STUDIES OF THE SUDDEN INFANT DEATH SYNDROME IN KING COUNTY, WASHINGTON. III. EPIDEMIOLOGY

Abstract

Excluding the first week of life, sudden infant death syndrome (SIDS) is the greatest single cause of death during the first year of life and second only to accidents as the greatest killer of children under age 15. All cases of SIDS occurring in King County, Washington (170) during a 44-month period were studied. Birth certificate data from all children born in the county during the same period were utilized for comparison. Findings include a characteristic age distribution (peak at 2 to 3 months), preponderance in males, low birth weight babies, and in lower socioeconomic class families. "Seasonality" and apparent "time clustering" were present in the infants. All SIDS infants died during sleep in a silent fashion. Forty-four percent of the babies had an upper respiratory infection in the 2-week period prior to death. The epidemiologic findings point to viral infection as playing a major contributory role in SIDS.