1,493 results match your criteria Tick-Borne Diseases Rocky Mountain Spotted Fever


Capybara (Hydrochoerus hydrochaeris) exposure to Rickettsia in the Federal District of Brazil, a non-endemic area for Brazilian spotted fever.

Rev Bras Parasitol Vet 2021 28;30(2):e028720. Epub 2021 May 28.

Laboratório de Patologia Clínica Veterinária, Faculdade de Agronomia e Veterinária - FAV, Universidade de Brasília - UnB, Brasília, DF, Brasil.

In this study, whole blood samples and ticks were collected from 57 capybaras in recreational areas in the Federal District, Brazil, aiming to investigate the presence of Rickettsia spp. using polymerase chain reaction (PCR) and indirect immunofluorescence (IFAT) assays. None of the capybara blood samples yielded rickettsial DNA by PCR. Read More

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Serological evidence of Rickettsia in horses from a semi-arid Brazilian region.

Rev Bras Parasitol Vet 2021 2;30(1):e026220. Epub 2021 Apr 2.

Laboratório de Doenças Parasitárias, Universidade Federal do Vale do São Francisco - UNIVASF, Petrolina, PE, Brasil.

Brazilian spotted fever (BSF) is a common tick-borne disease caused by Rickettsia rickettsii. Horses are the primary hosts of the main vector, Amblyomma sculptum, and are considered efficient sentinels for circulation of Rickettsia. Therefore, the aim of this study was to detect antibodies reactive to R. Read More

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Likely Geographic Distributional Shifts among Medically Important Tick Species and Tick-Associated Diseases under Climate Change in North America: A Review.

Insects 2021 Mar 5;12(3). Epub 2021 Mar 5.

Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA.

Ticks rank high among arthropod vectors in terms of numbers of infectious agents that they transmit to humans, including Lyme disease, Rocky Mountain spotted fever, Colorado tick fever, human monocytic ehrlichiosis, tularemia, and human granulocytic anaplasmosis. Increasing temperature is suspected to affect tick biting rates and pathogen developmental rates, thereby potentially increasing risk for disease incidence. Tick distributions respond to climate change, but how their geographic ranges will shift in future decades and how those shifts may translate into changes in disease incidence remain unclear. Read More

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A new focus of Brazilian spotted fever in the central-west region of São Paulo state, Brazil.

Rev Soc Bras Med Trop 2021 22;54:e0391-2020. Epub 2021 Mar 22.

Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia, Centro de Medicina e Pesquisa em Animais Selvagens, Departamento de Produção Animal e Medicina Veterinária Preventiva, Botucatu, SP, Brasil.

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Recent advances in understanding tick and rickettsiae interactions.

Parasite Immunol 2021 May 15;43(5):e12830. Epub 2021 Apr 15.

Center for Molecular and Cellular Biosciences, School of Biological. Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, USA.

Ticks are haematophagous arthropods with unique molecular mechanisms for digesting host blood meal while acting as vectors for various pathogens of public health significance. The tick's pharmacologically active saliva plays a fundamental role in modulating the host's immune system for several days to weeks, depending on the tick species. The vector tick has also developed sophisticated molecular mechanisms to serve as a competent vector for pathogens, including the spotted fever group (SFG) rickettsiae. Read More

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Significant Growth by Species within Human Macrophage-Like Cells Is a Phenotype Correlated with the Ability to Cause Disease in Mammals.

Pathogens 2021 Feb 19;10(2). Epub 2021 Feb 19.

Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA.

are significant sources of tick-borne diseases in humans worldwide. In North America, two species in the spotted fever group of have been conclusively associated with disease of humans: , the causative agent of Rocky Mountain spotted fever, and , the cause of rickettsiosis. Previous work in our lab demonstrated non-endothelial parasitism by another pathogenic SFG species, , within THP-1-derived macrophages, and we have hypothesized that this growth characteristic may be an underappreciated aspect of rickettsial pathogenesis in mammalian hosts. Read More

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February 2021

Assessment of the Pathogenicity of , , and in a Guinea Pig Model.

Vector Borne Zoonotic Dis 2021 Apr 17;21(4):232-241. Epub 2021 Feb 17.

Division of Vector Borne Diseases, Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.

Members of the genus range from nonpathogenic endosymbionts to virulent pathogens such as , the causative agent of Rocky Mountain spotted fever. Many rickettsiae are considered nonpathogenic because they have been isolated from ticks but not vertebrate hosts. We assessed the ability of three presumed endosymbionts: , , and , to infect a guinea pig animal model. Read More

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Isolate-Dependent Differences in Clinical, Pathological, and Transcriptional Profiles following and Infections with Rickettsia rickettsii.

Infect Immun 2021 Mar 17;89(4). Epub 2021 Mar 17.

Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.

, the etiological agent of Rocky Mountain spotted fever (RMSF), a life-threatening tick-borne disease that affects humans and various animal species, has been recognized in medicine and science for more than 100 years. Isolate-dependent differences in virulence of have been documented for many decades; nonetheless, the specific genetic and phenotypic factors responsible for these differences have not been characterized. Using and methods, we identified multiple phenotypic differences among six geographically distinct isolates of , representing isolates from the United States, Costa Rica, and Brazil. Read More

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The intracellular bacterium Rickettsia rickettsii exerts an inhibitory effect on the apoptosis of tick cells.

Parasit Vectors 2020 Dec 1;13(1):603. Epub 2020 Dec 1.

Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.

Background: Rickettsia rickettsii is a tick-borne obligate intracellular bacterium that causes Rocky Mountain spotted fever, a life-threatening illness. To obtain an insight into the vector-pathogen interactions, we assessed the effects of infection with R. rickettsii on the proteome cells of the tick embryonic cell line BME26. Read More

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December 2020

Rickettsial infection in equids, opossums and ticks in the municipality of Monte Mor, state of São Paulo, Brazil.

Rev Bras Parasitol Vet 2020 23;29(4):e015420. Epub 2020 Nov 23.

Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo - USP, São Paulo, SP, Brasil.

The aim of this study was to investigate rickettsial infection in equids, opossums and ticks in the municipality of Monte Mor, a place where a Brazilian spotted fever case occurred in 2005. In addition, characteristics possibly associated with seropositivity in horses were analyzed. Serum samples from horses, mules and opossums (Didelphis albiventris) were subjected to indirect immunofluorescence assay (IFA) against Rickettsia rickettsii. Read More

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January 2021

Knowledge, Attitudes, and Practices Related to Rocky Mountain Spotted Fever in Hermosillo, México.

Am J Trop Med Hyg 2021 01;104(1):184-189

4Department of Medicine and Health Sciences, University of Sonora, Hermosillo, Mexico.

Rocky Mountain spotted fever (RMSF) is a serious disease in northwest Mexico, particularly in low-income communities. This study aimed to evaluate RMSF-related knowledge, attitudes, and practices in an endemic urban area with a high burden of the disease. A cross-sectional study design using a non-probabilistic household survey was conducted with 400 residents in Hermosillo, Mexico. Read More

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January 2021

Is Rocky Mountain spotted fever the only disease of the spotted fever group rickettsioses found in Mexico?

Bol Med Hosp Infant Mex 2020 ;77(6):341-342

Departamento de Patología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City. Mexico.

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December 2020

A Space-Time Permutation Scan Statistic for Evaluating County-Level Tickborne Disease Clusters in Indiana, 2009-2016.

Health Secur 2021 Jan-Feb;19(1):108-115. Epub 2020 Nov 6.

Oghenekaro Omodior, PhD, is an Assistant Professor, School of Public Health, Indiana University, Bloomington, IN.

The purpose of this study was to identify age group, gender, rural-urban differences, and spatiotemporal clusters of tickborne disease diagnoses in Indiana. We analyzed retrospective surveillance data for Lyme disease, ehrlichiosis, Rocky Mountain spotted fever, typhus/rickettsial diseases, and tularemia diagnosed in Indiana from 2009 to 2016. We used chi-square cross tabulation to test gender, age group, and county classification (rural, rural-mixed, urban) differences in tickborne disease. Read More

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Epidemiology and Clinical Features of Rocky Mountain Spotted Fever from Enhanced Surveillance, Sonora, Mexico: 2015-2018.

Am J Trop Med Hyg 2021 01;104(1):190-197

2Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.

Rocky Mountain spotted fever (RMSF), caused by , is a severe and potentially fatal tick-borne disease. In 2015, Mexico issued a declaration of epidemiologic emergency in response to ongoing outbreaks of RMSF in northern Mexico. Sonora state is one of the most heavily impacted states in Mexico, with historic case fatality rates (CFRs) of 18%. Read More

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January 2021

Rickettsial pathogens circulating in urban districts of Rio de Janeiro, without report of human Brazilian Spotted Fever.

Rev Bras Parasitol Vet 2020 21;29(4):e014220. Epub 2020 Oct 21.

Pós-graduação em Medicina Veterinária, Clínica e Reprodução Animal, Faculdade de Veterinária, Universidade Federal Fluminense - UFF, Niterói, RJ, Brasil.

Spotted fever group rickettsioses are emerging diseases. In some of these diseases, domestic dogs act as sentinels. Canine serological studies have demonstrated that rickettsial dispersion is concentrated in rural areas, seroprevalence being higher where human rickettsioses are endemic. Read More

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January 2021

The guinea pig model for tick-borne spotted fever rickettsioses: A second look.

Ticks Tick Borne Dis 2020 11 7;11(6):101538. Epub 2020 Aug 7.

Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA. Electronic address:

The guinea pig (Cavia porcellus) has an established track record as an animal model, with its utility in rickettsial research documented as early as the turn of the 20 century. From identifying Rickettsia rickettsii as the agent of Rocky Mountain spotted fever and ticks as the natural transmission route to evaluating protective immunity and treatment for tick-borne rickettsiae, guinea pigs have been essential for advances in our understanding of spotted fever rickettsioses (SFR). Tick feeding on guinea pigs is feasible and results in transmission of tick-borne rickettsiae. Read More

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November 2020

Gastrointestinal and hepatic symptoms of tickborne diseases.

Vnitr Lek 2020 ;66(4):232-235

While investigating patients with gastrointestinal (GI) and/or hepatic symptoms, tickborne diseases are only rarely considered to be the cause. However, the Czech Republic is an endemic region for several of tickborne diseases and, therefore, they should be a part of differential diagnosis of GI symptoms of unknown origin. This article describes GI and hepatic symptoms of several tickborne diseases - Lyme disease, ehrlichiosis, Rocky mountain spotted fever, tularemia, Colorado tick fever, tickborne relapsing fever, Q fever and babesiosis. Read More

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November 2020

Habitat selection in natural and human-modified landscapes by capybaras (Hydrochoerus hydrochaeris), an important host for Amblyomma sculptum ticks.

PLoS One 2020 20;15(8):e0229277. Epub 2020 Aug 20.

Departamento de Ciências da Natureza, Matemática e Educação, Laboratório de Fauna, Universidade Federal de São Carlos, Araras, São Paulo, Brasil.

Human activities are changing landscape structure and function globally, affecting wildlife space use, and ultimately increasing human-wildlife conflicts and zoonotic disease spread. Capybaras (Hydrochoerus hydrochaeris) are linked to conflicts in human-modified landscapes (e.g. Read More

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September 2020

In vitro acaricidal activity of different ectoparasiticide classes against Amblyomma sculptum larvae.

Rev Bras Parasitol Vet 2020 Aug;29(3):e003020

Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro - UFRRJ, Seropédica, RJ, Brasil.

Zoonoses are major causes of morbidity and mortality worldwide. Among them, Brazilian Spotted Fever (BSF) is an important one that occurs in some regions of South America and can be transmitted by the "star tick" Amblyomma sculptum. Application of acaricides against the larval stage is important as strategy of population control. Read More

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Capybaras (Hydrochoerus hydrochaeris) as amplifying hosts of Rickettsia rickettsii to Amblyomma sculptum ticks: Evaluation during primary and subsequent exposures to R. rickettsii infection.

Ticks Tick Borne Dis 2020 09 7;11(5):101463. Epub 2020 May 7.

Department of Preventive Veterinary Medicine and Animal Health, Faculty of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil.

Rickettsia rickettsii is the agent of Brazilian spotted fever (BSF), the most lethal tick-borne disease in the western hemisphere. Amblyomma sculptum is the main vector of R. rickettsii in southeastern Brazil. Read More

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September 2020

Serosurvey of arthropod-borne diseases among shelter dogs in the Cumberland Gap Region of the United States.

BMC Vet Res 2020 Jun 30;16(1):221. Epub 2020 Jun 30.

College of Veterinary Medicine, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN, USA.

Background: The Cumberland Gap Region (CGR) of the United States is a natural corridor between the southeastern, northeastern, and midwestern regions of the country. CGR has also many species of ticks and mosquitos that serve as competent vectors for important animal and human pathogens. In this study, we tested dogs from six different animal shelters in the CGR for Rocky Mountain spotted fever (RMSF), anaplasmosis, Lyme disease, canine ehrlichiosis and canine heartworm disease. Read More

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New Jersey-Wide Survey of Spotted Fever Group (Proteobacteria: Rickettsiaceae) in and (Acari: Ixodida: Ixodidae).

Am J Trop Med Hyg 2020 09;103(3):1009-1016

Department of Entomology, Center for Vector Biology, Rutgers University, New Brunswick, New Jersey.

For the last decade, the New Jersey (NJ) Department of Health has reported between 42 and 144 new cases each year of "spotted fever group rickettsiosis" (SFGR), a statistic that reflects uncertainty regarding which rickettsial agents (Proteobacteria: Rickettsiaceae: ) are infecting NJ residents. To identify the circulating in NJ ticks, we used a combination of conventional and real time PCR approaches to screen 560 Say and 245 L. obtained from a 1-day state-wide surveillance in May 2018 and an additional 394 collected across NJ in 2013-2018. Read More

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September 2020

Brazilian spotted fever: A spatial analysis of human cases and vectors in the state of São Paulo, Brazil.

Zoonoses Public Health 2020 09 11;67(6):629-636. Epub 2020 Jun 11.

Universidade de São Paulo, São Paulo, Brazil.

Brazilian spotted fever (BSF) is a highly lethal disease caused by Rickettsia spp. and is transmitted by ticks of the genus Amblyomma. Understanding the epidemiology of BSF in each region can help direct health surveillance actions. Read More

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September 2020

An exploratory analysis of demography and movement patterns of dogs: New insights in the ecology of endemic Rocky Mountain-Spotted Fever in Mexicali, Mexico.

PLoS One 2020 21;15(5):e0233567. Epub 2020 May 21.

School of Veterinary Medicine, University of California, Davis, California, United States of America.

An outbreak of Rocky Mountain spotted fever (RMSF) transmitted by the brown dog tick (Rhipicephalus sanguineus sensu lato) has emerged as a major human and animal health concern in Mexicali, Mexico. Due to high rates of brown dog tick infestation, susceptibility, and association with humans, dogs serve as sentinels and have a key role in the ecology of RMSF. A cross-sectional household questionnaire study was conducted in six rural and urban locations to characterize dog ecology and demography in RMSF high-and low-risk areas of Mexicali. Read More

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Selective fragmentation of the trans-Golgi apparatus by Rickettsia rickettsii.

PLoS Pathog 2020 05 18;16(5):e1008582. Epub 2020 May 18.

Host-Parasite Interactions Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, United States of America.

Fragmentation of the Golgi apparatus is observed during a number of physiological processes including mitosis and apoptosis, but also occurs in pathological states such as neurodegenerative diseases and some infectious diseases. Here we show that highly virulent strains of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, induce selective fragmentation of the trans-Golgi network (TGN) soon after infection of host cells by secretion of the effector protein Rickettsial Ankyrin Repeat Protein 2 (RARP2). Remarkably, this fragmentation is pronounced for the trans-Golgi network but the cis-Golgi remains largely intact and appropriately localized. Read More

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Committee Opinion No. 399: Management of Tick Bites and Lyme Disease During Pregnancy.

J Obstet Gynaecol Can 2020 05;42(5):644-653

Halifax, NS.

Objective: Lyme disease is an emerging infection in Canada caused by the bacterium belonging to the Borrelia burgdorferi sensu lato species complex, which is transmitted via the bite of an infected blacklegged tick. Populations of blacklegged ticks continue to expand and are now established in different regions in Canada. It usually takes more than 24 hours of tick attachment to transfer B. Read More

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Tickborne Diseases: Diagnosis and Management.

Am Fam Physician 2020 05;101(9):530-540

Naval Hospital Camp Pendleton Family Medicine Residency Program, Camp Pendleton, CA, USA.

Tickborne diseases that affect patients in the United States include Lyme disease, Rocky Mountain spotted fever (RMSF), ehrlichiosis, anaplasmosis, babesiosis, tularemia, Colorado tick fever, and tickborne relapsing fever. Tickborne diseases are increasing in incidence and should be suspected in patients presenting with flulike symptoms during the spring and summer months. Prompt diagnosis and treatment can prevent complications and death. Read More

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The Ability of the Invasive Asian Longhorned Tick Haemaphysalis longicornis (Acari: Ixodidae) to Acquire and Transmit Rickettsia rickettsii (Rickettsiales: Rickettsiaceae), the Agent of Rocky Mountain Spotted Fever, Under Laboratory Conditions.

J Med Entomol 2020 09;57(5):1635-1639

Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA.

The invasive Asian longhorned tick, Haemaphysalis longicornis Neumann, was first detected in the United States in 2017. It has since been found in 12 states, and there is concern that the tick's parthenogenetic ability and wide variety of host species may allow for broader dissemination. Of the tick-borne diseases endemic to the United States, Rocky Mountain spotted fever (RMSF), a rapidly progressive and potentially fatal disease caused by Rickettsia rickettsii, is the most severe. Read More

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September 2020