Final; Childhood Viral Diseases Flashcards
What is the genome of the measles virus
-ssRNA
What type of virion does the measles virus have
enveloped
The fusion protein in the measles virus causes what
syncytia (mass containing several nuclei) formation
How is the measles virus transmitted
inhalation of aerosolized droplets
What is the incubation period of the measles virus
10-14 days
primary infection in respiratory epithelial tissues; primary viremia
What is characteristic of the the symptom onset of measles
the symptoms onset coincides with the second round of virus replication
occurs in LN, tonsils, lungs, GI tract, and spleen; secondary viremia
What is the recovery time for measles
approximately 20 days after infection
True or False
Measles is the most deadly of childhood rash/fever illnesses
True
What causes the characteristic rash of measles
viral and immune response damage to epithelial and endothelial cells
koplik spots
How does measles influence immune suppression
Interferes with CD46 and signaling lymphocyte activation molecule (SLAM) receptors
also allows opportunistic infections
This is a rare; 1:1000 in children demyelinating disease
acute disseminated encephalitis (ADEM)
This is very rare; 1:1million in children, 7-10 years after infection, progressive neurological deterioration
subacute sclerosing panencephalitis (SSPE)
What are the symptoms of measles
2-3 days fever and cough, coryza, and conjunctivitis
characteristic rash
How is measles diagnosed in the laboratory
virus isolation in culture (difficult)
serology
ELISA, RT-PCR
True or False
Measles is not very contagious
False; it is one of the most contagious diseases known
How much can humans spread measles
they are the only host
one illness in a naïve population can infect 15-20 people
people are infectious 2-3 prior to rash
What are some ways in preventing measles
vaccination (provides life long immunity)
vitamin A
there are no anti-virals
When was measles considered “eliminated” from the US
2000, but it is common in other countries
it arrives to the US through international travel
What is the genome of the respiratory syncytial virus
-ssRNA
What type of virion does the respiratory syncytial virus have
enveloped
What type of cells does the respiratory syncytial virus infect
ciliated ells in the respiratory tract epithelium
This protein in the respiratory syncytial virus creates the syncytia
fusion protein
How does the virus exit the cell
via budding
What is special about the respiratory syncytial virus in regards to respiratory tract infections
it is the most important viral agent of serious pediatric respiratory tract infections
How does one obtain the respiratory syncytial virus
via inhalation of aerosol
fomites
What is the incubation period of respiratory syncytial virus and where is it specifically found
4-5 days
lower respiratory tract 1-3 days after upper respiratory tract
How long is the recovery of the respiratory syncytial virus
7-12 days after symptom onset
Does the respiratory syncytial virus infect animals?
No, it only infects humans, no animal reservoir
Does respiratory syncytial virus infection result in life long immunity?
No, infants have an immature immune system and in the respiratory tract IgA is short lived
What are some risk factors for respiratory syncytial virus infection
attending day care
school aged siblings
What would put someone at risk for a more severe respiratory syncytial virus infection
premature birth
male
second-hand exposure to tobacco smoke
lack of breast feeding
What is the main prevention of the respiratory syncytial virus
no antivirals
no vaccine
can use passive immunoprophylasis; humanized monoclonal antibody (once a month)
What is the genome of the varicella zoster virus
dsDNA
What is the virion of the varicella zoster virus
enveloped
What is the main difference about the proteins varicella zoster virus produces
there are hundreds of proteins
What is the replication of the varicella zoster virus
active cell needed for replication
resting cell (neuron) = latent infection (circular genome)
will infect neighboring cell first
What is the transmission of the varicella zoster virus
inhalation of aerosolized droplets
What is the incubation period for the varicella zoster virus
10-21 days
What are the symptoms of the varicella zoster virus
chicken pox;
fever, malaise, headache
rash 1-2 days after the symptom onset, lasting for 3-6 days
Where is the chickenpox rash primarily located
scalp, face, and trunk
What is the recovery timeframe of the varicella zoster virus
usually by 2 weeks of symptom onset; cell mediated immunity most important
What happens upon re-activation of the varicella zoster virus
shingles
What are the prevention strategies of chickenpox
vaccination; life long immunity
antivirals; but it cannot eliminate latent virus because the DNA is not actively being replicated
What is the genome of the poliovirus
+ssRNA
What is the virion of the poliovirus
non-enveloped
What specific proteins does the poliovirus contain
4 protein capsid
What does the virus particle do to the cell
it creates a pore in the cell membrane
Where is the poliovirus prevalent
in endemic areas such that infections are most common in naïve children
How is the poliovirus transmitted
ingestion of material infected by the virus
Where is the location of the poliovirus manifestation
Peyers patches of the small intestine; minor viremia
secondary replication; major viremia
mild disease
How long does fecal shedding of the poliovirus occur
for 2 weeks
How prevalent is CNS involvement in polio
1:200 of infections
risk factors; physical exertion, trauma, and tonsillectomy
How does the poliovirus affect the CNS
it replicates in the gray matter of brain and spinal cord
limb paralysis from anterior horn damage
respiratory paralysis from damage to the medulla oblongata
What are the prevention strategies of the poliovirus
vaccination; 2 available
targeted for eradication
What is the genome of the rotavirus
dsRNA, 11 segments
What is the virion of the rotavirus
non-enveloped
What is special about the rotavirus replication
there is membrane disruption
genome is never exposed
How is rotavirus transmitted
ingestion of material containing the virus
What is the incubation of rotavirus
2 days; vomiting and fever
What are the symptoms of rotavirus
diarrhea 2-3 days after vomiting, 3-8 days in duration
How long does viral shedding last
weeks before symptom onset and days after the recovery
When is severe disease of rotavirus common
most common is 6-24 month children
How is rotavirus diagnosed
antigens in the stool
What are the prevention strategies of rotavirus
infant vaccines
no antivirals
good hygiene
treatment via oral rehydration
