Viral Hepatitis Flashcards
Describe the differences in acute and chronic hepatitis in terms of blood tests and presentation
- Acute will normally be symptomatic i.e. fever/flu like symptoms, usually jaundiced
- Acute: ALT and AST will most likely be raised
- Chronic are usually asymptomatic and blood tests/LFTs will most likely show mild abnormalities
What infections cause acute hepatitis?
- Hep A, B, C, D, E
- EBV, CMV, Toxoplasmosis
- Leptospirosis
- Q fever
- Syphilis
- Malaria
- Viral haemorrhagic fever
What are the non infectious causes of acute hepatitis?
- Toxins
- Drugs
- Alcohol
- Autoimmune
- Wilsons
- haemochromatosis
Describe the laboratory diagnosis of viral hepatitis
- Detection of specific immune response (IgM or IgG)
* Viral nucleic acid detection (RNA or DNA), or antigen detection (HBV and HCV)
What is the transmission of Hepatitis A?
- Faeco-oral
- Human reservoir
- Virus can survive for months in contaminated water
What is the incubation period of Hepatitis A?
2-4 weeks
What is the main determinant of severity of hepatitis A, how does this impact severity?
- Age
- Mostly asymptomatic in children <5 years
- Mortality rate is 1.5% if >50
Describe the clinical management of hepatitis A
- Tends to be supportive, there are no specific treatments
- Maintain hydration and avoid alcohol
- Usually self limiting
What serology results indicated an acute hepatitis A infection ?
IgM positive or HAV RNA in blood or stool
What serology result indicates previous hepatitis A or vaccination against Hep A?
IgG positive
Hepatitis A vaccination
- Inactivated virus
- 95% efficacy after 4 weeks
- 2nd dose gives lifelong protection
Who gets the hepatitis A vaccine?
- Travellers
- Men who have sex with men
- Intravenous drug users
- Chronic liver disease patients
- Those at risk in an outbreak post exposure
Who gets the hepatitis A immune Globulin?
- Those allergic to the vaccine
- If it is less than 4 weeks to travel
- post exposure to control an outbreak
How long does the immunity of the hepatitis A globulin last?
3-6 months
What is the transmission of Hepatitis E?
- Faeco-oral
- Pork products
- Minimal person to person transmission
What is the incubation period of hepatitis E?
40 days
What are the symptoms of hepatitis E?
- Diarrhoea
- fever
- myalgia
- jaundice
- Rare reports of neurological effects
Which patient groups are seen with chronic hepatitis E?
Very immunosuppressed patients e.g. bone marrow transplant
What is the treatment of Hepatitis E?
- Supportive, normally resolves without involvement
* Ribavirin in those who are immunocompromised/chronic hep E
Explain the hep E neurological manifestations
- Genotype 3 associated
- Guillain barre syndrome
- Encephalitis
- Ataxia
- Myopathy
What is the most common transmission of Hepatitis B?
Mother to baby - vertical transmission
What is the transmission of Hepatitis B?
- Vertical
- Transfusion
- Fluids
- Organs and tissue transplantation
- child to child
- Contaminated needles and syringes
What is the incubation period of hepatitis B?
2-6 months
What does age at the time of hepatitis B infection determine?
- Severity of acute illness: younger = usually asymptomatic
- Risk of chronic HBV infection: younger = more likely to lead to chronic infection, in adults it is normally cleared
What are the complications of chronic HBV?
- 25% develop chronic liver disease
* Cirrhosis, decompensation, hepatocellular carcinoma, death
Explain the hepatitis B lab tests
- sAg - surface antigen, tells if currently infected
- sAb - surface antibody, marker of immunity (previous infection or vaccination)
- cAb - core antibody, will be positive only in those who have previously had the infection
- eAg - e antigen, suggests there is high infectivity
- eAb - e antibody, suggests a low infectivity
- HBV DNA
When is hepatitis B diagnosed (lab tests)
If sAg or DNA are detectable
What defines chronic Hepatitis B infection?
•sAg detectable for >6 months
What are the two groups of chronic Hepatitis B infection?
- eAg positive (early disease)
* eAg negative (late disease)
Describe eAg positive chronic hep B infection
- high viral load
- high risk of CLD and HCC
- Highly infectious
Describe eAg negative chronic HBV infection
- Low viral disease
- Lower risk of CLD and HCC
- Less infectious
- e antibodies
- Late disease
What is the treatment of acute Hepatitis B infection?
Usually no treatment is needed and it resolves
What is the treatment of chronic hepatitis B?
- Most do not need treatment
- Treat those with liver inflammation (raised ALT or biopsy) or fibrosis (on fibroscan or biopsy)
- Immunoglobulins-modulatory treatment- interferon
- Suppress viral replication - tenofovir or entecavir
- Treatment is not curative, aims to suppress viral replication and prevent further liver damage
What are the prevention measures of hepatitis B?
•HBV sAg vaccine
•Education (safe sex, injecting etc.)
•Prevention of mother to child transmission
•Prevention of mother to child transmission
- HBV vaccination to newborn (first within 24 hours of birth
- HBV immunoglobulin if eAg+ or high VL
- Tenofovir during the last trimester if high viral load
What is hepatitis D?
ss RNA virus which requires HBV to replicate
How is hepatitis D acquired?
- Co infection with HBV
- Super infection of chronic HBV carriers
- Infection is only possible in people who are HBV sAg positive
What is the treatment of hepatitis D?
- Interferon
* New: Bulevirtide (suppressive treatment)
What is the transmission of hepatitis C?
- Injecting drugs
- Transfusion and transplant
- Sexual/vertical rare
What is the incubation period of hepatitis?
6-7 weeks
How are the majority of hepatitis c infections diagnosed?
Via screening of high risk groups (drug users and immigrants to the UK from high prevalence countries)
What does Anti HCV IgG positive mean?
Chronic infection or cleared infection
What are the treatments of hepatitis C infection?
- Direct acting antivirals that inhibit different stages of the replication cycle
- Aim is to cure the infection
