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.     

Rickettsia felis in Fleas, Southern Ethiopia, 2010

TO THE EDITOR: Fleas (order Siphonaptera) are obligate hematophagous insects. They are laterally flattened, holometabolous, and wingless ectoparasites. More than 2,500 species of flea, belonging to 16 families and 238 genera, have been described. A minority of these genera live in close association with humans (synanthropic), including fleas of these species: Pulex irritans, Ctenocephalides felis, Ctenocephalides canis, Xenopsylla cheopis, Nosopsyllus fasciatus, Echidnophaga gallinacea, and Tunga penetrans (1). Many fleas are capable of transmitting the following pathogens to their hosts: bacteria (e.g., Rickettsia typhi, R. felis, Yersinia pestis, and many Bartonella spp.); viruses (e.g., myxoma virus); protozoa (e.g., Trypanosoma spp.); or helminths (e.g., Hymenolepis spp.) (2). Ctenocephalides spp. fleas are of special interest as main reservoirs and vectors of R. felis, because this agent causes an emerging disease, fleaborne rickettsiosis. The distribution and prevalence of this disease have not been well studied. Symptoms of this disease range from mild to moderate and include fever, cutaneous rash, and sometimes an inoculation eschar (3,4). R. felis can also infect at least 10 other species of arthropods, including P. irritans fleas, trombiculid and mesostygmata mites, hard and soft ticks, and booklice (5,6).     

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.     

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).     

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.     

Rickettsia felis in Ctenocephalides spp. fleas, Brazil

In June 2000, suspected cases of Brazilian spotted fever (BSF) occurred in Coronel Fabriciano Municipality, Minas Gerais State, Brazil. Pooled fleas collected near two fatal cases contained rickettsial DNA. The nucleotide sequence alignment of the 391-bp segment of the 17-kDa protein gene showed that the products were identical to each other and to the R. felis 17-kDa gene, confirming circulation of R. felis in Brazil.     

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.     

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)).     

Rickettsia felis infection, Tunisia

We report, for the first time, serologic evidence of Rickettsia felis and R. aeschlimannii infections acquired in Tunisia from 1998 to 2003. We found that most patients with antibodies against both R. conorii and R. typhi had serologic evidence of R. felis infection.     

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.     

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.     

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.     

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。     

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。     

Serosurvey of wild rodents for Rickettsioses (spotted fever, murine typhus and Q fever) in Java Island, Indonesia

The prevalence of antibodies against spotted fever group rickettsia (SFGR), murine typhus and Q fever were investigated in wild rats captured in Indonesia. Sera of 327 rats were collected from Jakarta and Boyolali on Java Island. The prevalences of antibodies against SFGR and murine typhus were 128 (39.1%) and 48 (14.7%), respectively. Antibodies against Q fever were not detected in these serum samples. Antibodies against SFGR were found in all species of rats (20.8–51.9%). The antibody positive rate against murine typhus in Rattus norvegicus (38.0%) was significantly higher than that in other rat species (0–4.8%, p < 0.01). The antibody positive rates against SFGR and murine typhus in rats captured in Jakarta were significantly higher than those in rats captured in Boyolali (p < 0.01). In this survey, all species of rats had antibodies against SFGR, indicating that the 4 species of tested rats (R. norvegicus, R. rattus, R. exulans, R. tiomanicus) were infected with SFGR and that SFGR may infest the whole of Java Island. Most of the rats that were antibody-positive against murine typhus were captured in Jakarta. Therefore, R. norvegicus and R. rattus are likely to be important hosts of murine typhus in Jakarta. The antibody-positive rates against SFGR and murine typhus in rats captured in the dry season were significantly higher than those in rats captured in the rainy season. This may coincide with the active periods of ticks and fleas in Indonesia.     

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.     

Tick and flea infestations in captive Tapirus terrestris and Tapirus kabomani (Perissodactyla: Tapiridae) in the Brazilian Amazon

The present study aimed to identify tick and flea species infesting captive tapirs (Tapirus terrestris and Tapirus kabomani) in the Brazilian Amazon. Ectoparasites were collected from tapirs chemically restrained in Zoo-botanical Parks, breeding facilities, conservationists and, environmental compensation areas in the states of Amapá, Amazonas, and Pará. After collection, the tick and flea specimens were placed in plastic pots containing isopropanol and identified according to dichotomous keys. Ectoparasite infestations were observed in 55% (18/33) tapirs, of which 61% (11/18) were single infestations with ticks or fleas, and 39% (7/18) were mixed infestations with different species of ticks and/or fleas. In total, 227 ticks (15 larvae, 107 nymphs, 38 females and 67 males) and 14 fleas (eight females and six males) were collected, identifying four tick species (Amblyomma cajennense sensu stricto , Amblyomma naponense, Amblyomma oblongoguttatum, and Amblyomma pacae) and three flea species and/or subspecies (Ctenocephalides felis felis, Rhopalopsyllus australis australis, and Tunga penetrans). In conclusion, infestations with Ixodidae ticks and Rhopalopsyllidae, Pulicidae and Tungidae fleas were found in captive tapirs in the Brazilian Amazon, and A. cajennense s.s. was the most frequent species. Additionally, the present study reports new associations between A. pacae and R. a. australis with T. terrestris and between A. cajennense s.s. with T. kabomani.     

东山口岸1989～2004年鼠形动物及寄生蚤监测结果分析

〔目的〕通过分析东山口岸1989￣2004年鼠形动物及寄生蚤监测结果,掌握其变迁和染疫情况,为指导防鼠、灭鼠和灭蚤工作提供科学依据。〔方法〕1989￣2004年在东山口岸范围内和附近的居住区,采用笼捕法定期进行鼠形动物及寄生蚤调查。〔结果〕共捕获鼠形动物990只,经鉴定为2目2科4种;以褐家鼠为优势鼠类,占捕鼠总数的57.07%;年平均鼠密度为9.33%;带蚤鼠数162只,检蚤596匹,平均染蚤率为16.36%,蚤指数0.60,以黄胸鼠的染蚤率和蚤指数为最高,分别是43.56%和1.87;分离鼠体血清346份,经检测鼠疫F1抗体阴性。〔结论〕本次监测显示,年平均鼠密度已超过国家标准要求,虽没有发现鼠疫F1抗体存在,但一旦有鼠疫传入,极易造成鼠间鼠疫流行,甚至可能波及人类。