Role of respiratory viruses in childhood mortality.

Respiratory viruses have been identified at necropsy in the lungs of 13 out of 24 children who died with observed acute respiratory illness. The histological appearances of the lungs supported the association between virus and death in each of these 13 children and suggested an unidentified virus aetiology in a further five cases. Histological appearances compatible with bacterial infection were found in the lungs of only two of the 24 children. Similar virus and histological findings have been reported in about one-third of victims of the sudden infant death syndrome (cot deaths), indicating a rapid unobserved respiratory virus infection as the most likely mode of death in this group. Evidence that respiratory viruses may be involved in a larger proportion of sudden unexpected deaths, perhaps as antigens in a hypersensitivity reaction, is discussed. Respiratory viruses seem the major identifiable agents contributing to the maintenance of the postneonatal mortality rate since acute respiratory illness and the sudden infant death syndrome together account for about two-thirds of deaths at this age.