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Microbes and Infection 2015Bacteria of the genera Rickettsia and Orientia (family rickettsiaceae, order rickettsiales) cause rickettsioses worldwide, and are transmitted by lice, fleas, ticks and... (Review)
Review
Bacteria of the genera Rickettsia and Orientia (family rickettsiaceae, order rickettsiales) cause rickettsioses worldwide, and are transmitted by lice, fleas, ticks and mites. In Europe, only Rickettsia spp. cause rickettsioses. With improvement of hygiene, the risk of louse-borne rickettsiosis (epidemic typhus) is low in Europe. Nevertheless, recrudescent form of Rickettsia prowazekii infection persists. There could be an epidemic typhus outbreak if a body lice epidemic occurs under unfavorable sanitary conditions. In Europe, endemic typhus or Rickettsia typhi infection, transmitted by rats and fleas, causes febrile illness. At the beginning of this century, flea-borne spotted fever cases caused by Rickettsia felis were diagnosed. Flea-borne rickettsiosis should be suspected after flea bites if fever, with or without rash, is developed. Tick-borne rickettsioses are the main source of rickettsia infections in Europe. Apart from Rickettsia conorii, the Mediterranean Spotted Fever (MSF) agent, other Rickettsia spp. cause MSF-like: Rickettsia helvetica, Rickettsia monacensis, Rickettsia massiliae or Rickettsia aeschlimannii. In the 1990s, two 'new' rickettsioses were diagnosed: Lymphangitis Associated Rickettsiosis (LAR) caused by Rickettsia sibirica mongolitimonae, and Tick-Borne Lymphadenopathy/Dermacentor-Borne-Necrosis-Erythema-Lymphadenopathy/Scalp Eschar Neck Lymphadenopathy (TIBOLA/DEBONEL/SENLAT), caused by Rickettsia slovaca, Candidatus Rickettsia rioja and Rickettsia raoultii. Lastly, European reports about mite-borne rickettsiosis are scarce.
Topics: Animals; Arthropods; Europe; Humans; Orientia tsutsugamushi; Rickettsia; Rickettsia Infections; Scrub Typhus
PubMed: 26384814
DOI: 10.1016/j.micinf.2015.09.009 -
The American Journal of Tropical... Jan 2017Rickettsia typhi and Rickettsia felis are flea-borne rickettsiae that are distributed throughout the world. This mini-review outlines the ecology and epidemiology of... (Review)
Review
Rickettsia typhi and Rickettsia felis are flea-borne rickettsiae that are distributed throughout the world. This mini-review outlines the ecology and epidemiology of flea-borne rickettsioses; highlights important clinical, diagnostic, and therapeutic considerations; and discusses areas of uncertainty regarding Rickettsia felis and other rickettsiae harbored by fleas.
Topics: Animals; Ectoparasitic Infestations; Humans; Rickettsia Infections; Siphonaptera
PubMed: 27799640
DOI: 10.4269/ajtmh.16-0537 -
Current Tropical Medicine Reports 2016is an emerging insect-borne rickettsial pathogen and the causative agent of flea-borne spotted fever. First described as a human pathogen from the USA in 1991, is now... (Review)
Review
is an emerging insect-borne rickettsial pathogen and the causative agent of flea-borne spotted fever. First described as a human pathogen from the USA in 1991, is now identified throughout the world and considered a common cause of fever in Africa. The cosmopolitan distribution of this pathogen is credited to the equally widespread occurrence of cat fleas (), the primary vector and reservoir of . Although is a relatively new member of the pathogenic , limited knowledge of basic biology continues to hinder research progression of this unique bacterium. This is a comprehensive review examining what is known and unknown relative to transmission biology, epidemiology of the disease, and genetics, with an insight into areas of needed investigation.
PubMed: 27340613
DOI: 10.1007/s40475-016-0070-6 -
Research and Reports in Tropical... 2021Murine typhus and flea-borne spotted fever are undifferentiated febrile illnesses caused by and , respectively. These organisms are small obligately intracellular... (Review)
Review
Murine typhus and flea-borne spotted fever are undifferentiated febrile illnesses caused by and , respectively. These organisms are small obligately intracellular bacteria and are transmitted to humans by fleas. Murine typhus is endemic to coastal areas of the tropics and subtropics (especially port cities), where rats are the primary mammalian host and rat fleas () are the vector. In the United States, a cycle of transmission involving opossums and cat fleas () are the presumed reservoir and vector, respectively. The incidence and distribution of murine typhus appear to be increasing in endemic areas of the US. has also been reported throughout the world and is found within the ubiquitous cat flea. Flea-borne rickettsioses manifest as an undifferentiated febrile illness. Headache, malaise, and myalgia are frequent symptoms that accompany fever. The incidence of rash is variable, so its absence should not dissuade the clinician to consider a rickettsial illness as part of the differential diagnosis. When present, the rash is usually macular or papular. Although not a feature of murine typhus, eschar has been found in 12% of those with flea-borne spotted fever. Confirmatory laboratory diagnosis is usually obtained by serology; the indirect immunofluorescence assay is the serologic test of choice. Antibodies are seldom present during the first few days of illness. Thus, the diagnosis requires acute- and convalescent-phase specimens to document seroconversion or a four-fold increase in antibody titer. Since laboratory diagnosis is usually retrospective, when a flea-borne rickettsiosis is considered, empiric treatment should be initiated. The treatment of choice for both children and adults is doxycycline, which results in a swift and effective response. The following review is aimed to summarize the key clinical, epidemiological, ecological, diagnostic, and treatment aspects of flea-borne rickettsioses.
PubMed: 33574726
DOI: 10.2147/RRTM.S274724 -
Frontiers in Cellular and Infection... 2022We identified four flea-borne spotted fever cases caused by in a retrospective survey of 182 patients with fever of unknown origin (FUO) in China between 2021 and 2022....
We identified four flea-borne spotted fever cases caused by in a retrospective survey of 182 patients with fever of unknown origin (FUO) in China between 2021 and 2022. The clinical signs and symptoms of the patients were similar to those of other rickettsioses, including fever, rash, and liver and kidney dysfunction. All four patients in the present study developed pneumonia or lung lesions after infection. The cases of infection, a neglected infectious disease, were sporadic in multiple provinces of the country. The high prevalence (2.14%, 4/187) of among patients with FUO highlights the risk posed by this pathogen to public health in China.
Topics: China; Humans; Retrospective Studies; Rickettsia; Rickettsia Infections; Rickettsia felis
PubMed: 36211956
DOI: 10.3389/fcimb.2022.997315 -
Research and Reports in Tropical... 2018In this paper, we present a historical review of rickettsiosis in Central America and also the most recent findings of in ectoparasites. All countries of Central... (Review)
Review
In this paper, we present a historical review of rickettsiosis in Central America and also the most recent findings of in ectoparasites. All countries of Central America have records of rickettsiosis. Regarding the typhus group rickettsioses, there is clinical or serological evidence of in Guatemala, in Panama, Guatemala, and Costa Rica and unidentified species of the typhus group in El Salvador. Concerning spotted fever group rickettsiosis, there is serological evidence of infection by in Costa Rica and confirmed cases involving in Panama and Costa Rica. There are also reports of spotted fever group rickettsiosis in acute patients from Guatemala, Honduras, and Nicaragua. Serological studies in Central America show reactivity of , , , , and in domestic and wild mammals. Eight species of have been detected in ectoparasites from Central America: (or very similar), , , , , , , and , in addition to undescribed strains such as Atlantic Rainforest, Colombianensi, IbR/CRC, Barva, Aragaoi, and "Rickettsia nicoyana;" the latter being the only one associated with Argasidae (). is the most common species in Central America, seeing as it has been reported in 10 species of ticks and one of fleas in five of the seven countries of the region. In this study, we demonstrate that the genus is widely distributed in Central America and that rickettsiosis could be an underestimated problem in the absence of greater diagnostic efforts in undetermined febrile cases.
PubMed: 30050361
DOI: 10.2147/RRTM.S160951 -
Microorganisms Dec 2022Rickettsia felis is an emerging pathogen with increasing reports of human cases and detection in arthropod and animal host species worldwide. In this scoping review we... (Review)
Review
Rickettsia felis is an emerging pathogen with increasing reports of human cases and detection in arthropod and animal host species worldwide. In this scoping review we record the newest data reported for R. felis in Europe: the vector and host species found to be infected, and the geographical distribution and prevalence of R. felis infection in vectors and hosts. A total of 15 European countries reported the occurrence of R. felis in hosts and vectors during 2017−2022. The vectors found to be infected by R. felis were flea, tick and mite species; Ctenocephalides felis and Ixodes ricinus were the dominant ones. The hosts found to be infected and/or exposed to R. felis were humans, cats and small mammals. Physicians should be aware of the epidemiology and include illness caused by R. felis in the differential diagnosis of febrile disease. Veterinarians should keep training pet owners on the need for effective year-round arthropod control on their pets, especially for fleas.
PubMed: 36557744
DOI: 10.3390/microorganisms10122491 -
International Journal of Environmental... Apr 2022Although the cat flea, , has been identified as the primary vector of , additional flea, tick, mite, and louse species have also been associated with this bacterium by...
Although the cat flea, , has been identified as the primary vector of , additional flea, tick, mite, and louse species have also been associated with this bacterium by molecular means; however, the role of these arthropods in the transmission of has not been clarified. Here, we succeeded in culture isolation of from a host-seeking castor bean tick, , the most common tick in Slovakia. The bacterial isolation was performed on XTC-2 cells at 28 °C using the shell-vial technique. An evaluation of the growth properties was performed for both the XTC-2 and Vero cell lines. We observed in the infected host cells microscopically by Gimenez staining and immunofluorescence assay. The isolate was purified by gradient ultracentrifugation and visualized by electron microscopy. Fragments of the genes A, A, B, A, B, 4, E, and were amplified and compared with the corresponding sequences of the type strain URRWXCal2 and other culture -isolated strains. We did not detect any nucleotide polymorphisms; however, plasmid pRFδ, characteristic of the standard strain, was absent in our isolate. Herein, we describe the first successful isolation and characterization of a tick-derived strain "Danube", obtained from an nymph.
Topics: Animals; Arthropods; Cell Line; Ixodes; Rickettsia; Rickettsia felis
PubMed: 35410003
DOI: 10.3390/ijerph19074321 -
Frontiers in Veterinary Science 2018, the most well-characterized rickettsia of the -like organisms (RFLO), is relatively unknown within the vector-borne diseases research community. The agent was... (Review)
Review
, the most well-characterized rickettsia of the -like organisms (RFLO), is relatively unknown within the vector-borne diseases research community. The agent was initially identified in peri-domestic fleas from Asembo, Kenya in an area in which was associated with fever patients. Local fleas collected from domestic animals and within homes were predominately infected with with < 10% infected with . Since the identification of in Kenya, it has been reported in other locations within Africa, Asia, the Middle East, Europe, North America, and South America. With the description of -like genotypes across the globe, a need exists to isolate these genotypes in cell culture, conduct microscopic, and biological analysis, as well as whole genome sequencing to ascertain whether they are the same species. Additionally, interest has been building on the potential of in infecting vertebrate hosts including humans, non-human primates, dogs, and other animals. The current knowledge of the presence, prevalence, and distribution of worldwide, as well as its arthropod hosts and potential as a pathogen are discussed in this manuscript.
PubMed: 30687724
DOI: 10.3389/fvets.2018.00334