Hepatitis Flashcards
What is Hepatitis?
Inflammation of the liver
11 types
What are the different types of viral hepatitis?
Hepatitis A
Hepatitis B
Hepatitis C
Hepatitis D
Hepatitis E
Hepatitis F
Hepatitis G
Hepatitis X (does not exist as yet to encounter)
Cytomegalovirus (CMV)
Epstein-Barr virus (EBV; glandular fever virus)
Herpex Simplex
3 types
Which viral hepatitis transmit parentally (via bloodstream, transfusions, IV injections, sexual transmission)?
Hepatitis B
Hepatitis C
Hepatitis D
2 types
Which viral hepatitis transmit enterally (begins with the mouth/oral cavity)?
Hepatitis A
Hepatitis E
What does ACUTE viral hepatitis mean?
Infection of the hepatocytes with direct killing by effector lymphocytes (damage to the liver cells comes from the immune response to the virus, not from the virus itself)
Self-limiting liver inflammation
What does CHRONIC viral hepatitis mean?
Low-level long-term (longer than 6 months) immune damage with additional direct cytopathic effects as well as fibrosis and cirrhosis
What do the hepatitis A and E viruses cause?
Acute self-limited hepatitis
How to prevent hepatitis A?
Vaccination
Which food group is hepatitis A often found in?
Seafood
What is hepatitis E infection most commonly caused by?
Consumption of undercooked pork products
What may happen in immunosuppressed patients when infected with the hepatitis E virus?
Unable to clear the infection leading to chronic hepatitis
How can hepatitis E be prevented?
Food hygiene (cook pig meat well)
How can hepatitis B be prevented?
Vaccination
Why is there relatively little evolution of the hepatitis B virus compared to hepatitis C?
Hepatitis B is a DNA virus whereas hepatitis C is an RNA virus
Why does infection of the hepatitis B virus give rise to significantly different outcomes in different patients?
Hep B virus integrates into the human genome and then reappears as viral particles, which can result in different host response, hence the differing outcome seen
What promotes the longevity of the hepatitis B virus with an incubation period of 2-6 months?
Virus integrating into human genome and then reappearing as viral particles
The majority of adults clear the hepatitis B virus following the acute infection, but __ to __% of immunocompetent adults go on to develop chronic infection. This occurs in over 90% of those infected perinatally.
1 to 5%
What can chronic hepatitis B viral infection lead to?
Liver cirrhosis
Liver failure
Hepatocellular cancer
Some patients are carriers of hepatitis B. What does this mean?
The virus infects the liver cells but does not damage them so the liver function is normal
There is no immune response at all to the virus so there is a lot of virus around
Hence, cancer risk ++ remains
How might some people develop as carriers of hepatitis B?
Vertical transmission (mother to child), where people contract the virus either in utero or at delivery
How to diagnose chronic hepatitis B?
Surface antigen test (sAg) positive
DNA positive
Ongoing liver damage
Abnormal LFTs
When infected by Hepatitis B virus in adult life, __% of people will clear the virus normally. __% will fail to clear the virus and develop ______ hepatitis. ___% will develop ______ liver failure (reason in clarifier) which only treatment is liver transplant.
Acute clearance of the virus is so effective it kills all hepatocytes
95, 5, chronic, 0.1, fulminant
What are the risk factors of hepatitis B infection in adults?
Sexual transmission
IV drug abuse
Blood transfusion
‘Soft’ blood contact
Professional exposure
Soft blood contact = helping a bleeding stranger who is a hep B carrier
How long is the incubation period for hepatitis B?
Up to 6 weeks
After the incubation period, how long would the ‘flu-like’ symptoms of hepatitis B last?
1-2 weeks
How long does it take for jaundice or other symptoms to resolve after presenting flu-like symptoms from hepatitis B infection?
2-4 weeks
There is no way of knowing, during the acute illness, who will go on to develop chronic hepatitis B. Disease is defined as chronic at __ months. Patients with chronic hepatitis are at risk of developing ______ and _______-_______ ________.
6, cirrhosis, hepato-cellular carcinoma
What are the clinical features of acute hepatitis B?
Lethargy
Jaundice & dark urine
Liver pain/discomfort
What are the clinical features of chronic liver disease where cirrhosis has developed?
Skin thinning
Weight loss
Variceal bleeding (due to portal hypertension)
Can be totally asymptomatic
Varices are enlarged veins often on the lining of the oesophagus
What does liver function test measure?
Alanine transaminase (ALT)
Alkaline phosphatase (Alk Phos)
Bilirubin
Albumin
Prothrombin Time (PT)
What results from LFTs would confirm the diagnosis of hepatitis B?
Increase in ALT
Increase in Alk Phos
Increase in Bilirubin
What results from LFTs would indicate the severity of the liver disease? (What are indicators/features of liver injury?)
Decrease in albumin
Increase in prothrombin time
What is HepBsAg (surface antigen of hepatitis B) a marker of?
Marker of viral presence present in acute and chronic disease and carrier state
What is HepBeAg (e antigen of hepatitis B) a marker of?
Marker of degree of viral load in chronic disease and carrier state
What test is used to screen hepatitis B?
HepBsAg (presence indicates hep B; absence to 99% indicates not hepatitis B)
What is HepB DNA, which measures nucleic acid, a marker of?
Marker of degree of viral replication
What is HepBsAb (surface antibody of hepatitis B virus) marker of?
Marker of immunity
What are HepBeAb (e antibody of hep B virus) and HepBcAb (core antibody) markers of?
Markers of low risk in chronic hepatitis patients
What is the most common reason for someone to present HepBsAb (surface antibody) positive?
Vaccinated
If someone is HepBsAb positive, do they have hepatitis B?
No, because surface antibody positive indicates immunity to hepatitis B (can be vaccination or resolution of disease) and the virus has been cleared
You either have HepBeAg positive or HepBeAb positive. If you are HepBeAg positive you usually have high _______ states. HepBeAb positive indicates a _______ level of viral infection but can give more in the way of chronic injury.
Replication, lower
HepBcAb is usually tested alongside HepBsAg. If HepBsAg is negative but HepBcAb is positive, what does it indicate?
It indicates that the person is infected with a mutated hepatitis B (surface antigen is mutant)
All patients with acute HepB will be ____ and _____ positive. They will then develop ______ and _____, at which point the disease has resolved. They are now _______.
sAg, eAg. sAb, eAb. Immune.
After 6 months, when patients are defined as having chronic hepatitis they will remain sAg ___ and sAb ____ with one important exception of cAb +ve
positive, negative
Screen patients suspected to have hepatitis B by measuring ____ and _____. If negative, they do not have hepatitis B. If positive, do full markers to assess risk status.
sAg, cAb
Apart from adult infection, what is another type of hepatitis B infection?
Perinatal infection
What does perinatal infection mean?
These people are infected before birth, at birth or shortly afterwards
How many percent of children born by vaginal delivery will be infected and become chronic carriers?
50%
Why won’t the children who were delivered through the vagina and then became chronic carriers develop liver disease?
They have no immune response to the virus
The perinatally infected children will be very ______ and might be at risk of ______ _______.
Infectious, liver cancer
The aim of therapy is to clear the hepatitis B virus in patients with chronic hepatitis thereby reducing the risk of ________ and _________ ________.
Cirrhosis, hepatocellular cancer
What are examples of drugs included in antiviral therapy?
Interferon
Lamivudine
Adefovir
What drug is used in immuno-stimulatory therapy?
Interferon
What is the limitation of hepatitis B therapy?
Therapy can only control hep B virus, which permits and cannot be cleared/eliminated due to viral resistance
Transplantation is effective but it has a high __________ risk in people with chronic hepatitis B because the virus is present to the time of the transplant.
Reinfection
The best way of preventing hepatitis B is ____________
Vaccination
What is hepatitis C?
It is an RNA virus that does not integrate into the human genome. Its infection gives rise to a single clinical pattern which is chronic disease.
_________ host response does not occur in hepatitis C, so we don’t see a form of liver failure. Under-response is seen rather than anything else.
Excessive
What is the normal host response to hepatitis C infection?
Viral clearance with clinical resolution occurs in less than 20% of infected individuals
What does inadequate host response to hepatitis C virus lead to?
Chronic hepatitis with people being viraemic
What are the 3 risk groups of hepatitis C infection?
1) IV drug abusers
2) Receivers of blood products
3) ? (People who have never been IV drug abusers and have never received both products)
What do most people with hepatitis C present with?
Abnormal liver function tests
Clinical features of liver disease seen in hep B not typically present
When are hepatitis C usually found?
Screening of IV drug abusers as part of their detox programme
Blood donors screening for viral risk factors
Screening of recipients of blood products for studies
What types of investigations are carried out to diagnose hepatitis C?
ALT 50-100
ELISA
PCR
Biopsy (allows us to see the degree of liver injury)
How to prevent hepatitis C?
Risk modulation (no vaccine available)
What was the original treatment of hepatitis C?
Pegylated-interferon 180mg weekly + Ribavirin (results: 30-50% viral clearance rate)
What is the novel treatment of hepatitis C?
Protease and polymerase inhibitors (results: 90% control and clearance of the virus)
What type of therapy is given to avoid the development of viral resistance?
Combination therapy
What are the 3 pros of hepatitis C treatment?
Potential cure
Reduced progression to cirrhosis even if virus not cleared
Reduced risk of hepatocellular cancer even if virus not cleared
What are the cons (largely historical) of hepatitis C treatment?
Sustained response rate less than 50% until recently
Length and nature of old treatment (makes it not conducive to compliance)
Side effects of old treatment
Costs (+++ in case of new generation therapies)
If encountering a patient with chronic liver disease who starts bleeding during dental surgery, what can be done?
Apply pressure on the bleeding site
How do we as dental professionals prevent ourselves from hepatitis A and B infection by an infected patient?
Vaccination
In terms of hepatitis C and E which cannot be prevented by vaccination, what can we do if we get in contact?
Get onto therapy at a time that therapy will be highly effective
