Viral Hepatitis Flashcards
What are the differentials for viral hepatitis?
Hepatitis A-E viruses CMV EBV Paravirus B19 Adenovirus Enterovirus Yellow fever Dengue
What are the signs and symptoms of viral hepatitis?
Non-specific symptoms - malaise, fever, headache - anorexia, nausea, vomiting RUQ abdominal pain Dark urine Clay coloured faeces Jaundice
Name some complications of fulminant acute hepatitis.
Encephalopathy
- decline in brain function and liver can’t remove toxins from the blood stream
Coagulopathy
- lack of coagultion factors being produced
Multi-organ failure
What are the routes of transmission of the hepatitis viruses?
A&E - faecal-oral
Parenteral
- contact with body fluids
How can faecal-oral transmissible viruses spread?
Lack of hand-washing
Lack of clean water
Food-bourne
- e.g. oysters and shellfish in the UK a common cause of HAV
Through which ways do HBV and HCV spread?
HBV - mostly sexual - some parenteral and perinatal spread HCV - mostly parental - only perinatal in HIV - small amount sexually
How can viral hepatitis be diagnosed with lab tests?
IgM - high in acute hepatitis
IgG - high in chronic hepatitis
Viral nucleic acid detection
- RNA or DNA
What kind of virus is hepatitis A, and what is the incubation period?
ssRNA unenveloped hepatovirus
3-5 weeks
What are the clinical features of hepatitis A?
Acute - risk of jaundice increases with age Rare complications - fulminant hepatitis - relapsing hepatitis
What is the difference between chronic and acute hepatitis A?
Hep A is self-limting, so there is no chronic hepatitis
How is hepatitis A diagnosed?
HAV IgM in the blood
HAV RNA in the blood/stool
Name and describe the two methods of prevention in hepatitis A.
Passive (normal human Ig)
- immediate protection if there isn’t enough time to immunise
- household contacts
Active (inactivated vaccine e.g. Havrix)
- at risk groups: travellers, MSM, contacts or these
- occupational: sewage workers, foodhandlers
What kind of virus is hepatitis B, and what is the incubation period?
Partially dsDNA hepadnavirus
6 weeks to 6 months (average 2.5 months)
What are the clinical features of Hep B?
Acute hepatitis - 10% adults jaundice - children asymptomatic Fulminant hepatitis (1%) Chronic hepatitis - sAg positive - mostly found in babies Complications - cirrhosis - hepatocellular carcinoma
How is acute Hep B diagnosed?
Following markers are present in the blood
sAg
cIgM
eAg
sAb becomes present after the infection (also present in people with vaccines)
How is chronic Hep B diagnosed?
The following three makers are present
sAg
cIgG
eAg/eAb
When is chronic hepatitis B treated?
Evidence of active infection (HBV DNA>2000iu/ml) AND Evidence of inflammation - fibrosis scan - persistently raised LFTs - biopsy - cirrhosis
What is the treatment for chronic hepatitis B?
1st line
- four weeks of pegylated IFN
2nd line
- tenofovir or entecavir (antireteroviral)
Name and describe the two types of Hep B prevention.
Passive
- Hepatitis B immunoglobulin (needle-stick injury to susceptible, newborn babies of high infectivity carriers)
Active
- recombinant vaccine
- at risk groups (MSM, babies of HBV, IVDU)
- most countries immunise all babies
Describe the hepatitis D virus.
ssRNA virus enveloped by HBsAg
A defective virus - occurs only where HBV has occured
- co-infection with HBV
How is Hep D diagnosed?
Delta Abs and RNA in the blood
What kind of virus is hepatitis C, and what is the incubation period?
ssRNA enveloped flavivirus
6-12 weeks
What are the importance of Hep C genotypes?
7 different types
- worldwide distribution of genotypes
- mostly have genotype 1 and 3 in the UK
- treatment is different depending on the genotype
What are the main causes of Hep C?
IVDU
MSM
Vertical
Pre-1991 blood transfusion recipients
What are the clinical features of the Hep C virus?
Acute hepatitis - mostly asymptomatic - <1% fulminant Chronic infection - 20% cirrhosis - 3-7% hepatocellular carcinoma HCV accounts for 30% of liver transplants
Hoe is Hep C diagnosed?
HCV antibody testing
- negative (no infection)
- positive (reative - needs more testing)
If positive, a PCR/HCV antigen from the original sample is done
- non-reactive HCV Ag or negative PCR means there was a past infection
- RNA detected or HCV Ag reactive means there is an ongoing infection
How are genotypes 1 and 3 of Hep C treated?
- 1: Sofosbuvir (HCV NS5B polymerase inhibitor to suppress replication), Ledipasvir (also suppresses replication) and Ribavirin (an anti-viral)
- 3: the same but without Ledipasvir
What kind of virus is hepatitis E, and what is the incubation period?
ssRNA unenveloped virus
6 weeks
Describe the 4 genotypes associated with Hep E.
1 and 2 are found in Africa, Asia and South America, only in humans
- large, water borne outbreaks
3 and 4 are found worldwide in all kinds of animals (including humans)
- sporadic cases in the developed and developing world
What are the clinical features of Hep E?
Acute hepatitis - seen in young adults (developing countries) - elderly men (developed countries) Death (15-25% in pregnant women with G1) Complications - fulminant - haematological - neurological Chronic hepatitis - only in immunocompromised
How is Hep E diagnosed?
HEV IgM and IgG and RNA
Name and describe the ways in which Hep E can be prevented.
General - avoid drink water and shellfish when travelling - cook pork and venison products well Passive immunisation - nothing Acitve immunisation - vaccine not available in UK
