Lecture - Microbiology Of Pneumonia

Question 1

When is testing for microbiology in pneumonia beneficial?

Answer 1

• more severe cases
• if unusual pathogen is more likely
• sensitivity/specificity
• if results would influence therapy

Question 2

Less invasive non sterile site for microbiologic diagnosis

Answer 2

• sputum
• urine
• nasopharyngeal aspirate
• nasopharyngeal swab
• nasal washings

Question 3

More invasive normally sterile site for microbiologic diagnosis

Answer 3

• venepuncture
• bronchoscopy
• lung biopsy
• seldom done: transtracheal aspirate, lung puncture

Question 4

Test and causative organism for microbiologic diagnosis: bacteria

Answer 4

• strep pneumonia
• others (H. Influenzae, staph aureus)
• Culture: sputum, blood, pleural fluid

Question 5

Test and causative organisms for microbiologic diagnosis: atypical agents

Answer 5

• Mycoplasma
• legionella
• chlamydia
• Serology, urine antigen detection, PCR

Question 6

Test and causative organism for microbiologic diagnosis: viruses

Answer 6

• influenza, RSV

- immunofluorescence, PCR

Question 7

Test and causative organism for microbiologic diagnosis: uncommon

Answer 7

• TB, immune compromised patients

- special procedures and tests

Question 8

Examination of sputum

Answer 8

• prompt processing
• screen lower airways
• do before antibiotics

Question 9

Problems in sputum examination

Answer 9

• not available in children under 7-8
• 10-30% adults non productive cough at time of presentation
• 15-30% adults pre treated
• antibiotics - eradicate SP, HI, promote staph, GNB

Question 10

Specomem collection: Blood

• invasive
• age
• use

Answer 10

• minimally
• all
• culture, serology

Question 11

Specimen collection: pleural fluid

• invasive
• age
• use

Answer 11

• a bit more invasive
• all
• gram stain, biochemistry, culture

Question 12

Lung aspirate:

• invasive?
• age
• use

Answer 12

• very
• all
• full spectrum

Question 13

Lung biopsy

• invasive
• age
• use

Answer 13

• most invasive
• all
• full spectrum and histology

Question 14

Respiratory specimen collection - uncontaminated sites

Answer 14

• transtracheal aspirate
• bronchoscopy
• urine antigen
• nasopharyngeal swab
• nasopharyngeal aspirate
• Elisa
• PCR

Question 15

Nasopharyngeal aspirate

Answer 15

• mostly for viruses and pertussis
• mostly in children
• multiplex test

Question 16

Bronchoalveolar lavage

Answer 16

• PCR especially used for TB but also applicable to fungi and other pathogens

Question 17

Interpretation of PCR

Answer 17

• multoples tests more common
• false positives can occur
• multiple infections can be identified

Question 18

Incidence of pneumnia by age

Answer 18

• most common in infancy and old age

- disparity bw indifgenous and non indigenous community. That increases with age

Question 19

Age specific causes of pneumonia in otherwise healthy children

• less than 2 years
• over two years
• all ages

Answer 19

• less than 2 years: resp virus most important, mycoplasma uncommon
• over 2 years: viruses decrease, mycoplasma increases
• all ages: pneumococcus remains important

Question 20

Impact of pneumococcal vaccine on pneumonia in Australia

Answer 20

• pneumococcal vaccine reduces rate of pneumonia only in children
• but the vaccine reduces deaths in both age and children

Question 21

Changes in adult pneumonia between 1980 and 2008

Answer 21

• less pneumococcus
• blood culture down from 13% to 6% positive
• resistant staph emerging
• gram negatives associated with long term care and co morbidities
• mycoplasma associated with

Question 22

Major pathogens in patients

Answer 22

• S pneumonia
• M pneumonia
• Resp viruses
• C pneumonia
• H influenza

Question 23

Major pathogens in patients >60 yo or coexisting disease

Answer 23

• S pneumonia
• resp viruses
• H influenza
• Aerobic GNB
• S aureaus