Epidemiological characteristics and spatiotemporal patterns of scrub typhus in Fujian province during 2012–2020

Abstract

Background Scrub typhus has become a serious public health concern in the Asia-Pacific region including China. There were new natural foci continuously recognized and dramatically increased reported cases in mainland China. However, the epidemiological characteristics and spatiotemporal patterns of scrub typhus in Fujian province have yet to be investigated. Objective This study proposes to explore demographic characteristics and spatiotemporal dynamics of scrub typhus cases in Fujian province, and to detect high-risk regions between January 2012 and December 2020 at county/district scale and thereby help in devising public health strategies to improve scrub typhus prevention and control measures. Method Monthly cases of scrub typhus reported at the county level in Fujian province during 2012–2020 were collected from the National Notifiable Disease Surveillance System. Time-series analyses, spatial autocorrelation analyses and space-time scan statistics were applied to identify and visualize the spatiotemporal patterns of scrub typhus cases in Fujian province. The demographic differences of scrub typhus cases from high-risk and low-risk counties in Fujian province were also compared. Results A total of 11,859 scrub typhus cases reported in 87 counties from Fujian province were analyzed and the incidence showed an increasing trend from 2012 (2.31 per 100,000) to 2020 (3.20 per 100,000) with a peak in 2018 (4.59 per 100,000). There existed two seasonal peaks in June-July and September-October every year in Fujian province. A significant positive spatial autocorrelation of scrub typhus incidence in Fujian province was observed with Moran’s I values ranging from 0.258 to 0.471 (P<0.001). Several distinct spatiotemporal clusters mainly concentrated in north and southern parts of Fujian province. Compared to low-risk regions, a greater proportion of cases were female, farmer, and older residents in high-risk counties. Conclusions These results demonstrate a clear spatiotemporal heterogeneity of scrub typhus cases in Fujian province, and provide the evidence in directing future researches on risk factors and effectively assist local health authorities in the refinement of public health interventions against scrub typhus transmission in the high risk regions.

Using ecological niche modeling to predict the potential distribution of scrub typhus in Fujian Province, China

“…Similarly, Slope, Digital Elevation Model (Dem), Cropland and Forest were excluded from the land cover variables. However, the dependency ratio of old age (Dep_Old) was included in the socioeconomic factors, based on the results of our previous study [ 9 ]. The data used in the screening process are shown in Table 2 .…”

“…Leptotrombidium deliense is the major vector of scrub typhus south of the Yangtze River in China, and typically causes scrub typhus in the summer as people are more inclined to go outside during the summer holidays in this region [ 35 ]. In our previous study [ 9 ], scrub typhus cases in Fujian Province had two seasonal peaks, one in June-July and one in September–October, with the highest number of cases in the former. The seasonal peak of Leptotrombidium deliense coincided with the peak incidence of scrub typhus, which provided support for the assumption that temperature has a positive effect on scrub typhus.…”

“…Monthly scrub typhus cases were used for the analysis. All of the cases of scrub typhus had been diagnosed according to the unified diagnostic criteria of the Chinese Center for Disease Control and Prevention [ 9 , 10 ].…”

“…Fujian Province is historically an endemic area for scrub typhus in China [ 8 ]. In our previous study [ 9 ], which explored the demographic characteristics and spatiotemporal dynamics of scrub typhus cases from January 2012 to December 2020 in Fujian Province, both the frequency and geographic distribution of cases increased dramatically. However, one limitation in that study is that risk factors related to scrub typhus are not contained.…”

Acute septic deep venous thrombosis of the lower extremities due to foreign body injury and infection: a case report

“…[4] Most patients have a history of eld work, and the incubation period is 5-14 days. The onset of the disease is acute, with high fever, toxaemia, rash, eschar, lymphadenopathy and other characteristic clinical manifestations [5].Severe cases can be life-threatening due to cardiopulmonary and renal failure.…”