Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Micro and Immunology > Respiratory viruses > Flashcards

Respiratory viruses Flashcards

1
Q

Why do birds hardly ever get viral respiratory infections?

A

Birds have separate inspiratory and expiratory bronchi - flow through system causes them to hardly get viral infections of respiratory tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is the common adage that being in an area that is cold, gives you a cold, wrong?

A

Exposure to cold weather does not make you sick, but if sufficiently bad, can cause one to become immunosuppressed and be susceptible to respiratory virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Respiratory infections cause about ___% of acute illnesses that result in loss of time from work.

A

80

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What percentage of respiratory infections are viral?

A

80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Influenza and pneumonia cause long _______.

A

absences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the infectious cycling and incubation period of respiratory viruses.

A

respiratory viruses have seasonality

they have short incubation periods - 1-4 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How contagious are respiratory viruses?

A

Very

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What group do influenza viruses belong to?

A

Orthomyxovirus group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the morphology of influenza viruses, and genome.

A

Enveloped, single (-ve) stranded RNA virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the different types of influenza viruses?

What do they infect?

A

A, B, C
B and C infect only humans, do not cause pandemics
A is naturally found in the gut of waterfowl but can infect poultry, swine, horses and humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the surface proteins of Influenza virus?

A

Hemagglutinin

Neuraminidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How many subtypes of hemagglutinin are there? What does hemagglutinin do?

A

15
Binds to oligosaccharides (on cell surface) containing terminal sialic acids
i.e. allows adsoprtion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How many subtypes of neuraminidase are there?

A

9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does neuraminidase mediate?

A

Budding off from host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Point mutations in the genes that code for hemagluttinin and neuraminidase which produces minor antigenic variations from year to year within the same HA/NA type

A

antigenic drift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is antigenic drift usually not much of an issue?

A

The change is often not significant and people often have cross reactivity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the danger of antigenic shift?

A

Two different influenza viruses infect the same host cell, recombine genes and spit out a completely new virus - has the potential to cause a pandemic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are key characteristics of antigenic shift?

A

Random
can happen anywhere
Pandemic strains usually replace previously circulating strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pandemic strains of Inlfuenza usually present on average after how many years?

A

10-20 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Can you have a countdown to a pandemic of influenza?

A

No, it’s random

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the symptoms/signs of the flu?

How long do they last for?

A

Fever, chills, cough and myalgia

3-5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe the difference in impact of Influenza based on age.

A

Usually a minor illness in the young and healthy

often fatal in the elderly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

For who else can Influenza be fatal?

A

those with cardiorespiratory disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the flu not have, except in children?

A

No vomitting or diarrhea

except for about 25% of kids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What can influenza often trigger that can be fatal?

A

MIs and strokes

26
Q

What are the major indirect consequences of influenza?

A

huge in terms of hospitalization, serious loss of school and work time, and mortality

27
Q

Why was the 1889 H2N2 strain particularly deadly for the young?

A

Overactive immune response (cytokine storm) more prevalent in immunocompetent individuals

28
Q

Which was one of the most devastating influenza strains? What was it called?
How many people did it kill?
How lethal was it?
What was the mortality rate and who was mostly affected?

A

1918 - H1N1 - Spanish flu
killed 40-100 million
50x more lethal than most strains
2.5-5% mortality, esp. in young and healthy

29
Q

The H1 hemagluttinin from the Spanish flu caused what?

A

Produced an intense immune response

30
Q

What was a very unprecendented symptom caused by the Spanish flu?

A

Encephalitis lethargica

31
Q

What does encephalitis lethargica cause?

A

Personality alterations that make a person very persuasive and argumentative

32
Q

How many waves did the Spanish flu come in? Which was worse?

A

2

the second was worse

33
Q

What did the Spanish influenza cause?

A

Secondary bacterial pneumonia or cytokine storms

34
Q

What was the most recent influenza pandemic?

Who was affected?

A

H1N1 - Swine flu

- affected both pigs and humans (children and young adults)

35
Q

Why was the most recent H1N1 not a serious strain?

A

lacked the PB1-F2 protein

36
Q

Although this wasn’t a serious strain, a certain young hockey player died from it. Why?

A

Genetic defect causing overabundant interleukin 17 - died of a cytokine storm

37
Q

Canada produced a vaccine but Poland didn’t. Were the death tolls different?

A

No, since it wasn’t a deadly strain

38
Q

Why was this pandemic strain particularly non lethal (other than lack of PB1-F2 protein)?

A

People born before 1957 had cross-reacting antibodies
CD8 T cell response limited severity
Majority of T cell epitopes were similar to past H1N1 strains

39
Q

What does the PB1-f2 protein do?

A

Binds to inner mt membrane and sensitizes cells to apoptotic stimuli (TNF-a)

40
Q

Where do Influenza epidemics start? Why?

A

Usually start in Far East, possibly due to agrarian practices in China
(basically fowl mates with chickens, and then passes virus to pigs who have the receptor for bird viruses and human viruses)

41
Q

How is the North american vaccine produced?

A

Produce trivalent vaccine based on the strain that is circulating in the spring in China - will circulate in the fall here (for the most part)

42
Q

Why is the fear of getting guillain barré a little ridiculous?

A

can happen after ANY immune stimulus

43
Q

Why is the fear of microcephaly from the zika virus out of proportion?

A

Need to get it during early pregnancy, pretty rare - if already infected when younger, no issues

44
Q

Describe the influenza virus.

A

Inactivated whole virus
or inactivated virus composed mainly of hemagluttinin
also attenuated in flu mist form for kids

45
Q

What is the sick test that we ran out of money for to determine which influenza it is?

A

multiple real time PCR

46
Q

How can we treat outbreaks of influenza A or B

A

zanamivir or oseltamivir - antivirals

47
Q

What group do parainfluenza viruses belong to? What are they related to?

A

Paramyxoviruses

related to mumps

48
Q

What is the genetic organization of paramyxoviruses?

A

ss RNA (parainfluenza)

49
Q

How are the paramyxoviruses similar to influenza?

A

Have hemagglutinin and neurominidase

50
Q

Where can you not get mumps if you are post-pubertal?

A

In the testicles

51
Q

Parainfluenza _ and __ are closely related and cause acute laryngotrachietis, bronchiolitis and pneumonia, mainly in _______ ______.

A

1 and 3

young children

52
Q

This is one of the only diseases that you can reliably diagnose over the phone. What is the telltale sign?

A

Parainfluenzal “croup” (acute laryngotracheitis)

- get barking cough

53
Q

What breaks the spasm of croup?

A

Cool, moist air breaks the spasm very fast

54
Q

For severe cases of croup, was is done?

A

Racemic epinephrine (and corticosteroids) and special basinette that blows cool air into the child’s face

55
Q

Parainfluenza __ is more serious and causes severe ____ disease in young children.

A

2

severe LRT

56
Q

What does parainfluenza 4 cuase? Who can get it?

A

milder respiratory illness

all age groups

57
Q

Most important cause of respiratory disease in infants (worth remembering).

A

Respiratory syncytial virus

58
Q

What type of virus is RSV?

A

paramyxovirus

59
Q

Why is the virus named RSV?

A

for its ability to produce cell fusion in tissue cultures

60
Q

the symptoms of RSV begin with what? What can they progress to?

A

Being with rhinitis, progression to bronchiolitis and necrotizing pneumonia - can lead to hypoxia of lungs

61
Q

What is the mortality rate for RSV infection? Which age bracket is more severely affected?
Who is at the greatest risk?

A

0.5-1%
younger children more severely affected
infants with congenital heart disease or if immunocompromised can have a mortality rate of 15%

62
Q

When Professor Colby legit spazzed out and talked about “It’s in the eyes”, what virus was being discussed?

A

RSV

Micro and Immunology (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions