Temporal and spatial clustering of viral hepatitis C cases and its changing trend in the mainland of China

Objective To understand the population distribution, temporal and spatial clustering, of viral hepatitis C cases and its changing trend in the mainland of China and provide evidence for the prevention and control of hepatitis C. Methods The incidence data of hepatitis C were collected from national diseases reporting information system of China CDC between 2008 and 2013. Spatial scanning unit was 2886 districts/counties in the mainland of China; temporal scanning unit was month, and the time span was from January 2008 to December 2013. Kulldorff scan statistics was applied, and analyses were conducted by using software SaTScanTM 9.1. Map making and result visualizing were carried out with software ArcGIS 10.1. Results The scan analysis indicated that the incidence of hepatitis C increased over time and had its seasonality. The incidence peak was in March of a year. The surveillance for hepatitis C from 2008 to 2013 indicated that most cases (>60%) occurred in age group 30-59 years, more cases were in males than in females (1.16-1.35) and the cases in farmers accounted for about 60%. The results from SaTScan indicated the existence of the temporal and spatial clustering of hepatitis C cases. The temporal clustering of hepatitis C cases was mainly from June to October during a year; the spatial clustering occurred in central, northwestern, northeastern and southern regions. With respect to the changes of temporal and spatial clustering, class 1 clustering area was usually in central China, it expended to the western China only in 2011. Class 2 clustering area was in northwestern China except 2012. Class 3 clustering area was in northeastern China, but it became smaller in 2013. Class 4 and 5 clustering areas were in southern China and became larger over time. Conclusion Temporal and spatial clustering of hepatitis C cases in China was reported in this paper, but the clustering areas changed with year. Findings from this paper can be used in evidence-based decision making for the prevention and control of hepatitis C and in preparation and allocation of related health resources.