A TEMPORAL-SPATIAL CLUSTER OF SUDDEN-INFANT-DEATH-SYNDROME IN NAVARRE, SPAIN

An apparent temporal-spatial cluster of Sudden Infant Death Syndrome ( SIDS) was noted in the Autonomous Community of Navarre, Spain, when fo ur unrelated children aged between 1 and 6 months died unexpectedly wi thin a 7-day interval in January, 1990. The population under one year of age in Navarre was approximately 4,800. The scan test of temporal c lustering showed that the sudden infant deaths occurred closer to one another in time significantly more often than would be expected by cha nce. All four infants lived in a neighbourhood ofthe capital of Navarr e, which accounts for approximately half the region's population. The clustered cases coincided with an outbreak of influenza type A detecte d by the epidemiological surveillance system and seen by the increase in 1990 over the same period in the previous year in the number of pae diatric emergency-ward admissions during the 'epidemic' days. The resu lts confirm the presence of a temporal-spatial cluster of SIDS and fav our an environmental etiology where exposure to influenza A viruses is implicated.