Hepatitis Flashcards
What are the 5 types of hepatitis virus all very resistant to? (3)
low pH, organic solvents, and detergents
What is hepatitis? How many types are there?
Disease of the liver and there are 5 types
What type of virus is hepatitis A?
Picornavirus
What is the composition of the picornavirus?
ss+RNA genome, naked(un-enveloped) icosahedral capsid
What does hepatitis A cause?
infectious hepatitis
Which hepatitis accounts for about 40-50% of all cases?
Hepatitis A
How many serotypes for Hepatitis A are there?
Only one HAV serotype worldwide and humans are the reservoir
Which demographic is Hepatitis A common in?
Children
How does hepatitis A enter the body?
Enters the blood via the lining of the intestinal tract and then migrates to the liver
How long is the prodrome for Hepatitis A?
The incubation period is 15-40 days
With hepatitis A how long after prodrome until symptoms set in?
Suddenly
What causes the symptoms of Hepatitis A?
Symptoms are not caused by the presence on HAV in the liver but by the immunological response of the host to its presence
What are the symptoms produced in a Hepatitis A infection?
Fever, headache, vomiting, jaundice, pain in the abdomen due to liver inflammation
How long does it take to recover from Hepatitis A?
99% of patients make a complete recovery within 8-12 weeks without complications
How is hepatitis A controlled?
1-Proper sanitation
2-Chlorination of water
3-Before present vaccine, passive immunity was obtained using immune gamma globulin
4-Very effective vaccines used in the United States are killed(formalin) virus preparations recommended for those at high risk for exposure only (MSM, travelers, IV drug users)
Hepatitis B is what type of virus?
hepadnavirus- DNA virus and is enveloped
Hepatitis B causes what?
Serum hepatitis
HBV virions are also known as?
Dane particles
How many subtypes of HBV are there?
8
What is unusual about the replication process of the HBV virus?
contains partial dsDNA genome which must be replicated
Describe the replication process for HBV?
HBV enters the body via blood
Viral DNA forms complete ds circle
mRNA in capsid produces DNA using reverse transcriptase
RNA is degraded leaving partial ds DNA
How is HBV spread?
contact with bodily fluids, injection of blood, neonate infection during the birthing process
How long is the incubation period for HBV?
50-180 days
What are the symptoms for HBV?
jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomiting and joint pain
What is the fatality rate for HBV?
2%
Whatare the effects of the cell mediated immune response to HBV?
If cell mediated response is strong, disease is self limiting.
If weak chronic hepatitis ensues(leads to cirrhosis, hepatocellular carcinoma or liver failure)
How to control/prevent HBV?
Avoid contact with blood or blood products(universal precautions), Active immunization(subunit vaccines made in yeast), Passive immunization(HBV immune globulin)
What are the characteristics of the HCV virus?
Flavivirus- enveloped, icosahedral, +ssRNA cirus
What does HCV cause?
non-A, non-B hepatitis
What are the known reservoirs for HCV?
humans and chimpanzees
Is a major cause of post transfusion hepatitis. Which hepatitis is it?
HCV
How many HCV carriers are there world wide?
200 million
How is HCV transmitted?
Via contact with bodily fluids(IV drug use, sexual contact)
Which genders is HCV transmission most efficient?
Male to a female is more efficient thn male to male
How does HCV enter the body?
Enters blood stream and infects hepatocytes
What does the HCV virus do once it has infected a cell?
It does not kill the cell, sets u a persistent infection leading to chronic disease
How long is the prodrome phase for HCV and what are the symptoms after?
6-7 weeks and the symptoms are jaundice, abdominal pain, nausea, and dark urine
in 15-20% of patients how long does the infection last?
virus is cleared ending the infection in 4-6 months
In the majority of people how long does the HCV infection last?
there is a persistent infection that may last for many years leading to chronic active hepatitis
What are the two drugs used to treat HCV
Ribavirin and interferon
Can you treat HCV with Ribivirin alone?
No has very little effect unless paired with interferon. It enhances interferon
With the 2 drug treatment for HCV what percentage of patients can be cleared?
70%
HDV piggybacks of of which other form of Hepatitis?
HBV
Why does HDV need the HBV virus as a helper?
because it cannot code for its own surface protein and thus in order to produce more virus particles, it needs a helper virus
Who most commonly has HDV and how is it also transmitted?
Mostly seen in intravenous drug users and also spread through sexual intercourse
How is HDV acquired?
HDV is either acquired along with HBV(co-infection) or as a super-infection of an already HBV-infected individual
Describe the shape and features of the HEV virus?
small, round, icosahedral, +ss RNA naked virus
How is HEV transmitted?
Enteric non-A, non-B hepatitis transmitted via the fecal-oral route
In contrast to HAV how is HEV not transmitted?
not usually transmitted directly from one patient to another
How long is the incubation period for HEV?
16-60 days
What are the symptoms for HEV?
Typical hepatitis symptoms- jaundice, malaise, abdominal pain, nausea etc.
Describe chronic HEV infections
No evidence for chronic HEV infections
