Viral Hepatitis Flashcards
What is the causes of viral hepatitis?
Caused by 5 types of viruses:
A, B, C, D and E
Which viruses cause self limiting acute infections?
A and E
Which viruses cause chronic disease?
B, C and D
What type of viruses are A and E?
Enteric viruses: get through water
A: faecal-oral route or shellfish
E: water or undercooked pork
What type of viruses are B, C and D?
Parenteral viruses: blood
What do the viruses do to the liver?
Viruses cause inflammation of the liver
Liver cell damage and death of individual liver cells
What is the outcome of the acute inflammation they cause?
Resolution (liver returns to normal): hepatitis A, E
Acute liver failure if severe damage to liver: hepatitis A, B, E
Progression to chronic hepatitis and cirrhosis: hepatitis B, C
What can cirrhosis cause?
Liver failure (chronic liver failure)
What percentage of the Scottish population has hepatitis C?
1%
Does hepatitis C cause acute liver failure?
Rarely causes acute liver failure
What is the pathway of the disease?
After 6 months, 70-85% of those infected will have failed to clear the virus spontaneously, after this period the hepatitis C virus enters what is known as the chronic phase (85% chronic HCV infection)
It is now highly unlikely that the virus will be cleared without treatment
It is usually possible to cure the infection (90% = cured/cleared) with treatment
What happens in patients who develop chronic hepatitis C are not treated?
Disease varies: some people will have minimal liver damage with no scarring, while others can progress to cirrhosis (extensive scarring of the liver)
Cirrhosis can lead to hepatocellular carcinoma/liver failure
What type of virus is hepatitis C?
RNA virus
How is hepatitis C transmitted?
IV drug abuse (contaminated needles) Sexual contact (not as common) Vertical transmission (occasionally)
What is the presentation of hepatitis C?
10% of patients report acute jaundice
Most asymptomatic until cirrhotic (i.e. significant damage)
What are the investigations?
May have normal LFTs
What is HBV?
Hepatitis B virus: DNA virus
How is hepatitis B transmitted?
Vertical Contaminated needles (IVDU) Sexual intercourse (more common with hepatitis B than C)
What are some at risk groups for hepatitis B?
IVDU and their sexual partners/carers Health workers Men who have sex with men Staff or residents of prisons Babies of HBsAg +ve mothers
What does HBsAg in the blood suggest?
Hepatitis surface antigen
Presence of virus: HBsAg (surface antigen) is present 1-6 months after exposure, HBsAg persisting for >6 months defines carrier status and occurs in 5-10% of infections
What percentage of adults recover and therefore do not become chronically infected with hepatitis B?
95%
After infection 5% of patients remain chronic carriers (HBsAg carrier) and are therefore infectious
What does HBeAg in the blood mean?
Active replication
What does HBV DNA in the blood mean?
Active replication
What is HBcAg?
Hepatitis core antigen: active replication (not detected in blood)
What does anti-HBs in the blood mean?
Protection: antibodies to HBsAg alone imply vaccination
What does the presence of IgM anti-HBc mean?
Acute infection
What does the presence of IgG anti-HBc mean?
Chronic infection
What does the presence of anti-HBe mean?
Inactive virus
How is hepatitis B treated/managed?
Treatment for HBV depends on how long you have been infected for:
- If you have been exposed to the virus in the past few days, emergency treatment can help stop you becoming infected
- If you have only had the infection for a few weeks or months (acute hepatitis B), you may only need treatment to relieve your symptoms while your body fights off the infection
- If you have had the infection for more than 6 months (chronic hepatitis B), you may be offered treatment with medicines that can keep the virus under control and reduce the risk of liver damage - chronic hepatitis often requires long-term or lifelong treatment and regular monitoring to check for any further liver problems
What are the 2 main treatments for chronic HBV?
Pegylated interferon
Oral antiviral medicines
What are the complications of hepatitis B?
Chronic hepatitis B
Cirrhosis
Hepatocellular carcinoma
End-stage liver disease (liver failure)
Do all patients with chronic hepatitis B develop liver cirrhosis?
No, some patients have no further progression (not all patients have progressive disease)
Approximately 15-40% of chronic hepatitis B patients will progress to cirrhosis, HCC or liver failure
What is the treatment option for ESLD?
Liver transplant: HBV-related ESLD or HCC are responsible for 5-10% of cases of liver transplantation
What do we give to at risk groups for hepatitis B?
Hepatitis B vaccination
What is the presentation of hepatitis B patients?
Many people with hepatitis B will not experience any symptoms and may fight off the virus without realising they had it
If symptoms do develop, they tend to happen 2-3 months after exposure to the hepatitis B virus:
Flu-like symptoms, including tiredness, a fever, and general aches and pains
Loss of appetite
Feeling + being sick
Diarrhoea
Abdominal pain
Arthralgia
Urticaria
What is hepatitis A?
RNA virus
What is the presentation of patients with hepatitis A?
Asymptomatic cases very common
When does hepatitis A it occur?
Occurs sporadically or in epidemic form
Prevalence decreasing worldwide
How is HAV transmitted?
Faecal-oral
Sexual
Blood
What is the commonest age group that HAV affects?
5-14 years
How is HAV diagnosed?
Acute disease diagnosed by IgM antibodies (recent infection)
IgG is detectable for life
Who is the HAV immunisation given to?
Travellers Patients with chronic liver disease (e.g. IDU - especially with HCV or HBV) Haemophiliacs Occupational exposure e.g. lab workers Men who have sex with men (MSM)
What is HDV?
RNA virus: does not code for its own protein coat, enveloped by HBsAg
What does HDV occur?
Only occurs in people with hepatitis B: co-infection or super-infection with HBV
How is it HDV transmitted?
As for HBV
How is HDV treated?
Very resistant to treatment
What is HEV?
RNA virus
What is the commonest cause of acute hepatitis in Grampian?
Hepatitis E
What is the treatment of HEV?
No specific treatment
Is there a HEV vaccine?
No effective vaccine currently available
What are the complications of hepatitis E?
Fulminant hepatic failure in pregnancy
