Sudden and unexpected deaths in infants: histology and virology.

The histological appearance of lungs of children whose death had been sudden and unexpected has been studied in relation with the viruses found at necropsy. Fifty-one children were investigated and in 33 the lungs had the histological appearance widely accepted as characteristic of the condition previously termed "cot death." Sixteen had the histological appearance of lymphocytic bronchiolitis, and it was from this group only that viruses were isolated. The viruses isolated were those associated with respiratory infections. Two patients showed the histological appearance of bacterial bronchopneumonia. Viruses are probably responsible for a substantial proportion of unexpected sudden deaths in infancy.