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Flashcards in Childhood viral diseases Deck (36):

Biology of Measles including family, genome, virion

family: paramyxovirus
genome: - ssRNA
virion: enveloped
A helical enveloped virus that replicates in cytoplasm and buds outside of cell


Measles Virus replication

replicates in cell in the cytoplasm fusion protein causes syncytia formation


describe measles the disease

infected by inhalation of aerosolized droplets with a inoculation period of 10-14 days
recovery of about 20 days
most deadly of childhood viruses
symptoms onset coincides with second round of virus replication. occurs in LN, tonsils, lungs, GI tract, spleen
one in spleen secondary viremia


what is viremia

viremia is virus in the blood


characteristics of measles

virus and immune response damage to epithelial and endothelial cells, kopik spots


Complications of measles

immune suppression: interference with CD46 and signaling lymphocyte activation molecule (slam molecules)
Opportunistic infections- streps, staph, influenza
blindness from vitamin A deficeincy
ADEM - rare demyelinating disease
SSPE: very rare, 7-10 years after infection progressive neurological deterioration


diagnosis of measles

symptoms: 2-3 days fever and cough, coryza and conjunctivitis
rash: koplik spots (small bright red spots with bluish centers on buccal mucosa.
Lab: virus isolation in culture, Serology, ELISA RT-PCR


Measles Prevention

one infection causes 15- 20 very very contagious
infectious 2-3 prior to rash
humans only host
Vaccine: life long immunity, live vaccine, (Autism and colitis correlation retracted)
providing vitamin A can reduce severity


primary replication of measles?

local lymph nodes to lungs to aerosol spread
aerosol spread = transmission


Measles can lead to what?



Treatment of Measles is what?

prevention with vaccine


Measles in USA

measles declared eliminated in 2000 from USA. introduced to USA from international visitors outbreaks common in 2013 and 2011


Respiratory Syncytial Virus (RSV) Biology including family, genome and virion

Family: paramyxovirus
genome: -ssRNA
virion: enveloped
has several proteins including polymerase which is needed for replication


Replication of RSV

replicated in cytoplasm needs polymerase
like measles replication


RSV biology in cell and body

RSV infects ciliated cells in the respiratory tract epithelium
fusion protein creates syncytia and virus buds from cellular surface


Describe the infection of RSV

RSV limited to respiratory tract and recovery is 7 to 12 days after onset. Very serious in children where infection occurs by inhalation of aerosol famine.
inoculation period: 4-5 days. upper respiratory symptoms then lower


IgA response to measles is ______ so ______
IgA response to RSV _____ so _____

IgA response to measles is high so life long immunity occurs
IgA response to RSV is low so no immunity


RSV viral characteristics

RSV has no life long immunity and no animal reservoirs
low cytotoxicity thought to result in slower immune response
infection risk factors? day care, school
risk for more severe disease? premature birth, male, second hand smoke, lack of breast feeding


RSV prevention and treatment

No antiviral No Vaccine.
Passive immunoprophylaxis- targets F protein given IM once a month


Varicella Virus biology including family, genome, virion

Family: alphaherpersvirus
genome: dsDNA and large
virion: enveloped
lots and lots of proteins


Varicella bio facts

replicates in nucleus of cell, needs active cell for replication, infects neighboring cells first


Varicella transmission, infection

transmission: inhalation of aerosolized droplets
incubation: 10-21 days


varicella symptoms

fever, malaise, headache
rash 1 to 2 days after symptom onset rash progress for 3 -6 days, rash on scalp, face, trunk
recovery about 2 weeks


recovery from varicella induces what

cell mediated immunity


what happens when varicella becomes latent

can later develop into shingles


prevention and treatment of varicella

vaccination: primary option, life long immunity, life virus
antivirals:acyclovir: interferes with genome replication, cannot eliminate latent virus, does not prevent infection of cells, drug resistance being observed


Polovirus bio family, genome, and virion

family: picornavirus
genome: +ssRNA replicates in cytoplasm
virion: non enveloped
proteins: capsid non structural proteases and polymerases


polovirus bio facts

replicates in cytoplasm, virus particle creates pore in cell membrane, genome serves as mRNA
replication happens primarily in Peyers patches of small intestine and secondary in major viremia


Polio disease facts

prevalent in endemic areas in native children, infection occurs by ingestion of material with polio virus, low infectious dose, leaps from intestines to blood to nervous system where it causes greatest problems
fecal shedding of virus for 6 weeks


Polio disease and CNS

CNS involvement in 1 out of 200 infections.
Virus replicates in gray matter of brain and spinal cord causing limb paralysis from anterior horn damage and respiratory paralysis from damage to medulla


Polio prevention and treatment

Vaccine: salk (killed), sabin (live)
no animal reservoir
targeted for eradication


Rotavirus family, genome, vision, proteins

family: reoviridae
genome: dsRNA 11 segments (genome never exposed)
virion: non enveloped
proteins: VP4: attachment and fusion
VP1: polymerase
VP2: RNA binding
VP3: transferase


Rotavirus biology facts

replication in cell, disrupts membrane and genome is never exposed diagnosed by antigens in stool


how is rotavirus diagnosed

antigens in stool


Rotavirus the disease infections, symptoms

infection by ingestion of materials w virus
incubation: 2 days of vomitting and fever
diarrhea: 2 to 3 days after puking lasts 3 to 8 days
virus shedding for weeks
severest in children 6 to 24 months olds


treatment of rotavirus and prevention

prevention: vaccines for infants
NO antivirals
oral rehydration, hand washing