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update on tick-borne rickettsioses around the world: a geographic approach.tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus rickettsia. these zoonoses are among the oldest known vector-borne diseases. however, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. several species of tick-borne rickettsiae that wer ...024092850
rickettsia and vector biodiversity of spotted fever focus, atlantic rain forest biome, brazil. 024565262
spotted fever group rickettsia in the pampa biome, brazil, 2015-2016. 027767913
histopathology of tick-bite lesions in naturally infested capybaras (hydrochoerus hydrochaeris) in brazil.in the present work features of tick-bite lesions were evaluated in capybaras naturally infested with amblyomma cajennense and amblyomma dubitatum ticks. gross appearance of tick bite site was characterized by a mild swelling and erythema. microscopic examination revealed the cement cone, a tube-like homogenous eosinophilic mass penetrating deep into the dermis. this structure was surrounded in the dermis by a cellular infiltrate and free eosinophilic granules and was associated to edema of vari ...200516323054
[the effect of immersion in distilled water on the engorged larvae and nymphs of amblyomma dubitatum neumann, 1899 (acari: ixodidae)].to evaluate the effect of the immersion of engorged larvae and nymphs of amblyomma dubitatum experimentally fed on rabbits, the ticks were collected and formed control groups, without immersion, and groups witch were immersed by 24, 48, 72, 96 hours and, for engorged larvaes, by eight weeks, in test tubes containing distilled water. during all experiment ticks were kept at 27 +/- 1 degrees c, 80 +/- 10% ru and scotophase the parameters evaluated were: pre-ecdysis, ecdysis and moulting periods; a ...200616646997
species diversity and seasonality of free-living ticks (acari: ixodidae) in the natural habitat of wild marsh deer (blastocerus dichotomus) in southeastern brazil.this study evaluated the presence and seasonal activity of free-living ticks in remaining marsh areas by the paraná river, in brazil. eight field trips (once per season) for collection of ticks were performed during 2 years. using co2 traps, dragging, and visual inspection of vegetation, five free-living tick species were collected, in the following order of abundance: amblyomma cajennense, amblyomma dubitatum, amblyomma triste, amblyomma coelebs, and amblyomma nodosum. the seasonal pattern of a ...200716962241
isolation of rickettsia rhipicephali and rickettsia bellii from haemaphysalis juxtakochi ticks in the state of são paulo, brazil.in the present study, attempts to isolate rickettsia in cell culture were performed individually in seven specimens of haemaphysalis juxtakochi ticks collected in the state of são paulo (southeastern brazil). rickettsia was successfully isolated by the shell vial technique and established in vero cell culture from six ticks (six isolates). dna extracted from infected cells of these isolates was tested by pcr and dna sequencing, using genus-specific rickettsia primers targeting the genes glta, ht ...200717142361
rickettsia infection in five areas of the state of são paulo, brazil.this study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of são paulo. eight flea species (adoratopsylla antiquorum antiquorum, ctenocephalides felis felis, polygenis atopus, polygenis rimatus, polygenis roberti roberti, polygenis tripus, rhopalopsyllus lugubris, and rhopalopsyllus lutzi lutzi), and five tick species (amblyomma aureolatum, amblyomma cajennense, amblyomma dubitatum, ixodes loricatus, and rhipicephalus sanguineus) were ...200718094887
rickettsial infection in capybaras (hydrochoerus hydrochaeris) from são paulo, brazil: serological evidence for infection by rickettsia bellii and rickettsia parkeri.in brazil, capybaras (hydrochoerus hydrochaeris) are important hosts for amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. therefore, capybaras are potential sentinels for rickettsial infection.200718320102
molecular identification of rickettsia felis in ticks and fleas from an endemic area for brazilian spotted fever.rickettsioses are arthropod-borne diseases caused by parasites from the order rickettsiales. the most prevalent rickettsial disease in brazil is brazilian spotted fever (bsf). this work intends the molecular detection of those agents in ectoparasites from an endemic area of bsf in the state of espírito santo. a total of 502 ectoparasites, among them amblyomma cajennense, amblyomma dubitatum (a. cooperi), riphicephalus sanguineus, anocentor nitens and ctenocephalides felis, was collected from dom ...200818425272
[seasonal dynamics of the free-living stages of amblyomma cajennense and amblyomma dubitatum (acari: ixodidae) in an endemic area for spotted fever in coronel pacheco region, minas gerais state].a study on the population behavior of amblyomma cajennense and amblyomma dubitatum larvae, nymphs and adult free-living stages was carried out in coronel pacheco county, minas gerais state, brazil, a spotted feverendemic area from may 2006 to april 2008. larvae of amblyomma sp. were collected from pasture using the technique of drag sampling with flannelette during may to october 2006, starting from february 2007 to november 2007 and starting from march 2008. well-defined peaks of populations oc ...200820059821
francisella-like endosymbiont dna and francisella tularensis virulence-related genes in brazilian ticks (acari: ixodidae).ticks are vectors of a variety of pathogens, including francisella tularensis. bacteria in the genus francisella have been identified mostly in the northern hemisphere and include tick endosymbionts. francisella has never been described in brazil, where amblyomma spp. ticks are known as the vector of many bacterial zoonotic pathogens. in the present work, we have identified bacterial dna sequences with identity to francisella genes in amblyomma dubitatum neumann dermacentor nitens (neumann), and ...200919351090
[survey of rickettsia spp in the ticks amblyomma cajennense and amblyomma dubitatum in the state of são paulo].the presence of rickettsial infection was surveyed in 3,545 amblyomma cajennense ticks and 2,666 amblyomma dubitatum ticks. using the hemolymph test, polymerase chain reaction and isolation of rickettsia in cell cultures, all of the amblyomma cajennense were negative, whereas 634 (23.8%) of the amblyomma dubitatum ticks were shown to be infected with rickettsia bellii.200919684990
ticks (acari: ixodidae) within various phytophysiognomies of a cerrado reserve in uberlândia, minas gerais, brazil.cerrado biome, the south american savannah, covers about 2 million km(2) and is very rich in endemic species but threatened by agriculture. in this report free-living tick species are presented, and their seasonal and relative distribution within the various phytophysiognomies in a small cerrado reserve in minas gerais state, brazil. overall 2,694 free-living ticks were found during a 2 years sampling period with co(2) traps and cloth dragging. of these, 73.5% were amblyomma cajennense and 0.6% ...201019693680
hosts, distribution and genetic divergence (16s rdna) of amblyomma dubitatum (acari: ixodidae).we supply information about hosts and distribution of amblyomma dubitatum. in addition, we carry out an analysis of genetic divergence among specimens of a. dubitatum from different localities and with respect to other neotropical amblyomma species, using sequences of 16s rdna gene. although specimens of a. dubitatum were collected on several mammal species as cattle horse, tapirus terrestris, mazama gouazoubira, tayassu pecari, sus scrofa, cerdocyon thous, myocastor coypus, allouata caraya, glo ...201020084537
wide dispersal and possible multiple origins of low-copy-number plasmids in rickettsia species associated with blood-feeding arthropods.plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. we report the existence of plasmids in rickettsia (rickettsiales; rickettsiaceae) species, including rickettsia akari, "candidatus rickettsia amblyommii," r. bellii, r. rhipicephali, and reis, the rickettsial endosymbiont of ixodes scapularis. all of the rickettsiae were isolated from humans or north and south american ticks. r. parkeri isolates from b ...201020097813
isolation of rickettsia parkeri and identification of a novel spotted fever group rickettsia sp. from gulf coast ticks (amblyomma maculatum) in the united states.until recently, amblyomma maculatum (the gulf coast tick) had garnered little attention compared to other species of human-biting ticks in the united states. a. maculatum is now recognized as the principal vector of rickettsia parkeri, a pathogenic spotted fever group rickettsia (sfgr) that causes an eschar-associated illness in humans that resembles rocky mountain spotted fever. a novel sfgr, distinct from other recognized rickettsia spp., has also been detected recently in a. maculatum specime ...201020208020
experimental infection of the opossum didelphis aurita by rickettsia felis, rickettsia bellii, and rickettsia parkeri and evaluation of the transmission of the infection to ticks amblyomma cajennense and amblyomma dubitatum.this work evaluated the infection of opossums (didelphis aurita) by rickettsia felis, rickettsia bellii, and rickettsia parkeri and their role as amplifier hosts for horizontal transmission to amblyomma cajennense and/or amblyomma dubitatum ticks. infection in d. aurita was induced by intraperitoneal inoculation with r. felis (n = 4 opossums), r. bellii (n = 4), and r. parkeri (n = 2). another group of six opossums were inoculated intraperitoneally with leibovitz-15 sterile culture medium, repre ...201020455783
survey for tick-borne zoonoses in the state of espirito santo, southeastern brazil.blood samples collected from 201 humans, 92 dogs, and 27 horses in the state of espirito santo, brazil, were tested by polymerase chain reaction, indirect immunofluorescence assays, and indirect enzyme-linked immunosorbent assay for tick-borne diseases (rickettsiosis, ehrlichiosis, anaplasmosis, borreliosis, babesiosis). our results indicated that the surveyed counties are endemic for spotted fever group rickettsiosis because sera from 70 (34.8%) humans, 7 (7.6%) dogs, and 7 (25.9%) horses were ...201020595502
survey of ticks (acari: ixodidae) and their rickettsia in an atlantic rain forest reserve in the state of são paulo, brazil.the current study investigated the occurrence of ticks and their rickettsiae in the serra do mar state park, which encompasses one of the largest atlantic rain forest reserves of brazil. from july 2008 to june 2009, a total of 2439 ticks (2,196 free living and 243 collected on hosts) was collected, encompassing the following 13 species: amblyomma aureolatum (pallas), amblyomma brasiliense aragao, amblyomma dubitatum neumann, amblyomma fuscum neumann, amblyomma incisum neumann, amblyomma longiros ...201020939390
ticks infesting wildlife species in northeastern brazil with new host and locality records.from september 2008 to march 2010, 397 ticks (315 larvae, 33 nymphs, 23 females, and 26 males) were collected from captive and free-living wildlife species in northeastern brazil. six tick species were identified, including amblyomma auricularium (conil) on tamandua tetradactyla (l.), amblyomma dubitatum neumann on hydrochaeris hydrochaeris (l.), nectomys rattus (pelzen) and t. tetradactyla, amblyomma parvum aragão on t. tetradactyla, amblyomma rotundatum koch on boa constrictor l., chelonoidis ...201021175080
a novel rickettsia infecting amblyomma dubitatum ticks in brazil.a total of 130 adult free-living ticks of amblyomma cajennense and 9 free-living amblyomma dubitatum were collected in the surroundings of the pampulha lake, within belo horizonte city, state of minas gerais, south-eastern brazil. each adult tick was tested for rickettsial infection by pcr protocols targeting the rickettsial genes glta, htra, and ompa. all the 130 a. cajennense ticks were negative by pcr. in contrast, all 9 a. dubitatum ticks were shown to contain rickettsial dna. pcr products w ...201122108014
rickettsia species infecting amblyomma ticks from an area endemic for brazilian spotted fever in brazil.this study reports rickettsial infection in amblyomma cajennense and amblyomma dubitatum ticks collected in an area of the state of minas gerais, brazil, where brazilian spotted fever is considered endemic. for this purpose, 400 adults of a. cajenennse and 200 adults of a. dubitatum, plus 2,000 larvae and 2,000 nymphs of amblyomma spp. were collected from horses and from the vegetation. the ticks were tested for rickettsial infection through polymerase chain reaction (pcr) protocols targeting po ...201122166385
spotted fever group rickettsia infecting ticks (acari: ixodidae) in the state of santa catarina, brazil.during 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of santa catarina (sc), brazil, including areas where human cases of brazilian spotted fever have been reported. collected ticks belonging to nine species (amblyomma aureolatum, amblyomma cajennense, amblyomma dubitatum, amblyomma longirostre, amblyomma ovale, amblyomma tigrinum, dermacentor nitens, rhipicephalus microplus and rhipicephalus sanguineus) were tested by polym ...201122241112
rickettsial infection in ticks collected from road-killed wild animals in rio de janeiro, brazil.during 2008-2010, ticks were collected from road-killed wild animals within the serra dos orgãos national park area in the state of rio de janeiro, brazil. in total, 193 tick specimens were collected, including amblyomma dubitatum neumann and amblyomma cajennense (f.) from four hydrochoerus hydrochaeris (l.), amblyomma calcaratum neumann and a. cajennense from four tamandua tetradactyla (l.), amblyomma aureolatum (pallas) and a. cajennense from five cerdocyon thous l., amblyomma longirostre (koc ...201223270184
rickettsia bellii infecting amblyomma sabanerae ticks in el salvador.four amblyomma sabanerae ticks collected from a turtle (kinosternon sp.) in san miguel, el salvador, were found by molecular analysis to be infected by rickettsia bellii. we provide the first report of rickettsia bellii in central america, and the first report of a rickettsia species in el salvador.201223265378
comparative efficiency of two models of co2 traps in the collection of free-living stages of ixodides.traps using carbon dioxide (co(2)) as a chemical attractant are known to be effective when capturing nymphs and adults of some free-living tick species such as amblyomma cajennense and amblyomma parvum. despite the fact that the main source of co(2) is dry ice, the chemical trap which uses 20 % lactic acid (c(3)h(6)o(3)) and calcium carbonate (caco(3)) has been tested as an alternative source of co(2) whenever it is difficult to obtain dry ice. the objective of this paper was to test and compare ...201222915273
ticks (acari: ixodidae) associated with small terrestrial mammals in the state of minas gerais, southeastern brazil.from june 2005 to november 2010, 43 small mammals encompassing 6 species of didelphimorphia, 8 species of rodentia, and 1 species of lagomorpha were found parasitized by ticks in the state of minas gerais, southeastern brazil. nine tick species, in total 186 specimens, were identified as follows: amblyomma cajennense (larvae and nymphs) on opossums and rodents; amblyomma ovale (nymphs) on rodents; amblyomma parvum (nymphs) on rodents; amblyomma coelebs (nymphs) on opossums; amblyomma dubitatum ( ...201222585005
capybaras and ticks in the urban areas of uberlândia, minas gerais, brazil: ecological aspects for the epidemiology of tick-borne diseases.in brazil capybara, the biggest existing rodent species, and associated tick species, amblyomma cajennense and amblyomma dubitatum, are undergoing an unplanned host and parasite population expansion in both urban and rural areas. however, scientific information about such issue, particularly in urban areas, is scanty. such rodent and ticks are associated in some municipalities, particularly in southeastern brazil, with the transmission of the highly lethal rickettsia rickettsia caused spotted-fe ...201222349945
ticks on birds in a savanna (cerrado) reserve on the outskirts of uberlândia, minas gerais, brazil.we report tick infestations on birds, in the environment and on domestic animals in a non-forested phytophysiognomy, the savanna-like cerrado sensu stricto, in a natural reserve on the outskirts of the urban area of uberlândia, minas gerais, brazil. overall, 238 birds within 50 species, 15 families and six orders were caught. passeriformes were the most numerous, with 216 birds (90.75%), among which 22 had ticks (n = 31). within this order, the prevalence of tick infestation was 10.2%, and the a ...201323471429
environmental infestation and rickettsial infection in ticks in an area endemic for brazilian spotted fever.brazilian spotted fever (bsf), caused by rickettsia rickettsii, is endemic in the municipality of americana, southeastern brazil, where the disease is transmitted by the tick amblyomma cajennense. this study evaluated the tick fauna and rickettsial infection in free-living ticks that were captured monthly using dry ice traps in areas endemic for bsf in americana, from july 2009 to june 2010. two tick species were captured: a. cajennense (6,122 larvae; 4,265 nymphs; 2,355 adults) and amblyomma du ...201324142167
ecology, biology and distribution of spotted-fever tick vectors in brazil.spotted-fever-caused rickettsia rickettsii infection is in brazil the major tick-borne zoonotic disease. recently, a second and milder human rickettsiosis caused by an agent genetically related to r. parkeri was discovered in the country (atlantic rainforest strain). both diseases clearly have an ecological background linked to a few tick species and their environment. capybaras (hydrochoerus hydrochaeris) and amblyomma cajennense ticks in urban and rural areas close to water sources are the mai ...201323875178
importation of exotic ticks and tick-borne spotted fever group rickettsiae into the united states by migrating songbirds.birds are capable of carrying ticks and, consequently, tick-transmitted microorganisms over long distances and across geographical barriers such as oceans and deserts. ticks are hosts for several species of spotted fever group rickettsiae (sfgr), which can be transmitted to vertebrates during blood meals. in this study, the prevalence of this group of rickettsiae was examined in ticks infesting migratory songbirds by using polymerase chain reaction (pcr). during the 2009 and 2010 spring migratio ...201324252263
molecular epidemiology of the emerging zoonosis agent anaplasma phagocytophilum (foggie, 1949) in dogs and ixodid ticks in brazil.anaplasma phagocytophilum is an emerging pathogen of humans, dogs and other animals, and it is transmitted by ixodid ticks. the objective of the current study was a) detect a. phagocytophilum in dogs and ixodid ticks using real-time polymerase chain reaction (qpcr); and b) determine important variables associated to host, environment and potential tick vectors that are related to the presence of a. phagocytophilum in dogs domiciled in rio de janeiro, brazil.201324330631
rickettsial infection in amblyomma cajennense ticks and capybaras (hydrochoerus hydrochaeris) in a brazilian spotted fever-endemic area.brazilian spotted fever (bsf), caused by the bacterium rickettsia rickettsii, is the deadliest spotted fever of the world. in most of the bsf-endemic areas, capybaras (hydrochoerus hydrochaeris) are the principal host for the tick amblyomma cajennense, which is the main vector of bsf.201424387674
experimental infection with rickettsia rickettsii in an amblyomma dubitatum tick colony, naturally infected by rickettsia bellii.amblyomma dubitatum engorged females, naturally infected by rickettsia bellii, were used to establish a laboratory colony. larvae, nymphs, and adults were exposed to two strains of rickettsia rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs. after acquisition feeding, engorged larvae and nymphs molted to nymphs and adults, respectively, which were shown to be infected (confirming transstadial perpetuation), and were able to transmit both str ...201425108783
molecular detection of rickettsia species in amblyomma ticks collected from snakes in thailand.some reptile ticks are potential vectors of pathogens such as spotted fever group (sfg) rickettsiae. here, we report for the first time in detail the molecular evidence, dna sequences and phylogenetic studies, for the presence of rickettsia spp. in amblyomma ticks (amblyomma helvolum and amblyomma varanense) from snakes in thailand. a total of 24 tick samples was collected from 4 snake species and identified. a phylogenetic analysis inferred from the partial sequences of the glta gene indicated ...201425027232
ticks (acari: ixodidae) on wild birds in north-central argentina.ixodid ticks were collected from wild birds in five ecoregions in north-central argentina, namely: selva de las yungas, esteros del iberá, delta e islas del paraná, selva paranaense and chaco seco. a total of 2199 birds belonging to 139 species, 106 genera, 31 families and 11 orders were captured, but ticks were collected only from 121 birds (prevalence=5.5%) belonging to 39 species (28.1%) and three orders: tinamiformes (tinamidae) and falconiformes (falconidae) in selva de las yungas and passe ...201425108788
natural infestation of hydrochoerus hydrochaeris by amblyomma dubitatum ticks.natural infestation of amblyomma dubitatum in relation to individual specific attributes of hydrochoerus hydrochaeris such as sex, body mass and body condition was analyzed. the anatomical distribution of a. dubitatum on h. hyrochaeris was also evaluated. prevalence of adults and nymphs were significantly higher than prevalence of larvae. non-significant differences in the infestation levels were found among host sex. multiple regression analysis did not show any statistically significant associ ...201424469297
study of the life cycle of amblyomma dubitatum (acari: ixodidae) based on field and laboratory data.the life cycle of amblyomma dubitatum was described based on the seasonal distribution of all parasitic stages and the development periods of engorged ticks under different conditions of photoperiod and temperature. all stages were found active along the entire year in the study area. larvae peaked from may to july, nymphs peaked from july to october, and females peaked from november to march. this pattern represents a life cycle with one generation per year with most of the ticks reaching adult ...201424458810
first molecular detection of rickettsia parkeri in amblyomma tigrinum and amblyomma dubitatum ticks from uruguay.rickettsia parkei is the etiological agent of spotted fever in uruguay, where is transmitted to humans by the tick amblyomma triste. in the present study, ticks were collected from capybaras (hydrochoerus hydrochaeris) and domestic dogs during 2011-2012 in different parts of uruguay. three out of 11 (27.3%) amblyomma dubitatum ticks collected from capybaras, and 4 out of 6 (66.7%) amblyomma tigrinum ticks collected from dogs were shown by molecular analyses to be infected by rickettsia parkeri s ...201425108780
new tick records from the state of rondônia, western amazon, brazil.from 2005 to 2012, ticks were collected from different hosts at different localities of the state of rondônia. the following 16 ixodid tick species were identified: ixodes fuscipes, amblyomma auricularium, amblyomma coelebs, amblyomma dubitatum, amblyomma geayi, amblyomma humerale, amblyomma latepunctatum, amblyomma longirostre, amblyomma naponense, amblyomma nodosum, amblyomma oblongoguttatum, amblyomma ovale, amblyomma romitii, amblyomma rotundatum, amblyomma scalpturatum, and amblyomma varium ...201423975565
molecular detection of the human pathogenic rickettsia sp. strain atlantic rainforest in amblyomma dubitatum ticks from argentina.to date, three tick-borne pathogenic rickettsia species have been reported in different regions of argentina, namely, r. rickettsii, r. parkeri, and r. massiliae. however, there are no reports available for the presence of tick-borne pathogens from the northeastern region of argentina. this study evaluated the infection with rickettsia species of amblyomma dubitatum ticks collected from vegetation and feeding from capybaras (hydrochoerus hydrochaeris) in northeastern argentina. from a total of 3 ...201525700048
amblyomma yucumense n. sp. (acari: ixodidae), a parasite of wild mammals in southern brazil.during 2013-2014, adult ticks were collected on the vegetation and subadult ticks were collected from small mammals [didelphis aurita wied-neuwied, sooretamys angouya (fischer), euryoryzomys russatus (wagner), akodon montensis thomas, oxymycterus judex thomas] in an atlantic rainforest reserve in southern brazil. analyses of the external morphology of the adult ticks revealed that they represent a new species, amblyomma yucumense n. sp. partial 16s rrna sequences generated from males, females, a ...201526336277
rickettsia parkeri infecting free-living amblyomma triste ticks in the brazilian pantanal.the present study evaluated the infection of rickettsiae in 151 rhipicephalus sanguineus, 59 amblyomma ovale, 166 amblyomma triste, one amblyomma dissimile and four amblyomma dubitatum ticks collected in the municipality of poconé, state of mato grosso, within the pantanal biome of brazil. ticks were individually processed by the hemolymph test with gimenez staining, isolation of rickettsia in vero cell culture by the shell vial technique, and polymerase chain reaction (pcr) targeting the citrat ...201525650348
rickettsial infection in animals, humans and ticks in paulicéia, brazil.a previous study in paulicéia municipality, south-eastern brazil, reported 9.7% of the amblyomma triste ticks to be infected by rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. these a. triste ticks were shown to be associated with marsh areas, where the marsh deer blastocerus dichotomus is a primary host for this tick species. during 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (didelphis albiventris) and 26 humans in farms from ...201525643912
spotted fever group rickettsia in amblyomma dubitatum tick from the urban area of campo grande, mato grosso do sul, brazil.rickettsia infection of each tick was evaluated by the hemolymph test and polymerase chain reaction (pcr) targeting glta and ompa genes. all hemolymph tests were negative and pcr of one a. dubitatum detected both rickettsia genes. sequence of ompa exhibited a 99% identity with rickettsia parkeri and r. africae and a 98% identity with r. sibirica. rickettsia of the spotted fever group in a. dubitatum is described for the first time in an urban area within the municipality of campo grande in the s ...201525454606
association patterns of ticks (acari: ixodida: ixodidae, argasidae) of small mammals in cerrado fragments, western brazil.the present study describes ticks associated with small mammals and analyzes the aggregation patterns according to seasonal and host variations in the cerrado biome, central-western brazil. small mammals were systematically captured in 54 woodland fragments from february 2012 to july 2013. a total of 1,040 animals belonging to eight marsupial and 12 rodent species were captured; 265 animals were parasitized by eight tick species (in decreasing order of abundance): ornithodoros mimon, amblyomma c ...201525633262
ticks (acari: ixodidae) identified from prey-predator interactions via faecal analysis of brazilian wild carnivores.between july 2008 and may 2010, we conducted a trophic study on 12 brazilian wild carnivore species through their faecal analysis in a silvicultural landscape at angatuba municipality, southern são paulo state. predator faeces was identified by morphology, predator hair, and surrounding tracks; prey remnants within faeces were used for morphological identification of the prey. among the recovered ectoparasites, there were 89 specimens of six tick species in 21 (4.0%) out of 523 analysed samples. ...201525702204
high prevalence of "candidatus rickettsia andeanae" and apparent exclusion of rickettsia parkeri in adult amblyomma maculatum (acari: ixodidae) from kansas and oklahoma.amblyomma maculatum (the gulf coast tick), an aggressive, human-biting, nearctic and neotropical tick, is the principal vector of rickettsia parkeri in the united states. this pathogenic spotted fever group rickettsia species has been identified in 8-52% of questing adult gulf coast ticks in the southeastern united states. to our knowledge, r. parkeri has not been reported previously from adult specimens of a. maculatum collected in kansas or oklahoma. a total of 216 adult a. maculatum ticks wer ...201525773931
challenges posed by tick-borne rickettsiae: eco-epidemiology and public health implications.rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. however, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vert ...201525954738
epidemiological surveillance of capybaras and ticks on warning area for brazilian spotted fever.the vulnerability of tropical developing countries to the emerging disease constitutes a critical phenomenon in which the invasion of wild niches by human hosts, contributes to expansion of zoonotic diseases, such as the brazilian spotted fever (bsf). this study performed a diagnosis of species occurrence of their hosts (hydrochoerus hydrochaeris) and vectors (amblyomma sculptum and amblyomma dubitatum) on the warning area for this reemerging disease in brazil.201527047211
avian migrants facilitate invasions of neotropical ticks and tick-borne pathogens into the united states.migratory birds have the potential to transport exotic vectors and pathogens of human and animal health importance across vast distances. we systematically examined birds that recently migrated to the united states from the neotropics for ticks. we screened both ticks and birds for tick-borne pathogens, including rickettsia species and borrelia burgdorferi. over two spring seasons (2013 and 2014), 3.56% of birds (n = 3,844) representing 42.35% of the species examined (n = 85) were infested by ti ...201526431964
vector potential and population dynamics for amblyomma inornatum.we studied the natural life cycle of amblyomma inornatum and its vector potential in south texas. this tick is distributed throughout south texas and most of central america. a. inornatum represented 1.91% of the ticks collected by carbon dioxide traps during a study of free-living ticks in the tamaulipan biotic province in south texas. the life cycle of a. inornatum in south texas showed a clear seasonal pattern consistent with one generation per year. nymphs emerged in the spring with a peak i ...201525881916
high seroprevalence for rickettsia rickettsii in equines suggests risk of human infection in silent areas for the brazilian spotted fever.equines play a role in the epidemiology of brazilian spotted fever (bsf) since they are a primary host for the tick amblyomma sculptum. we studied the seroprevalence for three species of rickettsia in equines in four endemic (with human cases) and in four non-endemic areas (no human cases) in the piracicaba river basin, são paulo, brazil. a serological survey of 504 equines was performed: around 63 animals were sampled in each area and tested through indirect immunofluorescence assay for r. rick ...201627064788
ecology of a tick-borne spotted fever in southern brazil.rio grande do sul is the southernmost state of brazil, bordering uruguay. clinical cases of spotted fever group (sfg) rickettsiosis were recently reported in rio grande do sul. none of these cases was lethal, and all were confirmed by seroconversion to r. rickettsii antigens. because serological cross-reactions are well known to occur between different sfg agents, the sfg agent responsible for the clinical cases remains unknown in rio grande do sul, where no rickettsial agent is known to infect ...201627392739
serologic evidence of the exposure of small mammals to spotted-fever rickettsia and rickettsia bellii in minas gerais, brazil.sources of pathogenic rickettsia in wildlife are largely unknown in brazil. in this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group rickettsia (r. rickettsii, r. parkeri, r. amblyommii and r. rhipicephali) and rickettsia bellii from peri-urban areas of uberlândia, a major town in brazil, are described for the first time.201627031460
ticks infesting humans in northern misiones, argentina.this work presents records of ticks infesting humans in northern misiones province, argentina. also, notes on potential transmission of tick-borne pathogens are included. a total of 282 ticks attached to researchers were collected and identified by their morphological characters. eight tick species were found: amblyomma brasiliense, amblyomma coelebs, amblyomma dubitatum, amblyomma incisum, amblyomma ovale, haemaphysalis juxtakochi, rhipicephalus sanguineus and rhipicephalus microplus. some of t ...201627135846
evaluation of an association of alpha-cypermethrin and flufenoxuron for tick control in an area at risk of brazilian spotted fever.brazilian spotted fever (bsf) is an endemic anthropozoonosis caused by gram-negative bacteria (rickettsia rickettsii) that is associated with the risk of human infection by ticks. in the city of americana, são paulo (sp), brazil, there were 12 cases (67% lethal) between 2004 and 2015. this study evaluated the effectiveness of control over tick infestations in an area at risk of bsf, in a field trial on an association of alpha-cypermethrin (3%) and flufenoxuron (3%) (tenopa(®)) conducted in ameri ...201728377149
spotted fever: epidemiology and vector-rickettsia-host relationship in rio de janeiro state.the eco-epidemiological scenario of spotted fever (sf), a tick-borne disease that affects humans and other animals in several countries around the world, was analyzed in rio de janeiro (rj) state, brazil. during the last 34 years, 990 sf cases were reported in rj (the brazilian state with the highest population density), including 116 cases confirmed by serology (rifi) or pcr, among 42.39% of the municipalities with reported cases of sf. the epidemiologic dynamics of sf in rj state are very hete ...201728424664
microorganisms in ticks (acari: ixodidae) collected on marsupials and rodents from santa catarina, paraná and mato grosso do sul states, brazil.information about tick fauna and monitoring of pathogen prevalences in ticks (acari: ixodidae) in various habitat types can enhance knowledge about the epidemiology of tick-borne pathogens in brazil. this work shows the results of a study of tick parasitism of wild rodents and marsupials collected in seven localities in the southern part of brazil, within atlantic forest and cerrado biomes. a total of 61 ticks were collected from small mammals, and after identification to the species level, the ...201727769655
rickettsia parkeri in amblyomma dubitatum ticks in a spotted fever focus from the brazilian pampa.spotted fever is an acute febrile illness, which is considered severely underreported and misdiagnosed in the brazilian pampa, caused by tick-borne rickettsiae. here, we report an eco-epidemiological investigation of rickettsia spp. in ticks from a spotted fever focus in toropi, southern brazil. ticks were collected from capybara carcasses and processed individually to obtain genomic dna. rickettsia was investigated using pcr that amplified the rickettsial fragments of the glta, ompa and htra ge ...201728359827
influence of microhabitat use and behavior of amblyomma sculptum and amblyomma dubitatum nymphs (acari: ixodidae) on human risk for tick exposure, with notes on rickettsia infection.brazilian spotted fever (bsf) is a potentially lethal human disease caused by rickettsia rickettsii transmitted by ticks, including amblyomma sculptum. however, in southeast brazil, where most bsf cases occur, capybaras are key hosts for both a. sculptum and amblyomma dubitatum. we therefore compared the risk of human exposure to these ticks at a non-endemic anthropogenic site in southeast brazil where both tick species are maintained by capybaras and occur at high abundance. cloth dragging, hum ...201829050834
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