Viral Hepatitis (B & D) Flashcards
Definition (hepatitis B)
Hepatitis caused by infection with hepatitis B virus (HBV), which may follow an acute or
chronic course
o Chronic is defined as viraemia and hepatic inflammation continuing for > 6 months
Definition (hepatitis D)
Hepatitis D virus (HDV) is a defective virus, that may only co-infect with HBV or
superinfect people who are already carriers of HBV
Aetiology
- HBV is an enveloped, partially double-stranded DNA virus
- Transmission: sexual contact, blood and vertical transmission (from mother to baby)
• Various viral proteins are produced such as: o Core antigen (HBcAg) o Surface antigen (HBsAg) o e antigen (HBeAg) • This is a marker of high infectivity
- HDV is a single-stranded RNA virus coated with HBsAg
- Antibody and cell-mediated immune response to viral replication leads to liver inflammation and hepatocyte necrosis
- Histology can show mild to severe inflammation and changes to cirrhosis
Risk factors
o IV drug use
o Unscreened blood and blood products
o Infants of HBeAg-positive mothers
o Sexual contact with HBV carriers
o Younger individuals (particularly babies) are more likely to become chronic carriers
o Genetic factors are associated with varying rates of viral clearance
Epidemiology
- Common
- 1-2 million deaths annually
- Common in Southeast Asia, Africa and Mediterranean countries
- HDV is also found worldwide
Incubations period
Incubation period: 3-6 months
Presenting symptoms (prodrome period)
• 1-2 week prodrome consisting of:
o Malaise o Headache o Anorexia o Nausea and vomiting o Diarrhoea o RUQ pain o Serum-sickness type illness (e.g. fever, arthralgia, polyarthritis, urticaria, maculopapular rash)
Presenting symptoms (other)
- Jaundice develops with dark urine
- Recovery: 4-8 weeks
- 1% develop fulminant liver failure
- Chronic carriage may be diagnosed after routine LFT testing or if cirrhosis or decompensation develops
Signs on physical examination (acute)
o Jaundice
o Pyrexia
o Tender hepatomegaly
o Splenomegaly
o Cervical lymphadneopathy (in 10-20% of patients)
o Occasionally: urticaria and maculopapular rash
Signs on physical examination (chronic)
o May be no findings
o May have signs of chronic liver disease or decompensation
Investigations (serology)
o Acute HBV:
• HBsAg positive
• IgM anti-HBcAg
o Chronic HBV:
• HBsAg positive
• IgG anti-HBcAg
• HBeAg positive or negative
o HBV Cleared or Vaccinated against HBV:
• Anti-HBsAg antibody positive
• IgG anti-HBcAg
o HDV infection:
• Detected by IgM or IgG against HDV
• PCR is used for detection of HDV
Investigations (other)
• LFTs
o High: AST, ALT, ALP, bilirubin
• Clotting
o High PT (in severe disease)
• Liver Biopsy
Management plan (prevention)
Blood screening
Safe sex
Instrument sterilisation
Management plan (immunisation)
• Passive immunisation
o Hepatitis B immunoglobulin following acute exposure and to neonates born to
HBeAg-positive mothers (in addition to active immunisation)
• Active immunisation
o Recombinant HBsAg vaccine for individuals at risk and neonates born to HB
Management plan (in active disease)
• Acute HBV Hepatitis
o Symptomatic treatment (antipyretics, antiemetics and cholestyramine) and bed
rest
o Notifiable disease
• Chronic HBV
o Interferon alpha (standard or pegylated)
• Side-effects: flu-like symptoms such as fever, chills, myalgia, headaches,
bone marrow suppression and depression
o Nucleoside/nucleotide analogues (adefovir, entecavir, telbivudine, tenofovir)
