Lung infection

Question 1

What does acute lung infection have an impact on

Answer 1

DALYs- kills a lot of children- having a massive impact on DALYs- disease with highest DALYs

Question 2

What do a lot of exacerbations of COPD result in

Answer 2

COPD

Question 3

How can we determine pathogenesis

Answer 3

Measuring humoral and cellular immunity established, with live viral challenge bring important in establishing pathogenesis

Innate immunity increasingly realized as being critical in mediating susceptibility, severity and duration of respiratory infection.

Question 4

How many people die each year due to Acute Respiratory infections

Answer 4

4.25 million

Question 5

Describe CDC Etiology of Pneumonia in the Community (EPIC)

Answer 5

CAP is the leading infectious cause of hospitalization and death among adults in the United States

Medical costs of CAP exceed $10 billion annually (2011).

Prospective, multicenter, population-based, active surveillance study of U.S. adults.

Studied radiographically-confirmed pneumonia causing hospitalization.

Question 6

What causes hospital acquired pneumonia

Answer 6

Staphylococcus aureus (28%)
Pseudomonas aeruginosa (21.8%)
Klebsiella species (9.8%)
E. Coli (6.9%)
Acinetobacter species (6.8%)
Enterobacter species (6.3%)

Question 7

What causes community acquired pneumonia

Answer 7

Strep. Pneumoniae
Myxoplasma pneumoniae- NO BACTERIAL CELL WALL PENICILLIN INEFFECTIVE
Staph. Aureus
Chlamydophila pneumoniae
Haemophilus influenzae- gram-negative rod causes exacerbations of COPD

Question 8

Compare typical and atypical pathogens in CAP

Answer 8

Common ‘typical’ pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis
Atypical pathogens: Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophilia
Atypical bacteria are not covered by penicillins and require additional agents (e.g. macrolides).

Question 9

List the demographic and lifestyle risk factors for pneumonia

Answer 9

Demographic and lifestyle factors
Age <2 years or >65 years
Cigarette smoking
Excess alcohol consumption

Question 10

List the social risk factors for pneumonia

Answer 10

Social factors
Contact with children aged <15 years
Poverty
Overcrowding

Question 11

List the medication risks for pneumonia

Answer 11

Medications
Inhaled corticosteroids
Immunosuppresants (e.g steroids)
Proton pump inhibitors

Question 12

List the medical history often linked to pneumonias

Answer 12

Medical history
COPD, Asthma
Heart disease
Liver disease
Diabetes mellitus
HIV, Malignancy, Hyposplenism
Complement or Ig deficiencies
Risk factors for aspiration
Previous pneumonia

Question 13

List the specific risk factors for certain pathogens

Answer 13

Geographical variations
Animal contact
Healthcare contacts

Question 14

Why do different pathogens lead to CAP of HAP

Answer 14

Cooperative actions between virus and bacteria

different spectrum for CAP reflecting the disease background of disease and patients in the hospital

Question 15

Which age group has the highest mortality from CAP

Answer 15

60s

despite the elderly being more susceptible

Question 16

Summarise the initial investigations for suspected CAP

Answer 16

Chest radiograph
Blood tests: Full blood count, Urea + Electrolytes, Liver function,
C reactive Protein
Arterial Blood gases
Microbiological investigations – sputum culture, blood cultures, urine antigen tests for Legionella pneumophila and Streptococcus pneumoniae

Question 17

Explain the choices of different investigations

Answer 17

Full blood count- raised whit cell count and neutrophils confirm infection, raised inflammatory markers confirm infection

CRP/erythrocyte sedimentation rate and urea and electorlytes- dehydration common in pneumonia (raised urea and creatinine)

Liver function tests- can become deranged in atypical pneumonia (legionella)

cultures- only if patient is pyrexial- identify organism

Question 18

Compare the presentation of pneumonia to acute bronchitis

Answer 18

Pneumonia
New resp. symptoms or signs
Pleuritic chest pain
Usually febrile
Often hypoxic, confused
New X ray changes
Severe enough to be admitted

Acute Bronchitis
Cough +++
Tracheal pain, not pleuritic
No new X ray changes

Question 19

Where can the pneumococcal antigen be detected

Answer 19

Urine and various bodily fluids