virology Flashcards
what is herpangina?
an oral lesion caused by enteroviruses causing small bright white vesicles on back of mouth
Can be case by cocksacki virus (just like hand foot and mouth)
a usually but can be b or echovirus
oral hairy leucoplakia
ebstein barr virus (HIV patients)
what is a virus
‘…submicroscopic entity
….consisting of a single nucleic acid surrounded by a protein coat or capside
….capable of replication only within the cells of plants or animals
why is ran different
Rna can be positive or negative sense may be negative and have to be converted to be positive before replicated
viral capsid facts
The capsid is the protein coat surrounding the viral DNA or RNA
Can be a highly structured sphere or icosohedron.
Can coat the RNA or DNA directly
viral envelope facts
Some viruses are surrounded by a lipid envelope. Stolen from host cell with antigens from them.
Don’t have to have envelope
Acquired from the cell.
Contains viral protein which are required for the virus to attach to and infect a new cell.
Non-enveloped viruses attach and infect cell directly via the capsid.
what shape id herpes simplex
fried egg- capsized (yoke) inside and lipid envelope (white bit)
what does the measles virus look like
helical capsized with lipid envelope
influenza virus facts
lipid eveople and capside coating RNS with surface proteins
H1n1 antigens that sit on outside of virus
adenovirus
no lipid envelope/surface proteins and capsid(icosahedral)
viral life cycle
a) attachment
b) entry
c) replication and protein synthesises- viral replication
d) assembly
e) release-steals a bit of endothelium reticulum
viral classification negatives
cannot be classified by disease as:
same virus can cause same symptoms of disease
same virus may cause different disease
some viruses don’t normally cause disease
how are viruses classified
nucleic acid and replication strategy
double stranded DNA virus examples
herpes virus(cold sores, chicken pox)
hepatitis B virus
Adenovirus ( can have several presentations)
single stranded RNA virus
Influenza virus, measles, mumps rhinovirus(common cold) HEP C
What is the difference between - and _ single stranded RNA
if it is - it needs to be converted to MRNA so it is an extra step - could this be good fro drug targeting??
why is HIV not classes as RNA virus and what is it classed as instead
uses reverse transcriptase so called retroviruses
single stranded dna examples
double stranded RNA examples
parvovirus (childhood rash)
rotavirus ( childhood diarrhoea)
pathogenesis of certiorari viruses
Acute
e.g. measles, mumps, flu, cold – goes then better
Persistent- can become a asymptomatic carier of the virus
e.g. adenovirus
Latent
e.g. herpesvirus family-lie dormant
Reactivation
e.g. cold sores, shingles, often asymptomatic
Tissue damage by virus
e.g. oral herpes simplex
Secondary damage due to immune reaction to virus
e.g. acute hepatitis B virus infection huge immune cell attack inf makes you fell rubbish the bidy does not the virus
when are infection more prominent
extremes of age
immunocomprimised
pregnant-e.g. chickenpox) and can effect te baby inutero or shortening of limbs or when born
Infections may affect the foetus (e.g. rubella, cytomegalovirus- gmv bad haring in children around school age and can rwcativate and gte multiple limed)
new achievements in viral diagnosis
Traditional techniques (electron microscopy and viral culture) have made way for cutting edge techniques based on the polymerase chain reaction to detect viral RNA/DNA directly. Ig or igg to see if your immune system has had the virus and then polymerise it
