Hepatitis Self-Learning Guide Flashcards
What is the most obvious sign of hepatitis?
Jaunice with liver tenderness
True or false:
Viral hepatitis is a disease which should be notified to public health
True
What are the four presentations of viral hepatitis?
Subclinical illness Anicteric illness (symptoms but no jaundice) Icteric illness (symptoms with jaundice) Fulminant hepatitis (severe jaundice w hepatic failure & high mortality)
What will biochemistry Ix show in acute hepatitis infection?
Raised ALT and AST (which are released into serum in xs by damaged hepatocytes)
How does hepatitis A often present?
Usually mild/subclinical or anicteric in children under 5
Severity increases with age
What is the incubation period of Hep A?
28d
What are the symptoms of Hep A?
Fever, malaise, anorexia, nausea, vomiting, upper ab pain
Jaundice and darkening of urine develop later due to presence of unconjugated bilirubin
What is the transmission of Hep A?
Faecal-oral
In which groups of people are outbreaks of HAV more common?
MSM
IVDA
What kind of virus is HAV?
Picornavirus (small RNA virus)
What is the serology of someone with HAV like?
HAV IgM antibodies usually present at onset of symptoms & decline to non-detectable levels after 3-6m
What is the serology of someone who has had HAV in the past like?
Anti-HAV IgG antibodies present (reflecting immunity)
What is the treatment of HAV infection?
Supportive
How can HAV be prevented?
Good hygiene and sanitation
HAV vaccine
What is usually used as prophylaxis for close contacts for those with HAV?
Human normal Ig (which gives immediate passive protection for about 4m)
What kind of vaccine is HAV?
Killed
Who should be vaccinated against HAV?
Sewage workers, seronegative haemophiliacs, MSM with multiple partners, travellers to endemic areas, PWID, chronic liver disease, HIV patients
What is the prognosis of Hep A infection?
Usually good
No chronic liver damage
What are uncommon complications of Hep A infection?
Prolonged cholestatic jaundice
Relapsing hepatitis
Haematological problems, e.g. aplastic anaemia
What is the incubation period of Hep B?
Few weeks-6m
What are the symptoms of acute Hep B infection?
Anorexia, lethargy, nausea, fever, ab discomfort, arthralgia,
Later - urticarial skin lesions, dark urine, jaundice
What is the mechanism of acute hepatitis (HBV)?
Believed to be immune mediated - the greater the antibody/antigen reaction the more severe the hepatitis
How do children tend to present with HBV?
Neonates - asymptomatic
Subclinical/anicteric infection most common in childhood
Clinical disease increases with age
1% of patients with HBV infection develop what?
Fulminating hepatitis with DIC and encephalopathy
What is the course of HBV infection in most patients?
Full recovery and clearance of infection
What kind of virus is Hep B?
Hepadnavirus
What are the three viral forms of HBV seen in blood?
Infectious viral particles
Non-infectious spheres
Tubules which consist of Hep B surface antigen
Where is the Hep B core antigen found?
In the core/nucleocapsid
What is Hep B e antigen derived from?
It splits off from the HBcAg in the liver cell during new virus formation and is release in a free soluble form in the serum
Where is HBV-DNA found in the serum?
In infectious viral particles
What are the markers of viral replication in the blood in those infected with Hep B?
HBeAg and HBV-DNA
What is HBsAg a marker of?
Acute and chronic HBV infection
What Ag is a marker of high infectivity?
HBeAg +ve chronically infected individuals
Those individuals are also at increased risk of hepatoma
What are the routes of transmission of HBV?
Vertical, sexual, parenteral (e.g. needlestick injury)
What are the risk factors (most –> least) for HBV in the UK?
PWID
Multiple sexual partners
Immigration from area of high endemnicity
People with learning disability/live in residential care
Those on haemodialysis/with haemophilia
Sexual partners of those with above risk factors
Babies born to mothers at risk
Tattooing or body piercing with non-sterile equipment
Medical equipment not properly decontaminated
What is the issue with pregnant woman being infected with HBV?
Babies born to these mothers are at v high risk of perinatal infection
90% become chronically infected if no preventative immunisation given at birth
What is the risk of transmission following needle stick injury of HBV?
30%
In most patients who present with HBV infection, ______ can be detected in the serum
HBsAg
If present late/severe fulminant acute disease then anti-HBc IgM may be present
In patients who recover completely from acute infection, what seroconversion takes place?
HbsAg –> anti-HBs
i.e. development of antibodies against surface antigen
What is seroconversion?
Development of significant levels of specific antibody following vaccination or infection
Define chronic HBV infection
Persistence of HBsAg in the serum for more than 6 months
In which groups of people is chronic HBV infection more common?
Infants/children, males, immunodeficient
What are chronically HBV infected individuals at risk of?
Chronic liver disease, less commonly, membranous glomerulonephritis, polyarteritis nodosa
What are two of the long term sequlae of untreated liver disease?
Cirrhosis and hepatoma
True or false:
Jaundice is a common finding in HBV infection
False
Unless advanced disease
What are the indications for antiviral therapy in those with chronic HBV infection?
2 of the following:
- HBV DNA >2 000 IU/ml
- Raised ALT
- Significant liver inflammation or fibrosis
How do you treat chronic HBV infection?
Pegylated alpha-interferon (s/c injection once weekly for 12m)
Nucleotide analogues - entecavir/tenofovir
Liver transplant for advanced cirrhosis/hepatoma
How do the nucleotide analogues work?
Inhibit the viral enzyme reverse transcriptase which is req for HBV replication
What is the problem with transplanting a liver in someone with chronic HBV infection?
V. likely to get HBV infection in new liver
Must give combined antivirals and hep B specific immunoglobulin to reduce this risk
What are the most important ways of preventing HBV infection?
Immunisation
ICP
Screening of blood/organ donors
What does the HBV vaccine contain?
Contains HBsAg
What is the basic regimen for giving HBV vaccine?
0, 1, 6 months
What are poor responses to HBV vaccine associated with?
Age >40, smoker, obese, wrong injection site, immunocompromised
In which groups of people is HBV vaccine recommended?
Healthcare workers, those travelling to endemic areas for >1y, renal dialysis patients, those who change sexual partners frequently, selected police and emergency services personnel, close contacts of those with chronic/acute HBV infection
What is used for passive immunisation against HBV?
Hep B specific immunoglobulin
Who is Hep B specific immunoglobulin given to?
Infants born to mothers with chronic HBV infection who are HBsAg +ve following acute infection
Healthcare workers not adequately immunised who have had contact with mucous membranes/needle stick injuries with an infected patient
Previously unprotected sexual contacts & family contacts of individuals who have acute/chronic HBV infection
What are complications of hepatitis B infection?
Chronic hepatitis (Ground glass hepatocytes may be seen on light microscopy) Fulminant liver failure Hepatocellular carcinoma GN Polyarteritis nodosa Cryoglobulinaemia
What level of anti-HBs indicates an adequate response to the vaccine?
> 100
10-100 suboptimal give additional dose
<10 - nonresponder, give further vaccine course
What toxin does c. perfringens produce?
alpha-toxin which causes gas gangrene and haemolysis
What are features of c. perfringens infection?
Tender, oedematous skin with haemorrhagic blebs and bullae
What does c. botulinum infection lead to?
Prevents ACh release leading to flaccid paralysis
What toxins does c. difficile produce?
Exotoxin and cytotoxin
What does c. tetani infection lead to?
Releases exotoxin (tetanospasmin) that prevents release of glycine from Renshaw cells in spinal cord –> spastic paralysis
What two types of tests can be done to check for syphillis infection?
Cardiolipin test (not treponeme specific), e.g. VDRL or RPR become negative after treatment Treponemal specific antibody tests, e.g. TPHA remains positive after treatment
What are causes of false cardiolipin tests?
Pregnancy SLE Anti-phospholipid syndrome TB Leprosy Malaria HIV
What kind of virus is hepatitis E?
RNA hepevirus
How is hep E spread?
Faecal-oral
What are the symptoms/signs of hep E like?
Very similar to hep A
Can hep E lead to chronic liver disease/increased risk of hepatocellular carcinoma?
No
What organism causes diphtheria?
Gram positive bacteria corynebacterium diphtheriae
What are clinical features of diphtheria?
Diphtheria toxin causes diphtheric membrane on tonsils (due to necrotic mucosal cells)
Systemic distribution can lead to myocardial, neural, and renal tissue necrosis
Suspect in recent travel to Eastern europe/russia/asia Sore throat Bulky cervical lymphadenopathy Neuritis, e.g. cranial nerves Heart block
