Hepatitis

Question 1

Causes of viral hepatitis

Answer 1

Hepatitis A, B, C, D, E or G
Arbovirus - yellow fever
Cytomegalovirus, Epstein-Barr virus

Question 2

Hepatitis A

Answer 2

Spread by faecal-oral transmission

Incubation period 2-6 weeks

Question 3

HAV clinical features

Answer 3

Infants and young children: asymptomatic/non-specific febrile illness without jaundice
Older children: fever, malaise, anorexia, abdo pain and jaundice (may be preceded by dark urine)

Question 4

HAV Investigations

Answer 4

Diagnosis often made clinically
IgM anti-HAV Ab confirm
Serum transanimases and bilirubin elevated

Question 5

HAV treatment

Answer 5

Supportive
Mild, self-limiting in 2-4 weeks
Rare complication = fulminant hepatic failure
Active immunisation available
Close contacts given prophylactic IM human normal immunoglobulin (HNIG)

Question 6

Hepatitis B

Answer 6

DNA virus
Double-shelled, inner core (HBc) and surface Ag (HBsAg)
Parenteral transmission via blood and other bodily fluids
In infants, most commonly vertical transmission from maternal blood
Incubation period = 20 days

Question 7

HBV clinical features

Answer 7

Most children = asymptomatic
1% fulminant liver failure
Most important consequence is risk of becoming a carrier with subsequent development of cirrhosis or HCC
Risk of becoming carrier increases with young age (90% infected perinatally). 30-50% of carrier children develop chronic HBV liver disease

Question 8

HBV diagnosis

Answer 8

Acute: +HBsAg; -Anti-HBs; +Anti-HBc IgM; +Anti-HBc IgG
HBV carrier: +HBsAg; -Anti-HBs; +/-Anti-HBc IgM; +Anti-HBc IgG
Immune: previous infection: -HBsAg; +/-Anti-HBs; -Anti-HBc IgM; +Anti-HBc IgG
Immune: immunisation: -HBsAg; +Anti-HBs; -Anti-HBc IgM; +Anti-HBc IgG
Carrier status = HBsAg persisting more than six months
HBeAg (extracellular form of HBcAg) correlates with high infefctivity; Anti-HBeAg indicates low infectivity

Question 9

HBV treatment

Answer 9

No specific in UK (Interferon alpha and other antivirals in USA)

Question 10

HBV prevention

Answer 10

Immunisation (effective) recommended:
• After perinatal exposure
• For individuals at risk (docs, dentists, IVDU)
• After exposure (eg needlestick)
All pregnant women should have screening for HBsAg
All babies born to women known to be HBsAg +ve should begin course of HB vaccine within 24hours of birth
Unless mother is known to be anti-HBe +ve, baby should also receive hepatitis B specific immunoglobulin (HBIG)