Childhood Viral Diseases Flashcards
Measles Virus Causes
Measles
Respiratory Syncytial Virus Causes
Croup
Bronchitis
Respiratory tract infection
Varicella Zoster Virus Causes
Chickenpox
Rotavirus Causes
Gastroenteritis
Poliovirus causes
Gastroenteritis
what type of virus is the measles virus
Paramyxovirus
Genome of the measles virus
(-)ssRNA
Virion of the measles Virus
Enveloped
Proteins of the Measles virus
L - polymerase P (C&V)-phosphoprotein H - Hemagllutinin F - Fusion M - Matrix N - nucleocapsid
what type of protein do all Paramyxoviruses have
membrane fusion proteins
where does the measles virus replicate
in the cell and in the cytoplasm
what causes syncytia formation in the measles virus
Fusion protein
how does Measles virus leave the cell
Budding because it is enveloped
how does measles get in the body
Inhalation of aerosolized droplets
incubation period of measles
10-14 days
where does the primary measles infection occur
in respiratory epithelial tissues
the primary measles infection
Primary Viremia
when does symptoms begin for measles
Coincides with second round of virus replication
what are the trasnfer steps of measles around the body to eventually get to seconday viremia
in LN, tonsils, lungs, Gi, and speen
the 2nd round of measles virus replication
Seconday Viremia
Recovery time from measles
20 days after infection
what is the most deadly childhood rash/fever illness
Measles
clinical symptoms of measles (secondary Viremia)
Fever, Cough, Conjunctivitus
Koplik’s spots
Rash
Characterisitic rash of Mealses results from
Virus and Immune response damage to epithelial and endothelial cells
Immune suppression by measles
Interference with CD46 and signaling lymphocyte activation molecule (SLAM) receptors
opportunistic infections due to measles
Streptococcus pneumoniae
Staphylococcus aureus
Haemophilus influenzae
who with measles may also become blind
Vitamin A deficent children
demyelinating disease due to measles
Acute disseminated encphalomyelitis(ADEM)
commonnes of ADEM
rare, 1:1000 children
progressive neurological deterioration due to measles
Subacute sclerosing panencephalitis (SSPE)
commoness of SSPE
very rare 1:1000000 children
Symptoms of Measles
2-3 days fever+ cough, coryza and conjunctivitis
Rash: Koplik spots
small bright red spots with bluish centers on buccal mucosa … patognomonic for measles
Koplik spots
how to diagnose measles in the laboratory
Virus isolation in culture (hard)
Serology
ELISA, RT_PCR
contagiousness of measles
one of the most contagious diseases
number of cases from one illness in a naive pop is 15-20
when are people with measles infectious
2-3 days prior to rash
hosts of measles
just humans
preventing measles
Vaccination
Vitamin A reduces severity
no antivirals
how long deas the measles vaccine provide immunity
Life long
what kind of vaccine is the measles vaccine
live attenuated vaccine
safety of measles vaccine
autism and colitis correlation retracted
Measles in the world
declared eliminated in the US in 2000, but is found in other countries.
measles continues to be introduced to the US through international travel
cases of measles in 2011
222
outbreaks of measles
17 year old visited longon, came back and caused 58 cases for non vaccinated people
someone visited india, 22 cases resulted, most not vacinated, 3 had the vacine
what type of virus is Respiratory Syncytial Virus
PAramyxovirus
genome of Respiratory Syncytial Virus
(-)ssRNA
Virion of Respiratory Syncytial Virus
enveloped
Proteins of Respiratory Syncytial Virus
L - Polymerase G - Glycoprotein F - fusion M - matrix P - phosphoprotein N - nucleocapsid NS1&NS2 - replication and immune response
where does Respiratory Syncytial Virus replicate
in the cell - simialr to measles
what does Respiratory Syncytial Virus infect
limited to the ciliated cells in the respiratory tract epithelium
what does the Fusion protein of Respiratory Syncytial Virus create
syncytia
how does Respiratory Syncytial Virus leave the cellular surface
budding
The most important viral agent of serious pediatric respiratory tract infections
Respiratory Syncytial Virus
How does Respiratory Syncytial Virus establish itself
infection by inhalation of aerosol, formites
where does Respiratory Syncytial Virus replicate
limited to the respiratory tract
incubation period of Respiratory Syncytial Virus
4-5 days
symptoms of Respiratory Syncytial Virus after incubation
lower respiratory tract symptoms 1-3 days after upper respiratory tract symptoms
when do you recover from Respiratory Syncytial Virus
7-12 days after symptom onset
Who can Respiratory Syncytial Virus infect
infects humans, and not other animals
does infection by Respiratory Syncytial Virus lead to life long immunity
no, because infants have immature immune system
infection limited to respiratory tract epithelial cells where IgA response is short lived
VIrus can change its surface proteins easily
why does Respiratory Syncytial Virus result in a slow immune response
low cytotoxicity
risk factors for Respiratory Syncytial Virus infection
Attending day care
School age siblings
risk factors for a severe Respiratory Syncytial Virus disease
premature birth
male
second hand exposure to tobacco smoke
lack of breast feeding
prevention of Respiratory Syncytial Virus
Ribavirin administered by inhalation
No Vaccine
Passive immunoprophylaxis
Vaccine progress for Respiratory Syncytial Virus
in development
Formalin anactivated vaccine not successful
Challenge to immunize infants who are at the greatest risk
the passive immunoprophylaxis agent for Respiratory Syncytial Virus
Palivizumab - humanized monoclonal antibody
how does passive immunoprophylaxis work to fight Respiratory Syncytial Virus
targets F protein
how often do you take Palivizumab to fight Respiratory Syncytial Virus
IM once a month
what type of virus is Varicella Zoster Virus
Alphaherpesvirus
genome of Varicella Zoster Virus
large, dsDNA
Virion of Varicella Zoster Virus
enveloped
Proteins of Varicella Zoster Virus
hundreds
Replication area for Varicella Zoster Virus
in the cell (active cell) going into the nucleus
What does Varicella Zoster Virus infect first
Infects neighboring cells first
what does Varicella Zoster Virus create in a resting cell (neuron)
a latent infection
genome shape of a latent infection by Varicella Zoster Virus
circular
how does Varicella Zoster Virus get into the cell
membrane fusion
how does Varicella Zoster Virus get out of the cell
budding
how do you get Chickenpox(Varicella Zoster Virus)
inhalation of aeroslized droplets
incubation period of Varicella Zoster Virus
10-21 days
symptomes of Varicella Zoster Virus
Fever, malaise, headache
Rash 1-2 days after symptom onset
Rash progesses for 3-6 days
where does the Varicella Zoster Virus Rash hand out
scalp, face, trunk
recovery from Varicella Zoster Virus
2 weeks post symptom onset
how does one recover from Varicella Zoster Virus
cell mediated immunity
Reactivation of latent Varicella Zoster Virus infection leads to
shingles
are shingles the same as small pox
no (shingles on torso, smallpox on extremities)
Preventing Chickenpox
Vaccination
Anticirals
how long does Chickenpox vaccine work
life long immunity
vaccine for chickenpox type
Live attenuated vaccine
antiviral for chickenpox
acyvlovir
how does acyclovir work
interferes with genome replication
what does Acyclovir not do
cannot elimiate latent virus
does not prevent infection of cells
problem with Acylovir in future
drug resistance is being observed
what type of virus is Poliovirus
Picornavirus
Genome of Poliovirus
(+)ssRNA
Virion of PolioVirus
Non-enveloped
Proteins of Poliovirus
Capsid - VP1, VP2, VP3, VP4
Non-structureal - proteases, polymerase, others…
Where does the Poliovirus replicated
in the cell
how does the Poliovirus get in the cell
Creates pore in cell membrane
where is Poliovirus normally found
endemic areas such that infection are most common in naive children
how does one get poliovirus
infection by ingestion of material containing virus
TCID50 of Poliovirus
100
where does primary infection of Poliovirus occure
in Peyer’s patches of small intestin
Primary replication of Poliovirus leads to
Minor Viremia
Secondary repliation of Poliovirus
Major Viremia
how does one get rid of Poliovirus in the GI tract
Fecal Shedding of Virus for 6 weeks
travel of Poliovirus
goes into Peyers pathes, then lymph nodes, followed by blood stream and then possibly the CNS
how many people with poliovirus have CNS infections
1:200
Risk factors for Poliovirus in the CNS
Physical exertion
Trauma
Tonsillectomy
where in the CNS does Poliovirus replicate
gray matter of brain and spinal cord
CNS poliovirus symptoms
Limb paralysis from anterior horn cell damage
Respiratory paralysis from damage to medulla oblongata
How to prevent Poliovirus
Vaccines (Salk and Sabin)
Salk Poliovirus vaccine
killed (less side effects)
Sabin Poliovirus vaccine
live attenuated (more strength, more antibody creation)
how can get poliovirus
Humans, no animal reservoir
What type of virus is Rotavirus
Reoviridae
Genome of Rotavirus
dsRNA, 11 segments
Virion of Rotavirus
Non-enveloped
Proteins of Rotavirus
VP1 - Polymerase VP2 - RNA binding VP3 - transferase VP4 - attachment and fusion Other structural and non-structural proteins
capside number of Rotavirus
3 capsides
where does the Rotavirus replicate
in cell
how does Rotavirus get into cell
enters via and endosome
endosome forms due to virus attachment to cell
drop of pH
First layer disolved by proteases in the endosome
fusion proteins exposed and
Membrane disruption occures, dumping nucleocapsid into the cytoplasm
is the genome of Rotavirus exposed
no, because dsRNA is not normal and the Cell with try and destroy the dsRNA or do apoptosis
How does Rotavirus infect
Ingestion of material containing the virus
Incubation period of Rotavirus
VOmiting and fever
symptoms of rotavirus
Vomiting and Fever
Diarrhea 2-3 days after fever, lasting 3-8 days
how long does Rotavirus shed
weeks before symptom onset, and days after recover
who gest the most sever rotavirus
5-24 months old
diagnosing Rotavirus
Antigens in stool
PReventing Rotavirus
Infact Vaccines
No antivirals
Hygiene- hand washing
Treating Rotavirus
oral Rehydration
Vaccines for Rotavirus
RotaTeq - merck: 2,4,6 months
Rotarix - GlaxoSmithKline - 2,4 months