Rickettsia felis in Fleas, Germany

Among 310 fleas collected from dogs and cats in Germany, Rickettsia felis was detected in all specimens (34) of Archaeopsylla erinacei (hedgehog flea) and in 9% (24/226) of Ctenocephalides felis felis (cat flea). R. helvetica was detected in 1 Ceratophyllus gallinae (hen flea).     

Bartonella quintana and Rickettsia felis in Gabon

We detected Rickettsia felis DNA in Ctenocephalides felis and Bartonella quintana DNA in 3 Pulex irritans fleas taken from a pet Cercopithecus cephus monkey in Gabon, sub-Saharan Africa. This is the first report of B. quintana in the human flea.     

Rickettsia felis in Xenopsylla cheopis, Java, Indonesia

Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas.     

Rickettsia typhi and R. felis in rat fleas (Xenopsylla cheopis), Oahu, Hawaii

Rickettsia typhi (prevalence 1.9%) and R. felis (prevalence 24.8%) DNA were detected in rat fleas (Xenopsylla cheopis) collected from mice on Oahu Island, Hawaii. The low prevalence of R. typhi on Oahu suggests that R. felis may be a more common cause of rickettsiosis than R. typhi in Hawaii.     

用PCR方法检出蚤类携带巴尔通体

目的调查我国巴尔通体宿主动物体表寄生蚤类是否携带巴尔通体。方法2003年6～7月在云南省大理州云龙县居民区采集家猫、狗、鼠类等体表寄生蚤，用3对巴尔通体属特异性引物BhCS．781p—BhCS．1137n、Bh．311p—Bh．452n和TI1e．455p—TA1a．885n进行聚合酶链反应(PCR)，扩增巴尔通体gltA和16S～23S rRNA ITS中部分核酸片段，检测采集的蚤类是否感染巴尔通体。结果共采集251只寄生蚤，包括猫栉首蚤、人蚤、缓慢细蚤等7个常见蚤种，从1组猫栉首蚤和1组缓慢细蚤中扩增出目标带，证实有巴尔通体感染。结论猫栉首蚤和缓慢细蚤能够感染巴尔通体，是该种病原体的潜在传播媒介，间接表明当地家猫和鼠类动物存在巴尔通体感染。     

Rickettsia felis in fleas, Western Australia

This study is the first confirmation of Rickettsia felis in Australia. The organism was identified from 4 species of fleas obtained from dogs and cats in Western Australia, by using polymerase chain reaction amplification and DNA sequencing of the citrate synthase and outer membrane protein A genes.     

Y型嗅觉仪在蚤类对宿主选择性研究中的应用

目的应用Y型嗅觉仪,建立蚤类对宿主动物气味选择的测定方法,并研究猫栉首蚤、印鼠客蚤和缓慢细蚤对大白鼠和小白鼠的选择行为,为探究不同蚤种对不同宿主动物的特异性选择和了解＂蚤类-宿主动物或人-相关传染病＂的关系提供理论依据。方法以印鼠客蚤为试虫,用Y型嗅觉仪测定风速、Y型管臂管的几何位置、光照对其选择行为的影响,以猫栉首蚤、印鼠客蚤和缓慢细蚤成蚤为试虫分别测定对大白鼠和小白鼠的选择行为。结果在测定的20min内,当空气流速为0.6～1.5L/min时,Y型管臂管的几何位置和测定环境的光照（30W日光灯）与黑暗在印鼠客蚤对小白鼠的选择行为中没有显著影响。猫栉首蚤对大白鼠气味具有显著的选择性,而印鼠客蚤和缓慢细蚤对大白鼠和小白鼠气味的选择性差异无统计学意义。结论可以用Y型嗅觉仪测定蚤类对宿主动物的选择行为。通过研究蚤的选择行为可以了解其宿主特异性,进一步分析＂蚤类-宿主动物或人-相关传染病＂的相关关系。     

Flea-borne rickettsioses: ecologic considerations.

Ecologic and economic factors, as well as changes in human behavior, have resulted in the emergence of new and the reemergence of existing but forgotten infectious diseases during the past 20 years. Flea-borne disease organisms (e.g., Yersinia pestis, Rickettsia typhi, R. felis, and Bartonella henselae) are widely distributed throughout the world in endemic-disease foci, where components of the enzootic cycle are present. However, flea-borne diseases could reemerge in epidemic form because of changes in vector-host ecology due to environmental and human behavior modification. The changing ecology of murine typhus in southern California and Texas over the past 30 years is a good example of urban and suburban expansion affecting infectious disease outbreaks. In these areas, the classic rat-flea-rat cycle of R. typhi has been replaced by a peridomestic animal cycle involving, e.g., free-ranging cats, dogs, and opossums and their fleas. In addition to the vector-host components of the murine typhus cycle, we have uncovered a second typhuslike rickettsia, R. felis. This agent was identified from the blood of a hospitalized febrile patient and from opossums and their fleas. We reviewed the ecology of R. typhi and R. felis and present recent data relevant to the vector biology, immunology, and molecular characterization and phylogeny of flea-borne rickettsioses.     

Techniques for rearing and handling body lice,Oriental rat fleas,and cat fleas

The authors describe techniques for handling and rearing large numbers of body lice (Pediculus humanus humanus L.), oriental rat fleas (Xenopsylla cheopis (Rothschild)), and cat fleas (Ctenocephalides felis felis (Bouché)).     

Observations on the endemicity of plague in Karatu and Ngorongoro, northern Tanzania

Commensal and field rodents and wild small carnivores were live-trapped in five villages of Karatu district and one settlement in the Ngorongoro Conservation Area in Ngorongoro district in Tanzania. Blood samples were taken and serologically tested for plague, using the Blocking ELISA technique. Some domestic dogs and cats in the Karatu villages were aseptically bled and similarly tested for plague. Fleas were collected from the examined animals and from randomly selected residential houses. A total of 241 rodents, 1 Crocidura spp, 43 dogs, 12 cats and 4 slender mongooses were involved in the survey. Of the rodents, 14.5% were infested with fleas, which comprised of Xenopsylla brasiliensis (45.8%) and Dinopsyllus lypusus (54.2%), with an overall population density of 0.2 fleas/animal. Thirty one (72.1%) of the dogs were infested with fleas, all of which were Ctenocephalides spp. Thirty five (63.3%) houses were infested with fleas whose population was composed of Ctenocephalides spp, Pulex irritans, Tunga penetrans and Echinophaga gallinacea. Infected rodents were found in all the villages while the infected dog was found at Rhotia-Kati. Nineteen (11%) of the rodents and one (2%) dog harboured specific plague antibodies. It was broadly concluded that sylvatic plague was endemic in Karatu district and Ngorongoro Conservation Area and that outbreaks of the disease can occur in the area any time if and when relevant conditions become favourable. Prompt application of appropriate preventive and control measures and survey for substantiating the status in the Lake Manyara National Park, which is adjacent to some of the infected villages, are recommended.     

Rickettsia felis as emergent global threat for humans

Rickettsia felis is an emergent pathogen belonging to transitional group rickettsiae. First described in 1990, R. felis infections have been reported to occur worldwide in fleas, mammals, and humans. Because clinical signs of the illness are similar to those of murine typhus and other febrile illnesses such as dengue, the infection in humans is likely underestimated. R. felis has been found throughout the world in several types of ectoparasites; cat fleas appear to be the most common vectors. R. felis infection should be considered an emergent threat to human health.     

Rickettsial infections and fever, Vientiane, Laos

Rickettsial diseases have not been described previously from Laos, but in a prospective study, acute rickettsial infection was identified as the cause of fever in 115 (27%) of 427 adults with negative blood cultures admitted to Mahosot Hospital in Vientiane, Laos. The organisms identified by serologic analysis were Orientia tsutsugamushi (14.8%), Rickettsia typhi (9.6%), and spotted fever group rickettsia (2.6% [8 R. helvetica, 1 R. felis, 1 R. conorii subsp. indica, and 1 Rickettsia "AT1"]). Patients with murine typhus had a lower frequency of peripheral lymphadenopathy than those with scrub typhus (3% vs. 46%, p<0.001). Rickettsioses are an underrecognized cause of undifferentiated febrile illnesses among adults in Laos. This finding has implications for the local empiric treatment of fever.     

2000～2009年隆林县鼠疫主要宿主黄胸鼠密度及体表蚤监测分析

[目的]了解隆林县鼠疫自然疫源地内主要宿主黄胸鼠及其体表蚤的种类、构成和季节消长,为制定鼠疫防制对策提供依据。[方法]对隆林县2000-2009年鼠疫疫区处理、监测资料和鼠疫专题调查资料进行分析。[结果]2000-2009年累计布笼146 206笼次,捕获黄胸鼠3 956只,平均鼠密度为2.71%。平均鼠密度,各年分别为5.09%、1.39%、6.20%、2.04%、3.98%、2.26%、2.57%、2.61%、2.63%、2.75%,1-12月分别为2.71%、2.78%、3.17%、3.23%、3.35%、2.99%、2.59%、2.43%、1.82%、2.15%、2.94%、2.11%。2000-2009年合计梳检黄胸鼠3 956只,染蚤的1 143只,平均染蚤率为28.89%,收集体表蚤4 101匹,平均蚤指数为1.04。4 101匹蚤中,印鼠客蚤占78.59%（印鼠客蚤指数为0.81）,缓慢细蚤占18.09%,不等单蚤占2.17%,猫栉首蚤占0.63%,人蚤占0.49%,伍氏病蚤占0.02%。[结论]隆林县黄胸鼠密度和鼠体表蚤指数较高,印鼠客蚤是体表蚤的优势蚤种。     

Human Rickettsia felis infection, Canary Islands, Spain

We report the first cases of human infection by Rickettsia felis in the Canary Islands. Antibodies against R. felis were found in 5 adsorbed serum samples from 44 patients with clinically suspected rickettsiosis by Western blot serology. Fleas from 1 patient's dog were positive for R. felis by polymerase chain reaction.     

Characterization of Rickettsia spp. circulating in a silent peri-urban focus for Brazilian spotted fever in Caratinga, Minas Gerais, Brazil

The present study was intended to characterize Rickettsia spp. circulating in arthropod vectors in Caratinga, Minas Gerais, Brazil, by PCR and to investigate the presence of antibodies against the spotted fever Rickettsiae group (SFRG) in dogs and horses. 2,610 arthropods were collected and taxonomically identified. DNA samples obtained from these vectors were submitted to PCR and cycle-sequenced. Ctenocephalides and Amblyomma cajennense showed sequences presenting 100.0% homology with R. felis. A sequence obtained from Rhipicephalus sanguineus showed 99.0% homology with R. felis, and a sequence from A. cajennense showed 97.0% homology with R. honei and R. rickettsii. Canine (73) and equine (18) serum samples were tested by indirect fluorescent antibody (IFA) using R. rickettsii antigen. Only three of the equine sera tested (17.0%) had positive antibody titers. Molecular detection of rickettsiae species potentially pathogenic to humans in arthropod vectors and the presence of seroreactivity to SFRG in horses show the risk of transmission of rickettsiosis in this area and the need to maintain continuous epidemiological surveillance for rickettsial diseases.     

三峡重庆库区鼠形动物及其体表寄生蚤调查

目的 掌握三峡重庆库区鼠形动物及其体表寄生蚤种类及密度状况,为预防控制鼠、蚤传播的疾病提供依据.方法 采用夹夜法开展鼠形动物密度监测和种类调查;采用鼠笼法捕活鼠麻醉后梳检体表寄生蚤查染蚤情况.结果 2009-2010年三峡库区重庆段平均鼠密度为1.58％,其中室内鼠密度为1.56％,室外为1.60％;捕获鼠形动物2315只,隶属于2目2科11种,四川短尾鼩、小家鼠和褐家鼠为优势种类,分别占捕获总数的38.75％ 、25.14％和19.27％.鼠体平均染蚤率为6.74％;总蚤指数为0.29;共检获鼠蚤5种,分别为缓慢细蚤(占79.16％)、印鼠客蚤(占1.08％)、不等单蚤(占2.54％)、偏远古蚤(占8.90％)和猫栉首蚤(占8.32％).结论 三峡重庆库区存在鼠疫、钩端螺旋体病和肾综合征出血热的重要储存宿主鼠种及鼠疫重要传播媒介印鼠客蚤;鼠形动物结构较为丰富,但鼠密度、鼠体染蚤率和染蚤指数较低.     

猫栉首蚤不同性别和不同虫态的过冷却点测定

目的比较研究猫栉首蚤不同性别成虫和幼虫的过冷却点,旨在分析其分布及越冬规律,进而为猫栉首蚤及其相关传染病的预防控制与相关研究提供依据。方法采用热电偶和数字温度表,测定猫栉首蚤实验室种群雌雄成虫和3龄老熟幼虫的过冷却点与结冰点,分析其不同发育阶段和不同性别的抗寒性差异。结果在饥饿状态下,猫栉首蚤雌性成虫与雄性成虫的平均过冷却点温度分别为（-18.24±0.26）℃和（-18.45±0.26）℃,二者差异无统计学意义;雌性成虫与雄性成虫的结冰点温度分别为（-15.46±0.30）℃和（-15.19±0.31）℃,二者差异亦无统计学意义;而3龄老熟幼虫的平均过冷却点温度为（-8.73±0.40）℃,结冰点温度为（-6.63±0.37）℃,都分别显著高于猫栉首蚤雌雄成虫的过冷却点和结冰点。结论猫栉首蚤的成虫抗寒性差异无统计学意义;与成虫相比,幼虫不耐寒冷,因此在我国北方较寒冷的区域,其以成虫越冬的可能性较大。     

Mass flea outbreak at a child care facility: case report.

Cat fleas, Ctenocephalides felis Bouchet, were collected at a Mississippi child care facility after reports of large numbers of adult fleas occurring on children and personnel. One building yielded 161 (99 percent) of the fleas collected. Urticarial lesions due to flea bites occurred on the legs of six children. Flea presence was due to cats occupying the crawl space. Fleas were eradicated by eliminating entry of cats and using residual insecticides throughout the facility.