Hepatitis Flashcards
what do hepatitis cause?
inflammation of the liver primarily
how does Hepatitis A spread?
faecal-oral
poor hygiene/overcrowding
Some cases imported
what groups does hepatitis A cluster in?
gay men
people who inject drugs
what are the clinical effects of hepatitis A?
acute hepatitis, no chronic infection
peak incidence of symptomatic disease in older children/young adults
what is the lab confirmation of acute infection of Hep A?
clotted blood for serology (gold top container)
- same sample for all causes of viral hepatitis
- Hep A IgM (detectable at onset of illness)
how is Hep A controlled?
hygiene vaccine prophylaxis (only for at risk - travel, risk groups)
where is Hep E most common?
tropics
has become more common then Hep A in the UK
what is Hep E like clinically?
like Hep A
how does Hep E spread?
faecal-oral
often zoonosis in the UK (eg infected pigs, rabbits, deer)
which hepatitis is a real concern in pregnant women?
Hep E genotype in tropics causes severe disease in pregnant women
who is more likely to get a chronic Hep E infection?
immunocompromised
normal people get acute
hep D only occurs in people with Hep B, true or false?
true
what is Hep D?
parasite of a parasite
exacerbates Hep B
rare in scotland
how is Hep B spread?
sex
mother to child at delivery
blood to blood contact
who is at a higher risk of Hep B in the UK?
people born in areas of intermediate/high prevalence (outside NW Europe)
multiple sexual partners
people who inject drugs
children of infected mothers
Hep B and hep C are spread similarly, true or false?
true
is there a Hep B vaccine?
yes
given to many children in first year of life
how does lab confirm hep B?
hep B surface antigen in blood (HBsAg)
- present for >6 months = chronic
- HBeAg = highly infectious individuals
- Hep B virus DNA = high titre in highly infectious individuals, predicts risk of chronic liver disease and monitors therapy
Hep B IgM most likely present in recently infected cases
Anti HBs present in immunity/vaccinated
does everyone with chronic infection have chronic liver disease?
no
what are the 4 phases of chronic infection?
immune tolerance immune clearance immune control immune escape complex and dynamic relationship between virus and immune system so test values (ALT, HBV DNA etc) rise and fall
how is Hep B controlled?
minimise exposure
- safe blood
- safe sex
- needle exchange
- prevent needlesticks
- screen pregnant women
2 pre-exposure vaccination strategies used:
- vaccinate all children born since August 2017
- vaccinate at risk older children and adults
Post-exposure prophylaxis (eg. after sex with infected)
- vaccine
- plus HBIG (hyperimmune hep B immunoglobulin)
can a vaccine prevent Hep B infection after sex with an infected person? How?
Yes
Long incubation period
how is Hep C spread?
similar to Hep B
less easily by sex than Hep B
hoes Hep C have a vaccine?
no
how common is chronic infection in Hep C?
75% of cases
not dependant on age at time of infection
how does age affect likelihood of getting symptoms in Hep A?
older at time of infection = more likely to get symptoms
what defines a chronic infection of hepatitis?
6 months infection
Is spontaneous cure common in Hep B?
not uncommon
even after many years of infection
is spontaneous cure common in Hep C?
once chronic infection established, never seen
what is the time frame from infection to cirrhosis?
usually >20 years
what is the time frame from infection to cancer?
> 30 years
what is the most common hepatitis in Tayside?
C
some reduction in recent years
Hep E is very severe, true or false?
false
usually mild, rarely causes death
how does lab confirm hep C?
test if at risk or with signs of chronic liver disease test for antibody to Hep C virus - negative = not infected - positive = past or active infection if positive - test for Hep C virus RNA by PCR - positive = active infection - negative = no infection
how is Hep C controlled?
no vaccine
prevent needle sharing etc
how is acute viral hepatitis managed?
only if symptomatic no antivirals given monitor for encephalopathy monitor for resolution - of Hep B, C or E if immunocompromised notify public health immunise contacts test for other infections at risk of (eg. HIV, syphilis if having unprotected sex) vaccinate against other infections if at risk
how is chronic viral hepatitis managed?
antivirals - for Hep B and Hep C vaccination - other hep infections - if cirrhotic: influenza, pneumococcal infection control reduce alcohol hepatocellular carcinoma awareness/screening - important for patients with cirrhosis - serum alpha fetoprotein (AFP) and ultrasonography
what does ultrasound of liver look for?
nodules that could be cancer
what classifies a chronic infection?
HCV RNA present and genotype known
HBsAg and Hep B DNA present
> 6 months
what indicates risks of complications of treatment?
inflammation/fibrosis, cirrhosis sought, mainly in hep B high ALT (sign of inflammation)
when are people fit for treatment?
established cirrhosis more difficult to treat but are treated as priority
liver cancer = contraindication
HIV co-infection = urgent so stabilise HIV
when do you treat hepatitis?
before complications when evidence of inflammation (high ALT) -with advanced fibrosis, not yet cirrhosis and cirrhosis are priority when patient is ready clinical priority
what is interferon alpha?
used in Hep B
part of innate immune response to viral infection
given by injection as pegylated interferon (peginterferon)
complex mode of action, including as immune adjuvant
used less due to side effects
what are the side effects of peginterferon?
common - flu like symptoms less common - thyroid disease - autoimmune disease (SLE etc) - psychiatric disease - so if already have these don't use
what are the options for Hep B treatment?
usually option 1 1: - suppressive antiviral drug - safe and increasing range - only suppress don't cure - resistance can occur 2: - peginterferon alone - can cure but not always - side effects - good in HBsAg and HBeAg +ve people with good chance of cure
what are the aims of Hep B therapy?
virological - reduce HBV DNA - loose HBeAg - loose HBsAg (cure) improve liver biochem reduce infectivity reduce progression to cirrhosis/cancer etc reduce mortality
what are the aims of Hep C treatment?
loss of HCV RNA in blood sustained to 6 months after end therapy
- known as sustained virological response (SVR)
- relapse after SVR is rare but reinfection can happen
what is the choice of antiviral regime for HCV based on?
virus genotype patient's interferon response genes stage of disease past treatment experience likelihood of side effects cost effectiveness
what is the benchmark aim for HCV therapy?
> 90% SVR
what do antivirals end in?
“…vir”
can HCV be cured with oral antivirals?
yes
when is a chronic Hep B infection more likely?
chronic infection more likely if first exposure in childhood
IgG +ve, RNA -ve?
Past infection
IgG +ve, RNA +ve?
current infection
list a side effect of ribavirin?
anaemia
what are the results of SVR?
improved liver biochem reduced infectivity reduced incidence of cancer reduced mortality improved hisopathology rare relapse
what is the standard for Hep C treatment?
oral, interferon free courses of 2 or 3 antivirals for up to 12 weeks with high SVR
