Viral hepatitis: B & D Flashcards
Define viral hepatitis B
Hepatitis caused by infection w/ hepatitis B virus (HBV) which may follow acute or chronic course
Chronic defined as viraemia & hepatic inflammation continuing for >6 months
Define viral hepatitis D
Hepatitis D virus (HDV) is a defective virus that may only co-infect w/ HBV or superinfect people who are already carriers of HBV
Aetiology of viral hepatitis B & D
type x2, transmission, 3
HBV is enveloped, partially double stranded DNA virus
Transmission by sexual contact, blood & vertical transmission (mother to baby)
Various viral protein produced:
core antigen (HBcAg)
surface antigen (HBsAg)
e antigen (HBeAg): marker of high infectivity
HDV is a single stranded RNA virus coated w/ HBsAg
Antibody & cell mediated immune response to viral replication leads to liver inflammation & hepatocyte necrosis
Histology can show mild to severe inflammation & changes to cirrhosis
Risk factors for viral hepatitis B & D
6
IV drug use
Unscreened blood & blood products
Infants of HBeAg-positive mothers
Sexual contact w/ HBV carriers
Young individuals ( particularly babies) more likely to become chronic carriers
Genetic factors associated w/ varying rates of viral clearance
Epidemiology of viral hepatitis B & D
general, death, location x2
COMMON
1-2 million deaths annually
Common in South east Asia, Africa & Mediterranean countries
HDV also found worldwide
Presenting symptoms of viral hepatitis B & D
incubation, 2
Incubation period = 3-6 months
Prodrome period (1-2 weeks) Hepatitis
Presenting symptoms of viral hepatitis B & D - prodrome period
(7)
Malaise Headache Anorexia N&V Diarrhoea RUQ pain Serum sickness type illness (fever, arthralgia, polyarthritis, urticaria, maculopapular rash)
Presenting symptoms of viral hepatitis B & D - hepatitis
4 including recovery
Jaundice develops w/ dark urine
Recovery: 4-8 weeks
1% develop fulminant liver failure
Chronic carriage may be diagnosed after routine LFT testing or if cirrhosis or
Signs of viral hepatitis B & D on physical examination - acute
(6)
Jaundice
Pyrexia
Tender hepatomegaly
Splenomegaly
Cervical lymphadenopathy (10-20% patients)
Occasionally urticaria & maculopapular rash
Signs of viral hepatitis B & D on physical examination - chronic
(2)
May be no findings
May have signs of chronic liver disease or decompensation
Investigations for viral hepatitis B & D
4
Viral serology
LFTs
Clotting
Liver biopsy
Investigations for viral hepatitis B & D - viral serology
4
Acute HBV HBsAg positive IgM anti HBcAg Chronic HBV HBsAg positive IgG anti HBcAg HBeAg positive or negative HBV cleared or vaccinated against anti HBsAg antibody positive IgG anti HBcAg HDV infection detected by IgM or IgG against HDV PCR used for detection
Investigations for viral hepatitis B & D - LFTs
High AST, ALT, ALP, bilirubin
Investigations for viral hepatitis B & D - clotting
High PT in severe disease
Management of viral hepatitis B & D
3 + 2 acute + 2 chronic
Prevention - blood screening, safe sex, instrument sterilisation
Passive immunisation
Active immunisation
Acute HBV
Symptomatic treatment (antipyretics, antiemetics & cholestyramine) & bed rest
Notifiable disease
Chronic HV
Interferon α (standard or pegylated)
Nucleoside/nucleotide analogues (adefovir, entecavir, telbivudine, tenofovir)
