Viral Hepatitis Flashcards
what do hepatitis viruses cause
liver disease as their chief or sole manifestation
how is hep A spread
faecal oral, poor hygiene/ overcrowding
what are the clusters of hep A
in gay men/ PWIDs
can you get chronic hep A infection
no
how can all hep infections be confirmed
yellow top bottle of blood
how is acute hep A infection confirmed in the lab
clotted blood for serology (gold top vacutainer),
hep A IgM- usually detectable by onset
where is Hep E more common
in tropics
how is hep e spread
faecal oral
cases of hep e in the uk are thought to be acquired from
zoonoses- animals/ animal meat (pigs, dear, rabbits)
is there a vaccine for hep a
yes
is there a vaccine for hep e
no
who gets chronic hep e infection
immunocompromised
where in hep d found
only in people already infected with hep b
how is hep b spread
sex, mother to child, blood to blood
who is at higher risk of hep b in the uk
multiple sex partners, PWIDs, children of infected mothers,
what is vertical transmission
from blood at delivery
when is an infection chronic
when more than 6 months (presence of HBsAg)
what does a positive HBsAg mean
hep b surface antigen- present in blood of all infectious individuals
what is usually present in highly infectious hep b patients
hep b e antigen HBeAg
what s found in highly infectious hep b patients
HBeAg, hep B virus DNA in high titre
where is hep B IgM most likely found
in recently infected patients
when are anti-HBs present
in immunity to hep B
what can provide hep B immunity
vaccine or past infection
what can Hep B DNA test predict
risk of chronic liver disease
when does hep B affect liver function
when high HBV DNA level and inflammation of liver high as immune clearance or escape occurs
how is HEP B controlled
minimise exposure, vaccination (pre and post exposure), post exposure prophylaxis (vaccine + HBIG)
how is hep c transmitted
same as hep B- sex, blood to blood, mother to child
is there a vaccine for hep B
yes
is there a vaccine for hep C
no
can you get chronic hep C
yes- 75% of cases are chronic
what are the three immediate outcomes of hep a infection
asymptomatic- resolution
acute hepatitis- resolution
acute liver failure (rare)- resolution or death
what happens if acute hepatitis develops into chronic infection
can cause chronic hepatitis- resolution or cirrhosis
cirrhosis- leads to cancer/chronic liver failure then death
in hep c and hep b is there spontaneous cures to chronic infections
in hep B only
how long usually does it take for cirrhosis to occur from chronic infection
more than 20 years
how long does it take for cancer (hepatocellular carcinoma) to typically develop from chronic infection
more than 30 years
what is another possible cure for hep infections
antiviral
what are the outcomes of hep c infections
acute infection or asymptomatic
asymptomatic- (25% resolution) chronic infection- chronic hepatitis, cirrhosis 9or cancer), chronic liver failure, death
what is usually the presenting complaint asymptomatic hep c infection
signs of chronic liver disease after decades of no symptoms
how many people develop chronic infection in hep B
less than 5%, most resolve naturally
what is infection of children with hep B like
more like pattern of hep C infection: high levels of chronic infection and complications
what is the most common hep infection locally
hep E
what can a positive antibody test for hep c not distinguish between
past or active infection
how do you distinguish between a past or active hep c infection
hep c virus RNS by PCR- pos= active infection
what is the antibody for hep c
IgG
what is hep c virus control
no vaccine- minimise exposure
what is the management for acute viral hepatitis
no antivirals
monitor for encephalopathy (brain disease, damage or malfunction)
monitor for resolution
notify public health
immunisation of contacts
test for other infections
vaccinate against other infections if at risk
how is chronic viral hepatitis managed
anti virals (adefovir, entercavir, tenofovir, interferon alpha, peginterferon etc)
vaccination (against other hep viruses and if cirrhotic influenza and pneumococcal)
infection control
reduced alcohol
hepatocellular carcinoma awareness/ screening
who should get antivirals
patients with;
chronic infection
risk of complications (evidence of inflammation/ fibrosis)
who are fit for treatment (cirrhotic treated as priority although established cirrhosis harder to treat, liver cancer contraindication, HIV coinfection contraindication)
when should anti virals be given
before complications,
when evidence of inflammation,
when patient ready/ clinical priority
what is interferon alpha
human protein that is part of the immune response to viral infection
what are the side effects of interferon
alpha when given as antiviral via injection
minor; flu like symptoms
major: autoimmune disease, psychosis
what is peginterferon used to treat
hep c
what are the adverse effects of peginterferon
common: flu like symptoms- chills, sore muscles- malaise
rare, more severe: thyroid disease, autoimmune disease (SLE), psychiatric disease
what are the adverse effects of ribavirin
anaemia
what are the two treatment options for chronic hep b
suppressive antiviral drug (entecavir, tenofovir)- safer but suppression not cure
peginterferon- cure but side effects
how does viral suppression work
reduction in HBV DNA and loss of HBeAg
how do anti viral cures work
loss of HBsAg
what are the aims/ benefits of chronic hep C therapy
virological, improved liver biochem and histopathology, reduced infectivity progression to cirrhosis and cancer and mortality
what is sustained virological response (SVR)
loss of HCV RNA in blood sustained to 6 months after end of therapy
what antiviral works against all virus genotypes
sofosbuvir, voxilaprevir, velpatasvir
what is the standard treatment for HCV
interferon free courses of 2 or 3 antivirals- choice based on genotype of virus and load, stage of disease
