内蒙古自治区牙克石市全沟硬蜱携带立克次体的研究

  目的  了解内蒙古自治区（内蒙古）大兴安岭地区蜱携带的斑点热群立克次体和无形体属细菌的流行情况与种类。  方法  在阿龙山林区采集蜱并根据形态学特征进行鉴定,运用PCR方法扩增17 kDa与16S rRNA基因分别对2010年捕获蜱中的两类病原体进行检测,同时扩增阳性样本中立克次体的全长16S rRNA和gltA基因,将扩增产物测序后进行序列分析。 运用MegAlign软件分析序列的相似性,并通过PhyML3.1软件构建进化树进行系统发生分析。  结果  在阿龙山林区采集点共捕获蜱293只,经形态学鉴定全部为全沟硬蜱。 其中斑点热群立克次体、无形体的感染率分别为9.56%和0。 序列分析显示该地区蜱携带的斑点热群立克次体均为新塔拉塞维奇立克次体,16S rRNA和gltA基因与该种立克次体已知序列的同源性分别为100.00%和99.80%,氨基酸同源性为100.00%。 进化分析结果显示本研究在牙克石市全沟硬蜱中检测到的新塔拉塞维奇立克次体与俄罗斯的菌株为同一基因型。  结论  内蒙古大兴安岭地区蜱中存在可致病的斑点热群新塔拉塞维奇立克次体。     

蜱斑点热群立克次体脱氧核糖核酸序列初步分析

目的了解浙江省媒介蜱斑点热群立克次体带菌状况。方法通过扩增斑点热群立克次体外膜蛋白A基因片段,对浙江省金华市野兔、野猪寄生蜱标本进行检测分析。结果对343份蜱标本分47组进行检测,分别从1组龟形花蜱和1组镰形扇头蜱中扩增出DNA阳性条带;经测序分析,分别命名为ZJ42和ZJ43株片段。ZJ42株与R.sp JL-95株关系较近,该株在外ompA的575～580位点有6个碱基(AAATAT)的插入缺失,可能是一个新菌株或种。ZJ43株与马赛立克次体、Rickettsia BAR-29和Rickettsia rhipicephali关系较近。结论浙江省存在斑点热群立克次体的媒介蜱,应加强在媒介蜱,特别是镰形扇头蜱和龟形花蜱中对斑点热群立克次体的监测,并研究它们的致病性。     

广东省首次发现斑点热群立克次体的感染

本文采用微量间接免疫荧光方法首次在广东省大埔县、平远县和梅县１０１２名健康人中进行了斑点热群立克次体感染的血清流行病学调查。结果表明，三县西伯利亚立克次体的感染率平均为１６.９９％，其中大埔县为２８.４７％、平远县为２０.４６％、梅县为６.８％；康氏立克次体的感染率平均为２２.６３％，其中大埔县为２７.７８％、平远县为１３.４２％、梅县为２５.５９％；三县小蛛立克次体的感染率平均为１８.２８％，其中大埔县为２１.８８％、平远县为１８.８０％、梅县为１５.４９％。健康人群血清中斑点热群立克次体ＩｇＧ抗体阳性率经统计学处理未见有性别、年龄和职业的差别。上述结果提示在广东省大埔县、平远县和梅县可能存在有斑点热的自然疫源地     

秭归县日本斑点热临床和实验室特征分析

目的分析秭归县日本斑点热患者的流行和临床特征, 为提高日本斑点热的防治措施提供依据。方法病例系列分析。研究秭归县人民医院2021年4月至2022年8月确诊并住院的18例日本斑点热患者, 其中男7例, 女11例;年龄60(54, 68)岁。收集病历资料, 分析其流行病学特征、临床特征、实验室检查及影像学特点。结果 18例日本斑点热患者, 17例为农民, 1例为教师, 均有野外接触史。主要发病时间为4至10月, 春秋季最多。患者首发症状一般为高热、头痛、乏力、全身肌肉酸痛;15例患者出现皮疹, 12例出现焦痂, 3例患者无皮疹和焦痂;患者中10例双下肢水肿, 3例出现意识障碍等精神症状。实验室检查发现:15例患者白细胞正常或降低, 11例血小板降低, C反应蛋白、降钙素原、D-二聚体、乳酸脱氢酶、α-羟丁酸脱氢酶均升高, 17例白蛋白降低;13例丙氨酸转氨酶和14例天冬氨酸转氨酶升高;11例尿蛋白异常。结论日本斑点热最常见的临床表现为高热寒战、乏力、头痛、全身肌肉酸痛, 作为立克次体感染主要特征的焦痂与皮疹并非在所有患者中存在, 因此增加了日本斑点热的诊断难度, 造成患者病情的延误, 甚至...     

海南省澄迈县新发斑点热流行病学调查

目的 对海南省澄迈县进行斑点热自然疫源地现场调查.方法 以病原学证实的首发患儿居住村外延收集可疑病例并采集当地野生啮齿动物抗凝血,用现代Shell vial培养技术进行立克次体病原分离,对分离株进行16S rRNA、gltA、ompA、17 kD蛋白基因及groEL基因扩增并测序分析.以WHO立克次体协作中心推荐间接免...     

中哈边境阿拉山口口岸亚洲璃眼蜱首次检测到Q热立克次体核酸

目的 对新疆阿拉山口口岸地区蜱类进行Q热立克次体核酸检测。方法 采集蜱样本并进行形态学和分子生物学鉴定。聚合酶链反应扩增Q热com1基因,通过Blast软件比对分析测序产物,利用Mega 6.0软件构建分子遗传进化树。结果 共采集253只蜱,其中优势蜱种为亚洲璃眼蜱,蜱类的形态学鉴定与分子生物学鉴定结果一致。阿拉山口口岸地区蜱携带Q热立克次体核酸平均阳性率为16.21%（41/253）,亚洲璃眼蜱阳性率为22.65%（41/181）,血红扇头蜱、短垫血蜱和边缘革蜱均为阴性,亚洲璃眼蜱显著高于其他蜱种。序列分析显示与Coxiella burnetii Cb175_Guyana（HG825990,圭亚那）进化关系较近,核苷酸同源性为99%。结论 阿拉山口口岸地区亚洲璃眼蜱在16S rRNA和COⅠ基因序列间存在多样性,并首次在中哈边境地区亚洲璃眼蜱中检测到Q热立克次体核酸。     

斑点热病原体及其实验室检出的研究进展

斑点热群(Spotted Fever Group,SFG)立克次体是立克次体属下的一个群,有多种立克次体组成,分布于世界各地。近年来,大量血清学资料及病原学研究表明,由SFG 立克次体引起的斑点热病在我国很多地区广泛存在。本文就近年来斑点热病原体及其检出的研究进展作一简要概述。一、斑点热群立克次体的分类SFG 是立克次体属中最复杂的一群立克次体。根据Bergey 氏手册包括:立氏立克次体、康氏立克次体、西伯利亚立克次体、小蛛立克次体、派克立克次体、澳大利亚立克次体、蒙它那立克次体及扇头蜱立克次体等。近年来,欧洲、亚洲等地不断发现SFG 立克次体新的生物种(或血清型),使SFG 成员明显增加。1978年在瑞士北部与西部,由Ixodes ricinus tic-     

猫立克次体--新出现的全球人类健康威胁

猫立克次体属于立克次体属,由胞内病原体组成,所引起的感染一般被称为立克次体病。还没有已知的亚种,通常分为2个亚群：斑点热群（SFG）和斑疹伤寒群。这2种亚群引起的感染在临床上是不能区分的,但可通过外膜蛋白OmpA（斑疹伤寒群无）和媒介进行鉴别。斑点热群由蜱传播，斑疹伤寒群由蚤和虱传播。最近，Gillespie等报道通过指定立克次体属过渡群（transitional group）和一种立克次体属遗传群（ancestral group）而扩大了立克次体属的分类。     

宏基因组二代测序辅助诊断Q热立克次体肺炎1例

Q热是由贝纳柯克斯体(又称Q热立克次体)引起的人畜共患病,自然疫源地多见,广东地区报道较少.其临床症状与影像学表现缺乏特异性,容易被漏诊误诊,且传统的培养方法难以明确诊断.本文报道1例表现为腹痛、发热、呼吸衰竭被误诊为腹腔感染的患者,经宏基因组二代测序(mNGS)检出贝纳柯克斯体序列而确诊Q热立克次体肺炎,为诊治该类疾...     

用基因探针检测立克次氏体

近年来,采用标记 DNA 探针识别靶细胞已成为检测微生物和侵入人体的外源性基因的重要手段。DNA 探针具有较高的特异性和敏感性。我们应用[α~-~(32)P]dATP 制备了1号和2号探针。1号探针是落矶山斑点热立克次体探针,可以检测斑点热及斑疹伤寒立克次体;而不能检测 Q 热及恙虫病立克次体。2号探针是斑疹伤寒立克次体探针只能检测斑疹伤寒直克次体;而不能检测Q 热、恙虫病和斑点热立克次体,现将工作结果报道如下。材料和方法立克次体株:北亚蜱传斑点热立克次体,人232株;Q 热立克次体,Henzerling     

Predictive values of clinical parameters for severe Japanese spotted fever

Japanese spotted fever (JSF) is severe and can progress to disseminated intravascular coagulation (DIC) with a poor prognosis. We considered whether patient factors are related to serious complications. Between August 1999 and March 2009, all patients with JSF and retrievable clinical data (age, gender, length of hospital stay, medication, comorbidities), vital signs (blood pressure, heart rate, temperature), and laboratory test results [blood cell count, liver function, renal function, electrolytes, blood sugar, C-reactive protein (CRP), CRP normalization period, and aspartate aminotransferase normalization period] from the Integrated Intelligent Management System (IIMS) database, were retrospectively analyzed by logistic regression. There were 51 JSF patients (24 men, 27 women) with a mean age of 63.0 years. Six patients (11.8%) had DIC, but there were no in-hospital deaths. The time between fever onset and initiation of medication was approximately 5 days, but this delay was not associated with disease severity. We identified values correlating with disease severity (p < 0.1) by univariate analysis and then applied logistic regression. We found renal dysfunction [serum creatinine (Cr) ≥1.5 mg/dl] at the time of initial presentation to be predictive of DIC. Cr was also predictive of a prolonged disease course. In patients with JSF, renal function must be carefully monitored when determining clinical management.     

Early diagnosis of Japan spotted fever by PCR using skin samples

We studied the suitability of a PCR method using samples of skin and whole blood and serological tests for the early diagnosis of Japan spotted fever (JSF) in its acute and convalescent stages and compared the advantages and disadvantages of these different diagnostic methods. In the acute stage, the percentage of positive results was 91.2 % for the PCR method using skin samples, 52.3 % for the PCR method using whole blood samples, and 40.4 % for the serological tests with IgM. In the convalescent stage, paired serum showed positive results (IgM, 98.5 %; IgC, 94.0 %). The PCR method using samples of skin (eschar) is the most sensitive, specific, and suitable method for promptly and accurately diagnosing JSF in the early stage. Therefore, this method is recommended for early definite diagnosis of JSF in the critical stage.     

Japanese spotted fever associated with multiorgan failure

A 49-year-old man was admitted to our hospital, with a diagnosis of multiple organ failure, on June 10, 2000. Physical examination revealed high fever, generalized maculopapular erythema, and an eschar on his lower leg. Laboratory findings revealed severe renal and liver dysfunction, disseminated intravascular coagulation (DIC), and markedly elevated soluble interleukin 2-receptor (sIL2-R) level (>10 000 U/ml). Administration of minocycline was started immediately, with a diagnosis of rickettsial infection. Simultaneously, anti-thrombin III and heparin were started to treat the DIC, and hemodialysis was also initiated. However, the day after admission, his consciousness level lapsed, to the level of coma, and blood pressure was less than 60 mmHg, indicating shock. Therefore, 500 mg of methylprednisolone was administered once; as a result, rapid pyretolysis and improvement of consciousness disturbance were achieved. Laboratory data indicative of inflammation gradually improved after a few days. Hemodialysis was required ten times. During the recovery period, the level of specific IgM antibody against Rickettsia japonica increased to ×2560, and he was diagnosed as having Japanese spotted fever. On July 11, he was discharged without sequelae. The course in our patient was very severe, and treatment with minocycline alone may have resulted in a fatal outcome. The level of sIL2-R, which is produced by activated lymphocytes, was markedly increased. Therefore, markedly elevated lymphocyte activation and hypercytokinemia may have been present on admission. The short-term steroid therapy may have been effective in inhibiting the excessive activation of lymphocytes in the critical stage. In the severe form of Japanese spotted fever with organ failure, combination therapy with minocycline and short-term steroids may be very useful. Received: May 10, 2001 / Accepted: July 6, 2001     

Managing Rocky Mountain spotted fever

Rocky Mountain spotted fever is caused by the tick-borne bacterium Rickettsia rickettsii. Symptoms range from moderate illness to severe illness, including cardiovascular compromise, coma and death. The disease is prevalent in most of the USA, especially during warmer months. The trademark presentation is fever and rash with a history of tick bite, although tick exposure is unappreciated in over a third of cases. Other signature symptoms include headache and abdominal pain. The antibiotic therapy of choice for R. rickettsii infection is doxycycline. Preventive measures for Rocky Mountain spotted fever and other tick-borne diseases include: wearing long-sleeved, light colored clothing; checking for tick attachment and removing attached ticks promptly; applying topical insect repellent; and treating clothing with permethrin.     

Fulminant Japanese spotted fever definitively diagnosed by the polymerase chain reaction method

 A 72-year-old man was admitted to the emergency ward in our hospital on July 20, 2001, because of consciousness disturbance, fever, generalized skin eruption, and severe general weakness beginning 7 days previously. Physical examination on admission revealed marked systemic cyanosis, erythema, and purpura. Laboratory findings indicated disseminated intravascular coagulation (DIC) and multiorgan failure (platelet count, 0.9 × 10⁴/μl; fibrin degradation product, 110 μg/ml; C-reactive protein, 22.6 mg/dl). Soluble interleukin 2-receptor (sIL-2R) was markedly increased to 14 710 U/ml. Blood gas analysis demonstrated severe metabolic acidosis. He was diagnosed with multiorgan failure due to DIC. Administration of heparin and sodium bicarbonate was started immediately, but respiratory failure was exacerbated and systemic spasm caused by encephalitis was noted. Although he was supported by an artificial ventilator, deterioration of metabolic acidosis occurred, and the blood pressure decreased to less than 60 mm Hg. He died 5.5 h after admission. The serological test showed no positive antibody titers against Orientia tsutsugamushi, Rickettsia japonica, or Rickettsia typhi. However, a specific DNA band derived from R. japonica was detected by the polymerase chain reaction (PCR) method using a primer from a blood clot. Therefore, he was definitively diagnosed as having Japanese spotted fever. The PCR method may be markedly useful for establishing a definitive diagnosis of Japanese spotted fever during the critical stage. Received: January 30, 2002 / Accepted: April 30, 2002     

Surveillance, recognition, and reporting of Tsutsugamushi disease (scrub typhus) and Japanese spotted fever by general practice clinics in Miyazaki Prefecture, determined by questionnaire survey in 2007

In June 2007, a questionnaire survey related to the surveillance, recognition, and reporting of Tsutsugamushi disease (TD) and Japanese spotted fever (JSF) — diseases considered endemic in Miyazaki Prefecture — was distributed to general practice clinics in the prefecture. The response rate was 40.9% (232/567). While 75.5% of the responding clinics knew TD to be a notifiable disease, only 41.8% knew JSF was notifiable. The recognition level of JSF surveillance was lower in the low-incidence areas of JSF within Miyazaki Prefecture. In 2006, 25 cases were clinically suspected as TD by the responding clinics; of the 25 cases, 9 were confirmed and 8 of these were reported to the National Epidemiological Surveillance of Infectious Diseases (NESID). Only 1 of 6 clinically suspected JSF cases from the responding clinics was confirmed in 2006, and it was not reported to NESID. The clinics located in the high-incidence areas for TD tended not to perform laboratory confirmation of the clinically suspected cases of either of the diseases. Considering that NESID requires laboratory confirmation of the reported cases of these diseases, their extent may be underestimated, especially in the high-incidence areas. For clinics in Miyazaki Prefecture, we need to publicize the existence of JSF surveillance and inform clinics about the laboratories available for confirmation of JSF and TD in the prefecture.     

Clinical study of Japanese spotted fever and its aggravating factors

 Twenty-eight patients with Japanese spotted fever were clinically investigated. The diagnosis was determined by confirming an increase of specific antibody. All patients were treated with minocycline, and all recovered, excluding one patient with a fulminant course. Fever and exanthema were observed in all patients, and an eschar was pointed out in 20 (71%) patients. The platelet count was 10 × 10⁴/μl or lower in 8 (28%) patients. The fibrin degradation product (FDP)-level was abnormally high, 10 μg/ml or more, in 16 (57%) patients. The creatine kinase (CK) value was high in 14 of 22 patients, suggesting the presence of myositis. The leukocyte count, FDP, C-reactive protein, and soluble interleukin 2 receptor (sIL2-R) levels were significantly higher in severe cases. In the group without concomitant steroid therapy, mean times of 54.7 h and 101.4 h were required to reduce the temperature to 38°C and 37°C or lower, respectively, after the initiation of tetracycline treatment. There were 6 severe cases: 1 with disseminated intravascular coagulation, 2 with multiorgan failure, 1 with acute respiratory distress syndrome, and 2 with meningoencephalitis. These severe cases formed a group that required 6 or more days to initiate therapy after the onset (P < 0.005 vs non-severe group), showing that delay in diagnosis and therapy is the major cause of aggravation. In the 2 patients complicated by multiorgan failure, the sIL2-R level, produced by activated lymphocytes, was 10 000 U/ml or higher, suggesting that an sIL2-R level of more than 10 000 U/ml can be used as a marker of poor prognosis. It may be better that moderate to severe cases are treated with minocycline plus short-term steroid therapy. Received: May 10, 2002 / Accepted: November 27, 2002 Acknowledgments The authors greatly thank Drs. Yoshiki Tange and Takanori Okada (the First Department of Internal Medicine, Ehime University School of Medicine); Dr. Motohiko Ogawa (First Department of Virology, the National Institute of Infectious Disease); Dr. Hiromi Fujita (Ohara Research Laboratory, Ohara General Hospital); and Mr. Tsuguto Fujimoto (The Public Health Institute of Hyogo Prefecture) for the measurement of specific antibodies.