Infectious Causes of Hepatitis Flashcards
What hepatitis viruses are most common?
Hepatitis A, B, C
This type of test is used to diagnose hepatitis infection by testing for viral antibodies.
ELISA test
This hepatitis antigen is secreted and serves as a marker for the level of infection.
HBeAg
What are the two most common risk factors for HBV & HCV infection?
Injection drug use and having multiple sex partners
A patient previously diagnosed with HBV is tested for the presence of HBsAg antibodies. The test returns negative. What does this indicate?
The patient is still infected with the virus and does not have immunity. If it has been years since the initial diagnosis, the patient is chronically infected.
How does co-infection with HBV & HDV differ from superinfection?
Co-infection is infection with both viruses in a patient who was previously hepatitis negative.
Superinfection occurs when a patient with chronic HBV develops HDV.
HCV is most common in the USA among millennials and baby boomers. Why is this?
Millennials - injection drug use
Baby boomers - blood transfusions before screening
This hepatitis antigen is responsible for forming the capsid.
HBcAg
These hepatitis viruses are transmitted via fecal/oral route.
HAV, HEV
The patients are at higher risk of severe HEV infection.
Pregnant women in their third trimester, organ transplant recipients
What genotype of HEV is responsible for chronic infections?
Genotype 3
True/False. HBV HBsAg antibodies do not appear until HBsAg is cleared from the body.
True. Positive HBsAg indicates active infection. Antibodies to HBsAg indicate immunity.
A patient with active HBV infection has high levels of HBeAg, no antibodies to HBe, and high liver enzymes. What is the classification of their infection?
HBeAg+ Immune Active HBV
This hepatitis virus can spread from them other to the fetus via the placenta.
HBV
What is the HBV infection classification of a patient with low HBeAg levels, positive for HBeAg antibodies, and high HBV DNA levels?
HBeAg-Negative Immune Reactive HBV
What is the HBV infection classification of a patient with low HBeAg levels, positive for HBeAg antibodies, and normal liver enzyme levels?
Inactive HBV Carrier
This hepatitis antigen is present on the surface of all viral particles.
HBsAg
In the USA, HAV infections have decreased due to vaccination. In recent years, among what populations are most new infections found?
Injection drug users and people experiencing homelessness
This hepatitis virus cannot cause chronic infection.
HAV (& HEV, except in rare cases of organ transplants)
This hepatitis virus only infects in the presence of HBV.
HDV
The presence of this antibody indicates prior exposure to HAV and protective immunity.
IgG
A patient is infected with HBV. They have relatively high viral levels, but normal liver enzymes. What is the classification of their infection?
Immune-Tolerant HBV - generally infected as infants
What mechanism of HCV shields the virus from the immune response and contributes to chronic infection?
HCV associated with VLDLs to form a lipoviral particle that shields viral antigens
What are the routes of transmission for HBV, HCV, & HDV?
Blood, IV drugs, sexual (except HDV)
How can an active HCV infection be identified?
A positive test for HCV antibodies only indicates exposure to the virus. A follow-up test for viral RNA must be completed. A positive test indicates active infection. A negative test in the presence of viral antibodies likely rules out chronic infection, but additional tests may be recommended.
What is the window period in HBV infection?
HBsAg antibodies are not present until HBsAg is cleared from the body. The window period is the time between antigen clearance and the development of antibodies.
How is the replication of HBV unique compared to other hepatitis viruses?
HBV is a DNA virus, but it replicates via an RNA intermediate using a reverse transcriptase
