Childhood Viral Diseases Flashcards
Measles mode of transmission:
inhalation of aerosolized droplets
measles incubation period
10-14 days
Symptom onset of measles coincides with:
second round of virus replication ; LN, tonsils, lungs, GI tract, spleen
measles primary viremia
primary infection in respiratory epithelium
measles secondary viremia
sx onset in lymph nodes, lungs, spleen, tonsils, GI tract
Measles rash -
Koplik spots
Virus and immune response damage to epithelial and endothelial tissues
Complications of measles
Immune suppresion & opportunistic infections
Blindness in VitA deficient children
Acute disseminated encephalomyelitis (ADEM)
Subacute sclerosing panencephalitis (SSPE)
Immune suppression in measles occurs because
interference with CD46 and signaling lymphocyte activation molecule (SLAM) receptors
Measles diagnosis
2-3 days fever, cough, conjunctivitis, coryza Koplik spots Viral isolation in culture (difficult) Serology ELISA, PCR
Koplik spots
small, bright red spots with blue centers on buccal mucosa
T/F? Measles is one of the most contagious diseases known
true; people are infectious 2-3 days before rash
Measles prevention
vaccine. lifelong immunity, live attenuated vaccine, safe.
Respiratory Syncytial Virus (RSV) characteristicsg
replication limited to respiratory tract
inhalation of aerosol, fomites
no animal reservoir
T/F? Once you’ve had RSV you have lifelong immunity
False; does not yield lifelong immunity
Why doesn’t a RSV infection yield lifelong immunity?
infants have immature immune system
infection limited to respiratory tract epithelium where IgA response is short lived
low cytotoxicity = slow immune response
These populations are at higher risk for severe RSV
premature birth
male
second hand smoke
formula fed
RSV prevention
no antivirals
no vaccine
passive immunoprophylaxis - Palivizumab
Palivizumab acts by:
passive immunoprophylaxis to RSV
humanized monoclonal antibody
targets fusion protein that creates sycytia
IM injection once a month
RSV replication
infects ciliated cells in respiratory tract epithelium
fusion “F” protein creates syncytia
virus buds from cell surface
Varicella Zoster replication
replication in cell
active cell - replication
resting cell - latent infection
infects neighboring cells first
Chickenpox contraction
inhalation of aerosolized droplets
chickenpox incubation period
10-21 days
chickenpox symptoms
fever, malaise, headache
rash 1-2 after symptom onset
recovery usually 2 weeks after sx onset
chickenpox rash
starts 1-2 days after symptom onset
lasts 3-6 days
rash primarily on scalp, face, trunk
what type of immunity is most important in chickenpox virus?
cell mediated
What is shingles?
Chickenpox virus establishes latent infection that can later be reactivated as shingles
Chickenpox prevention
vaccination - lifelong immunity (live attenuated)
antivirals - acyclovir
Acyclovir MOA for chickenpox prevention
antiviral
interferes with genome replication
*can’t eliminate latent virus, doesn’t prevent infection of cells
Poliovirus replication and spread
replication in cell
virus particle creates pore in cell membrane
genome serves as mRNA
How is polio contracted?
ingestion of material containing virus
primary replication of poliovirus
peyer’s patches of small intestine
minor viremia
secondary replication of poliovirus
major viremia
This virus is characterized by fecal shedding of virus for 6 weeks
poliovirus
implications of CNS involvement in poliovirus
virus replicates in gray matter or brain and SC
anterior horn damage = limb paralysis
medulla oblongata damage = respiratory paralysis
risk factors for CNS involvement in poliovirus
physical exertion
trauma
tonsillectomy
Poliovirus prevention
Vaccine (2 options) - live attenuated and killed
No animal reservoir
Rotavirus replication and spread
replication in cell
membrane disruption
genome never exposed
Rotavirus spread
ingestion of material containing virus
Rotavirus incubation period
2 days - vomiting & fever
Rotavirus symptoms
diarrhea a few days after vomiting
lasts for 3-8 days
viral shedding weeks before sx onset & days after recovery
severe disease in Rotavirus is most common in which population
6-24 months old
Rotavirus diagnosis
antigens in stool
Rotavirus prevention
Infant vaccines (2 options) given at @ 2, 4, 6 months
no antivirals
hygiene
Rotavirus treatment
oral rehydration
These two childhood viruses are Paramyxoviruses
Measles and RSV
These childhood viruses have genome: (-)ssRNA
measles, RSV
Genome: dsDNA
Varicella Zoster
Genome: dsRNA
Rotavirus
Genome (+)ssRNA
Poliovirus
Which childhood viruses have a non-envoloped virion?
Poliovirus and Rotavirus
Alphaherpesvirus
Varicella Zoster Virus
Picomavirus
Poliovirus
Reoviridae
Rotavirus
Which virus has 11 segments of genome?
Rotavirus
