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Vector Tick Transmission Model of Spotted Fever Rickettsiosis.

Many aspects of rickettsial infections have been characterized, including pathogenic and immune pathways and mechanisms of rickettsial survi … vels, histopathologic changes, and antibody response during tick transmission in mice infested with Amblyomma maculatum ticks carrying the emerging pathogen, Rickettia parkeri, were studied. Results showed distinct clinical signs in C3H/HeN mice infected intravenously, leading to selection of this mouse strain for tick transmission studies. Active infection …

Distribution of Spotted Fever Group Rickettsiae in Hard Ticks (Ixodida: Ixodidae) from Panamanian Urban and Rural Environments (2007-2013).

Tick-borne rickettsiosis is an important emerging disease in Panama; to date, there have been 12 confirmed cases, including eight fatalities. To evaluate the distribution of rickettsiae in Panamanian ticks, we collected questing and on-host ticks in urban and rural towns in elevations varying between 0 and 2300 m. A total of 63 sites (13 urban and 50 rural towns) were used to develop models of spatial distributions. We found the following tick species: Rhipicephalus sanguineus s.l. (present in 54 of 63 towns and cities), Amblyomma mixtum (45/63), Dermacentor nitens (40/63), A. ovale (37/63), R…

Risk factors associated with the transmission of Brazilian spotted fever in the Piracicaba river basin, State of São Paulo, Brazil.

INTRODUCTION: Brazilian spotted fever (BSF) is a disease transmitted by ticks for which the etiological agent is Rickettsia rickettsii. The … odel using a confidence interval (CI) of 95% were age (OR = 1.025 CI: 1.015-1.035), the presence of Amblyomma sculptum in the environment (OR = 1.629 CI: 1.097-2.439), the collection of ticks from horses (OR = 1.939 CI: 0.999-3.764), the presence of capybaras (OR = 1.467 CI: 1.009-2.138), an urban environment (OR = 1.515 CI: 1.036-2.231), and the existence …

A hard tick relapsing fever group spirochete in a Brazilian Rhipicephalus (Boophilus) microplus.

Tick-borne diseases usually comprise a complex epidemiological and ecological network connecting the vector, pathogen, and a group of host species. Symptoms associated with Lyme disease have been reported in Brazil, but no Borrelia sp. has been definitively related to these events. Here we have identified a B. lonestari/B. theileri-related spirochete DNA in the cattle tick Rhipicephalus (Boophilus) microplus from Brazil. Four hundred R. microplus and 80 Amblyomma cajennense ticks were screened, and only 1 horse-fed R. microplus was infected. A Borrelia sp. 16S rDNA sequence was amplified by po…

Emerging tick-borne disease in African vipers caused by a Cowdria-like organism.

Heartwater is a tick-borne infectious disease caused by the rickettsial organism Cowdria ruminantium, currently Ehrlichia ruminantium. It poses an imminent threat to the Western Hemisphere, where it could cause mortality in cattle and other ruminant livestock in excess of 70%. It has been reported in the Caribbean; and its vector, Amblyomma sparsum, has been found on imported African spurred tortoises (Geochelone sulcata) and leopard tortoises (Geochelone pardalis) in southern Florida in the United States, leading to an importation ban on these reptiles. Symptoms have not been previously repor…

Geographic distribution of ticks (Acari: Ixodidae) in Iowa with emphasis on Ixodes scapularis and their infection with Borrelia burgdorferi.

In Iowa, public concern regarding Lyme disease has increased markedly over the last decade. In response to these concerns, a statewide surveillance program was initiated in 1990 based on ticks received by the Department of Entomology at Iowa State University. Ticks were received from health care professionals, state government agencies, and the general public. A total of 5,343 ticks from all 99 Iowa counties were identified during the 12 years of this study. Dermacentor variabilis was the most numerous species, followed by Amblyomma americanum, and Ixodes scapularis. Dermacentor variabilis wer…

Introduced ticks and tick-borne diseases: the threat and approaches to eradication.

Exotic tick species and tick-borne diseases are serious threats to live-stock, companion animals, and wildlife in the United States. Recurri … d related infectious agents that threaten the United States, Boophilus ticks and bovine babesiosis, Amblyomma species (especially the tropical bont tick) and heartwater, and equine babesiosis, for which endemic vectors exist, are of special concern. Risk assessments to accumulate, evaluate, and synthesize information needed to appraise risks, consequences, …

Parasites of domestic and wild animals in South Africa. XL. Ticks on dogs belonging to people in rural communities and carnivore ticks on the vegetation.

Ixodid ticks were collected at weekly intervals from February 1999 to April 2000 from domestic dogs belonging to people in rural communities in north-eastern KwaZulu-Natal. Seven ticks were identified to species level and adult Haemaphysalis leachi followed by immature Amblyomma hebraeum and adult Rhipicephalus simus were the most prevalent. Infestation with adult H. leachi was most intense during February and March 1999 and from January to April 2000, and least intense during October 1999. Infestation with adult R. simus was most intense during February and March 1999 and least during July an…

Control of tsetse flies in Uganda by dipping cattle in deltamethrin.

The effect of treating cattle with deltamethrin to control tsetse flies and ticks was investigated on 2 ranches 8 km apart in central Uganda where there is a high risk of trypanosomosis. This area had a moderate challenge of Glossina pallidipes. The cattle had very low challenge of Rhipicephalus appendiculatus, Amblyomma variegatum, Boophilus decolaratus and Rhipicephalus evertsi evertsi, due to regular treatment with dioxathion. On one ranch a dip was charged with deltamethrin to treat cattle regularly for 3 months. The other ranch was used as a control for the tsetse population, but the anim…

Epidemiology of theileriosis in calves in an endemic area of Kenya.

Thirty-one calves born into five Maasai zebu cattle herds over a period of 1 month in the Trans-Mara Division of Kenya, endemic for theileri … es by 111 days of age. The earlier parasitosis by T. mutans reflected the higher infection rates in Amblyomma spp. than in Rhipicephalus appendiculatus. The mean number of R. appendiculatus on the ears of calves during the observations was 9.1 adults and 1.5 nymphs. Clinical episodes of T. mutans and T. parva infection were associated with febrile responses …

Records for ticks (Acari: Ixodidae) on free-ranging Coendou spinosus from State of São Paulo, Brazil.

Ticks and tick-borne diseases have spread since the mid-twentieth century largely due to major anthropogenic changes impacting natural ecosy … imals presented mixed infestations, with more than one tick species. The most prevalent species was Amblyomma longirostre, with samples from 86 animals, followed by A. parkeri (18 animals), A. dubitatum (1 animal), A. ovale (1 animal), A. sculptum (1 animal), and Haemaphysalis juxtakochi (1 animal). To the best of our knowledge, this is the first report of …

Diversity and prevalence of ticks associated to cattle and wild animals in lagoon ecosystems of northern Veracruz, México.

Understanding the diversity of ticks is crucial to comprehending their population dynamics and role in pathogen transmission. Between July 2 … three genera: Rhipicephalus microplus, Haemaphysalis leporispalustris, and six species of the genus Amblyomma (A. auricularium, A. dissimile, A. cf. tenellum, A. mixtum, A. ovale, and A. rotundatum). In wild animals, greater species richness was recorded with A. auricularium being the dominant species. In contrast, only two species were found in cattle. Int …

The Current State of Knowledge on Baggio-Yoshinari Syndrome (Brazilian Lyme Disease-like Illness): Chronological Presentation of Historical and Scientific Events Observed over the Last 30 Years.

Baggio-Yoshinari Syndrome (BYS) is an emerging Brazilian tick-borne infectious disease that clinically mimics Lyme Disease (LD) present in the Northern Hemisphere. LD is caused by spirochetes belonging to the Borrelia burgdorferi sensu lato complex and transmitted by Ixodid ticks of complex Ixodes rticinus. On the contrary, BYS is transmitted by hard Ixodid ticks of the genera Amblyomma, Rhipicephalus and Dermacentor. In 1992, the first cases of BYS were described in patients that developed EM rash, flu-like symptoms and arthritis after tick bite episodes. Since these findings, research in BYS…

Screening of the Promising Direct Thrombin Inhibitors from Haematophagous Organisms. Part I: Recombinant Analogues and Their Antithrombotic Activity In Vitro.

The success in treatment of venous thromboembolism and acute coronary syndromes using direct thrombin inhibitors has stimulated research aimed at finding a new anticoagulant from haematophagous organisms. This study deals with the comparison between hirudin-1 from Hirudomedicinalis(desirudin), being the first-known and most well-studied natural anticoagulant, along with recombinant analogs of haemadin from the leech Haemadipsa sylvestris, variegin from the tick Amblyomma variegatum, and anophelin from Anopheles albimanus. These polypeptides were chosen due to their high specificity and affinit…

Isolation of Severe Fever with Thrombocytopenia Syndrome Virus from Various Tick Species in Area with Human Severe Fever with Thrombocytopenia Syndrome Cases.

Severe fever with thrombocytopenia syndrome (SFTS), caused by Dabie bandavirus, generally called SFTS virus (SFTSV), is an emerging zoonosis in East Asia. In Japan, 50-100 cases of SFTS have been reported each year since the first case was reported in 2013. SFTS is a tick-borne infectious disease, and SFTSV has been isolated from ticks in China and South Korea. Haemaphysalis longicornis and Amblyomma testudinarium are considered the primary vectors in Japan. However, the other tick species seldom feeding on humans might also play an important role in maintaining the virus in nature. In this st…

Host movement and time of year influence tick parasitism in Pantanal birds.

Ticks are among the best studied parasitic groups as they spread important pathogens of medical and veterinary importance worldwide. Migratory birds can play an important role in transporting ticks infected with pathogens across wide geographic regions. It is therefore important to understand which factors promote tick parasitism rates across their avian hosts and the associated potential for disease spread. Here, we identified the host attributes of infestation probability of ticks from the genus Amblyomma in 955 birds from Pantanal, Brazil. Infestation rates exhibited considerable variation …

Prevalence of ectoparasite infestations in owned dogs in Kwara State, Nigeria.

In Nigeria, dogs are the common companions in many households and, harbor wide range of ectoparasites of severe zoonotic potentials. A cross … f three taxa were identified: ticks (Rhipicephalus sanguineus sensu lato, Haemaphysalis leachii and Amblyomma variegatum), fleas (Ctenocephalides canis and C. felis) and louse (Heterodoxus spiniger). R. sanguineus s.l. was the most prevalent (70.3%) followed by C. felis (42.1%) and H. spiniger (30.0%). Intensities of C. felis, H. spiniger and R. sanguineus …

Мобильность хостов и пространственное распространение Рикетсии Рикеттси.

Существует огромное число патогенов с многокомпонентными циклами передачи, включая приемные устройства усилителя, векторы или сложные патогенные жизненный циклы. Эти сложные системы создают проблемы с точки зрения моделирования и разработки политики. Одним из важных примеров этого является смертельное инфекционное заболевание, вызванное " клещами " , - бразильский " жар " (BSF). Текущее увеличение числа случаев применения БФС связано с присутствием и расширением гидрохера Капибары Гидрохера, усилителя для агента Рикетсии Рикеттсии и основного хоста для вектора Амблиоммы ску

Совпадение в аннотации оригинала
There are a huge number of pathogens with multi-component transmission cycles, involving amplifier hosts, vectors or complex pathogen life c … drochaeris, amplifier host for the agent Rickettsia rickettsii and primary host for the tick vector Amblyomma sculptum. We introduce a stochastic dynamical model that captures the spatial distribution of capybaras and ticks to gain a better understanding of the spatial spread of the R. rickettsii and potentially predict future epidemic outcomes. We implemen …

Conjugative Transposons and Their Cargo Genes Vary across Natural Populations of Rickettsia buchneri Infecting the Tick Ixodes scapularis.

Rickettsia buchneri (formerly Rickettsia endosymbiont of Ixodes scapularis, or REIS) is an obligate intracellular endoparasite of the black- … iont of Ixodes pacificus strain Humboldt, as well as a closely related species R. tamurae infecting Amblyomma testudinarium ticks. We further develop a novel multiplex droplet digital PCR assay and use it to quantify copy number ratios of chromosomal R. buchneri RAGE-A and RAGE-B to the single-copy gene gltA within natural populations of I. scapularis. Our …

Not All Erythema Migrans Lesions Are Lyme Disease.

BACKGROUND: Lyme disease is the number one arthropod-transmitted disease in the US, and one of the diagnostic criteria for the illness is development of an erythematous bull's-eye rash around a tick bite that may expand over time, hence the term erythema migrans. However, there are other erythema migrans-like rashes, such as those from a condition known as southern tick-associated rash illness. This article describes a patient with an erythema migrans-like lesion similar to that associated with Lyme disease, resulting from a bite by a nymphal-stage lone star tick, Amblyomma americanum. METHOD…