Viral Hepatitides Flashcards
(56 cards)
How is Hep A spread
Faeco-oral route
Where are there high rates of Hep A
In communities with low standards of sanitation
Where are there outbreaks of Hep A
Daycare centres
association with sewage contaminated shellfish
Homosexual men
IV drug abusers
What is the incubation period for Hep A
15-50 days
What are the clinical features in symptomatic individuals
Acute febrile illness with jaundice anorexia nausea abdominal discomfort malaise dark urine
What happens to the severity of Hep A as age increases
The severity increases
How is Hep A diagnosed
It relies on the detection of serum antibodies to HAV
What does high IgM indicate
Recent infection
What is the management of Hep A
Largely symptomatic
Vaccination is effective in preventing infection and disease
What is the vaccine for Hep A
Inactivated hepatitis A vaccines
Who is the Hep A vaccine recommended for
Those at high risk of infection Those infected with Hep B and C Travellers to countries with high rates of Hep A Employees of early childhood services Healthcare workers exposed to faeces Men who have sex with men Injecting drug users
How many people are estimated to be carriers of the Hep B virus
400 million worldwide
What are the risk factors for HBV infection
Transfusion Needle sharing sexual transmission perinatal transmission men who have sex with men promiscuous heterosexuals immunosuppressed patients patients on haemodialysis transplantation health care transmission
How many genotypes are recognised for Hep B
8
What immune response is initiated in Hep B
Adaptive
What are the clinical manifestations of HBV in the acute phase
Most are asymptomatic or demonstrate mild fatigue
What are the clinical manifestations of HBV in the chronic phase
Some are asymptomatic,
Abnormal LFTs
Cirrhosis
HCC
What does the severity of the acute disease determine
The progression to chronicity
What are the 3 phases of Hep B
- Replicative, during which aminotransferases are largely normal and there is little liver damage
- Inflammatory - where the aminotransferases become elevated, liver biopsy shows chronic hepatitis and viral replication declines
- Patients may enter the inactive phase where viral replication has stopped, the amino transferases normalise and there is no ongoing liver inflammation
How is a diagnosis of Hep B made
The hepatitis B surface antigen (HBsAg) must be positive for 6 months
What does the level of HBV-DNA correlate with
The amount of virus in the circulation and has prognostic implications
What is the management for Hep B
Prevention is the cornerstone!
Safe sex
Avoidance of sharing of IV drug use
Use of gloves
Careful cleaning of blood or body fluid spills
Disposal or adequate sterilisation of surgical instruments (tattoo and piercing)
Careful disposal of sharps
Use of goggle where there is a risk of infected material splashing into the eye
Immunisation
Who is the Hep B vaccination recommended for in the UK
Those exposed to blood or blood born products
Travellers who plan to spend long periods in high prevalence areas or with pre-existing medical conditions that place them at a higher risk of requiring medical procedures abroad
Haemophiliacs
Prisoners and prison officers
What is the treatment for Hep B
Oral nucleoside and nucleotide analogues (lamivudine)
IFN-alpha: used for a finite period with durable response in a subset of patients
