Viral Hepatitis Flashcards
How is hepatitis A spread?
Faecal-oral
Poor hygiene/overcrowding
Some cases are imported
Who usually gets hep A?
Gay men
People who inject drugs
What might be the clinical presentation of hep a?
Acute hep, no chronic infection
Peak incidence of symptomatic disease in older children/younger adults
What might you find on investigation when diagnosing hep?
Hep A IgM
How would you treat/control hep a?
Supportive treatment
Hygiene
Vaccine prophylaxis - takes about 10 days to take effect
Infected food handlers excluded from the workplace
Where is hep e more common?
In the tropics
What is the transmission of hep e?
Faecal oral transmission
Zoonoses (infected animals can pass it onto humans)
Causes acquired in the topics are thought to be human to human spread
Can hep E become chronic?
Not usually but some immunocompromised humans can get chronic infection
No vaccine yet
When do you find hep D?
Only found with Hep B
What does hep D do to help B?
Exacerbates hep b virus infection
Co-infection or superinfection
How is hep B viruses transmitted?
Blood-Blood
Sexual transmission
Vertical transmission - mother to child
When are you more likely to get chronic infection of hep B?
If you had your first exposure in childhood
Who are at a higher risk of getting hep B in the UK?
People who are born in areas of intermediate/high prevalence
Multiple sexual partners
People who inject drugs
Children of infected mothers
Describe HBsAg?
Present in the blood of all infectious individuals
Present for more than 6 months in chronic infection
Describe HBeAg?
Occurs shortly after HBsAg usually indicates highly infectious individual
Describe Hep B virus DNA
Gives indication of infectivity - the more you have the more infectious you are
Also used to predict risk of chronic liver disease and to monitor therapy
Describe Hep B IgM?
Most likely to be present in recently infected - acute
Describe Anti-HBs?
Present in immunity
Are HBV DNA more or less sensitive predictors or prognosis and infectivity than HBeAg?
More sensitive
What might immunity be due to?
vaccine or due to past infection
How would you control and treat Hep B?
minimise exposure - safe blood, sex, needle exhancge, screening of pennant women
Pre-exposure vaccination - vaccination of at risk people, vaccination of all children/adolescents
Post exposure prophylaxis - vaccine, plus HBIG (hyperimmune Hep B immunoglobulin)
What is the transmission of hep c?
Similar to hep B
blood/sexual
What is the treatment for hep c?
No vaccine available
What does infection of hep c usually result in?
Chronic infection
If a patient comes back with positive for hep c virus antibody, how do you know if they have an active infection or a past infection?
Test for hep c virus RNA by PCR
Negative - past
Positive - active
How many months of an infection defines chronic?
More than 6 months
How long does is usually take from the time of infection to develop cirrhosis?
Typically >20 years
How long does it usually take from the time of infection to develop hepatocellular carcinoma?
Typically >30 years
What is the management of acute viral hepatitis?
Symptomatic No antivirals given Monitor for encephalopathy Monitor for resolution (of hep b,c, or e if immunocompromised) Notify public health Immunisation of contacts Test for other infections if at risk Vaccinate against other infections if at risk
What is the management of chronic viral hepatitis?
Antivirals
Vaccination
- other hepatitis viruses, if cirrhotic - influenza, pneumococcal
Infection control
Alcohol decrease
Hepatocellular carcinoma awareness/screening
What are the common antivirals used in chronic infection?
Adefovir
Entecavir
Who do you treat with antivirals?
Those with HCV RNA present and genotype known
HBsAg and Hep B DNA present
Risk of complications
Fit for treatment - liver cancer = contraindication
What is interferon alfa?
A human protein - part of the immune response to viral infection
What are some adverse effects of peginterferon?
Flu like symptoms - chills, sore muscles, malaise
Less common but more severe - thyroid disease, autoimmune disease
What is an adverse effect of Ribavirin?
Anaemia
Describe 2 diffrent options to treat chronic hep b?
1 - Peginterferon alone. (HBsAg and HBeAg positive - compensated disease and prediction of good chance of cure)
2 - Suppressive antiviral drug (entecavir, tenofovir) - safer, suppression not a cure
When do you know if you have cured hep B?
When there is loss of HbsAg
What is response defined by in hep C?
By loss of HCV RNA in the blood sustained to 6 months after end of therapy
What is the aim in Hep C therapy?
Move towards interferon free combination drugs
