Lantos Paul M, Tsao Jean, Nigrovic Lise E, Auwaerter Paul G, Fowler Vance G, Ruffin Felicia, Foster Erik, Hickling Graham
Divisions of Pediatric Infectious Diseases.
General Internal Medicine.
Open Forum Infect Dis. 2017 Jan 9;4(1):ofw269. doi: 10.1093/ofid/ofw269. eCollection 2017 Winter.
Most Lyme disease cases in the Midwestern United States are reported in Minnesota and Wisconsin. In recent years, however, a widening geographic extent of Lyme disease has been noted with evidence of expansion eastwards into Michigan and neighboring states with historically low incidence rates.
We collected confirmed and probable cases of Lyme disease from 2000 through 2014 from the Michigan Department of Health and Human Services, entering them in a geographic information system. We performed spatial focal cluster analyses to characterize Lyme disease expansion. We compared the distribution of human cases with recent tick distribution studies.
Lyme disease cases in both the Upper and Lower Peninsulas of Michigan expanded more than 5-fold over the study period. Although increases were seen throughout the Upper Peninsula, the Lower Peninsula particularly expanded along the Indiana border north along the eastern shore of Lake Michigan. Human cases corresponded to a simultaneous expansion in established tick populations.
The geographic distribution of Lyme disease cases significantly expanded in Michigan between 2000 and 2014, particularly northward along the Lake Michigan shore. If such dynamic trends continue, Michigan-and possibly neighboring areas of Indiana, Ohio, and Ontario, Canada-can expect a continued increase in Lyme disease cases.
美国中西部地区的大多数莱姆病病例报告来自明尼苏达州和威斯康星州。然而，近年来，莱姆病的地理范围不断扩大，有证据表明其正向东扩展至密歇根州以及历史发病率较低的周边各州。
我们收集了2000年至2014年密歇根州卫生与公众服务部确诊和疑似的莱姆病病例，并将其录入地理信息系统。我们进行了空间聚集分析以描述莱姆病的扩散情况。我们将人类病例的分布与近期蜱虫分布研究进行了比较。
在研究期间，密歇根州上半岛和下半岛的莱姆病病例数均增长了5倍多。虽然上半岛各地都有病例增加，但下半岛的病例尤其沿着密歇根湖东岸向北扩展至印第安纳州边界。人类病例的增加与已确定的蜱虫种群的同时扩张相对应。
2000年至2014年间，密歇根州莱姆病病例的地理分布显著扩大，尤其是沿着密歇根湖沿岸向北扩展。如果这种动态趋势持续下去，密歇根州以及可能的印第安纳州、俄亥俄州和加拿大安大略省的邻近地区的莱姆病病例可能会持续增加。
