Space Statistic Methods's Application In The Space-Time Clustering Detection Of Gonorrhea Epidemic In A City

Objective:To explore the space-time distribution regularities of gonorrhea epidemic situation during 2005～2009 in Shenzhen in order to study the value and significance of applying space statistical methods to gonorrhea epidemic situation. The aim was to find out the features of spatial-temporal clustering in Shenzhen, which could provide new idea and theoretical basis concerning gonorrhea control and prevention for health administrations.Methods:All the gonorrhea cases and the geographic coordinates in all 55 streets of Shenzhen during 2005～2009,were collected from the"China information system for disease control and prevention" system. A database with spatial attributes of the disease was established. Then the spatial and temporal distribution was analyzed by using space autocorrelation and scan statistics methods with the help of SaTScan and ArcGIS etc.Results:1.The results of global autocorrelation analysis showed: there was a significant spatial autocorrelation in the average incidence of gonorrhea reported between 2005 and 2009 in Shenzhen(Global Moran's I=0.02, Z=2.07,Global G=0.02,Z=4.02);The three-dimensional trend analysis showed:gonorrhea incidence presented a downtrend from west to east; and a trend of "high ends,low middle" from north to south; the Local autocorrelation analysis showed:Nantou street(Local Moran's I=0.41,Z=3.72) Shekou street (Local Moran's I=0.31,Z=2.47) and Xin'an street (Local Moran's I=0.21,Z=2.25)in the southwest of Shenzhen were the high-incidence cluster areas.Dapeng street(Local Moran's I=0.18,Z=2.08) and Kengzi street(Local Moran's I=0.16, Z=1.97)in the east of Shenzhen were the low-incidence cluster areas. 2.The purely spatial analyses showed:the high-incidence cluster areas of gonorrhea in 2005 were Songgang Street and Gongming Street, Nanshan Street and Nantou Street in 2006, Songgang Street and Gongming Street in 2007, Nantou Street in 2008,Nanshan Street and Nantou Street in 2009.The purely temporal analyses showed:the temporal cluster period was between November and December in 2005 and 2007, between October and November in 2006, between July and September in 2008, between May and July in 2009.The space-time analyses showed the aggregation were from March to July 2005 in Yuehai street, Nantou street, Nanshan street and Shahe street(LLR=84.06,RR=2.40);between April and June 2006 in Nanshan street, Nantou street, Yuehai street, Zhaoshang street and Shekou street(LLR=869.75,RR=8.87);between April and June 2007 in Nantou street, Nanshan street, Yuehai street and Xin'an street(LLR=645.47,RR=6.45);between April and June 2008 in Nantou street, Nanshan street, Yuehai street, Zhaoshang street and Shekou street (LLR=959.05,RR=7.65);between April and June 2009 in Xin'an street, Xili street, Nantou street,Xixiang street, Yuehai street and Nanshan street (LLR=1157.85,RR=6.78)Conclusion:The phenomenon of spatial and temporal clustering existed at the gonorrhea incidence and its cases in Shenzhen. During 2005-2009,the high-incidence cluster area was located in the southwest. And the low-incidence cluster area located in the northeast. The spatial cluster area of gonorrhea cases were in southeast and northeast of Shenzhen; the temporal cluster was being forwarded from the fourth quarter between 2004 and 2009;The space-time cluster were in every second quarter in the southwest of Shenzhen. Space autocorrelation and scan statistics methods can applied to study the space-time cluster characteristics of gonorrhea epidemic situation in Shenzhen...