Recent Emergence of Anaplasma phagocytophilum in Ontario, Canada: Early Serological and Entomological Indicators
Recent Emergence of Anaplasma phagocytophilum in Ontario, Canada: Early Serological and Entomological Indicators
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DOI：
10.4269/ajtmh.19-0166
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发表时间：
2019-01-01
影响因子：
3.3
通讯作者：
Patel, Samir N.
中科院分区：
文献类型：
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作者：
Nelder, Mark P.;Russell, Curtis B.;Patel, Samir N.
人粒细胞无形体病(HGA)是由吞噬细胞无形体细菌引起的，在北美东部通过黑腿硬蜱(Ixodes Sharularis)传播给人类。为了评估吞噬细胞素在安大略省的出现情况，我们分析了2011至2017年间患者的血清学和临床数据，并结合对黑腿蜱的病原体检测。我们的样本人群包括所有接受医生安排的无浆体血清学检测的患者(n=851)。吞噬弧菌血清阳性83例(10.8%)，阴性686例(89.2%)。根据已公布的监测病例定义，我们将0例列为确诊病例，5例为可能病例，78例为疑似病例。血清阳性患者的百分比大体保持稳定在13.6%。血清阳性患者大多为成年女性，年龄40-59岁，报告非特异性体征和症状，如疲倦、头痛和发烧。较高的血清阳性率(每10万人1.5名患者)出现在安大略省东部和西北部。通过被动和主动监测，吞噬细胞素呈阳性的黑腿硬蜱的百分比分别为0.4%和1.1%，并随着时间的推移而增加。在该省存在已建立的黑腿硬蜱种群的地区，吞噬细胞库活动的血清学和昆虫学指标有所增加。目前，安大略省HGA的风险较低；然而，需要进一步的研究来证明该省HGA的流行病学。为了最大限度地减少安大略省出现HGA的影响，建议提高公众和卫生保健提供者的认识和教育，并考虑使HGA成为安大略省可报告的感染。
Human granulocytic anaplasmosis (HGA), caused by the bacteria Anaplasma phagocytophilum, is transmitted to humans by blacklegged ticks (Ixodes scapularis) in eastern North America. To assess the emergence of A. phagocytophilum in Ontario, we analyzed patient serological and clinical data in combination with pathogen detection in blacklegged ticks from 2011 to 2017. Our sample population included all patients who had Anaplasma serological testing ordered by their physicians (n = 851). Eighty-three patients (10.8%) were A. phagocytophilum seropositive (IgG titers >= 1: 64) and 686 (89.2%) were seronegative (IgG titers < 1:64). Applying published surveillance case definitions, we classified zero as confirmed, five as probable, and 78 as suspected cases. The percentage of seropositive patients remained generally stable at 13.6%. Seropositive patients were most often adult females, 40-59 years of age, and reported nonspecific signs and symptoms, such as fatigue, headache, and fever. Higher seropositivity rates (>= 1.5 patients per 100,000 population) occurred in eastern and northwestern Ontario. The percentage of A. phagocytophilum-positive blacklegged ticks, through passive and active surveillance, was 0.4 and 1.1%, respectively, and increased over time. Serological and entomological indicators of A. phagocytophilum activity increased in areas of the province with established blacklegged tick populations. The risk of HGA is presently low in Ontario; however, further research is required to document the epidemiology of HGA in the province. To minimize the impact of HGA emergence in Ontario, increased awareness and education of the public and health-care providers is recommended, with consideration to making HGA a reportable infection in Ontario.