URTI Flashcards

1
Q

Describe rhinovirus

A

Icosahedral, non-enveloped positive sense single-stranded linear RNA virus

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

What family does Rhinovirus belong to?

A

Picornavirus

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

Rhinovirus is the most common cause of what?

A

common cold (more common in fall and winter)

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

T or F. Rhinovirus is acid labile

A

T. Destroyed by stomach acid

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

How is rhinovirus transmitted?

A

person-to-person via respiratory droplets or indirectly by respiratory droplets on hands

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

Pathogenesis of rhinovirus

A

virus binds to ICAM-1 on respiratory epithelial cells and elicits inflammation to cause vasodilation, mucous secretion, and stimulation of sneeze and cough reflexes

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

What is the incubation period of rhinovirus?

A

2-4 days (illness lasts about 1 week)

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

Treatment of rhinovirus?

A

Supportive only

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

Describe coronavirus

A

Helical, enveloped, + sense single-stranded linear RNA that accounts for 15-20% of URTIs

active in winter in a 2-3 yr cycle

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

T or F. Coronavirus does NOT cause LRTIs

A

T. except SARS and MERS

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

What else can coronavirus cause?

A

GI illness

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

Describe Bordetella pertussis

A

small coccobacillary, encapsulated gram negative rod

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

What disease does Bordetella pertussis cause?

A

Whooping Cough

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

What major toxin does Bordetella pertussis use?

A

A-B toxin

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

What does A-B toxin do?

A

stimulates adenylate cyclase by catalyzing the addition of ADP-ribosylation to the inhibitory subunit of the G protein complex, resulting in overactive cAMP- dependent protein kinase activity which impairs phagocytosis

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

How is Bordetella pertussis transmitted?

A

airborne droplets (very contagious)

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

What are the stages of Bordetella pertussis infection?

A
  • catarrhal (2 wks of mild URT symptoms)
  • paroxysmal (2-3 months of severe cough)
  • Convalescent (1-2 wks of cough reducing)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is Bordetella pertussis diagnosed?

A
  • Nasopharyngeal swab (PCR)
  • Culture
  • CBC With LYMPHOCYTOSIS
19
Q

Why is lymphocytosis seen Bordetella pertussis?

A

pertussis toxin inhibits signal transduction by chemokine receptors, resulting in failure of lymphocytes to enter lymphoid tissue such as spleen and lymph nodes

20
Q

How is Bordetella pertussis treated?

A

-Azithro for all regardless of age or symptom presentation (if given very early it can shorter course duration but if given later the toxin has probably already damaged the respiratory mucosa BUT will reduce risk of complications such as PNA or respiratory failure)

21
Q

Describe Corynebacterium diphtheriae

A

gram + pleomorphic bacillus, club shaped

22
Q

Pathogenesis of Corynebacterium diphtheriae

A

A-B toxin blocks protein synthesis by inactivating elongation factor 2 (EF-2) by ADP ribosylation AND

can induce formation of a pseudomembrane

23
Q

How does Diphtheria present?

A

gradual onset of:

  • sore throat
  • malaise/fatigue/fever
  • cervical LAD (‘bull neck’)
  • neuropathies
24
Q

How does Diphtheria affect the heart?

A

myocarditis 7-14 days after onset of respiratory symptoms

25
Q

What is a pseudomembrane?

A

membrane composed of necrotic fibrin, leukocytes, RBCs, epithelial cells, and organisms that adheres tightly to underlying tissue and bleeds with scraping

26
Q

How is Diphtheria diagnosed?

A
  • Throat swab culture of Loeffler’s medium, tellurite plate

- Methylene blue plate good for revealing metachromatic granules

27
Q

What color tellurite plate is positive?

A

gray-black

28
Q

How is Diphtheria treated?

A

Antitoxin administration AND either penicillin or erythromycin. Treat immediately!!

29
Q

What are the most common causes of acute otitis media?

A

Strep pneumo, H. influenzae, or Moraxella catarrhalis

30
Q

Treatment for acute otitis media?

A

Amoxicillin or

Augmentin for those who have had recent ABX or have a history of AOM unresponsive to amoxicillin (give if you see purulent conjunctivitis)

31
Q

Treatment of acute sinusitis?

A

Augmentin (if they get better or get worse)

32
Q

What is epiglottitis?

A

inflammation of the supraglottic region of the oropharynx with inflammation of the epiglottis, vallecula, and arytenoids

33
Q

Major causes of epiglottis?

A
  • H. influenza
  • H. parainfluenzae
  • GAS
  • Strep pneum
34
Q

Typical patient population for epiglottitis?

A

urban male in 40s

35
Q

How does epiglottitis present? Treatment?

A

sore throat, dysphagia, muffled voice

treat with ceftriaxone because severe

prognosis good normally

36
Q

What factors does H. flu require for growth?

A

V and X (grows on chocolate age)

37
Q

Strep pneumo is becoming more resistant to penicillin. How?

A

altered penicillin binding proteins

38
Q

Why is altered penicillin binding proteins the more likely cause of resistance in gram + and B-lactamases more likely in gram negatives?

A

Gram negatives can secrete the lactamases into the peri-nuclear space and it is more concentrated

39
Q

Why is otitis media more common in children?

A

Eustachian tubes are shorter, narrower, and more horizontal than in adults.

40
Q

Rhinovirus grows better at lower temperatures. There is evidence that rhinovirus can contribute to pneumonia.

A

Rhinovirus grows better at lower temperatures. There is evidence that rhinovirus can contribute to pneumonia.

41
Q

What is a gram+, forming long branching filaments, anaerobics; associated with “sulfur granules”?

A

Actinomyces

42
Q

What should be done if C. diphtheria is recovered from culture?

A

either Ab inoculation or antibody-based gel diffusion precipitin test is performed to document toxin production. or PCR for presence of toxin gene

43
Q

Vaccine schedule for Dtap?

A

2,4,6; 15-18 months and kindergarten; booster at 11 and in between 19-64 yoa

44
Q

An x-ray of epiglottis would show what?

A

thumb sign showing inflammation