MI: Viral Hepatitis Flashcards
Name some primary and secondary hepatotropic viruses?
Primary - hepatitis A, B, C, D, E
Secondary - EBV, CMV, HIV, parovirus B19
What type of virus is hepatitis A?How is hepatitis A spread?
Single-stranded RNA virus
Faecal-oral
- Person-to-person (sex)
- Contaminated food/drink
What is the incubation period for hepatitis A?
2-6 weeks (usually 4 weeks)
What are symptoms of hepatitis A infection?
Symptoms of acute hepatitis
- Non-specific - fever, fatigue, abdominal pain, malaise, loss of appetite
- Elevated bilirubin - jaundice, pale stools + dark urine, pruritius
Describe the natural history of hepatitis A infection.
- 2-6 weeks after the infection you will develop hepatitis (transaminitis)
- This will be accompanied by a rise in IgM
- A more gradual rise in IgG will follow
NOTE: hepatitis A infection is often subclinical
What is the diagnostic test for acute hepatitis A?
Anti-hepatitis A IgM
- Only request if symptomatic patient has if ALT >500u/L)
- If <500 may get false negative because antibody titres have not risen enough
may be negative in 1st week
Which antibodies will be present if someone has received a hepatitis A vaccine?
Anti-HAV IgG
(if infected, they will have high IgM and IgM, but no transaminitis)
When are those with hepatitis A infectious?
2 weeks before until 1 week after onset of jaundice
How is HAV treated?
Supportive, no chronicity
What type of virus is hepatitis B?How is hepatitis B transmitted?
DNA virus
* Sexually transmitted
* Blood products
* Mother-to-baby (eAg is the biggest predictor)
What is the incubation period of hepatitis B?
2-6 months
What are 3 possible courses of hepatitis B infection in adults?
- Clearance (90%)
- Chronic infection (10%)
- Fulminant liver failure (0.5-1%)
40% are symptomatic
What is the course of HBV infection in children under 5 ?
Asymptomatic, 90% develop chronic infection
What the biochemical definition of chronic HBV infection?
HBsAg positive > 6 months
What do the presence of the following antigen/antibodies indicate:
- HBsAg
- HBeAg
- Anti-HBc IgM
- Anti-HBc IgG
- Anti-HBe IgG
- Anti-HBs IgG
What are some possible consequences of chronic HBV infection?
- Hepatocellular carcinoma
- Cirrhosis
What is a strong predictor of risk of cirrhosis in people with hepatitis B infection?
HBV DNA level (copies/mL)
Scored with Child-Pugh score, diagnosed fibroscan
List some treatment options for chronic HBV.
Pegylated IFN-a - aim is to induce long term immune control
* 48 weeks
* Low tolerability, lots of contraindications
Nucleoside analogues - aim is to inhibit viral replication
* Tenofovir
* Entecavir
* Lamivudine
* Adefovir
What is the mechanism of action of nucleoside analogues?
Inhibit viral reverse transcriptase
Which of these treatments should not be used in liver transplant patients?
Interferon alpha
What is the management of babies born to mothers with chronic HBV?
Depends on HBeAg status
- HBsAg positive, HBeAg negative - give vaccine at birth
- HBsAg positive, HBeAg positive - give vaccine at birth PLUS HBIG
Give HBIG also if HBV DNA >1 x 10^6 IU/ml
What type of virus is HCV and how many genotypes are there? How is it transmitted?
Single-stranded RNA virus (6 genotypes)
- Sexually transmitted (MSM)
- Blood products (IVDU)
What is the incubation period of HCV?
2 weeks - 6 months
Describe the course of acute HCV infection
Most asymptomatic
- 30% will clear vrius
- 70% progress to chronic infection