Isolation and Identification of Rickettsia raoultii in Human Cases: A Surveillance Study in 3 Medical Centers in China
Isolation and Identification of Rickettsia raoultii in Human Cases: A Surveillance Study in 3 Medical Centers in China
复制标题
DOI：
10.1093/cid/cix917
复制
发表时间：
2018-04-01
影响因子：
11.8
通讯作者：
Liu, Wei
中科院分区：
文献类型：
--
作者：
Li, Hao;Zhang, Pan-He;Liu, Wei
背景资料。拉氏立克次体在多种硬体动物中经常被检测到，而人类感染的研究还很少。在中国的3家哨所进行了一项监测研究，以招募疑似扁虱暴露的参与者。通过聚合酶链式反应、测序和血清学确认罗氏立克次体感染。进行细胞培养分离，并对分离株进行基因组测序。26名受试者被确定为罗氏杆菌感染，其中7人为无症状感染，15人为轻、中度感染，4人为重症。19例轻、中、重度患者常见的非特异性表现为发热(100%)、不适(95%)、肌痛(58%)、淋巴结肿大(53%)和恶心(42%)。只有5%的人有皮疹，16%的人有焦痂。扁虱咬伤综合征后头皮焦痂和颈部淋巴结病仅见于2例患者。4例严重并发症中，3例出现肺水肿，1例出现神志不清、嗜睡。常见的实验室检查异常包括白细胞减少、血小板减少、淋巴细胞减少、中性粒细胞减少、低蛋白血症，以及总胆红素、肝氨基转移酶、乳酸脱氢酶和肌酸激酶水平升高。19例患者经多西环素治疗后均痊愈，无后遗症。分离到两株罗氏立克次体，其基因组退化程度明显低于其他毒力较强的立克次体，表明当前菌株的致病性较低。人类感染罗氏杆菌的临床范围很广，从亚临床感染到严重的并发症。医生需要意识到罗氏杆菌感染的高潜在性和临床复杂性，以确保在流行地区进行适当的检测和治疗。
Background. Rickettsia raoultii is frequently detected in multiple tick species, whereas human infection remains scarcely studied.Methods. A surveillance study was performed at 3 sentinel hospitals in China, to recruit participants with suspected tick exposure. Rickettsia raoultii infection was identified through polymerase chain reaction, followed by sequencing, and confirmed serologically. Isolation by cell culture was performed and the isolates were genome sequenced.Results. Twenty-six subjects were determined to have R. raoultii infection, including 7 with asymptomatic infection, 15 with mild to moderate illness, and 4 with severe illness. Common nonspecific manifestations in the 19 patients with mild to moderate or severe illness included fever (100%), malaise (95%), myalgia (58%), lymphadenopathy (53%), and nausea (42%). Only 5% of them had rash, and 16% had eschar. Scalp eschar and neck lymphadenopathy after a tick bite syndrome was only seen in 2 patients. Of the 4 patients with severe complications, 3 developed pulmonary edema, and 1 developed clouding of consciousness and lethargy. Frequent abnormalities of laboratory testing included leukopenia, thrombocytopenia, lymphopenia, neutropenia, hypoproteinemia, and elevated levels of total bilirubin, hepatic aminotransferases, lactate dehydrogenase, and creatine kinase. All the 19 patients recovered without sequelae after receiving doxycycline treatment. Two R. raoultii strains were isolated, and a significantly less degraded genome was observed than other more virulent Rickettsia strains, indicating a low pathogenicity of the current strain.Conclusions. Human infection with R. raoultii has a wide clinical spectrum that ranged from subclinical infection to severe complications. Physicians need to be aware of the high potential and clinical complexity of R. raoultii infection, to ensure appropriate testing and treatment in endemic regions.