Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, Oslo NO-0316, Norway.
Norwegian Veterinary Institute, PO Box 64, NO-1431 Ås, Norway.
Proc Biol Sci. 2023 Feb 22;290(1993):20222420. doi: 10.1098/rspb.2022.2420.
Climate change has had a major impact on seasonal weather patterns, resulting in marked phenological changes in a wide range of taxa. However, empirical studies of how changes in seasonality impact the emergence and seasonal dynamics of vector-borne diseases have been limited. Lyme borreliosis, a bacterial infection spread by hard-bodied ticks, is the most common vector-borne disease in the northern hemisphere and has been rapidly increasing in both incidence and geographical distribution in many regions of Europe and North America. By analysis of long-term surveillance data (1995-2019) from across Norway (latitude 57°58'-71°08' N), we demonstrate a marked change in the within-year timing of Lyme borreliosis cases accompanying an increase in the annual number of cases. The seasonal peak in cases is now six weeks earlier than 25 years ago, exceeding seasonal shifts in plant phenology and previous model predictions. The seasonal shift occurred predominantly in the first 10 years of the study period. The concurrent upsurgence in case number and shift in case timing indicate a major change in the Lyme borreliosis disease system over recent decades. This study highlights the potential for climate change to shape the seasonal dynamics of vector-borne disease systems.
气候变化对季节性天气模式产生了重大影响，导致广泛分类群的物候变化明显。然而，关于季节变化如何影响虫媒传染病的出现和季节性动态的实证研究一直很有限。莱姆病是一种由硬壳蜱传播的细菌性感染，是北半球最常见的虫媒传染病，在欧洲和北美的许多地区，其发病率和地理分布都在迅速增加。通过对挪威各地（纬度 57°58'-71°08' N）长期监测数据（1995-2019 年）的分析，我们证明了莱姆病病例在年内时间的明显变化伴随着病例数量的逐年增加。现在，病例的季节性高峰比 25 年前提前了六周，超过了植物物候的季节性变化和以前的模型预测。季节性变化主要发生在研究期的前 10 年。病例数量的同时增加和病例时间的变化表明，莱姆病疾病系统在最近几十年发生了重大变化。本研究强调了气候变化可能塑造虫媒传染病系统季节性动态的潜力。
