Histopathology of childhood pneumonia in developing countries.

Acute lower respiratory infection in children is a major cause of morbidity and mortality in developing countries. Viral and bacterial agents incite characteristic host responses at the level of the bronchi, bronchioles, alveolar walls, and air spaces that correlate with the clinical course. A systematic review of histopathologic features will enhance the understanding of the pathogenetic mechanisms and cofactors that influence the disease process, particularly how tissue injury may be influenced by nutritional status and access to antibiotics. Research priorities include immunologic assessment, micronutrient assays, and standardized autopsies in developing countries. DNA probes for organisms and immunocytochemical identification of cell markers in tissue promise a new era in microscopic visualization of pathogen-host interactions. International collaborative research between ministries of public health and medical universities must be encouraged as a means of providing technical assistance and of advancing new knowledge. Systematic standardized autopsy studies from multiple geographic areas may help define pathologic mechanisms, monitor the natural history of disease, and evaluate interventions in diverse populations.