Viral Hepatitis Flashcards
(34 cards)
What kind of virus is Hep A?
RNA
How is Hep A transmitted?
Faeco-oral
Contaminated water/food
Person-person
Describe clinical features of Hep A infection?
Incubation period - 30 days.
Fever, pair, diarrhoea, jaundice, itch, muscle pain.
Severity is age dependent.
- Asymptomatic in <5yo.
- Higher mortality rate in >50s (but still low).
Usually self-limiting, no role for vaccine or IgG.
No chronic carriage, good immunity after infection.
How is Hep A diagnoses?
Acute: IgM positive or RNA in blood/stool.
Previous Hep A or vaccinated: IgG.
Describe the Hep A vaccine?
Inactivated virus.
Protection 4 weeks after first dose. Second dose gives life protection.
Given in travellers, homosexual men, IV drug users and chronic liver disease patients before exposure.
Describe Hep A Immunoglobulin?
Pooled Immunoglobulin.
Given as pre-exposure if vaccine allergic.
Confers 3-6 months immunity.
What kind of virus is Hep E?
RNA
How is Hep E transmitted?
Faeco-oral route
Pork products
Minimal person-person
How many genotypes of Hep E is there?
4
Describe the clinical features of Hep E?
Incubation period of 40 days.
Fever, pain, diarrhoea, vomiting, pain, jaundice.
Neurological manefestations with genotype 3 (Guillian-Barre, ataxia, myopathy).
No vaccine.
What patients would get chronic Hep E and how is it treated?
Immunosuppressed patients.
Treated with Ribaviran.
What kind of virus is Hep B?
Hepadnavirus (DNA)
How is Hep B transmitted?
Vertical transmission - Mother to baby usually at birth. Contaminated needles and syringes. Child-child (horizontal). Organ and tissue transplant. Fluids (blood/semen).
In tropics usually sexual contact, vertical, contact with open sores, scarifiction, circumcision.
What is it important to test for in patients who have Hep B?
HIV as transmission is the same.
Describe acute Hep B infection and how it differs in different age groups?
(incubation period, clinical features)
Incubation period of 2-6 months.
Fever, fatigue, jaundice, joint pain, myalgia (muscle pain).
Infection at birth is usually asymptomatic but leads to chronic infection as babies dont have an adequate immune system to attack infected cells.
In adults is symptomatic, but can be cleared.
Symptoms can lead to cachexia (wasting), a mass in the abdomen and bloody ascites.
Describe complications of chronic Hep B infection?
Causes development of chronic liver disease in 25%.
Can get cirrhosis, jaundice, ascites, variceal haemorrhage, hepatocellular carcinoma or death.
HEP B SEROLOGY
What is sAg and sAb? What do they indicate?
sAg: Surface antigen - marks infection (e.g. they have the virus).
sAb: Surface antibody - marks immunity (e.g. Had the infection or vaccine).
HEP B SEROLOGY
What is cAb, eAg and eAb? What do they indicate?
cAb: Core antibody - have it now or have had it in the past.
eAg: E antigen - suggests highly infective.
eAb: E antibody - suggest low infectivity.
HEP B SEROLOGY
What is HBV DNA?
How much virus is in the blood.
How does eAg result indicate the course of Hep B disease?
eAg POSITIVE;
- Early in disease, high viral load and highly infectious.
- High risk of chronic liver disease and hepatocellular carcinoma.
eAg NEGATIVE;
- Late in disease, low viral low, less infectious.
Lower CLD and HCC risk.
When is sAg detectable?
> 6/12
How do you treat acute Hep B?
Nothing … supportive treatment.
How do you treat chronic Hep B?
Treat those with liver inflammation.
Small number will clear sAg spontaneously.
Aim of treatment is to suppress viral replication and convert eAg+ to eAb+.
Can use immunological therapies;
- Pegylated interferon alpha injection in stomach for a year.
- Tries to boost immune system and increase cellular response.
- Many side effects.
Can use Anti-viral drugs;
- Nucleosides or nucleosides to suppress viral replication.
- Tenofovir
- Tablets are for life.
How can Hep B be prevented?
Education (sex, IV drugs).
Screening of pregnant women and healthcare workers.
Immunisations
- Active: (HBV sAg vaccine) - high risk groups in UK.
- Passive (HBIG) - Babies born to HBV+ mothers. Post-exposure in non-immune.
