Liver Disorders: Viral Hepatitis Flashcards
What do the clinical features of acute viral hepatitis include?
Nausea, vomiting Abdominal pain Lethargy Jaundice Hepatomegaly and tender liver Splenomegaly Liver transaminases usually markedly elevated Coagulation usually normal
In cases of viral hepatitis, what percentage of children do not develop jaundice?
30 to 50%
What type of virus is hepatitis A?
An RNA virus
How is hepatitis A spread?
Faecal oral route
Has the incidence of hepatitis A in childhood risen or fallen?
Fallen as socioeconomic conditions have improved
Is vaccination against hepatitis A routinely offered in the UK?
No - required for travellers to endemic areas
What symptoms are associated with hepatitis A?
May be asymptomatic The majority of children have a mild illness Nausea, vomiting Abdominal pain Jaundice Fatigue Appetite loss Fever
Most children recover from hepatitis A both clinically and biochemically within…
2-4 weeks
Some of those with hepatitis A may develop…
Prolonged cholestatic hepatitis (self limiting) or fulminant hepatitis.
Does chronic liver disease occur with hepatitis A?
No
How is hepatitis diagnosed?
Detecting IgM antibody to the virus
Is there treatment for hepatitis A?
No
In children with hepatitis A, what should close contacts be given?
Vaccination within 2 weeks of the onset of illness
What type of virus is hepatitis B?
A DNA virus
Does hepatitis B produce acute and chronic disease?
Yes an important cause of acute and chronic disease worldwide
In what parts of the world is there a high prevalence and carrier rate of hepatitis B?
Sub Saharan Africa
Far East
How is hepatitis B transmitted?
Vertical spread - from mother to child during birth
Inoculation with infected blood via blood transfusion, needlestick injuries, renal dialysis
Body fluid contact e.g saliva, menstrual, vaginal, seminal fluids
(Among adults - unprotected sex)
Infants who contract hepatitis B perinatal are asymptomatic, but what percentage become chronic carriers?
At least 90%
In contrast to infection in adulthood - chronic hepatitis in less than 5% cases
Older children who contract hepatitis B may be asymptomatic or…
Have classical features of acute hepatitis
The majority will resolve spontaneously, 1-2% develop fulminant hepatic failure while 5-10% become chronic carriers
What is the incubation period of hepatitis B on average?
6 weeks to 6 months
How is hepatitis B diagnosed?
Detecting HBV antigens and antibodies
1) surface antigen detected within 6 weeks HBsAg
2) e antigen (HBeAg) = marker of high level of viral replication
3) IgM antibody to core antigen (anti-HBc)
4) e antibody (disappearance of e antigen and infectivity)
5) surface antibody = clearance of virus
6) IgG core antibody - persists for life, signals at some point had hep B
In hepatitis B, chronic infection is characterised by the persistence of what antigen?
HBsAg for at least 6 months
Is there treatment for acute HBV infection?
No
What percentage of asymptomatic carrier children of hepatitis B will develop chronic HBV liver disease?
30-50% which may progress to cirrhosis in 10%
There is a long term risk of hepatocellular carcinoma
Is it true that current treatment regimes for chronic HBV have poor efficacy?
Yes - interferon treatment is successful in 50% of children infected horizontally and 30% infected perinatally
Oral antivirals if effective in 25%
How is HBV prevented?
All pregnant women should have antenatal screening for HBsAg
Babies of all HBsAg positive mothers should receive a course of hepatitis B vaccination, with hep B immunoglobulin given if mother also hepatitis B e antigen positive
Other members of family should also be vaccinated
