0071643192.pdf

THORACIC AND RESPIRATORY

DISORDERS

TABLE 10.8. Common Community-Acquired Pneumonia Pathogens

ORGANISM CLASSICPATIENT CLASSICCLINICALPRESENTATION

Typical aerobic organisms

S. pneumoniae Extremes of age and chronically ill Peak incidence in winter and early spring

immunocompromise (eg, HIV, Abrupt onset of single-shaking chill

splenectomy) Rusty-colored sputum

Sepsis or multisystem illness

Haemophilus influenzae Elderly Peak incidence in winter and early spring

Underlying lung disease (eg, COPD) Less abrupt in onset

Klebsiellasp. Alcoholic or chronically debilitated Abrupt onset rigors (multiple) and chills

patient Currant-jelly sputum

Right upper lobe infiltrate with bulging fissure

Staphylococcus aureus Elderly Insidious onset

(MSSA, MRSA) Hematogenous (IVDA) Low-grade fever

Postinfluenza pneumonia Necrotizing pneumonia (empyema, lung abscess)

Anaerobes

Peptostretococcus Aspiration Subacute or chronic presentations

Fusobacterium Poor dental hygiene Necrotizing pneumonia (empyema or lung

Bacteroides abscess)

Prevotella

Atypical organisms

Mycoplasmasp. Younger, healthy patient Year round

Subacute illness

May see extrapulmonary manifestions (eg, rash,

bullous myringitis, pericarditis)

Legionella sp. Immunosuppressed Year round

Smokers Mild to multisystem illness

Outbreaks associated with aerosolized GI symptoms

water (eg, showers) Hyponatremia

Pleuritic CP and pleural effusions common

Chlamydophila(formerly Younger, healthy patient Mild, subacute illness

Chlamydia) pneumoniae

Viral pathogens

RSV Infants and young children Autumn and winter months

Parainfluenza

Influenza