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Incidence |
- most common viral hepatitis
worldwide; commonly seen in autumn |
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Age |
- children and young adults |
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Sex |
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Geography |
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Aetiology |
- RNA picornavirus
- short incubation 2-3 weeks
- no carrier state
- spread is mostly by faecal-oral route
- ingestion of contaminated food/water
- overcrowding/poor sanitation
- notifiable disease in UK
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Presentation |
History
- viraemia -> nonspecific symptoms - nausea, anorexia, distaste
for cigarettes
- many recover at this stage without jaundice
- 1-2 weeks; some patients become jaundiced, symptoms often improve
- dark urine and pale stools
- jaundice lessens over next 3-6 weeks
Examination
- at 1-2 weeks, moderate hepatomegaly, spleen palpable in 10%
- may be tender lymphadenopathy
- may be transient rash
Differential diagnosis
- other causes of jaundice
- especially viral/drug induced hepatitis
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Investigations |
LFTs
- prodromal phase:
- serum bilirubin normal; bilirubinuria and increased urinary
urobilinogen
- raised AST/ALT precede jaundice
- icteric phase:
- raised serum bilirubin
- AST reaches maximum at 1-2 days after appearance of jaundice
- up to 500 IU/L
- ALP usually < 300 IU/L
- post-icteric:
- AST/ALT may be raised for weeks-months
Haematological tests
- leucopenia
- relative lymphocytosis
- prolonged PTT in severe cases
- raised ESR
Viral markers
- anti-HAV IgM antibodies indicate acute disease
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Macro |
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Micro |
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Staging |
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Serum markers |
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Management |
- no specific treatment
- admission to hospital usually unnecessary
Prevention and prophylaxis
- HAV is resistant to chlorination, but can be inactivated by
boiling water for 10 minutes
- active immunization - formaldehyde inactivated
- passive immunisation - human Ig
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Prognosis |
- overall prognosis is excellent;
mortality in young adults is 0.1%
- acute mortality < 0.5%
- in (rare) very severe disease, there may be fulimant
hepatitis, liver coma and death
- 10-15% relapse during convalescence, with recurrence of jaundice |
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Complications |
- extrahepatic complications (rare): arthritis, vasculitis,
myocarditis, renal failure
- patients may complain of debility for several months following
resoultion of symptoms and biochemical parameters - "post-hepatitis
syndrome"; treat with reassurance
- never progresses to chronic liver disease
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