Infectious Causes of Hepatitis 1 Flashcards
What is hepatitis?
Inflammation of the liver
How long does acute hepatitis last?
weeks to months
What are the symptoms of acute hepatitis?
non specific flu like symptoms, jaundice, dark urine, pale faeces
How long does chronic hepatitis last?
years to a lifetime
What are the symptoms of chronic hepatitis?
general malaise with progression to cirrhosis and possibly liver cancer
What is fulminant hepatitis?
very quick necrosis of hepatic tissue - leads to death due to acute liver failure
What causes the liver damage?
The immune response
What does exposure to hepatitis early in life mean?
The acute disease will be less severe but there are higher rates of chronic infection
If you immunised against one hepatitis virus are you immunised against them all?
No - the viruses are unrelated and so there is no cross protection
Which hepatitis viruses cause chronic infection?
HBV and HCV
What is the route of transmission for hepatitis A and E?
faecal oral
What type of infection is caused by hepatitis A and E?
acute
How are hepatitis A and E prevented?
sanitation and also immunisation for A
What areas have the highest prevalence for hepatitis A?
Areas of poor sanitation - Asia, Africa, South America
Which area of Australia has the highs prevalence of hepatitis A?
indigenous communities
To what family does the hepatitis A virus belong?
picornaviridae family
To what genus does the hepatitis A virus belong?
hepatovirus
What is the structure of the hepatitis A virus?
non-enveloped + sense ssRNA virus
Where do hepatitis A and E replicated?
Both in the intestinal epithelia and in hepatocytes
How is hepatitis A and E excreted?
In the bile which goes into the faeces
Is there perinatal transmission of hepatitis A and E?
No
What does liver enzyme ALT indicate?
The presence of replicating virus
Which antibodies are present in response to hepatitis A and E?
IgM first then IgG
How is acute viral hepatitis diagnosed?
serological tests or nucleic acid tests
How can you tell in a serological test if the infection is acute?
Either by the presence of IgM antibodies or a rising titre of IgG antibodies
What is the incubation period of hepatitis A?
on average 30 days
What are the complications of hepatitis A?
fulminant hepatitis or cholestatic hepatitis
Can hepatitis A become a chronic infection?
no
How long do the symptoms of hepatitis A last?
2-3 weeks
What is the treatment for hepatitis A?
supportive rehydration and nutrition
How effective is the hepatitis A vaccine?
100% effective after 2 doses
Why is the hepatitis A vaccine expensive to produce?
Because it has to be in diploid cells and has to have testing to check that the virus is fully inactivated
What family does the hepatitis E virus belong to?
Hepeviridae
What genus does the hepatitis E virus belong to?
hepevirus
What is the structure of the hepatitis E virus?
Non enveloped icosahedral with + sense ssRNA
Which of hepatitis E and hepatitis A viruses is more fragile in the environment?
hepatitis E
What is the distribution of hepatitis E virus?
Asia, Africa and Central America
What is the incubation period for hepatitis E?
40 days
Which group of patients have increased risk of fatality from hepatitis E?
pregnant women
Can hepatitis E lead to a chronic infection?
no
Is there a vaccine currently for hepatitis E?
No
What are the symptoms of hepatitis E?
jaundice, malaise, anorexia, abdominal pain, hepatomegaly, nausea and vomiting, fever, pruritus
What is the lab diagnosis of hepatitis E?
serology, nucleic acid tests, and cultured in vitro
What is the treatment for hepatitis E?
supportive therapy - no antiviral available
Is immune serum globulin therapy effective to prevent hepatitis A and E?
A yes but E no
Is a vaccine possible for hepatitis E?
Yes - it is a good prospect because it can be cultured in vitro
