Viral Hepatitis Flashcards
transmission of hep A
faecal-oral poor hygiene overcrowding gay men PWID
clinical symptoms of hep A
acute hepatitis - no chronic infection
peak incidence of symptomatic disease in older children/young adults
tests for hep A
laboratory confirmation;
clotted blood for serology
hep A IgM detected
control of hep A
usually results in complete resolution hygiene vaccine prophylaxis - long term protection monitor for encephalopathy notify public health
clinical symptoms of hep E
similar to hep A;
acute hepatitis - no chronic inaction
peak incidence of symptomatic disease in older children/young adults
epidemiology of hep E
tropical continents
most common acute hep virus
tropical genotypes associated with severe disease in pregnant woman
immunocompromised humans can get chronic infection
transmission of hep E
faecal-oral
control of hep E
no vaccine available
monitor for encephalopathy
monitor for resolution
notify public health
aetiology of hep E
animals can be infected and are source of infection
epidemiology of hep D
only found with hep B - parasite of a parasite
exacerbates hep B infection
rare
transmission of hep B
sex
mother to child - vertical (blood at delivery)
blood to blood
chronic infection of hep B
occurs if first exposure is in childhood
relatively uncommon
epidemiology of hep B
those born in areas of intermediate/high prevalence
multiple sexual partners
PWIDs
children of infected mothers
tests for hep B
hep B surface antigen (HBaAg+)
anti-HB
IgM - differentiates acute from chronic infection
what does anti-HB indicate in hep B
presents in immunity
what does hep B IgM indicate
presents in recently infected cases
what does HBaAg+ indicate in hep B
present <6 months is chronic infection (uncommon)
high titre amount seen in highly infectious individuals
predicts risk of chronic liver disease
clinical course of chronic hep B infection
immune tolerance
immune clearance
immune control
immune escape
describe immune clearance in hep B
high hep B DNA level
abnormal LFTs - increased ALT
hep B antien positive
risks of immune clearance in hep B
progression to;
cirrhosis >20 years
hepatocellular carcinoma > 30 years (greater the patient’s HBV DNA load, greater risk of cancer)
immune control in hep clearnace
low hep B DNA level
normal LFTs
hep B antigen negative
immune escape in hep B
high hep B DNA level
abnormal LFTs - increased ALT
hep B antigen negative
hep B antibody antibody postive
risks of immune escape in hep B
progression to;
cirrhosis >20 years
hepatocellular carcinoma > 30 years (greater the patient’s HBV DNA load, greater risk of cancer)
control of hep B
treatment when ALT raised and high HBC DNA; minimise exposure antivirals 2 pre-exposure vaccines post-exposure prophylaxis infection control decrease alcohol intake hepatocellular carcinoma screening
spontaneous cure
how is exposure minimised in hep B
safe blood safe sex needle exchange prevention of meedlesticks screening of pregnant woman
pre-exposure vaccines in hep B
- all children
2. adults at risk of exposure
post exposure prophylaxis treatment in hep B
vaccine
hyperimune hep B immunoglobin (HBIG)
transmission of hep C
similar to hep B;
sex - less easily transmitted
mother to child - vertical (blood at delivery)
blood to blood
control of hep C
treatment immediately; anti virals no vaccine minimise exposure infection control decrease alcohol intake hepatocellular carcinoma screening
epidemiology of hep C
usually chronic infection (no spontaneous cure is seen)
most common chronic hep virus
complications of hep A
acute liver failure - failure of resolution and so causes death
clinical symptoms of hep C
asymptomatic until they develop chronic liver disease due to cirrhosis as a result of chronic infection
tests for hep C
test hep C virus RNA by PCR
postive - active infection
antivirals of hep B treatment
combination;
those ending in -vir and used in combination
mono therapy - first line;
interferon alfa
antivirals of hep C treatment
interferon alpfa - first line
others include those ending in -vir and are used in combination
describe interfon alfa
human protein - part of immune response to viral infection
given as pegylated interferon
side effects of interfon alfa
flu-like symptoms
autoimmune disease
psychosis
thyroid disease
