Epidemiology, Pathogenesis, Diagnosis and Dental Relevance of Hep B, C and HIV Flashcards
what are the 3 main types of blood borne virus?
hep B, C and HIV
which type of hepatitis is a co-infection hepatitis?
type D with type B
what is the antigen of hepatitis B
a protein which sits on the surface of the virus
what is the Dance particle of hep B
the infectious part of the virus
what is the structure of hep B
double shelled structure, outer coat surrounds central portion containing core antigen, DNA and DNA polymerase
what type of virus is hep B
DNA
what are the antigens present in hep B
surface antigen, core antigen, hep E antigen (early antigen)
how long does hepatitis B survive outside the body in a blood spillage e.g.,
a week+
what are the mods of transmission of hep B
parenteral and perinatal
which groups of people are more likely to contract hep B?
IV drug users, sexually active people, children of immigrants, healthcare workers, mucosal splashes, haemodialysis patients
how many people normally recovery from hep B
90-95%
what is the clinical course of hep B
1 - infected
2 - incubation period of 2-3 months (from infection to presence of symptoms)
3 - clearance of antigens from blood and creation of antibodies within 6 months
what are the symptoms of hep B?
flu like illness, nausea, tiredness, yellowing of skin
what antibodies appear to fight off hep B?
IgM which is antibody to the core, IgG takes over after and then antibody to E antigen
what shows that a person has immunity to hep B
the antibody to the surface antigen
what shows in a hep B test for someone who has recently been infected?
IgM antibody to core antigen
what shows in a hep B test for someone who is chronically infected?
surface antigen, antibodies to the core but no surface antibody
if you have previously been infected with hep B what antibodies are present in hep B test?
antibodies to the core and the surface
if you are vaccinated against hep B which antibody shows up in a hep B test?
surface antibody only
what percentage of people with develop chronic hep B?
5-10%
what is post exposure prophylaxis?
treatment/drug/process which is applied after someone has received mucosal injury after exposure
who is PEP not given to with hep B?
people who had positive response from vaccine
what PEP is given for hep B and when?
hepatitis B immunoglobin which is antibody which gives 70-75% protection, administered ASAP after exposure within a week
what type of drug is given to treat hep B
drugs to reduce the viral load meaning you are less infectious to others
