Investigation of unexplained sudden death clustered in Fengqing, Yunnan, 2003-2012

Objective To understand the epidemiological and clinical characteristics of 15 cases of unexplained sudden death occurred in a village in Fengqing county of Yunnan province from 2003 to 2012, and provide evidence for the prevention and control of such events. Methods The investigation was conducted according to Surveillance, prevention and control protocol of unexplained sudden deaths of Yunnan province, in which the clinical and epidemiological data of the death cases were collected, and systematic autopsy, pathological study and poisonous substance detection were performed. Results The 15 unexplained sudden cases occurred in 8 families in a village in Fengqing county in summer from 2003-2012, all the death cases were young adults. The deaths occurred rapidly after sudden onset of illness without specific clinical manifestation, the epidemiological survey didn't find possible exposures to wild mushrooms, poisonous substances. No consistent pathological changes were found in autopsies of 3 death cases in 2 families, 2 death cases were negative for common poisonous substances and 1 death case was negative for toxin of Trogia venenata. Conclusion The 15 unexplained sudden deaths occurred in Fengqing, Yunnan had no relationship with the intake of Trogia venenata, but might be associated with the common oral exposure to the localized risk factor. It is necessary to conduct the systematic surveillance for similar events in this village and nearby areas, and conduct further investigation and research.