Viral Hepatitis Flashcards
What’s chronic hepatitis?
Hepatitis present for more than 6 months.
Causes variable changes in liver function
Name three causes of acute hepatitis.
Infection Toxins/drugs/alcohol Autoimmune - wilson's - heamochromatosis
Name some causes of infectious hepatitis.
EBV/cytomegalovirus Toxoplasmosis Leptospirosis Q fever Syphilis Malaria VHF - viral haemorrhagic fevers (e.g. Ebola)
What antibiotics are created in a hepatitis infection?
IgM is made first
IgG is made second
What class of virus is hepatitis A?
It’s an ssRNA virus enterovirus (infects the enteric tract)
How is hepatitis A transmitted?
Feaco-oral
Contaminated food or water.
Human only reservoir
How long can hepatitis A survive inside and outside of the body?
Can survive for months in contaminated water.
There is no chronic carriage in humans.
Is hepatitis A likely to return after one infection?
No- there is a good immunity after infection
What is acute hepatitis and what does it cause?
Inflammation of the liver.
It raises ALT/AST and causes jaundice and clotting problems.
What are the clinical features of hepatitis A?
Fever Abdominal Pain Diarrhoea Jaundice Itch Muscle Pain However it is a self-limiting illness
What is the fatality rate of hepatitis A?
0.4% (1.75% in over 50s)
What is the treatment of hepatitis A?
No specific treatment
- maintain hydration
- avoid alcohol
- no vaccine to treat
How is hepatitis A diagnosed?
- Yields a positive IgM serology test
- RNA can be found in blood and/or stool
- IgG in the blood suggest they had it once, not currently
Who is normally vaccinated against hepatitis A?
Travellers Gay men IVDU Chronic liver disease patients - to contain any outbreak
What class of virus is hepatitis E?
A calicivirus (ssRNA)
How is hepatitis E transmitted?
Feaco-oral
Feacal contamination of water supply
What is the incubation period of hepatitis E?
40 days
What are the clinical features of hepatitis E?
Fever Abdominal Pain Diarrhoea Jaundice Itch Muscle Pain Some rare neurological effects
What is the fatality rate of hepatitis E?
1-3% (15-25% in pregnant women)
What is the treatment for hepatitis E?
- supportive
- pooled IgG doesn’t prevent infection
- no vaccine to treat
Does the body chronically carry hepatitis E?
Yes - but usually only in immunosuppressed patients
Name the feaco-orally transmitted forms of hepatitis
A and E
Name the blood bourne hepatitis viruses.
B, C and D
What class of virus is hepatitis B?
It’s a DNA virus (the only one out of A,B,C,D and E)
What are the vaccination guidelines for hepatitis B? (The most common hepatitis virus in the world?
Not commonly vaccinated against, unless in a high risk profession like medicine.
How is hepatitis B transmitted?
- vertical transmission
- contaminated needle
- child to child
- transplants/fluid
- most cases in the UK are from immigrants (picked up at antenatal screening)
Acute hepatitis has an incubation period of 2-6 months, and can cause what symptoms?
Fever Fatigue Jaundice Myalgia Joint Pain
If a child is infected with hepatitis B, what other symptoms might they have?
- asymptomatic
- can lead to chronic infection
How does clearing affect adults with hepatitis B?
At first they present symptomatically, but once they’ve cleared the virus, it attacks the liver
What’s the fatality rate of hepatitis B?
0.5-1%
What are the problems associated with chronic hepatitis B?
- weight loss
- chronic liver damage
- abdominal pain/masses
- fever
- cachexia
- bloody ascites
- cirrhosis
- hepatocellular carcinoma
- death
What’s the serology for hepatitis B?
Hep B antigen positive
What’s the difference between a positive eAg serology and a negative?
eAg positive = high viral load, highly infectious, higher risk of CLD and hepatocellular carcinoma
eAg negative = opposite, but still has a small level of infection
What is the treatment for hepatitis B?
Acute has no treatment
Chronic has two types of therapy
- immunological
- anti-viral drugs
Describe the immunological and anti-viral treatment for hepatitis B.
Immunological
- pegylated interferon increases cellular immune response, but has lots of side effects
Anti-viral drugs
- tenofovir/entecavir suppress viral replication
How is vertical transmission of hepatitis B prevented?
- HBV vaccination for all newborns
- HBV immunoglobulin if eAg is positive
- Tenofovir is given to the mother during the last trimester
Hepatitis D needs which other hepatitis virus to replicate?
Hepatitis B
- so therefore has the same transmission
- vertical transmission is rare
How is hepatitis D acquired?
Co-infection with hepatitis B
Super infection of chronic HBV carries
How is hepatitis D treated?
Pegylated interferon alpha
How is hepatitis C transmitted?
Injections
Transfusion/transplant
Sexual
Vertical (rare)
How is hepatitis C prevented?
- no vaccine
- no reliable immunity after infection
How is hepatitis C diagnosed?
Because it’s mostly asymptomatic, its normally picked up at screening.
HCV IgG positive means a chronic or cleared infection.
PCR positive means they currently have an infection
What’s the treatment for hepatitis C?
There’s a cure
Pegylated interferon alpha and ribavirin
In all hepatitis infections, what does sAg and sAb mean?
sAg = surface antigen, a marker of infection sAb = surface antibody, a marker of immunity
In all hepatitis infections, what does cAb mean?
cAb = core antibody, means they have chronic or acute hepatitis
In all hepatitis infections, what does eAg and eAb mean?
eAg = suggests high infection eAb = suggests low infection
