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Flashcards in Viral Respiratory Tract Infections Deck (86)
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1
Q

What are the types of respiratory tract infections?

A
  • Upper
  • Middle
  • Lower
2
Q

What are the upper respiratory tract infections?

A
  • Rhinitis
  • Pharyngitis
  • Tonsillitis
  • Otitis Media
  • Sinusitis
3
Q

What is rhinitis commonly caused by?

A

Rhinovirus

4
Q

What are the symptoms of rhinitis?

A

Runny nose’ and sneezing

5
Q

What is pharyngitis caused by?

A

Adenoviruses or coxsackie virus

6
Q

What does pharyngitis result in?

A

Fever and painful infected throat producing pus or exudates

7
Q

What happens in tonsillitis?

A

The tonsils become red and swollen, and exudates produced

8
Q

What is a common cause of tonsillitis?

A

EBV

9
Q

What is a potential complication of tonsillitis?

A

Quincy

10
Q

When do otitis media and sinusitis usually occur?

A

When sinuses or the middle ear (Eustachian tube) become occluded from inflammation

11
Q

What does otitis media and sinusitis produce?

A

Fever and pain

12
Q

What is otitis media and sinusitis caused by?

A
  • S. Pyogenes
  • S. Pneumonia
  • H. Influenzae
13
Q

What are the middle respiratory tract infections?

A
  • Laryngitis
  • Tracheitis
  • Laryngo-tracheo-bronchitis
14
Q

What does laryngitis produce?

A

A hoarseness and loss of voice

15
Q

What does tracheitis produce?

A
  • Tracheal tiredness
  • Retrosternal pain on breathing
16
Q

What is laryngo-tracheo-bronchitis known as?

A

Croup

17
Q

How common is croup?

A

Relatively

18
Q

What are the symptoms of croup?

A
  • Barking cough
  • Hoarseness
  • Stridor
19
Q

What is stridor?

A

High-pitched wheezing

20
Q

What causes stridor in croup?

A

Occlusion from inflammation, as cartilage rings make trachea non-expandable

21
Q

What are the lower respiratory tract infections?

A
  • Acute bronchitis
  • Bronchiolitis
  • Pneumonia
22
Q

What is acute bronchitis?

A

Cough associated with whitish sputum

23
Q

What change is seen on chest X-ray with acute bronchitis?

A

None

24
Q

In whom does bronchiolitis mainly occur?

A

Infants

25
Q

What are the symptoms of bronchiolitis?

A
  • Wheeze
  • Cough
  • Dyspnoea
26
Q

How long does bronchiolitis last?

A

Several days

27
Q

What is the most common cause of bronchiolitis?

A

RSV

28
Q

What can viruses act as triggers to?

A

Underlying chronic conditions

29
Q

What underlying chronic conditions can viruses act as triggers to?

A
  • Asthma
  • Cystic Fibrosis
  • COPD exacerbations
30
Q

What adversaries for viral RTIs are there?

A
  • Influenza types A, B, and C
  • Adenoviruses
  • Respiratory syncytical virus (RSV)
  • Parainfluenza virus types 1, 2, and 3
  • Rhinovirus
  • Coxsackie virus
  • Coronaviruses
31
Q

How can influenza A be further classified?

A

Depending on the antigens on their surface

32
Q

What happens to the antigens on the surface of influenza A?

A

Point mutations occur

33
Q

What do point mutations in the antigens on the surface of influenza A produce?

A

Antigenic drift

34
Q

What are adenoviruses?

A

DNA viruses

35
Q

How many serotypes are there of adenoviruses?

A

More than 50

36
Q

How many of the serotypes of adenoviruses cause disease?

A

9

37
Q

What is RSV?

A

A paramyxovirus

38
Q

How many major serotypes of RSV are there?

A

2

39
Q

How do the major serotypes of RSV differ?

A

In their antigenic properties

40
Q

Who does RSV infect?

A

Children in their first 3 years of life

41
Q

What does RSV cause?

A

Bronchitis, bronchiolitis, and pneumonia in infants

42
Q

Is there a vaccine to RSV?

A

No

43
Q

What is parainfluenza virus the major cause of?

A

Croup in children

44
Q

How does parainfluenza virus cause croup?

A

By infecting the tracheobronchial tree

45
Q

Where can parainfluenza virus be found in adults?

A

In the upper respiratory tract

46
Q

What does rhinovirus cause?

A

Rhinitis

47
Q

How many serotypes of rhinovirus are there?

A

More than 100

48
Q

What type of viruses are rhinoviruses?

A

Picornaviruses

49
Q

What kind of viruses are coxsackie?

A

Echoviruses

50
Q

What do coronaviruses cause?

A

Coryza-like illness, similar to rhinitis

51
Q

Can a virus be identified by the symptoms and syndromes caused?

A

No

52
Q

Why can a virus not be identified simply by the symptoms and syndromes caused?

A

As there is so much overlap between viruses and conditions caused

53
Q

What do acute viral respiratory illnesses cause?

A

High rates of illness in children

54
Q

What is the result of acute viral respiratory illnesses caused high rates of illness in children?

A

They are a large proportion of GP consultations

55
Q

In whom do acute viral respiratory illnesses cause a large proportion of deaths?

A

The elderly

56
Q

What are influenza viruses made up of?

A

3 different subtypes, A, B, and C

57
Q

What does type A influenza undergo?

A

Genetic shift

58
Q

What do the influenza viruses contain?

A

A lipid protein coat

59
Q

What does the lipid protein coat of influenza viruses have?

A

Two main antigens expressed within it

60
Q

What are the main antigens expressed within the lipid protein coat of influenza viruses?

A
  • Haemagglutin
  • Neuraminidase
61
Q

What are haemagglutin and neuraminidase used to do?

A

Classify the virus into sub-classification

62
Q

How does the virus use haemagglutin?

A
  • To adhere to the host cell
  • Facilitates the entry of the viral genome into the target cells
63
Q

How does the virus use neuraminidase?

A

To facilitate its release from the host cell

64
Q

What is the clinical significance of the influenza viruses use of neuraminidase?

A

It can be used to some effect against influenza viruses for antiviral therapy

65
Q

Give two examples of influenza viral classifications based on haemagglutin and neuraminidase?

A
  • H1N1
  • H3N2
66
Q

What part of influenza viruses undergo antigenic changes?

A
  • Haemagglutin
  • Neuraminidase
67
Q

What is antigenic drift?

A

Point mutations that occur in the virus genome that allow slightly new variants of the haemagglutin and neuraminidase to be altered slighlty.

The introduction of a new influenza subtype into the population

68
Q

What does antigenic drift allow haemagglutin and neuraminidase to do?

A

Evade the immune system

69
Q

What is antigenic drift responsible for?

A

Seasonal changes in the influenza virus

70
Q

What is the result in the seasonal change in the influenza virus?

A

Vaccination against it needs to be renewed annually

71
Q

What is the purpose of the antigenic drift process?

A

It is a process of continual evolution such that antibodies intended for its predecessor are ineffective against it

72
Q

Currently, what are the stable lineages of influenza?

A
  • H1N1
  • H2N2
  • H3N2
73
Q

How are new strains of influenza produced?

A

A new subtype evolves as a result of genetic reassortment between human and animal influenza viruses

74
Q

What do genetic reassortments between human and animal influenza viruses occur as a result of?

A

Direct reassortment, or via an intermediate host

75
Q

In what species has genetic rearrangement occurred with human viruses?

A
  • Avian flu
  • Swine flu
76
Q

Evaluate the use of current vaccines for influenza?

A

They are a good means of prevention, yet constantly have to be altered each year for that specific antigenic drift sequence

77
Q

What does the influenza vaccine contain?

A

Attenuated viruses or purified surface antigens

78
Q

What purified surface antigens may the influenza virus contain?

A
  • HA
  • NA
79
Q

Who is given the vaccine for influenza?

A

Those at most risk of complications if infected with the virus

80
Q

Who is at most risk of complications if infected with influenza?

A
  • Over 65
  • Diabetes
  • Heart failure
  • Renal failure
81
Q

What is the purpose of the influenza vaccine?

A

Prevent morbidity or mortality

82
Q

What are the main influenza antivirals that can be used?

A

Neuraminidase inhibitors

83
Q

Give an example of a neurominidase inhibitor?

A

Zanaminvir

84
Q

How do neurominidase inhibitors work?

A

As NA is essential for the release of viruses from virally infected cells, inhibiting the NA prevents further infection of other uninfected cells

85
Q

What are the main problems with NA inhibitors?

A
  • The rapid development of resistance
  • The cost of treatment
  • Only beneficial if given within 48 hours of onset of symptoms
86
Q

How is diagnosis of influenza viruses made?

A

By direct immunoflouresence and NAAT