Respiratory Viruses I, II, & III Flashcards

1
Q

In general, symptoms from a viral infection depend on ______________.

A

where the virus has infected (e.g., nasopharynx, upper airway) and not on the specific virus itself

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

Name the viral syndrome based on where it infects.

A
Rhinitis (nasal turbinate)
Pharyngitis 
Laryngitis 
Tracheitis 
Bronchitis
Bronchiolitis 
Bronchopneumonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What viruses most commonly infect the respiratory tract?

A
Influenza
Parainfluenza
Coronavirus
Rhinovirus 
Adenovirus 
Respiratory syncytial virus
Human metapneumovirus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Some viruses prefer different ______________.

A

temperatures; Rhinovirus, for instance, prefers to replicate at 33º (which is the temperature of the nasopharynx)

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

Describe the three patterns of viral replication.

A
  • Acute infection with replication confined to respiratory mucosal surface: RSV, Coronovirus, Picornavirus, Parainfluenza virus, and Othomyxovirus
  • Persistent replication confined to mucosal surface: EBV, HPV, and adenovirus
  • Primary infection followed by systemic infection: VZV, HHV6, Poxvirus, Paramyxovirus, and Rubella
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What family is influenzavirus in?

A

Orthomyxoviridae

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

The only RNA virus that replicates in the nucleus is ______________.

A

Influenzavirus

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

Give a rundown on Influenzavirus.

A
  • ssRNA
  • Negative sense
  • Enveloped
  • Segmented
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The paramyxoviridae family includes ______________.

A
  • Paramyxovirus: Mumps and Parainfluenza
  • Morbillivirus: Measles
  • Pneumovirus: RSV
  • Henipavirus: Hendra and Nipah
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do the H and N stand for in influenza nomenclature?

A

Envelope glycoproteins:
•H: hemagglutinin
•N: neuraminidase

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

What organisms can influenza A, B, and C infect?

A

A: humans and many other animals
B: humans
C: humans

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

Influenza vaccines target which strains of influenza?

A

A and B

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

The surface proteins of __________ are the most variable.

A

influenza strain A

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

Very few people infected with ____________ are asymptomatic.

A

influenza

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

Research shows that about __________ people are infected per case of influenza.

A

three to nine

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

True or false: in rare cases, influenza can develop systemic viremia.

A

False. Influenza is confined to the respiratory mucosa.

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

It is estimated that about ___________ influenza deaths per year could be prevented by better vaccination rates.

A

20,000

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

What’s the difference between antigenic drift and antigenic shift?

A

•Antigenic drift is the accumulation of point mutations that leads to immune escape.
–Occurs in all strains of influenza

•Antigenic shift is the sudden accumulation of new surface proteins from other virions, such as in a person who got infected with two strains of A.
– Occurs only in strain A because that is the only one that can move from animals to humans

(“Shift is Sudden. DRIft occurs DRIp by DRIp.”)

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

Amantadine blocks ____________.

A

M2

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

Why do paramyxoviruses have less variation than orthomyxoviruses?

A

Paramyxoviruses are not segmented!

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

Where do paramyxoviruses replicate?

A

In the cytoplasm (unlike orthomyxoviruses)

22
Q

Has there ever been a vaccine for RSV?

A

Yes. In the 1960s, there was an RSV vaccine but it was shown to increase mortality via an eosinophil-mediated reaction.

23
Q

In the absence of vaccination, __________ infection is almost universal.

A

measles

24
Q

Worldwide, measles kills greater than ___________ children per year.

A

one million

25
Q

The mortality of measles is about ____________ in developing countries.

A

5-10%

26
Q

Most measles deaths are due to ___________________.

A

secondary infections from a poorly understood mechanism in which measles suppresses the immune system

27
Q

How is measles transmitted?

A

Respiratory

Note: measles is not transmitted by the rash that it produces.

28
Q

Where does measles replicate?

A

Nasopharynx and regional lymph nodes

29
Q

What are Koplik’s spots?

A

Characteristic of measles, Koplik’s spots are erythematous macular spots in the mouth with white centers.

30
Q

Measles in pregnancy can cause __________.

A

premature labor, spontaneous abortion, and low birthweight infants

31
Q

_______________ are the only reservoir for mumps.

A

Humans

32
Q

Mumps is transmitted by _____________.

A

respiratory secretions (the rash is not infectious)

33
Q

Where does mumps replicate?

A

Respiratory epithelium, lymph nodes, and eventually the blood

34
Q

Human metapneumovirus is in the _____________ family.

A

paramyxovirus (in the pneumoviridae)

35
Q

Give a rundown on HPMV.

A
  • Negative-sense ssRNA
  • Non-segmented
  • Four subtypes
  • Discovered in 2001
  • Causes both URT and LRT infections
36
Q

Give a rundown on Adenovirus.

A
  • Isolated from the adenoidal tissue of children with febrile illness
  • 47 serotypes that can infect humans (53 more that )
  • dsDNA virus
  • Icosahedral
  • Non-enveloped
37
Q

Most Adenovirus infections present with __________.

A

nothing (i.e., most people are asymptomatic)

38
Q

What can Adenovirus cause?

A
  • Myocarditis
  • Hemorrhagic cystitis
  • Conjunctivitis
39
Q

A vaccine was recently approved for _____________.

A

four strains of Adenovirus

40
Q

__________ is the most common cause of URTs.

A

Rhinovirus

41
Q

______________ are the largest positive-sense RNA virus.

A

Coronavirus

42
Q

Where does the name Coronavirus come from?

A

The large glycoprotein spikes make the virus look like a crown on transmission electron microscope.

43
Q

Coronaviruses are _____________ and thus less stable in the environment.

A

enveloped

44
Q

What kind of virus causes SARS and MERS?

A

Coronavirus

45
Q

Which three viruses cause the most respiratory infections?

A

Rhinovirus (50%), Coronavirus (15%), and Influenza (15%)

46
Q

Measles mortality is highest in ____________.

A

girls

47
Q

The incubation period for Measles is roughly _______________.

A

6 days

48
Q

CMV prefers the __________ respiratory tract.

A

lower

49
Q

There are typically _____________ infections per clinical case of influenza.

A

3-9

50
Q

What two Adenovirus diseases are not in the Sketchy scene?

A

Respiratory infections and gastroenteritis