Rocky mountain spotted fever from an unexpected tick vector in Arizona
Rocky mountain spotted fever from an unexpected tick vector in Arizona
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DOI：
10.1056/nejmoa050043
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发表时间：
2005-08-11
影响因子：
158.5
通讯作者：
McQuiston, JH
中科院分区：
文献类型：
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作者：
Demma, LJ;Traeger, MS;McQuiston, JH
背景：落基山斑疹热是由立克次体引起的一种危及生命的蜱传疾病。这种疾病在亚利桑那州很少报告，其主要病媒——革蜱在该州并不常见。从2002年到2004年，在亚利桑那州东部农村调查了落基山斑疹热的一个焦点。方法：从疑似落基山斑疹热和蜱虫患者家中采集血样和组织标本。进行血清学、分子、免疫组织化学和培养试验以确定病原体。根据具体的实验室标准，将患者分类为确诊或可能感染落基山斑疹热。结果：共发现16例落基山斑疹热感染患者，其中确诊11例，疑似5例。在这些患者中，13名（81%）是12岁或以下的儿童，15名（94%）住院，2名（12%）死亡。在狗身上和患者住所的院子里发现了密集的血根头蜱种群。所有确诊的落基山斑疹热患者都曾接触过感染蜱虫的狗，其中4人在发病前报告有蜱虫叮咬史。在一个家庭采集的非充血血蜱中检测到立克次体DNA，并从这些蜱中培养出立克次体分离株。结论：本调查记录了亚利桑那州东部落基山斑疹热的存在，常见的棕色狗蜱（血蜱）可能是立克次体的媒介。这种常见蜱虫的广泛分布引起了人们对其在其他环境中传播立克次体的可能性的关注。
BACKGROUND:Rocky Mountain spotted fever is a life-threatening, tick-borne disease caused by Rickettsia rickettsii. This disease is rarely reported in Arizona, and the principal vectors, Dermacentor species ticks, are uncommon in the state. From 2002 through 2004, a focus of Rocky Mountain spotted fever was investigated in rural eastern Arizona.METHODS:We obtained blood and tissue specimens from patients with suspected Rocky Mountain spotted fever and ticks from patients' homesites. Serologic, molecular, immunohistochemical, and culture assays were performed to identify the causative agent. On the basis of specific laboratory criteria, patients were classified as having confirmed or probable Rocky Mountain spotted fever infection.RESULTS:A total of 16 patients with Rocky Mountain spotted fever infection (11 with confirmed and 5 with probable infection) were identified. Of these patients, 13 (81 percent) were children 12 years of age or younger, 15 (94 percent) were hospitalized, and 2 (12 percent) died. Dense populations of Rhipicephalus sanguineus ticks were found on dogs and in the yards of patients' homesites. All patients with confirmed Rocky Mountain spotted fever had contact with tick-infested dogs, and four had a reported history of tick bite preceding the illness. R. rickettsii DNA was detected in nonengorged R. sanguineus ticks collected at one home, and R. rickettsii isolates were cultured from these ticks.CONCLUSIONS:This investigation documents the presence of Rocky Mountain spotted fever in eastern Arizona, with common brown dog ticks (R. sanguineus) implicated as a vector of R. rickettsii. The broad distribution of this common tick raises concern about its potential to transmit R. rickettsii in other settings.