Pathology: Infectious Lung Disease

What is the most common cause of community acquired pneumonia?
streptococcus pneumoniae

Haemophilus influenzae usually infects who? How are they protected?
– neonates and children with comorbidities such as prematurity, malignancy and immunodeficiency
– capsular polysaccharide b is incorporated in the widely used vaccine against H. influenzae

Staphylococcus aureus usually infects who?
IV drug users – pneumonia in association with endocarditis
– also important in hospital-acquired pneumonia