Sudden unexplained death syndrome (SUDS) occurs when a relatively young healthy person, usually male and Asian, dies unexpectedly while sleeping. The victim has no known antecedent illnesses, and there are no factors that might precipitate cardiac arrest. At autopsy, no cause of death can be identified in the heart, lung, or brain. Postmortem toxicologic screening tests reveal no poisons. A sudden fatality during sleep in a previously healthy member of an ethnic group subject to SUDS, but whose death is not investigated with an autopsy, is defined as a presumptive case of SUDS.
Distribution and Incidence
SUDS has occurred in the 1980s among Southeast Asian refugees and immigrants in the United States, mainly among Laotians, Hmong, Kampucheans, and Filipinos. In Asia, SUDS has been described in the Japanese and Filipino medical literature and is also observed in refugee camps in Thailand. In 1983 the death rate ascribed to SUDS in the 25- to 44-year age group of Laotian and Hmong males in the United States, 87 per 100,000, was comparable to the sum of the four leading causes of natural death among other U.S. males in that age group. The incidence of SUDS has decreased since 1983, and there is evidence that the longer a refugee has been in the United States, the lower the risk.
Epidemiology
The first comprehensive report of SUDS in the United States was published by the Centers for Disease Control (CDC) on December 4, 1981; it described 38 victims, all Southeast Asian refugees. All but one of the cases were males: 25 Hmong, 8 Laotian, 4 Vietnamese, and 1 Kampuchean.