Khadilkar Amole, Waddell Lisa, Acheson Emily S, Ogden Nicholas H
Environmental Public Health Division, Indigenous Services Canada, Ottawa, ON.
Public Health Risk Sciences, National Microbiology Laboratory Branch, Public Health Agency of Canada, Guelph, ON.
Can Commun Dis Rep. 2024 Nov 7;50(11):400-411. doi: 10.14745/ccdr.v50i11a04. eCollection 2024 Nov.
Blastomycosis is a disease of potentially varied presentations caused by thermally dimorphic fungi that appear as mold at ambient temperatures and transform to yeast at body temperature. Inhalation of aerosolized fungal spores represents the primary mode of transmission. Exposure may follow outdoor activities that disturb soil, which is warm, moist, acidic and rich in organic debris, particularly within forested areas and in proximity to waterways. Blastomycosis is endemic to several parts of Canada, but is only reportable in Ontario and Manitoba, with Northwestern Ontario being considered a hyperendemic area with average annual incidence rates of over 25 cases per 100,000 population. Delays in diagnosis and treatment are frequently observed as the symptoms and imaging findings of blastomycosis may initially be mistaken for community-acquired pneumonia, tuberculosis or malignancy, which can result in interim disease progression and worsening clinical outcomes. Risks from fungal infections such as blastomycosis are likely to increase with climate change-associated shifts in temperature and rainfall, and this may contribute to the geographic expansion of cases, a phenomenon that appears to be already underway. Further research investigating the ecological niche of and its climate sensitivity could help facilitate better modelling of the potential impacts of climate change on risks to Canadians and inform more effective methods of exposure prevention. Early clinical recognition and treatment of blastomycosis remain the key to minimizing morbidity and mortality.
芽生菌病是一种由双相真菌引起的疾病，其临床表现可能多种多样。这种真菌在环境温度下呈霉菌形态，在体温下转变为酵母形态。吸入雾化的真菌孢子是主要传播方式。接触可能发生在干扰土壤的户外活动之后，这些土壤温暖、潮湿、呈酸性且富含有机碎屑，特别是在林区和靠近水道的地方。芽生菌病在加拿大的几个地区流行，但仅在安大略省和马尼托巴省需要上报，安大略省西北部被认为是高流行区，年平均发病率超过每10万人25例。由于芽生菌病的症状和影像学表现最初可能被误诊为社区获得性肺炎、肺结核或恶性肿瘤，经常会出现诊断和治疗延迟的情况，这可能导致疾病进展并使临床结果恶化。随着气候变化导致温度和降雨的变化，芽生菌病等真菌感染的风险可能会增加，这可能导致病例的地理范围扩大，这种现象似乎已经在发生。进一步研究调查芽生菌的生态位及其对气候的敏感性，有助于更好地模拟气候变化对加拿大人风险的潜在影响，并为更有效的暴露预防方法提供依据。芽生菌病的早期临床识别和治疗仍然是将发病率和死亡率降至最低的关键。
