Mayo Clinic, Division of Clinical Microbiology, Hilton 470-B, 200 1st St. SW, Rochester, MN 55905, USA.
N Engl J Med. 2011 Aug 4;365(5):422-9. doi: 10.1056/NEJMoa1010493.
Ehrlichiosis is a clinically important, emerging zoonosis. Only Ehrlichia chaffeensis and E. ewingii have been thought to cause ehrlichiosis in humans in the United States. Patients with suspected ehrlichiosis routinely undergo testing to ensure proper diagnosis and to ascertain the cause.
We used molecular methods, culturing, and serologic testing to diagnose and ascertain the cause of cases of ehrlichiosis.
On testing, four cases of ehrlichiosis in Minnesota or Wisconsin were found not to be from E. chaffeensis or E. ewingii and instead to be caused by a newly discovered ehrlichia species. All patients had fever, malaise, headache, and lymphopenia; three had thrombocytopenia; and two had elevated liver-enzyme levels. All recovered after receiving doxycycline treatment. At least 17 of 697 Ixodes scapularis ticks collected in Minnesota or Wisconsin were positive for the same ehrlichia species on polymerase-chain-reaction testing. Genetic analyses revealed that this new ehrlichia species is closely related to E. muris.
We report a new ehrlichia species in Minnesota and Wisconsin and provide supportive clinical, epidemiologic, culture, DNA-sequence, and vector data. Physicians need to be aware of this newly discovered close relative of E. muris to ensure appropriate testing, treatment, and regional surveillance. (Funded by the National Institutes of Health and the Centers for Disease Control and Prevention.).
埃立克体病是一种具有重要临床意义的新兴人畜共患病。在美国，人们认为只有查菲埃立克体和伊氏埃立克体可导致人类埃立克体病。疑似埃立克体病患者通常需要进行检测，以确保正确诊断并确定病因。
我们使用分子方法、培养和血清学检测来诊断和确定埃立克体病的病因。
在检测中，发现明尼苏达州或威斯康星州的 4 例埃立克体病并非由查菲埃立克体或伊氏埃立克体引起，而是由一种新发现的埃立克体物种引起。所有患者均有发热、不适、头痛和淋巴细胞减少症；3 例有血小板减少症；2 例有肝酶水平升高。所有患者在接受多西环素治疗后均康复。在明尼苏达州或威斯康星州采集的 697 只硬蜱中有至少 17 只在聚合酶链反应检测中呈同一埃立克体物种阳性。基因分析显示，这种新的埃立克体物种与鼠埃立克体密切相关。
我们报告了在明尼苏达州和威斯康星州发现的一种新的埃立克体物种，并提供了支持性的临床、流行病学、培养、DNA 序列和媒介数据。医生需要意识到这种新发现的鼠埃立克体密切相关的病原体，以确保进行适当的检测、治疗和区域性监测。（由美国国立卫生研究院和疾病控制与预防中心资助）。
