The Early Warning Of HFMD Based On Prospective Space-time Rearrangement Scan Statistic And Empirical Research

Objective:Outbreaks of infectious diseases are one of the major challenges for human along with other public health problems. Setting up public health emergency response systems, including early warning system of infectious disease, is the effective measure to control outbreaks of infectious disease. This study intends to implement prospective space-time aggregation characteristics analysis using Sa TScan software in order to discusses its role in aggregation detection and early warning of infectious diseases.Methods:Data of HFMD in Nanchang City during 2008 to 2012 was derived from the National Notifiable Infectious Disease Reporting System(NNIDRS). We used descriptive methods to describe the epidemiological characteristics of HFMD. Space-time scan statistic, based on the Prospective Space-Time Permutation model, was adopted to determine the presence of space-time interaction clusters of HFMD in Nanchang. Based on case data, geographic coordinates data, this analysis was implemented at county level to obtain warning signs and signs last days of clusters.Results:â‘ There were 29062 HFMD cases reported in Nanchang during 2008 to 2012. The annual average incidence rate was 118.56 per 100000 inhabitants. There were two peaks in HFMD occurrence. Children aged 0-5 years accounted for 92.91% of cases. Scattered children(children not in nursery or kindergarten) accounted for 73.72%. There was a male predominance, with a male-to-female ratio of 1.82:1. The average annual incidence of HFMD was more than 118.86/100000(the average annual incidence of Nanchang), in Qing Shanhu, Qing Yunpu, Xinjian. The average annual incidence of HFMD was more than 118.86/100000(the average annual incidence of Nanchang), in Anyi, Jinxian, Wanli.â‘¡The following were results of space-time interaction clusters of HFMD, based on the Prospective Space-Time Permutation model. Three clusters in the city respectively issued a warning on May 3, July 12, November 5, 2008, covering four counties. The first clusters included Donmghu, Xihu, Qing Yunpu, and Qing Shahu was the secondary cluster. Three clusters in the city respectively issued a warning on April 2, August 3, December 11, 2009, covering five counties. The first clusters included Xihu, Qing Yunpu, Xinjian. And Jinxian was the secondary cluster. Two clusters in the city respectively issued a warning on April 12, December 25, 2010, covering four counties. The first clusters included Donghu, Xihu, Qing Yunpu. Two clusters in the city respectively issued a warning on May 6, November 27, 2011, covering three counties. The first clusters included Nancahng, Qing Shanhu. And Jinxian was the secondary cluster. Four clusters in the city respectively issued a warning on March 28, April 6, April 9, August 20, 2012, covering four counties. The first clusters included Donghu, Qing Yunpu, Qing Shanhu. And Jinxian was the secondary cluster.â‘¢The early warning information of HFMD during 2008 to 2012 based on the Prospective Space-Time Permutation model, was consistent with the real-time monitoring information.Conclusions:Space-time scan statistics could make full use of time and space data for diseases monitoring to detect space-time clusters of infectious diseases. The early warning system established by Prospective space-time rearrangement scanning model could effectively make the early warning.