Organism

Laryngotracheobronchitis

Infant/child: RSV (50–75%) (bronchiolitis), adenovirus, parainfluenza virus (HPIV types 1, 2, 3) (80%) (croup), B. pertussis (GNCB) (whooping cough), other viruses, including rhinovirus, coronavirus, influenza, bocavirus, human metapneumovirus.

Adolescent/adult: Usually viruses, M. pneumoniae, C. pneumoniae, B. pertussis.

Chronic adult: S. pneumoniae (GPDC), H. influenzae (GNCB), M. catarrhalis (GNDC), Klebsiella (GNR), other Enterobacteriaceae (GNR), viruses (eg, influenza), aspergillus (allergic bronchopulmonary aspergillosis).

Chronic obstructive airway disease: Viral (25–50%), S. pneumoniae (GPC), H. influenzae (GNCB), S. aureus (GPC), Enterobacteriaceae (GNR), anaerobes (<10%).