Etiology of acute severe lower respiratory tract infection in hospital-based patients.

Acute respiratory infections are common childhood illnesses. Most are mild and self-limiting. Five percent are lower respiratory tract diseases and are potentially serious. A prospective study was conducted to ascertain the etiology of community-acquired severe lower respiratory tract infections (LRTI) in hospital based patients. Mycoplasma was the most frequently identified agent (33%). This was followed by viruses (28%) and bacteria (15%). Twenty-four percent of children had no identified causative agent.