Bruce Light R, Kralt Doug, Embil John M, Trepman Elly, Wiebe Lyle, Limerick Bill, Sarsfield Pete, Hammond Greg, Macdonald Kerry
Section of Infectious Diseases, Department of Medicine, University of Manitoba, Winnipeg.
Med Mycol. 2008 Dec;46(8):835-41. doi: 10.1080/13693780802132763.
Blastomycosis is a granulomatous infection caused by the thermally dimorphic fungus, Blastomyces dermatitidis, for which seasonal variation has been proposed. We conducted a retrospective review of medical records of 324 patients with blastomycosis in Manitoba and northwestern Ontario. The average age of patients at the time of diagnosis was 39+/-20 (range, 0-85) years. Symptoms referable to blastomycosis were first noted in the autumn and winter (September to February) by 63% of the patients. The seasonal distribution of cases was different for localized pulmonary infection than the disseminated disease (P<0.0001). For localized lung disease, the peak incidence of symptom onset occurred in the autumn, and lowest incidence in the spring; one half (50%) of the patients with diffuse lung disease had onset of symptoms in the spring months and a few (11%) cases occurred during the summer. We noted a distinct seasonal variation in the clinical presentation of blastomycosis. The observed pattern suggests that summer environmental exposure and acquisition of the infection results in an early (1-6 months) localized pneumonia in the majority of cases, followed by later (4-9 months) reactivation or slow progression of asymptomatic infection resulting in isolated extrapulmonary or disseminated hematogenous disease in the minority.
芽生菌病是由双态真菌皮炎芽生菌引起的一种肉芽肿性感染，该病存在季节性变化。我们对马尼托巴省和安大略省西北部324例芽生菌病患者的病历进行了回顾性研究。诊断时患者的平均年龄为39±20岁（范围0 - 85岁）。63%的患者首次出现芽生菌病相关症状是在秋季和冬季（9月至2月）。局限性肺部感染与播散性疾病的病例季节性分布不同（P<0.0001）。对于局限性肺部疾病，症状出现的高峰发生率在秋季，春季发生率最低；一半（50%）的弥漫性肺部疾病患者在春季出现症状，少数（11%）病例发生在夏季。我们注意到芽生菌病的临床表现存在明显的季节性变化。观察到的模式表明，夏季环境暴露和感染导致大多数病例早期（1 - 6个月）出现局限性肺炎，随后少数病例后期（4 - 9个月）无症状感染重新激活或缓慢进展，导致孤立的肺外或血行播散性疾病。
