[Epidemiological characters of Yunnan sudden death syndrome and its research progress].

Yunnan sudden death syndrome (YSDS) is an abruptly fatal disease of unknown etiology, found mostly in central or northwestern mountain area (with altitude between 1,815 and 2,225 meters) of Yunnan province from June to September every year. It occurs mostly in young female adults, with high incidences in Lisu, Yi and Miao ethnics and high familial aggregation. The clinical manifestation of YSDS is changeful and the pathological characteristic is lack of specificity.