Lecture 17 - Hepatitis Flashcards
Hepatitis is an inflammation of what body organ?
Liver
What classifies a virus as a hepatitis virus?
Must be a virus that routinely replicates in and damages hepatocytes. There are many viral diseases that can cause liver damage but not necessarily is classified as a hepatitis virus
There are 5 major hepatitis viruses. What are they?
Hepatitis A virus Hepatitis B virus Hepatitis C virus Hepatitis D virus Hepatitis E virus
T or F, Hepatitis viruses only cause chronic inflammation of the liver.
False, Hepatitis can be either acute or chronic with liver damage ranging from slight to absolute
What are the 4 causes of Hepatitis?
Alcohol, Drugs, Autoimmunity and Viruses
Which Hepatitis viruses are transmitted through the fecal-oral route
HAV and HEV
Which Hepatitis viruses are enveloped and which are non-enveloped
Enveloped: HBV, HCV, HDV
Non-Enveloped: HAV, HEV
Which of the Hepatitis viruses are considered less sturdy?
The Enveloped viruses –> HBV, HCV, HDV
What is the mode of transmission for HBV, HCV and HDV?
Exchange of bodily fluids (blood, semen, saliva, mother’s milk, etc.) over percutaneous and mucosal surfaces.
Which Hepatitis viruses are considered sturdy or stable?
The Non-Enveloped viruses –> HAV, HEV
Which Hepatitis viruses produce a ‘Chronic Infection’?
HBV, HCV, HDV
What are the preventions of HAV? Also know when they can be used.
- Clean water
- Immune globulin (anti-hepatitis Ab) and hepatitis A vaccine.
- Immune globulin –> either pre or post exposure prophylaxis
- Hepatitis A vaccine –> Can be used for pre-exposure prophylaxis
Which Hepatitis viruses cause only acute infection?
HAV and HEV
What is the primary measure for prevention of HBV?
- Immunization
- Pre-exposure prophylaxis with Hep B vaccine
- Post-exposure prophylaxis with Hep B immune globulin (HBIG) and Hep B vaccine
What are the preventions of HCV?
- Currently no products available to specifically prevent hepatitis C
- Primary strategies are Blood Donor Screening and Risk behavior modification
Are HBV and HDV associated in any way? How?
Yes. HDV infection is dependent on HBV for replication
What are the preventions of HDV?
- Because HDV infection is dependent on HBV for replication, the primary means to prevent HDV is to immunize to prevent HBV infection, through either pre or post-exposure prophylaxis.
- If already infected with HBV, primary means of prevention is Risk Behavior Modification
What are the preventions for HEV?
- No specific products are available for prevention.
- Ensure safe drinking water as well as sanitation procedures
What Hep virus is very rare in the U.S. but is relatively common in some ‘developing’ countries where it takes a substantial toll amount pregnant women (20-25% fatality)
HEV
Which Hep virus has the most chronic infections and deaths per year?
HCV with HBV in second place
Hepatitis A virus characteristics
- Virus family
- Envelope or No Envelope
- Transmission?
- Acute or Chronic
- Vaccine available?
- Develop antibodies?
- ssRNA Picornavirus
- Non-enveloped (Sturdy)
- Fecal-Oral transmission
- Acute disease and asymptomatic infection (no chronic)
- Vaccine (inactivated) available since 1996
- Protective antibodies develop in response to infection –> confers lifelong immunity
Can one become immune to HAV?
Yes. Once protective antibodies are developed in response to infection, patient would have lifelong immunity
HEV in developing countries takes a tragic toll on whom?
Pregnant women
HAV has a very similar pathology to what other Hep virus?
HEV
What antibody is involved in treating HAV?
pooled IgG
What part of the U.S. has more HAV infections?
The western U.S.
Hepatitis B virus characteristics
- Virus family
- Envelope or No Envelope
- Mode of transmission
- Acute or Chronic
- Vaccine available?
- Develop antibodies?
- DNA Hepadnaviridae
- Enveloped (Unsturdy)
- Sexual, Parenteral, Perinatal transmission
- Acute disease, Asymptomatic infection leading to a Chronic infection
- Vaccine (inactivated) available wince 1981
- Protective antibodies develop - confers lifelong immunity
Outer membrane of HBV contains what?
Hepatitis B surface antigen (HBsAg) which also circulates in blood as particles. HBsAg is the primary component of hepatitis B vaccine.
What does HbsAg do?
Induces a protective, neutralizing antibody that provides long-term protection against HBV infection. Used in Hep B vaccines
What does the inner core of Hep B virus contain? (4 things)
- Hepatitis B core antigen (HBcAg)
- Hepatitis B e antigen (HBeAg)
- Single molecule of partially dsDNA
- DNA polymerase
What is the population that is at high risk to acquire HBV?
Health care personnel Dialyses patients People from high risk areas Military personnel People with multiple sex partners IV drug abusers
The major source of infectious HBV virus is what?
Blood but it can be found in any bodily fluid. So most effective way to transmit HBV is to inject it into bloodstream. Therefore, unvaccinated health care providers are of great concern for infection
T or F, Cell-mediated immunity and inflammation are primarily responsible both for the pathology of HBV and eliminating the viral infection
True
Chronic HBV infection has what three results?
Asymptomatic, mild chronic hepatitis, or severe chronic hepatitis
Can people infected with HBV become carriers?
Yes and will shed HBV indefinitely
Sever chronic hepatitis can result in what two things?
Cirrhosis or Cancer
What Hepatitis virus has a similar pathology to HBV but has a much higher carrier rate and higher death rates.
HCV
How many genes are in the HBV genome?
4 genes that code for 5 proteins
What are the 5 proteins coded for in HBV?
HBcAg (capsid protein) HBeAg (Immune modulator) HBsAg (surface proteins) Reverse transcriptase x-protein (Regulatory protein)
What molecules are used diagnostically in HBV infections?
Liver Enzymes HBcAg HBeAg HBsAG Antibodies to HBcAG, HBeAG, and HBsAg
In what percentage of people, the immune response will effectively resolve the infection?
80-90% of people will have infection resolved. However, 10% of individuals do not mount a sufficient immune response and HBV infection becomes chronic
What antibody is significantly developed and is seen diagnostically when a person is infected?
Anti-HBsAg antibody develops significantly and HBsAg drops.
