Community Acquired Pneumonia

Pneumonia in Different Patient Groups

Patient group

Bug

Mortality/ therapy

Age < 60 without coexisting illness

Strep pneumonia, Mycoplasma pneumoniae, respiratory viruses, Chlamydia pneumoniae, H. influenzae

Low (1-5%), outpatient management

Age > 60 with coexisting illness

S. pneumoniae, respiratory viruses, H. influenzae, Staph aureus

Low, 20% require hospitilization

Hospitalized patients with CAP

S. pneumoniae, H. flu, anaerobes, aerobic gram – bacilli, Legionella, S. aureus, respiratory viruses

5-25%, most deaths occur within first 7 days

Severe CAP (respiratory failure)

S. pneumoniae, Legionella, aerobic gram – bacilli, respiratory viruses

50%

Presentation

Presentation

Bug

Atypical pneumoniae

Legionella, Chylamydia, mycoplasma (20-25%), Staph aureus (infrequent cause)

Gram – pneumoniae

very very unusual

Iatrogenic pneumoniae:

Up to 50% of time don’t know etiologic agent. Hence, imperic treatment of CAP. Therefore, treatment includes treatment for pneumococcus and atypical.

Alcoholism

anaerobic, gram -, pneumococcus, Klebsiella

COPD

pneumococcus, h flu, moraxella catarallha

Post –Influenza

Staph aureus, pneumococcus

Nursing home

gram negative, s.aureus

HIV:

PCP

CNS disease

mycoplasma pneumoniae – bullous myringitis

Skin rash: erythema multiforme, nodosum

mycoplasma, fungi

Causative Agents of Pneumonia