Spatiotemporal Dynamics of Scrub Typhus in Jiangxi Province, China, from 2006 to 2018.

Shu Yang,Guichang Li,Chenying Yuan,Yuan Gao,Renlong Fu,Liang Lu,Weiqing Zheng,Baizhou Chen,Haiying Chen,Qiyong Liu,Xiaobo Liu

doi:10.3390/ijerph18094599

Abstract

Background: Scrub typhus (ST) has become a significant potential threat to public health in Jiangxi. Further investigation is essential for the control and management of the spatiotemporal patterns of the disease. Methods: Time-series analyses, spatial distribution analyses, spatial autocorrelation analysis, and space-time scan statistics were performed to detect spatiotemporal dynamics distribution of the incidence of ST. Results: From 2006 to 2018, a total of 5508 ST cases occurred in Jiangxi, covering 79 counties. The number of ST cases increased continuously from 2006 to 2018, and there was obvious seasonality during the variation process in each year, with a primary peak in autumn (September to October) and a smaller peak in summer (June to August). From 2007 to 2018, the spatial distribution of the ST epidemic was significant heterogeneity, and Nanfeng, Huichang, Xunwu, Anyuan, Longnan, and Xinfeng were hotspots. Seven spatiotemporal clusters were observed using Kulldorff’s space-time scan statistic, and the most likely cluster only included one county, Nanfeng county. The high-risk areas of the disease were in the mountainous, hilly region of Wuyi and the southern mountainous region of Jiangxi. Conclusions: Targeted interventions should be executed in high-risk regions for the precise prevention and control of ST.

Highlights

Scrub typhus (ST) is a neglected life-threatening vector-borne infectious disease
Through referring to previous studies on the geographic distribution of rodents [21,28], Jiangxi was divided into five zoogeographic regions, including the plain region bordering on rivers and lakes, Jiangxi’s northern hilly region, Wuyi’s mountainous hilly region, Wugong’s mountainous hilly region, and Jiangxi’s southern mountainous region (Figure 1C)
The primary peak was in autumn (September–October), a smaller peak was in summer (June–August), and there were sporadic cases reported in winter-spring (January–April)

Summary

Introduction

Scrub typhus (ST) is a neglected life-threatening vector-borne infectious disease. The disease is transmitted by chigger mites (larval trombiculid mites) infected with the gramnegative intracellular rickettsial bacterium Orientia tsutsugamushi bacteria [1,2,3]. It is estimated that one million ST cases are found each year within this region, and at least one billion people are at risk of becoming infected [12,13]. Scrub typhus (ST) has become a significant potential threat to public health in Jiangxi. Methods: Time-series analyses, spatial distribution analyses, spatial autocorrelation analysis, and space-time scan statistics were performed to detect spatiotemporal dynamics distribution of the incidence of ST. Seven spatiotemporal clusters were observed using Kulldorff’s space-time scan statistic, and the most likely cluster only included one county, Nanfeng county. The high-risk areas of the disease were in the mountainous, hilly region of Wuyi and the southern mountainous region of Jiangxi.

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Discussion

Conclusion