Viral Disease Flashcards
What are the two types of RNA
Positive sense
Negative sense
What is the difference between positive and negative sense RNA
Negative sense must be transferred to mRNA first to become readable by host ribosomes
What are the 3 types of capsid
Helical
Icosahedral
Complex
What are the two viral families
Paramyxovirus
Togaviridae
Describe the characteristics of a paramyxovirus Genome
SsRNA
Linear
Non-segmented
Negative sense
Describe the characteristics of a paramyxovirus envelope
Flexible helical nucleocapsid Pleomorphic Haemagglutanin (GP) spikes Membrane fusion spikes 129-250nm D
Characteristics of Togaviridae
Positive sense ssRNA
Enveloped icosahedron 70nm D
Haemagglutanin spikes
What are the characteristics of measles
Mainly asymptomatic
Prodromal
- onset of fever, malaise and anorexia, following by conjunctivitis
What’s the average incubation time fore measles
~10 days
What can be secondary to measles
Bacterial infections: pneumonia, seizures, brain damage
Encephalitis (1/100)
Generally poor recovery
Characteristics of the Mumps
Onset of unilateral or bilateral tender swelling of parotid or other salivary glands (90% bilateral)
Average incubation time for mumps
18 days
How would you go about diagnosing mumps
- Isolate virus in subculture
- detecting viral RNA in saliva, CSF or urine
- Detecting mumps specific Ig antibody
How does mumps infect
- enters through respiratory tract
- grows in salivary glands and lymphoid
- virus spread to spleen and dust and lymphoid —> viraemia
- virus spreads to testes, ovaries, pancreas, thyroid —> DISEASE
How do you prevent/treat mumps
- only vaccine for prevention
- currently no anti-viral medications available
- treatment focuses on relieving symptoms