Han Ling, Sun Zhaobin, Zhang Guwei, Zhang Yunfei, Ren Hongyu, Teng Zhongqiu, Xu Jianguo, Qin Tian
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Chinese Center for Disease Control and Prevention National Institute for Communicable Disease Control and Prevention Beijing China.
State Key Laboratory of Severe Weather of CMA Chinese Academy of Meteorological Sciences Beijing China.
Geohealth. 2025 Sep 14;9(9):e2024GH001203. doi: 10.1029/2024GH001203. eCollection 2025 Sep.
The widespread concern surrounding the enhanced spillover risk of infectious diseases due to dramatic global land use changes has sparked significant discussion. However, the specific implications of these changes on scrub typhus, a vector-borne infectious disease facing increasing incidence and substantial expansion, remain unclear. Here, we constructed a comprehensive landscape fragmentation index (LFI), which reflects the interaction between human activities and natural habitats. Then we utilized a generalized additive model (GAM) to estimate the comprehensive and segmented impacts of LFI on scrub typhus incidence in China, grouping the results by year, land use type and fragmentation level. Additionally, we projected changes in such impacts under four shared socioeconomic pathways (SSPs), including SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5. Key results were: (a) The LFI exhibited a nonlinear positive correlation with scrub typhus incidence. Each 0.1 increase in the LFI was associated with a relative risk of 1.20 (95% CI:1.19-1.21) for scrub typhus. Notably, at higher fragmentation levels, scrub typhus incidence tended to decrease. (b) Forest fragmentation had the most significant impact on scrub typhus, followed by cropland fragmentation, whereas construction land fragmentation was negatively associated. (c) The future areas of elevated scrub typhus risk varied among the SSPs, but they were mainly concentrated at the interface between urban expansion and natural habitats. Our results indicate that human interference with the natural ecosystem is a critical factor for the incidence of scrub typhus. These findings are conducive to promoting ecological protection and the prevention and control of scrub typhus.
全球土地利用的急剧变化导致传染病溢出风险增加，这一广泛关注引发了大量讨论。然而，这些变化对恙虫病（一种发病率不断上升且范围大幅扩大的媒介传播传染病）的具体影响仍不明确。在此，我们构建了一个综合景观破碎化指数（LFI），该指数反映了人类活动与自然栖息地之间的相互作用。然后，我们利用广义相加模型（GAM）来估计LFI对中国恙虫病发病率的综合和细分影响，并按年份、土地利用类型和破碎化水平对结果进行分组。此外，我们预测了在四种共享社会经济路径（SSP）下这种影响的变化，包括SSP1-2.6、SSP2-4.5、SSP3-7.0和SSP5-8.5。主要结果如下：（a）LFI与恙虫病发病率呈非线性正相关。LFI每增加0.1，恙虫病的相对风险为1.20（95%置信区间：1.19-1.21）。值得注意的是，在较高的破碎化水平下，恙虫病发病率趋于下降。（b）森林破碎化对恙虫病的影响最为显著，其次是农田破碎化，而建设用地破碎化与之呈负相关。（c）未来恙虫病高风险区域在不同的SSP之间有所不同，但主要集中在城市扩张与自然栖息地的交界处。我们的结果表明，人类对自然生态系统的干扰是恙虫病发病的关键因素。这些发现有助于促进生态保护以及恙虫病的预防和控制。
