OBJECTIVETo discuss the clustering of Yunnan unexplained sudden death (YUSD) in household and village.

METHODSFifty-two cases were found by YUSD surveillance system in 2005. Poisson distribution and beta-binomial distribution (BBD) were employed in studying the household distribution of the disease. Poisson distribution and negative binomial distribution (NBD) were employed in studying the village distribution of the disease.

RESULTSBBD were fitted household distribution of YUSD very well (chi(2) = 0.25, P = 0.62), while Poisson distribution was consistent with it (chi(2) = 46.01, P < 0.001). And NBD were fitted village distribution of YUSD very well (chi(2) = 0.05, P = 0.58), however the consistency in Poisson distribution was not observed (chi(2) = 110.57, P < 0.001).

CONCLUSIONHousehold and village clustering of YUSD does exist.

Bias ; Binomial Distribution ; Cause of Death ; China ; epidemiology ; Death, Sudden ; epidemiology ; Family ; Humans

Objective: To analyze the trend change of the drowning mortality among children and adolescents in Chongqing, 2012-2021, and to provide suggestion for drowning prevention and control. Methods: Drowning death cases (ICD-10:W65.0-W74.9) among children and adolescents in Chongqing from 2012 to 2021 were derived from Chongqing death registration system. The difference of the drowning mortality between male and female, urban and rural area were compared by Chi square test. The trend change of the drowning mortality between 2012 and 2021 was analyzed by annual percent change( APC ). Results: The mortality and ASMR of drowning among children and adolescents decreased from 9.57/10 5, 9.42/10 5 in 2012 to 2.80/10 5, 2.83/10 5 in 2021 significantly( t=10.93, 10.52, P <0.01). And its APC were -13.15% and 13.06% respectively. The drowning mortality in male was higher than that in female( P <0.05). The drowning mortality in rural area was higher than that in urban area( P <0.05). The mortality of drowning among children aged between 0 and 4 years old, 5 and 9 years old, 10 and 14 years old decreased by 15.30 %,17.80% and 11.40%( APC =-15.30%, -17.80%, -11.40%, t=11.11, 9.22, 5.62, P <0.05). The proportion of drowning in natural water field among children and adolescents accounted for about 80%. Conclusion The mortality of drowning among children and adolescents in Chongqing decreases rapidly. Vulnerable population of drowning includes boys, rural children and adolescents, and children age of 0-14 years old. Comprehensive prevention for drowning should be carried out continuously.