Brainscape's Knowledge GenomeTM

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


See full index

IDMM > LRTIs (3) > Flashcards

LRTIs (3) Flashcards

1
Q

list the LRTIs we are expected to know

A
  1. influenza
  2. acute bronchitis
  3. acute exacerbation of chronic bronchitis (AECB)
  4. community acquired pneumonia (CAP)
  5. nosocomial pneumonia
  6. empyema/lung abcess
  7. TB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

epidemiology of influenza

A

distinct outbreaks every year–>typically in winter months

begin abruptly and attack about 10-20% of the population

transmission depends on the virus and the susceptibility of the population

death rates are disproportionately high in elderly and infants

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

what causes vaccine mismatches with influenza

A

antigenic drift

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

what causes influenza

A

influenza A virus

3 major subtypes of HEMAGLUTININ (H1, H2, H3)
2 subtypes of NEURAMINIDASE (N1, N2)

have ability to undergo changes in antigenic characteristics of envelope glycoproteins

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

how does the influenza A virus cause infection and spread

A

HEMAGLUTININ binds to SIALIC ACID on epithelial cell surface to initiate infection

NEURAMINIDASE cleaves the link between progeny and host cell, allowing new virions to escape

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

when does viral shedding of influenza A begin

A

24-48 hours before symptom onset

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

clinical presentation of influenza

A

ABRUPT onset

fever, cough, headache, myalgias, malaise, sore throat, rhinorrhea

exam usually unremarkable–> flushing and mild cervical lymphadenopathy in some patients

uncomplicated patients improve in 3-5 days
viral shedding stops after 6-7 days

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

what is the most common complication of influenza

A

pneumonia

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

Tx for influenza

A

most cases are self limited and dont require treatment

antivirals are indicated for the severely ill or those at risk of complications

Ab Tx of secondary infection when needed

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

in a patient with influenza in which antivirals are indicated, what is the medication used

A

oseltamivir (Tamiflu)

needs to be given early to see benefit

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

bacterial causes of acute bronchitis

A

mycoplasma pneumoniae

chlamydophila pneumoniae

Bordatella pertussis (if cough >3 weeks suspect this)

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

viral causes of acute bronchitis

A

respiratory viruses :

influenza
coronaviruses
adenovirus
entero/rhinoviruses
RSV
measles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

is acute bronchitis most often viral or bacterial

A

viral

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

clinical presentation of acute bronchitis

A

cough

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

what is one way to distinguish between viral and bacterial causes

A

procalcitonin levels (>0.25 mcg/L suggest bacterial)

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

what causes AECB

A

about 50% viral cause

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

how is AECB diagnosed (criteria)

A

PRODUCTIVE cough for at least 3 months/year for the last 2 consecutive years=chronic bronchitis

criteria for AECB (need at least 2 to diagnose):

  1. increased sputum volume
  2. increased sputum purulence
  3. increased dyspnea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how is AECB prevented

A

COPD patients should receive flu vaccine yearly and pneumococcal vaccine every 6 years

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

what is CAP

A

pneumonia in a person who is not has not recently been hospitalized

top disease in children worldwide, and among adults in the US

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

how do pathogens reach the lungs to cause infection in CAP

A

via inhalation, aspiration or by blood

blood = less common

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

what are some conditions that may raise your risk for CAP

A 
alcoholism
diabetes
CHF
COPD
smoking
aspiration prone
post-influenza
cystic fibrosis
22
Q

causative agents of CAP in neonates

A
  1. GBS
  2. E. Coli
  3. S. aureus
  4. Pseudomonas
  5. C. trachomatis
23
Q

causative agents of CAP in infants

A
  1. RSV
  2. influenza
  3. S. pneumoniae
  4. H. influenzae
  5. S. aureus
24
Q

causative agents of CAP in adults

A

more often bacterial than viral

STREP PNEUMONIAE = most common cause

25
Q

how do you diagnose CAP

A

Hx, physical exam
**CREPITATIONS/RALES (crackles)

Diagnostic testing–> sputum (gram stain), bronchoscopy/lung biopsy/thoracentesis, CBC/procalcitonin/blood cultures/serology/urine antigen, diagnostic imaging

CXR–> location and nature of infiltrates, cavitation, volume loss, pleural fluid, mediastinal adenopathy

26
Q

Tx for S. pneumoniae (in CAP)

A

empiric = AMOXICILLIN in high dose

note that a significant number of isolates are resistant to macrolides and doxycyline

27
Q

what agents cause hospital acquired pneumonia

A

Enterobacteriaceae–> E. coli, Klebsiella, Serratia

S. aureus

28
Q

what agents cause ventilator acquired pneumonia

A

Pseudomonas aeruginosa

+E. coli, Klebsiella, Serratia and S. aureus

29
Q

empiric Tx for HAP

A

ceftriaxone

30
Q

empiric Tx for VAP

A

pipercillin/tazobactam

31
Q

what is a lung abcess

A

microbiological infection causing necrosis of lung parenchyma

producing 1 or more cavities

32
Q

what agents tend to cause lung abcesses

A

mouth flora/oral anaerobes

Eikenella corrodens

Strep spp

33
Q

Tx for lung abcess

A

clindamycin

or penicillin with metronidazole

consider TB/fungal/malignancy if cavitiations without air fluid level

34
Q

what is pleural effusion

A

fluid in the pleural space

35
Q

what is empyema

A

infection of fluid in the pleural space

36
Q

risk factors for pleural effusion/empyema

A

HIV
neoplasm
pulmonary disease
alcoholism

37
Q

what agents cause empyema most commonly

A
  1. if pre-antibiotic:
    S. PNEUMONIAE (60-70%)
    S. pyogenes
    S. aureus
  2. if post-antibiotic:
    anaerobes (bacteroides, fusobacterium, peptostreptococcus)
    Strep. anginosus
    enterobacteriaeceae
38
Q

how is empyema diagnosed

A

drain pleural space and obtain sample to gram stain and determine C & S to guide therapy

ultrasound

xray

39
Q

clinical presentation of empyema

A

cough
chest pain
SOB
fever

40
Q

Tx of empyema

A

empiric = CEFTRIAXONE

add metronidazole if chronic

41
Q

what is the global prevalence of TB

42
Q

how is TB passed

A

it is carried in AIRBORNE particles and then inhaled

inhalation can result in 3 outcomes

  1. immediate clearance
  2. primary active disease
  3. latent infection with possibility of active disease later in life
43
Q

where in Canada is TB prevalence higher

A
  1. in medically underserved communities
  2. urban poor, homeless
  3. prison inmates
  4. alcoholics and IV drug users
  5. elderly
  6. foreign-born
  7. contacts of active cases
44
Q

what causes TB

A

mycobacterium

acid fast bacilli
strictly aerobic
slow growing (2-6 weeks)

pathogenic: M. tuberculosis, M. bovis, M. ulcerans

potentially pathogenic: M. kansasii, M. avium compex

45
Q

TB pathophysiology

A

M. tuberculosis organisms are inhaled and then engulfed by macrophages, which forms a cavitation

host immune response typically limits spread but bacilli can remain dormant for years

46
Q

clinical presentation of TB

A 
PULM INFECTION with COUGH, hemoptysis, dyspnea
weight loss
NIGHT SWEATS
low grade fever
chest pain
47
Q

how do you diagnose TB

A

most commonly through MICROSCOPY–ZIEHL-NEELSON stain for acid fast bacilli

culture or molecular probe is necessary to distinguish from nontuberculous mycobacteria (NTM)

culture necessary to test drug susceptibility

TB skin test–MANTOUX

48
Q

does a - TB skin test rule out active infection

49
Q

how does the TB skin test work

A

interferon gamma release assays (IGRA)

measures cell mediated immune response

T cells in patients blood bind to TB antigen and release IFN-gamma

increased IFN-gamma expected in those who have been exposed

50
Q

Tx for TB

A 
isoniazid
rifampin
ethambutol
streptomycin
pyrazinamide

duration of 6 months to two years

IDMM (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions