mumps, measles and slow viruses Flashcards
review of structure of paramyxoviruses
- enveloped?
- nucleocapsid symmetry?
- genome structure?
- -/+ stranded?
enveloped virion
helical symmetry
genome consists of a single molecule of RNA
RNA genome is minus-stranded
what type of virus are mumps and measles?
paramyxoviruses
are mumps and measles antigenically related to parainfluenza viruses?
mumps is
measles is not
describe mumps and measles:
- nucleocapsid
- genome
- +/-
- envelope?
helical nucleocapsid
minus-stranded RNA
envelope with virus-specified glycoproteins
do mumps and measles hemagglutinate red cells?
yes
do paramyxoviruses carry an RNA polymerase?
yes
can measles and mumps viruses reassort? why or why not?
since the RNA is only one piece, genetic reassortment is impossible
as a result, no significant antigenic variation has been seen
what types of infections do mumps and measles (and paramyxoviruses) cause?
systemic infections with viremia as an essential step in pathogenesis
what is an essential step in the pathogenesis of mumps and measles
viremia
what kinds of infections do orthomyxoviruses and paramyxoviruses generally cause?
local, nonsystemic noviremic infections
what is the significance of the fact that mumps and measles cause systemic infection (summary)?
incubation period is longer for mumps and measles because cycles of multiplication in several sites in sucession are required
lifelong immunity occurs in individuals who have had the disease - obligatory viremia allows neutralization by IgG
how does the incubation period of mumps and measles compare with that of orthomyxoviruses and paramyxoviruses (so flu and paraflu)?
it’s longer because the cycles of multiplication is several sites in succession are required to establish infection in mumps and measles
how long is immunity to mumps and measles after infection?
lifelong
what antibody type is involved in the reaction to mumps and measles?
obligatory viremia allows for neutralization by IgG
how many serotypes of mumps are there?
only one
how many types of species can mumps infect?
humans are the sole reservoir of mumps
how is mumps transmitted?
by respiratory droplets
how long is the average incubation period of mumps before symptoms appear?
18 days
what are the symptoms of mumps? what would allow you to diagnose mumps (ie what would you look for)?
around 18 days, a prodromal period of fever, malaise, and anorexia is followed by unilateral or bilateral swelling of the parotid gland (parotiditis) = usual presenting clinical symptom
will have inflamed parotid duct (stensens duct) in mouth
also get orchitis in males after age of puberty
what is paratiditis
caused by mumps
infection of the parotid gland
the virus grows in the enlarged parotid salivary glands
becomes painful
is excreted in saliva several days before and after swelling of the gland begins
why does mumps cause pain?
pressure and swelling within organs in tight capusles, so ones like the parotid gland and testis (orchitis) after puberty
are most mumps infections symptomatic or asymptomatic?
most are symptomatic - only 30% are subclinical/asymptomatic
where does mumps virus multiply, primarily?
in respiratory epithelium and local lymph nodes
what is the result of primary mumps multiplicaton (ie what’s the secondary step in infection)?
in viremia that spreads to the salivary glands and other organs
| what type of environment (think population) does measles need to survive?
a large, concentrated human population since it's enveloped, it's unstable and so must be growing in some individual at all times