Oliver Jonathan D, Bennett Steve W, Beati Lorenza, Bartholomay Lyric C
School of Public Health - Division of Environmental Health Sciences, University of Minnesota, 420 Delaware St. S.E., Minneapolis, MN 55455.
University of St. Thomas, 2115 Summit Ave., Saint Paul, MN 55105.
J Med Entomol. 2017 Nov 7;54(6):1727-1734. doi: 10.1093/jme/tjx121.
A passive surveillance program monitored ticks submitted by the public in Iowa from 1990-2013. Submitted ticks were identified to species and life stage, and Ixodes scapularis Say nymphs and adults were tested for the presence of Borrelia burgdorferi. An average of 2.6 of Iowa's 99 counties submitted first reports of I. scapularis per year over the surveillance period, indicating expansion of this tick species across the state. The proportion of vector ticks infected by B. burgdorferi increased over time between 1998 and 2013. In 2013, 23.5% of nymphal and adult I. scapularis were infected with B. burgdorferi, the highest proportion of any year. Active surveillance was performed at selected sites from 2007-2009. Ixodes scapularis nymphs collected at these sites were tested for the presence of B. burgdorferi, Anaplasma phagocytophilum, and spotted fever group Rickettsia spp. (likely representing Rickettsia buchneri). Nymphs tested were 17.3% positive for B. burgdorferi, 28.9% for A. phagocytophilum, and 67.3% for Rickettsia spp. The results of these surveillance programs indicate an increasing risk of disease transmission by I. scapularis in Iowa.
一项被动监测计划对1990年至2013年爱荷华州公众提交的蜱虫进行了监测。对提交的蜱虫进行了物种和生命阶段鉴定，并对肩突硬蜱若虫和成虫进行了伯氏疏螺旋体检测。在监测期间，爱荷华州99个县平均每年有2.6个县首次报告发现肩突硬蜱，这表明该蜱虫物种在该州范围内不断扩散。1998年至2013年期间，感染伯氏疏螺旋体的媒介蜱虫比例随时间增加。2013年，23.5%的肩突硬蜱若虫和成虫感染了伯氏疏螺旋体，这是历年中最高的比例。2007年至2009年在选定地点进行了主动监测。对在这些地点采集的肩突硬蜱若虫进行了伯氏疏螺旋体、嗜吞噬细胞无形体和斑点热群立克次体属（可能代表布氏立克次体）检测。检测的若虫中，伯氏疏螺旋体阳性率为17.3%，嗜吞噬细胞无形体为28.9%，立克次体属为67.3%。这些监测计划的结果表明，爱荷华州肩突硬蜱传播疾病的风险在增加。
