It has been estimated that each year in the United States several thousand young infants in apparently good health die suddenly and unexpectedly. These deaths have been attributed by different observers to accidental mechanical suffocation, enlargement of the thymus, adrenal hormone imbalance, and various forms of infection such as interstitial pneumonitis or focal bronchopneumonia.1 Only a diagnosis of infection, particularly that of the upper and lower respiratory tracts, appears to have any validity in the vast majority of these cases. However, careful investigation into the circumstances surrounding these cases and detailed gross and histological postmortem examination have as yet failed to adequately explain the suddenness of these deaths as well as the absence of any significant symptoms. The usual history is that a healthy infant between 1½ and 3½ months of age has been put to bed in a crib or carriage and several hours later is found dead.
Spain DM, Bradess VA, Greenblatt IJ. POSSIBLE FACTOR IN SUDDEN AND UNEXPECTED DEATH DURING INFANCY. JAMA. 1954;156(3):246-247. doi:10.1001/jama.1954.02950030038011b