Characteristics of spatiotemporal distribution on severe fever with thrombocytopenia syndrome in Henan province

Abstract

Objective: To explore the characteristics regarding temporal, spatial and spatiotemporal distribution on severe fever with thrombocytopenia syndrome (SFTS) in Henan province. Methods: Surveillance data related to SFTS was collected in Henan province, from year 2014 to 2016. Descriptive method was used to analyze the distribution of SFTS. 1.7.0 software related to the Public health geographic information system (PHGIS), was applied to draw the spatial distribution map of SFTS. Chi-square test was used to compare the different incidence rates. Results: A total of 2 781 SFTS cases, including 34 deaths, were reported in Henan province from 2014 to 2016, with an average annual fatality rate as 1.22%. There were statistically significant differences for the incidence rates of SFTS between different years (P<0.01). Cases were mainly concentrated from April to October, which accounted for 96.66% of the total number, with the incidence peak seen in May. Incidence rates of SFTS in spring, summer, autumn were higher than that in winter. The cases were scattering around in 26 counties of 8 cities. Xinyang city reported 2 714 cases, accounting for 97.59% of the total number of cases in the province. The average annual incidence rate in Xinyang city was 17.22 per 100 000, much higher than that for the whole Henan province (0.98 per 100 000), with statistically significant difference (P<0.01). Six counties reported having death cases, that accounted for 23.08% of the total number of counties, reported to have death cases. Two kinds of incidence patterns of SFTS were noticed in Henan province, with aggregation in some local regions or sporadic in individual counties. The number of counties with reporting cases increased annually. The epidemic area was expanding and gradually spreading from south to north areas of the province. Conclusions: SFTS was characterized with both temporal and spatial clusters in Henan province. Effective prevention and control measures should be made in accordance with the spatiotemporal distribution and the trend on SFTS.