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Major etiological agents of colds
- Rhino-30-50%
- Corona-25-30%
- Adeno-5-10%
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How many serotypes does the piconavirdae virus have?
100+
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Which agent is the cause of most common colds?
Rhino--> Rhinitis
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What is the seq of events for Rhino colds
- VP1 binds ICAM receptors on host cells
- virus spreds as fomites
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What is immunity due to? Last how long?
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Why is it NOT a good candidate for a vaccine
- Ad drift (major change in viral surf proteins)
- sIgA response
- too many serotypes
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Coronavirus
(+) RNA virus
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What does the coronavirus have in it?
glycoproteins (spike) IN envelope=males it look like a crown
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What is the etiological agent of corona?
Human Coronavirus (HCoV)
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What can the coronavirus cause?
upper/lower resp tract infections
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What does SARS stand for?
Severe acute respiratory distress syndrome
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Etiological agent of SARS called what?
SARS-CoV
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SARS signs and symptoms
fever, influenza-like, malaise, loss of appetite, myalgia
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What is the new Coronavirus known as?
London1_new CoV 2012
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Adenovirus structure
Naked ds DNA virus
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How many serotypes of adenovirus? How many can infect human?
- 100+ serotypes
- 52 infect humans
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What S&S does adenovirus cause?
Fever, sore throat, lymphadenopathy
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Influenze structure
- Orthomyxovirus
- ss (-) RNA
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How many parts of influenza are there?
Orthomyxovirus, Hemagglutinin, and Neruaminidase
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How many segments does influenza have?
- 8 segments
- it is also enveloped
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How many Hemagglutinin does influenza have?
16 of them
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What is trimeric?
major surface glycoproteins
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What does trimeric do?
allows silaic acid residue on cell surface to allow attachment
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What occurs after trimeric attachment? Encoded by what?
- mediates fusion of endocytosed vision with endosome
- Encoded by segment 4
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How many Neuraminidase (N or NA) are there?
9 segments
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What do neruaminidase do?
leave silica residues on host cells
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What does the M1 part do?
- it is the matrix protein
- promotes assembly
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What does the M2 part FORM?
forms protein channels in host cell memb
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What does the M2 part promote
promotes uncoating&viral release
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What does the M2 part target?
Target of amantadine and rimantadine
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What is the NP part?
nucleoprotein
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What did the M1, M2, and NP distinguish?
influenza A, B, and C
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What is the pathogenesis of Influenza?
- ENTRY INTO HOST
- HA binds siliac acid on host cells
- NA cleaves siliac acid residues
- Virus endocytosed
- ciliated, epith, mucus-secreting cells die
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What is the pathogenesis of the viral infection?
- causes desqumation of alveloar epithelium
- caused by SARS and Influenza
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What does the viral infection influe cause?
- inflammation response
- edema and alveolar wall necrosis
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What is the time course determined by?
IFN and T-cell response
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What is the classic flu symptoms due to?
IFN induction
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What is the incubation period for influenza?
1-4 days
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How many flu types are there?
3 (A, B, and C)
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Type A is what/affects what?
- avian
- affects mammalian hosts
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A has how many segments/proteins?
8 segments and 10 proteins
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Type A drift?
antigenic shift and drift
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Type B seg/proteins
- NO antigenic shift
- YES antigenic drift
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Type C
affects pigs/humans
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Type C seg/proteins
7 segments and 7 proteins
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Type C shift and drift
- no antigenic shift
- yes antigenic drift
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How are viruses classified?
- types
- place of original isolation
- date of isolation
- antigen
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What is the antigenic drift?
repeated mutations cause slow change in hemagglutinin Ags
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What is antigenic shift?
genomic re-assortmnet cause abrupt, major change in hemagglutinin
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What does the CDC recommend neuraminidase inhibitors
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Why do they recommend it?
neuraminidase inhibitors block Inf A by inhibiting endosomal acidification
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