This paper presents an empirical analysis of the epidemiological data concerning the 18445 HFMD-infected cases in Beijing in 2008.The main findings are as follows.(i) Seasonal variations in incidence were observed,wit...This paper presents an empirical analysis of the epidemiological data concerning the 18445 HFMD-infected cases in Beijing in 2008.The main findings are as follows.(i) Seasonal variations in incidence were observed,with a peak observed during the summer season,especially in May.Male patients outnumber female patients by 1.57:1.(ii) Most cases occurred in children 4 years old or younger.Outperforming Weibull distribution and Gamma distribution as to model fitness when analyzing patient ages,log-normal distribution indicates that the estimated mean age is 3.4 years.(iii) The age distribution seems to indicate cyclic peaks with roughly one-year intervals.(iv) Correlation analyses (ρ=0.9864) show that time of birth in different months has an impact on the chance of being infected by HFMD.Birth month seems to present a high risk factor on infants and young children.(v) The morbidity rate is 132.7/100000 during the HFMD epidemic in Beijing in 2008.The morbidity map shows that the risks of HFMD infection in areas close to the city center and suburbans are much lower than those in the urban-rural transition zones.Spatial risks inferred from the morbidity map demonstrate a clear circular pattern.(vi) The prevention and control measures taken by the public health departments seem to be effective during the summer season,resulting in the early ending of the epidemic (one month earlier than the natural season) and reduced outbreak size.展开更多
Studying spatio-temporal evolution of epidemics can uncover important aspects of interaction among people, infectious diseases, and the environment, providing useful insights and modeling support to facilitate public ...Studying spatio-temporal evolution of epidemics can uncover important aspects of interaction among people, infectious diseases, and the environment, providing useful insights and modeling support to facilitate public health response and possibly prevention measures. This paper presents an empirical spatio-temporal analysis of epidemiological data concerning 2321 SARS-infected patients in Beijing in 2003. We mapped the SARS morbidity data with the spatial data resolution at the level of street and township. Two smoothing methods, Bayesian adjustment and spatial smoothing, were applied to identify the spatial risks and spatial transmission trends. Furthermore, we explored various spatial patterns and spatio-temporal evolution of Beijing 2003 SARS epidemic using spatial statistics such as Moran’s I and LISA. Part of this study is targeted at evaluating the effectiveness of public health control measures implemented during the SARS epidemic. The main findings are as follows. (1) The diffusion speed of SARS in the northwest-southeast direction is weaker than that in northeast-southwest direction. (2) SARS’s spread risk is positively spatially associated and the strength of this spatial association has experienced changes from weak to strong and then back to weak during the lifetime of the Beijing SARS epidemic. (3) Two spatial clusters of disease cases are identified: one in the city center and the other in the eastern suburban area. These two clusters followed different evolutionary paths but interacted with each other as well. (4) Although the government missed the opportunity to contain the early outbreak of SARS in March 2003, the response strategies implemented after the mid of April were effective. These response measures not only controlled the growth of the disease cases, but also mitigated the spatial diffusion.展开更多
基金supported by US NSF (Grant Nos. IIS-0839990 and IIS-0428241)US DHS (Grant No. 2008-ST-061-BS0002)+3 种基金the Ministry of Health of the People’s Republic of China (Grant No. 2009ZX10004-315100)the Chinese Academy of Sciences (Grant Nos. 2F07C01 and 2F08N03)the National Natural Science Fundation of China (Grant Nos. 40901219 and 60621001)China Postdoctoral Science Fund (Grant No. 20080440559)
文摘This paper presents an empirical analysis of the epidemiological data concerning the 18445 HFMD-infected cases in Beijing in 2008.The main findings are as follows.(i) Seasonal variations in incidence were observed,with a peak observed during the summer season,especially in May.Male patients outnumber female patients by 1.57:1.(ii) Most cases occurred in children 4 years old or younger.Outperforming Weibull distribution and Gamma distribution as to model fitness when analyzing patient ages,log-normal distribution indicates that the estimated mean age is 3.4 years.(iii) The age distribution seems to indicate cyclic peaks with roughly one-year intervals.(iv) Correlation analyses (ρ=0.9864) show that time of birth in different months has an impact on the chance of being infected by HFMD.Birth month seems to present a high risk factor on infants and young children.(v) The morbidity rate is 132.7/100000 during the HFMD epidemic in Beijing in 2008.The morbidity map shows that the risks of HFMD infection in areas close to the city center and suburbans are much lower than those in the urban-rural transition zones.Spatial risks inferred from the morbidity map demonstrate a clear circular pattern.(vi) The prevention and control measures taken by the public health departments seem to be effective during the summer season,resulting in the early ending of the epidemic (one month earlier than the natural season) and reduced outbreak size.
基金supported by National Science Foundation of the United State (Grant Nos. IIS-0839990, IIS-0428241)Department of Homeland Security of the United State (Grant No. 2008-ST-061-BS0002)+4 种基金Important National Science & Technology Specific Projects (Grant Nos. 2009ZX10004- 315, 2008ZX10005-013)the Chinese Academy of Sciences (Grants Nos. 2F07C01, 2F08N03)China Postdoctoral Science Fund (Grant No. 20080440559)National High Technology Research and Development Pro-gram of China (Grant No. 2006AA010106)National Natural Science Foundation of China (Grant Nos. 60621001, 40901219, 90924302)
文摘Studying spatio-temporal evolution of epidemics can uncover important aspects of interaction among people, infectious diseases, and the environment, providing useful insights and modeling support to facilitate public health response and possibly prevention measures. This paper presents an empirical spatio-temporal analysis of epidemiological data concerning 2321 SARS-infected patients in Beijing in 2003. We mapped the SARS morbidity data with the spatial data resolution at the level of street and township. Two smoothing methods, Bayesian adjustment and spatial smoothing, were applied to identify the spatial risks and spatial transmission trends. Furthermore, we explored various spatial patterns and spatio-temporal evolution of Beijing 2003 SARS epidemic using spatial statistics such as Moran’s I and LISA. Part of this study is targeted at evaluating the effectiveness of public health control measures implemented during the SARS epidemic. The main findings are as follows. (1) The diffusion speed of SARS in the northwest-southeast direction is weaker than that in northeast-southwest direction. (2) SARS’s spread risk is positively spatially associated and the strength of this spatial association has experienced changes from weak to strong and then back to weak during the lifetime of the Beijing SARS epidemic. (3) Two spatial clusters of disease cases are identified: one in the city center and the other in the eastern suburban area. These two clusters followed different evolutionary paths but interacted with each other as well. (4) Although the government missed the opportunity to contain the early outbreak of SARS in March 2003, the response strategies implemented after the mid of April were effective. These response measures not only controlled the growth of the disease cases, but also mitigated the spatial diffusion.
