Siebels Kevin, Ng Victoria, Ogden Nicholas, Schofield Steven, Ludwig Antoinette
Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 rue Sicotte, St. Hyacinthe, QC, C.P. 5000, J2S 2M2, Canada.
Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 110 Stone Road West, Guelph, ON, N1G 3W4, Canada.
Int J Health Geogr. 2025 Aug 6;24(1):21. doi: 10.1186/s12942-025-00407-9.
Malaria continues to be one of the most significant infectious diseases in terms of morbidity and mortality. In many parts of North America, including parts of southern Canada, competent malaria vectors Anopheles quadrimaculatus and Anopheles freeborni are present. With climate change, Canada may be increasingly suitable for transmission of the malaria parasite Plasmodium spp. The objective of this study was to identify the geographic locations in Canada where, and the frequency with which, temperature conditions may be suitable for autochthonous transmission of Plasmodium vivax and Plasmodium falciparum under current and projected climate.
Temperature and duration thresholds from historic Plasmodium spp. transmission studies were applied on gridded historical and projected data to compute yearly frequencies of suitable conditions in Canada.
The resulting yearly frequencies from 2000 to 2023 show rising trends for both Plasmodium species, with surges reaching 34% of the Canadian population temporarily living under suitable temperature conditions for Plasmodium falciparum, and 56% for Plasmodium vivax. Projected populations percentages vary significantly with the Plasmodium species, climate change scenario, and climate model considered.
Our results underscore the increasing risk of autochthonous transmission of malaria in Canada due to climate change.
疟疾仍是发病率和死亡率方面最为严重的传染病之一。在北美许多地区，包括加拿大南部部分地区，存在适宜传播疟疾的媒介四斑按蚊和弗里伯恩按蚊。随着气候变化，加拿大可能越来越适合疟原虫属疟原虫的传播。本研究的目的是确定在当前和预测气候条件下，加拿大境内温度条件可能适合间日疟原虫和恶性疟原虫本地传播的地理位置以及频率。
将历史上疟原虫属传播研究中的温度和持续时间阈值应用于网格化的历史数据和预测数据，以计算加拿大适宜条件的年频率。
2000年至2023年的年频率结果显示，两种疟原虫的频率均呈上升趋势，恶性疟原虫的激增情况达到暂时生活在适宜温度条件下的加拿大人口的34%，间日疟原虫为56%。预测的人口百分比因疟原虫种类、气候变化情景和所考虑的气候模型而有显著差异。
我们的结果强调了由于气候变化，加拿大疟疾本地传播风险不断增加。
