Lecture 11 - Viruses & diseases Flashcards
what are the morphogical divisions of viruses
- helical or icosahedral
- naked or membrane bound
what is transmission by inoculation
needle contamination
infection through skin
what is iatrogenic transmission
caused unintentionally by doctors
e.g. blood transfusion, transplants (e.g. cornea transplantation can transmit rabies cuz rabies infects corneas)
what is congenital transmission
mother to foetus e.g. rubella
what are 4 ways to diagnose a viral diseasw
Whole virus - looking through microscope (only works for some)
Viral antigen – immunological tests e.g. covid test
Viral nucleic acid - PCR = vey sensitive
Specific antibody response = can test for diff immunoglobulins
what are picornaviruses
very small
ssRNA
icosahedreal
naked
4 types of picornaviruses
enterovirus
hepatovirus
rhinovirus
aphthovirus
these are all genus names btw, family is picornaviridae
how do symptoms present in polio (enterovirus) and how is polio spreas
95% asymptomatic
5 % flaccid paralysis
some have complete recovery
1% have permanent paralysis and death
Spread via foecal oral route
what is the most frequent cause of the common cold
rhinoviruses (rhino means nose)
why do rhinoviruses have so many serotypes
ssRNA virus
so no proofreading unlike DNA
lots of mutations
what common disease caused by an orthomyxovirus
influenza
type A (most common) and b and c
why is secondary disease common after influenza
cells in muscoescalatory escalator destroyed
secondary bacterial pneumonia common
what are the 2 antigens on influenza
haemmaglutinin (16 types)
neuraminidase (9 types)
which of the influenza antigens are human specific
H1,2 and 3
and N1, 2 and 3
cause of new influenza strains emerging
antigenic drift
basically genetic mutatiosn = new antigens
ssRNA = easily mutation
which antigen allow the virus to bud off of cells after its replicated
neuraminidase
some meds can block this action
what are the 3 subfamilies of herpesviridae
alphaherpesviridae
betaherpesviridae
and gammaherpesviridae
which of the herpesviridae causes a chronic disease
herpes simplex (HSV) dsDNA
oral or genital herpes, recurring sores
common feature of herpesviridae
life long latent infections that can reactivate
how much of pop have HSV1
40-80%
not everyone is sympotomatic
what is HSV treatment and what does it do
Acyclovir (ACV)
blocks viral DNA synthesis
what is varicella zoster virus
chicken pox (also part of herpesviridae)
only vry dangerous in immunocompromised people
what develops if dormant chickenpox gets reactivated?
shingles
3 common types of paramyxoviruses
measles
mumps
rubella
what are some complications of measles
encephalomyelitis
pneumonia
SSPE = a progressive neurological disorder
overall 10% mortality
name of the swelling brought about by mumps
parotitis
b99
complications of mumps
meningitis
deafness
males - orchitis (swelling of testicles)
what group is rubella very harmful for
pregnant women
if contracted in first 16 weeks of pregnancy - congential rubella
deafness, blindness, mental retardation
what does papilloma virus cause
warts
some of which can be cancerous - cervical cancer
hence HPV vaccine
