Objective: The purpose of this study was to analyze the distribution, temporal and spatial clustering characteristics and changes of severe hand, foot, and mouth disease (HFMD) in order to provide evidence-based decision making strategy for control and prevention of severe HFMD cases.
Methods: Severe HFMD cares were extracted from the National Diseases Reporting System of Chinese Center for Disease Control and Prevention (CDC) between 2008 and 2013. Definition and clinical diagnostic criteria of severe HFMD cases were set up by China CDC in the Hand, Foot, and Mouth Disease Control and Prevention Guideline, version 2010. Spatial scan unit was under the district/county of 2 900 in mainland China with temporal scan unit as month and time span as from May 2008 to August 2013. Kulldorff scan statistics was applied and analyses were conducted by SaTScan(TM) 9.1. Mapping and visualizing the results were carried out with ArcGIS 10.0.
Results: Data related to the monitoring program on severe HFMD from 2008 to 2013 demonstrated that above 96% of the severe HFMD cases occurred under 5 years old, mostly males, with the ratio of males to females as 1.73-1.80 and over 84% of the children were 'scattered'. Results from SaTScan illustrated that the temporal and spatial clustering existed among severe HFMD cases. The temporal dimension of severe HFMD was from May to July each year. Spatial dimension was located in south-east coastal area and middle-east area. With respect to the changes of temporal and spatial clustering phenomena, Class 1 clustering area was located in south-east coastal region in 2008 and in middle-east region in 2009 and was shifting to the west from middle-east region in 2010. It moved to the north-east from middle-east region in 2011 and to the north-west and south-west from middle-east region in 2012. Class 1 clustering area covered districts/countries from 18 provinces in 2012. The same pattern of Class 1 clustering area was observed as in the previous year-2013, but with less districts/countries from the 13 provinces.
Conclusion: Temporal and spatial clustering areas of severe HFMD were presented in this report, and the yearly changing pattern of the clustering areas was noted. Findings from this study provided evidence-based data to the decision-making authorities so as to prevent deaths from severe HFMD cases under reasonable prevention and control strategies.