Blood Borne Viruses Flashcards
Define blood borne virus
It is a disease that can be spread through contamination by blood and other body fluids
Name the the most common examples of blood borne viruses
- HIV
- Hepatitis B
- Viral haemorrhagic fever
Which classification do we use to classify viruses?
The Baltimore Classification
What is viral hepatitis?
It is liver inflammation du to a viral infection
Name the different Baltimore Classification
Hep A, B ,C, D, E
They are all unrelated
Name some viruses the can cause hepatitis
- hepatitis viruses
- Cytomegalovirus,
- Epstein-Barr virus
- Flavivirus [Yellow fever ].
If a patient comes in with hepatitis what must you ask and establish?
Which type of hepatitis they have and what was the cause of their hepatitis
How is hepatitis A passed?
Passed via food and drink usually infected with faeces
How many cases of hepatitis A have been recorded?
1.4 million cases every year
How can hepatitis A be prevented?
With good hygiene, water systems and vaccine
How is hepatitis A diagnosed?
Diagnosis through IgM antibodies in blood
How many deaths are caused by hepatitis A?
102,000 deaths per year
How is hepatitis A treated?
Treatment is usually rest and fluid
How is hepatitis B passed on?
Through anything contaminated with blood, semen and vaginal fluid
Can also be transmitted vertically from mother to child
How many people globally have been infected with hepatitis b?
Approx 1/3 of the global population has been infected at some point
Is hepatitis B fatal?
It can be fatal
How can hepatitis B be replicated?
It replicates in liver cells
How does hepatitis B cause damage?
Hepatitis B replicates in the liver cells
Host immune reposes then causes damage to hepatocytes
Talk through the stages of viral replication of hepatitis B
- Entry via endocytosis
- Viral capsid is shed and viral DNA is transferred to the cell nucleus
- viral polymerase transforms the DNA into a double stranded circular top (cccDNA)
- The circular DNA contains transcripts for 4 viral mRNAs translated by host RNA polymerase
- The mRNAs make new copies of the viral genome and capsid which are processed to form new irons
- New virons are released from the cell
What type of virus is hepatitis b?
A pararetroviruses
What is a pararetroviruses?
It is a non retrovirus that still use reverse transcription in their replication process
How does viral hepatitis B gain access into the cell?
Gain access by binding to NTCP on the surface and being endocytose
Once inside a cell what does. virus need to do?
As viruses multiply via RNA the viral genomic DNA has to be transferred into the cells nucleus so that the virus can use the cells resources to multiply
This process is aided by proteins called chaperones
Describe what happens to viral DNA in the nucleus
It is made into a closed Circular DNA by viral polymerase