (~400 million people are carriers, ~80% of all chronic carriers live in Asia and the Western Pacific rim)
hepatitis B
found in the blood during the late stages of a prolonged incubation period: 4-26 weeks
hepatitis B
present in all physiological and pathologic body fluids, except stool
hepatitis B
can withstand extreme temperatures and humidity
hepatitis B
spread by contact with bodily secretions
hepatitis B
in endemic regions, vertical transmission from mother to child during birth constitutes main mode of transmission
hepatitis B
in areas of low prevalence, horizontal transmission via blood transfusion, dialysis, needlestick accidents, needle sharing among IV drug users, and sexual transmission
hepatitis B
chronically infected patients are at increased risk for hepatocellular carcinoma
hepatitis B and C
Four clinical patterns: Acute self-limited hepatitis Fulminant acute hepatitis Chronic hepatitis Asymptomatic chronic infection
hepatitis B
largely prevented by vaccination and the screening of donor blood, organs, and tissues
hepatitis B
vaccination produces a protective anti-HBS antibody
hepatitis B
usually given 2, 3, or 4 injections of vaccine
hepatitis B
infants should be given first dose at birth and complete series at 6 months of age
hepatitis B
adults who have Hep __ + sex partner, people who share needles, healthcare workers, travelers to regions with increased Hep __ rates, anyone who wants to be protected
hepatitis B
major cause of liver disease (~175 million people worldwide are carriers)
hepatitis C
persistent chronic infection is present in 3-4 million in the US
hepatitis C
new cases have dropped since the mid 1980s due to reduction in transfusion-associated Hep __ and decline in infection between IV drug users
hepatitis C
death rate will continue to rise due to the decades long lag time between acute infection and liver failure
hepatitis C
major route of transmission in US: blood inoculation, with IV drug use accounting for 60%
hepatitis C
occupational exposure (healthcare workers) account for 4% of cases
hepatitis C
single condition most frequently necessitating liver transplantation in the US
hepatitis C
much higher rate of progression to chronic disease and eventual cirrhosis than Hep B
hepatitis C
positive ss-RNA virus belonging to the Flavividae family
hepatitis C
subclassified into 6 genotypes based on genetic sequence
hepatitis C
quasispecies (many variants)
hepatitis C
no vaccine
hepatitis C
incubation period of 2-26 weeks, average of 6-12 weeks
hepatitis C
asymptomatic in 75% of affected persons
hepatitis C
RNA can be detected in blood within days to 8 weeks depending on size of inoculation
hepatitis C
neutralizing anti-HC_ antibodies develop within weeks to a few months but do NOT confer effective immunity
hepatitis C
a strong immune response involving CD4+ and CD8+ cells are associated with self-limited infections
hepatitis C
persistent infection is the HALLMARK of infection, seen in 80-85% of patients with clinical or asymptomatic acute infection
hepatitis C
cirrhosis will develop in 20% of persistently infected patients, can be present at time of diagnosis or may take up to 20 years
hepatitis C
some patients will have decades long chronic infection without progressing to cirrhosis
hepatitis C
fulminant hepatitis is rare
hepatitis C
unique RNA virus that is replication-defective (only causes infection when encapsulated by HbsAg)
hepatitis D
dependent on HBV coinfection for multiplication
hepatitis D
Infection occurs in 2 ways:
Acute coinfection after exposure to serum containing both HDV and HBV (HBV infection must be established first, followed by HBsAg made in sufficient amounts for HDV virions to be produced)
Super infection of a chronic carrier of HBV with a new inoculum of HDV
hepatitis D
most superinfected persons experience an acceleration of hepatitis, progressing to a more severe chronic hepatitis 4-7 weeks later
hepatitis D
in the US, infection is largely restricted to PWID and persons receiving multiple blood transfusions
hepatitis D
most reliable indicator of HDV exposure
IgM and anti-HDV
