Hep B&C and HIV Flashcards
what hepatitis viruses are transmitted via the faecal-oral route?
- hep A
- hep E
what type of viruses are Hep B & C?
blood borne viruses
what type of virus is Hep D? what makes it different?
- blood borne virus
- can only become infected if you are infected with Hep B first
what is the meaning of parenteral?
transmitted outwith the gastrointestinal system (via blood to blood contact)
what particles are found in the blood of someone who has Hepatitis B?
- the Dane particle
- spherical particles
- filamentous forms
what is the infectious particle for hep B?
the Dane particle
- largest particle
- comprises of the complete viron
what is the structure of the Hep B viron like?
- double shelled structure
- the outer HBsAg coat (outer antigen) surrounds the central HBcAg (core antigen), DNA and DNA polymerase
is Hep B a DNA or RNA virus?
DNA virus!
what is known as the ‘early antigen’ in reference to Hep B?
the hepatitis E antigen
- found near surface
- detected early in blood
if blood is spilled, how long can HBV survive for in dried blood?
1 week (or more)
what people are more susceptible to developing Hep B virus?
- IV drug users
- sexually active people
- haemodialysis patients
- sharps injury sufferers
- infants born to infected mothers
what is the typical incubation period of Hepatitis B?
2-3 months
if you are testing for Hepatitis B in a patient who has been recently infected, what would the test show?
positive for IgM core antibodies
if you are testing for Hep B in a patient who is suffering from chronic infection, what would results show?
positive for IgG core antibodies
if you are testing for Hep B in a patient who has been previously infected, what would the test show?
positive for both core and surface antibodies (immune)
if you are testing for Hep B in a patient who has been vaccinated against the disease, what would the test show?
positive for surface antigen (not core antigen)
what does the Hep B vaccine contain?
hepatitis B surface antigen (HBsAg) adsorbed on aluminium hydroxide adjuvant
how is the Hep B vaccination administered?
- intramuscular
- three doses given (time zero, one month, 6 months)
what would you do if you have been exposed to Hep B and have not been vaccinated against it?
post exposure prophylaxis (as soon as possible after exposure)
what are the most common treatments for Hep B?
- nucleotide analogues
- oral nucleoside analogues
what are the chances of infection of Hepatitis B for a non-immune individual following a needle stick injury?
1 in 3
what is the chance of infection of Hepatitis C for a non-immune individual following a needle stick injury?
1 in 30
what is the chance of infection of HIV for a non-immune individual following a needle stick injury?
1 in 300
what is the structure of the Hepatitis C virus?
enveloped, single stranded RNA virus
what tests are done to look for Hep C infection?
- Anti-HCV test
- HCV-RNA test
- Viral load/Quantitative HCV test
- Viral genotyping
what blood borne virus has a vaccine?
only Hep B
what is the structure of the HIV virus?
HIV contains a single stranded RNA and has an envelope of lipid and viral proteins
how is HIV killed?
- easily killed by heat
- doesn’t survive long outside of body
what is the clinical course of HIV once infected?
- HIV results in destruction of CD4 T cells (helper T lymphocytes)
what tests are used to detect HIV infection?
- ELISA antibody test
- blood radioimmunoassay
- blood immunofluorescence
if untreated, what is the survival rate of someone infected with HIV?
1 year
what treatments are used for HIV?
anti-retroviral drugs:
- NRTIs
- NNRTIs
- PI (protein inhibitors)
- FI (fusion inhibitors)
