DD- Virology of influenza Flashcards

1
Q

An infectious disease caused by the influenza virus. The most common symptoms include: a high fever, runny nose, sore throat, muscle pains, headache, coughing, and feeling tired.

A

The flu

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2
Q

Persons _________of age account for more than 90% of deaths from the Flu

A

> 65 years

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3
Q

Influenza cases peak during the ______season

A

winter/spring

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4
Q

Influenza virus is an______virus with a segmented genome

A

RNA

Its genome is made up of 8 different pieces of single-stranded RNA, which encode several different viral proteins

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5
Q

Surrounding the core of influenza is a lipid envelope, with a lining of ______on the inner side of the envelope.

A

matrix protein

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6
Q

Two of the best characterized_________are the hemagglutinin (H) and neuraminidase (N) glycoproteins.

A

flu viral proteins

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7
Q

Influenza viral subtypes are identified by the combination of________on the viral coat (e.g. H1N1, H3N2 etc).

A

H and N proteins

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8
Q

There are 3 types of influenza virus.

Type A and Type B strains circulate in the population every year.

Type C strains cause__________

A

mild or clinically-insignificant illness

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9
Q

Type A strains are the cause of both epidemics and pandemics. Type A strains can infect__________

A

other animals

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10
Q

Two of the best characterized flu viral proteins are the_________ and neuraminidase (N) glycoproteins.

A

hemagglutinin (H)

*Both hemagglutinin and neuraminidase are surface proteins.

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11
Q

Hemagglutinin (HA) is involved in

A
  • cell entry
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12
Q

Neuraminidase (NA) is involved in:

A

cell escape

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13
Q

There are 3 types of influenza virus.

Type A and Type B strains_________

Type C strains cause mild or clinically-insignificant illness

A

circulate in the population every year.

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14
Q

Two of the best characterized flu viral proteins are the hemagglutinin (H) and __________

A

neuraminidase (N) glycoproteins.

*Both hemagglutinin and neuraminidase are surface proteins.

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15
Q

Influenza binds _______ to enter cell

A

sialic acid

Common in lungs

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16
Q

Potentially severe illness:

Epidemics and pandemics
Rapidly changing
Birds, swine, dogs, cats, horses, seals, whales, humans

A

Type A Influenza

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17
Q

RNA virus are sloppy when they replicate leading to many:

A

mutations

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18
Q

Usually less severe illness

Epidemics, no pandemics
More uniform
Humans

A

Type B Influenza

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19
Q

Type A Name example:

A/California/7/2009 (H1N1)

A
a- Virus type
California- Geographic origin
7- Strain number
2009- year of isolation 
(H1N1)- subtype
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20
Q

Antigenic Drift

A

a mechanism for variation in viruses that involves the accumulation of mutations within the genes that code for antibody-binding sites.

21
Q

Antigenic Drift in flu virus can affect________ to stop AB binding

A

Hemagglutinin

22
Q

Antigenic Shift is in _____ only

A

Type A

23
Q

Major change, new subtype
Caused by exchange of gene segments
May result in pandemic

A

Antigenic SHIFT

24
Q

Minor change, same subtype
Caused by point mutations in gene
May result in epidemic

A

Antigenic DRIFT

25
Q

Transmission of Influenza

A

Droplet spread- Small particle aerosols

26
Q

Influenza is transmitted primarily by the ________route

A

respiratory

27
Q

Signs and symptoms of influenza in adolescents and adults

A

acute onset of fever, chills, myalgias, headache and cough

28
Q

presentation tends to resemble that of bacterial sepsis, including lethargy, decreased eating and mottling

A

flu in neonates

29
Q

tend to present with gastrointestinal symptoms (NVD); fever; anorexia; and various respiratory syndromes, including (croup), bronchiolitis, bronchitis and febrile convulsions

A

flu in Infants and toddlers

30
Q

Major groups of Flu Rx

A

Matrix protein inhibitors

Neuraminidase Inhibitors

31
Q

Matrix protein inhibitors:
Amantadine
Rimantadine

Only work on Influenza______subtypes

A

Type A

32
Q

Neuraminidase Inhibitors:
Oseltamivir
Zanamivir
Peramivir (just approved 12/14)

Work on Influenza__________subtypes

A

types A and B

33
Q

Matrix protein inhibitors

Work on?

A

M2 protein

a proton-selective ion channel protein, integral in the viral envelope of the influenza A virus.

34
Q

Neuraminidase Inhibitors

works on?

A

preventing its reproduction by budding from the host cell.

block the neuraminidase enzyme

35
Q

an influenza that reassorts in swine and then infects humans

A

Swine Influenza

ex: Pandemic H1N1

36
Q

__________ were at exceptionally high risk for hospitalization and death if infected with Pandemic H1N1 (or any influenza)

A

Pregnant women

37
Q

Infectious disease of birds caused by type A Influenza virus

A

Avian Influenza

38
Q

There are 2 types of licensed seasonal influenza vaccines

A

iInactivated influenza vaccine (IIV)

Live attenuated influenza vaccine (LAIV)

39
Q

this vaccine is an injectable, killed
vaccine; licensed for all individuals 6 months of age and older.

There are both trivalent and quadrivalent IIVs approved and available.

The quadrivalent is newer, but it will likely completely replace all trivalent vaccines. The additional strain is a second B virus.

A

Inactivated influenza vaccine (IIV)

40
Q

Both influenza vaccines contain the same 3 strains of influenza and the ________ vaccines contain the same second B strain.

A

quadrivalent

41
Q

this is delivered intranasally via a small, needle-free syringe that delivers a fine mist into the nose; licensed for healthy persons 2 yrs through 49 years of age. This contains the same influenza strains as IIV, however, it is only quadrivalent. An additional strain is a second B virus.

A

Live attenuated influenza vaccine (LAIV)

this is a live, attenuated (weakened strain) vaccine;

42
Q

3 conditions must be met to declare a pandemic

A

1) Emergence of a new influenza virus subtype
2) Virus must infect humans and cause serious illness
3) Virus must have sustained transmission and spread easily among humans

43
Q

Both inactivated and live vaccines are
reformulated annually to provide the best protection possible for what strains are
_________ to be circulating during the next season

A

anticipated

44
Q

Intramuscular or intradermal

Trivalent and quadrivalent, moving toward all quadrivalent

Killed virus

Standard-dose and high-dose (HD for adults 65 and older)

A

Inactivated Vaccine (IIV)

45
Q

Intranasal
Quadrivalent
Live

A

Live attenuated influenza vaccine (LAIV) (cold adapted, attenuated influenza vaccine)

46
Q

50-70% effective among healthy persons <65 in well-matched years

30%-40% effective among frail elderly

Greater efficacy for prevention of hospitalization and death

A

Inactivated Vaccine (IIV)

47
Q

Temperature-sensitive (do not replicate efficiently in lower airways)

Cold-adapted (replicate efficiently in upper airway)

Indicated for healthy 2-49 year olds

A

Live Attenuated Influenza Vaccine (LAIV)

48
Q

Influenza Vaccine is Recommended for:

A

Everyone >6 months unless there is a contraindication to vaccination