Epidemic Intelligence Service, Scientific Education and Professional Development Program Office, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS C-09, Atlanta, GA 30307, USA.
Clin Infect Dis. 2013 Sep;57(5):655-62. doi: 10.1093/cid/cit366. Epub 2013 Jun 3.
Blastomycosis is a potentially life-threatening infection caused by the soil-based dimorphic fungus Blastomyces dermatitidis, which is endemic throughout much of the Midwestern United States. We investigated an increase in reported cases of blastomycosis that occurred during 2009-2010 in Marathon County, Wisconsin.
Case detection was conducted using the Wisconsin Electronic Disease Surveillance System (WEDSS). WEDSS data were used to compare demographic, clinical, and exposure characteristics between outbreak-related and historical case patients, and to calculate blastomycosis incidence rates. Because initial mapping of outbreak case patients' homes and recreational sites demonstrated unusual neighborhood and household case clustering, we conducted a 1:3 matched case-control study to identify factors associated with being in a geographic cluster.
Among the 55 patients with outbreak-related cases, 33 (70%) were hospitalized, 2 (5%) died, 30 (55%) had cluster-related cases, and 20 (45%) were Hmong. The overall incidence increased significantly since 2005 (average 11% increase per year, P < .001), and incidence during 2005-2010 was significantly higher among Asians than non-Asians (2010 incidence: 168 vs 13 per 100 000 population). Thirty of the outbreak cases grouped into 5 residential clusters. Outdoor activities were not risk factors for blastomycosis among cluster case patients or when comparing outbreak cases to historical cases.
This outbreak of blastomycosis, the largest ever reported, was characterized by unique household and neighborhood clustering likely related to multifocal environmental sources. The reasons for the large number of Hmong affected are unclear, but may involve genetic predisposition.
芽生菌病是一种由土壤二相真菌皮炎芽生菌引起的潜在危及生命的感染，这种真菌在美国中西部的大部分地区都有地方性分布。我们调查了威斯康星州马拉松县 2009-2010 年间报告的芽生菌病病例增加情况。
采用威斯康星州电子疾病监测系统（WEDSS）进行病例发现。使用 WEDSS 数据比较暴发相关病例患者和历史病例患者的人口统计学、临床和暴露特征，并计算芽生菌病发病率。由于最初对暴发病例患者家庭和娱乐场所的地图绘制显示出不寻常的邻里和家庭病例聚集，我们进行了 1:3 匹配病例对照研究，以确定与地理聚集相关的因素。
在 55 例暴发相关病例中，33 例（70%）住院，2 例（5%）死亡，30 例（55%）有聚集相关病例，20 例（45%）是苗族。自 2005 年以来，总发病率显著增加（平均每年增加 11%，P <.001），2005-2010 年间亚洲人的发病率明显高于非亚洲人（2010 年发病率：每 10 万人中有 168 例与 13 例）。30 例暴发病例分为 5 个居住集群。户外活动不是集群病例患者或暴发病例与历史病例相比的芽生菌病的危险因素。
此次暴发的芽生菌病是有史以来规模最大的一次，其特征是具有独特的家庭和邻里聚集性，可能与多灶性环境来源有关。苗族受影响人数众多的原因尚不清楚，但可能涉及遗传易感性。
