2,753 results match your criteria Rickettsialpox


Fluazuron orally administered to guinea pigs: pharmacokinetic and efficacy against Amblyomma sculptum.

Parasit Vectors 2022 Jun 10;15(1):198. Epub 2022 Jun 10.

Animal Parasitology Department, Veterinary Institute, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil.

Background: Brazilian spotted fever (BSF), the most lethal tick-borne disease in the Western Hemisphere, is caused by the bacterium Rickettsia rickettsii and transmitted by the bite of Amblyomma sculptum. Capybaras are considered primary hosts of this tick and amplifier hosts of R. rickettsii, generating new infected lineages of A. Read More

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Seasonal dynamics of Amblyomma sculptum: a review.

Parasit Vectors 2022 Jun 6;15(1):193. Epub 2022 Jun 6.

Programa de Pós-Graduação em Ciência Animal, Universidade Federal de Goiás (UFG), Avenida Esperança, s/n, Campus Samambaia, Goiânia, Goiás, 74690-900, Brazil.

Background: Amblyomma sculptum is a hard tick that is associated with domestic animals and the transmission of Brazilian spotted fever. This association has motivated several field studies on this ixodid tick within its distribution area in South America. Thorough knowledge of the seasonal dynamics of A. Read More

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Multiplex TaqMan Quantitative PCR Assays for Host-Tick-Pathogen Studies Using the Guinea Pig-Tick- System.

Pathogens 2022 May 18;11(5). Epub 2022 May 18.

Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA.

Spotted Fever Rickettsiosis (SFR) is caused by spotted fever group spp. (SFGR), and is associated with symptoms common to other illnesses, making it challenging to diagnose before detecting SFGR-specific antibodies. The guinea pig is a valuable biomedical model for studying Spotted Fever Rickettsiosis (SFR); its immune system is more like the human immune system than that of the murine model, and guinea pigs develop characteristic clinical signs. Read More

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Incidence Rate of Somatic Dysfunction in Previously Undiagnosed Spotted Fever Rickettsiosis: A Case Report.

Cureus 2022 Apr 23;14(4):e24416. Epub 2022 Apr 23.

Osteopathic Neuromusculoskeletal Medicine, Liberty Mountain Medical Group, Lynchburg, USA.

Spotted Fever Rickettsiosis (SFR) is a systemic vasculopathy due to tick-borne rickettsial infection. Presenting symptoms and signs may be nonspecific or include the triad of fever, headache, and a rash. Established long-term complications of SFR include debilitating neuromusculoskeletal sequelae; however, no reports describe the incidence of somatic dysfunction (SD) in SFR. Read More

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Entomological risk of African tick-bite fever (Rickettsia africae infection) in Eswatini.

PLoS Negl Trop Dis 2022 05 16;16(5):e0010437. Epub 2022 May 16.

Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America.

Background: Rickettsia africae is a tick-borne bacterium that causes African tick-bite fever (ATBF) in humans. In southern Africa, the tick Amblyomma hebraeum serves as the primary vector and reservoir for R. africae and transmits the bacterium during any life stage. Read More

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Patterns Testing for Tick-Borne Diseases and Implications for Surveillance in the Southeastern US.

JAMA Netw Open 2022 05 2;5(5):e2212334. Epub 2022 May 2.

Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.

Importance: Tick-borne diseases (TBD), including spotted fever group rickettsiosis (SFGR), ehrlichiosis, and, increasingly, Lyme disease, represent a substantial public health concern throughout much of the southeastern United States. Yet, there is uncertainty about the epidemiology of these diseases because of pitfalls in existing diagnostic test methods.

Objective: To examine patterns of diagnostic testing and incidence of TBD in a large, academic health care system. Read More

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Inflammatory cytokine profile and T cell responses in African tick bite fever patients.

Med Microbiol Immunol 2022 Jun 11;211(2-3):143-152. Epub 2022 May 11.

Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359, Hamburg, Germany.

African tick bite fever, an acute febrile illness, is caused by the obligate intracellular bacterium Rickettsia africae. Immune responses to rickettsial infections have so far mainly been investigated in vitro with infected endothelial cells as the main target cells, and in mouse models. Patient studies are rare and little is known about the immunology of human infections. Read More

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Prevalence of Rickettsia africae in tick vectors collected from mammalian hosts in sub-Saharan Africa: A systematic review and meta-analysis.

Ticks Tick Borne Dis 2022 Jul 26;13(4):101960. Epub 2022 Apr 26.

School of Life Sciences, Biological Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Durban, South Africa; One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies.

African tick bite fever (ATBF) is one of the most important rickettsial infections in international travellers to sub-Saharan Africa. The heterogeneity of Rickettsia africae infection rates among tick vector species has been studied. However, this information has not been systematised to allow for comparative estimates. Read More

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A molecular survey of spotted fever group rickettsiae in introduced raccoons (Procyon lotor).

Parasit Vectors 2022 May 7;15(1):162. Epub 2022 May 7.

Department of Parasitology, University of Wrocław, Wrocław, Poland.

Background: The raccoon Procyon lotor (Linnaeus, 1758) (Carnivora; Procyonidae) is one of the most important and most intensively studied invasive mammal species in Europe. Within the last 30 years the raccoon has spread at an increasing rate, resulting in the establishment of local populations in various regions of Europe. In these newly colonised areas, gaps in knowledge of the raccoon's biology concern not only most aspects of its ecology in a broad sense, but also its pathogens and parasites. Read More

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Diagnostic Value of IgA Antibody Measurement in Tick-Borne Spotted Fever (Astrakhan Rickettsial Fever).

Microbiol Spectr 2022 Apr 25:e0168721. Epub 2022 Apr 25.

Laboratory of Gene Engineering of Pathogenic Microorganisms, N. F. Gamaleya National Research Center of Epidemiology and Microbiology, Moscow, Russia.

Tick-borne spotted fevers caused by occur worldwide. The symptoms of this bacterial infection are similar to those of viral infection, and thus, diagnostic accuracy has special clinical importance. One of the commonly used methods for the diagnosis of tick-borne spotted fever is enzyme-linked immunosorbent assay (ELISA), which is based on estimation of the presence of specific IgM antibodies in blood. Read More

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Records and altitudinal assessment of Amblyomma aureolatum and Amblyomma ovale (Acari: Ixodidae) in the State of Rio de Janeiro, southeast Brazil.

Parasit Vectors 2022 Apr 21;15(1):136. Epub 2022 Apr 21.

Postgraduate Program in Health and Environment, UFMA, São Luís, MA, Brazil.

Information on the altitudinal distribution of the hard ticks Amblyomma aureolatum and Amblyomma ovale in Brazil is scarce and mainly limited to occasional records. In this study we report our evaluation of records on the altitudinal distribution of A. aureolatum and A. Read More

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Research of Rickettsia spp. and Borrelia spp. in dogs in Southeast Brazil.

Vet Parasitol Reg Stud Reports 2022 05 16;30:100706. Epub 2022 Feb 16.

Postgraduate Program in Reproduction, Health and Animal Welfare of the José do Rosário Vellano University (UNIFENAS), Alfenas, Minas Gerais, Brazil.

Dogs are important in the epidemiology of tick-borne diseases, playing a significant role mainly in endemic areas of rickettsiosis and borreliosis, and serving as sentinels in epidemiological surveys. We analyzed the distribution of Rickettsia and Borrelia spp. in dogs and their ticks in the municipalities of Guaxupé, Minas Gerais, and Tapiratiba, São Paulo, Brazil, two areas non-endemic for Baggio-Yoshinari Syndrome (BYS) and rickettsiosis. Read More

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Rickettsia amblyommatis-infected Amblyomma coelebs parasitizing a human traveler in Rio Grande do Sul, southern Brazil, after returning from the Amazon.

Travel Med Infect Dis 2022 Jul-Aug;48:102328. Epub 2022 Apr 10.

Faculdade de Veterinária - FAVET, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brazil. Electronic address:

With increased national and international transportation, humans as well as domestic and wild animals are able to get from one end to the other within hours, accidently carrying transboundary vectors and pathogens. We report here, the introduction of Amblyomma coelebs in Rio Grande do Sul, the southernmost state of Brazil, via a man travelling to the Carajás National Forest in the state of Pará (2661 km away). Upon return to his residence in Porto Alegre, RS, he realized that he was parasitized by one tick. Read More

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Imported African Tick Bite Fever in Japan: A Literature Review and Report of Three Cases.

Intern Med 2022 1;61(7):1093-1098. Epub 2022 Apr 1.

Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan.

African tick bite fever (ATBF) is an acute febrile illness caused by Rickettsia africae. ATBF is an important differential diagnosis of acute febrile illness among returned travelers. However, little information is available on ATBF cases imported to Japan, as only seven have been reported to date. Read More

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Prevalence of causative agents of transmissive tick-borned ricketsious in the Crimean peninsula.

Klin Lab Diagn 2022 Mar;67(3):170-176

Medical Academy named after S.I. Georgievsky of Vernadsky CFU.

The paper presents the results of a study of the prevalence of Ixodid ticks - potential carriers of tick-borne rickettsiosis pathogens. Ectoparasites were collected in various natural and climatic zones of the Crimean Peninsula within the year 2016-2018. As a result of screening with the help of real-time PCR analysis (PCR-RT), a genetic marker (a section of the gltA gene) of the rickettsia group of tick-borne spotted fever was detected in ticks. Read More

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A new focus of spotted fever caused by Rickettsia parkeri in Brazil.

Rev Inst Med Trop Sao Paulo 2022 11;64:e22. Epub 2022 Mar 11.

Fundação Oswaldo Cruz, Laboratório de Referência Nacional em Vetores das Riquetsioses, Rio de Janeiro, Rio de Janeiro, Brazil.

Spotted fever (SF) is a tick-borne zoonosis caused by bacteria of the genus Rickettsia . The disease varies in severity from mild clinical forms to severe cases. In Brazil, Rickettsia rickettsii SF is the most serious rickettsiosis and can result in death if not diagnosed and treated at the onset of symptoms. Read More

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Regulator of Actin-Based Motility (RoaM) Downregulates Actin Tail Formation by Rickettsia rickettsii and Is Negatively Selected in Mammalian Cell Culture.

mBio 2022 04 14;13(2):e0035322. Epub 2022 Mar 14.

Host-Parasite Interactions Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.

The etiological agent of Rocky Mountain spotted fever, Rickettsia rickettsii, is an obligately intracellular pathogen that induces the polymerization of actin filaments to propel the bacterium through the cytoplasm and spread to new host cells. Cell-to-cell spread via actin-based motility is considered a key virulence determinant for spotted fever group rickettsiae, as interruption of , the gene directly responsible for actin polymerization, has been shown to reduce fever in guinea pigs. However, little is known about how, or if, motility is regulated by the bacterium itself. Read More

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Molecular detection of () and spp. in hard ticks distributed in Tokachi District, eastern Hokkaido, Japan.

Curr Res Parasitol Vector Borne Dis 2021 11;1:100059. Epub 2021 Nov 11.

National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.

Ticks transmit various pathogens, including parasites, bacteria and viruses to humans and animals. To investigate the ticks and the potentially zoonotic pathogens that they may carry, questing ticks were collected in 2017 from 7 sites in Tokachi District, eastern Hokkaido, Japan. A total of 1563 ticks including adults (male and female), nymphs and larvae were collected. Read More

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November 2021

Genomic evolution and adaptation of arthropod-associated Rickettsia.

Sci Rep 2022 03 9;12(1):3807. Epub 2022 Mar 9.

Aix-Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France.

Rickettsia species are endosymbionts hosted by arthropods and are known to cause mild to fatal diseases in humans. Here, we analyse the evolution and diversity of 34 Rickettsia species using a pangenomic meta-analysis (80 genomes/41 plasmids). Phylogenomic trees showed that Rickettsia spp. Read More

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Meningo-Encephalitis due to Spotted Fever Group Rickettsia--A Rare Case Report with Serial Follow up MRI.

Neurol India 2022 Jan-Feb;70(1):412-414

Consultant in Neurology, Care Hospital, Prachi Enclave, Bhubaneswar, Odisha, India.

Spotted fever group (SFG) Rickettsial infection has rarely been reported to develop severe central nervous system involvement. We report a case of meningoencephalitis presenting with fever, headache, drowsiness, seizures, and a skin rash, showing ELISA IgM positivity to SFG Rickettsia group. MRI brain showed multifocal bilateral asymmetric patchy areas of T2W/FLAIR hyperintensity with significant diffusion restriction. Read More

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A serosurvey for spotted fever group Rickettsia and Coxiella burnetii antibodies in rural dogs and foxes, Chile.

Comp Immunol Microbiol Infect Dis 2022 Apr 13;83:101769. Epub 2022 Feb 13.

Facultad de Ciencias de la Vida, Universidad Andres Bello, República 440, Santiago, Chile; Instituto Agroalimentario de Aragón-IA2 (Universidad de Zaragoza-CITA), Miguel Servet 177, Zaragoza 50013, Spain; Fundación ARAID, Avda. de Ranillas, Zaragoza 50018, Spain. Electronic address:

Antibodies against Spotted Fever Group (SFG) Rickettsia and Coxiella burnetii, investigated through indirect antibody immunofluorescence tests, were detected in serum samples from 3.1% and 0% of 358 rural dogs, respectively, and in none of 32 wild foxes tested. SFG Rickettsia seropositive dogs were only detected in the Mountain Desert (8%) and the Steppe-Mediterranean (9%) regions. Read More

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Occurrence and clinical manifestations of tick-borne rickettsioses in Western Siberia: First Russian cases of Rickettsia aeschlimannii and Rickettsia slovaca infections.

Ticks Tick Borne Dis 2022 05 16;13(3):101927. Epub 2022 Feb 16.

Institute of Chemical Biology and Fundamental Medicine, SB RAS, prosp. Lavrent'eva 8 630090, Novosibirsk, Russian Federation. Electronic address:

Rickettsia sibirica subsp. sibirica is a main agent of tick-borne rickettsioses in Western Siberia, Russia. Recently, the first cases of Rickettsia raoultii infection in patients hospitalized in Novosibirsk Province were described. Read More

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Rickettsia africae infection rates and transovarial transmission in Amblyomma hebraeum ticks in Mnisi, Bushbuckridge, South Africa.

Exp Appl Acarol 2022 Mar 25;86(3):407-418. Epub 2022 Feb 25.

Vector and Vector-borne Diseases Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, South Africa.

Rickettsia africae is a gram-negative bacterium, which causes African tick bite fever (ATBF) in humans. ATBF is a febrile disease mainly affecting travellers to southern Africa. This bacterium is known to be transmitted by Amblyomma hebraeum and Amblyomma variegatum ticks. Read More

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Prevalence of tick infestation and molecular characterization of spotted fever Rickettsia massiliae in Rhipicephalus species parasitizing domestic small ruminants in north-central Nigeria.

PLoS One 2022 14;17(2):e0263843. Epub 2022 Feb 14.

School of Health, Sport and Bioscience, University of East London, London, United Kingdom.

Ticks are of great menace to animal and human health. They serve as vectors to both animals and human pathogens including Rickettsia species. Tick-borne rickettsiosis in West Africa remains incompletely understood. Read More

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February 2022

Molecular confirmation of Rickettsia parkeri in humans from Southern Mexico.

Zoonoses Public Health 2022 Jun 9;69(4):382-386. Epub 2022 Feb 9.

Universidad Autónoma de Yucatán, Mérida, México.

Human tick-borne rickettsioses are caused by Rickettsia africae, Rickettsia massiliae, Rickettsia parkeri, Rickettsia philipi and Rickettsia rickettsii in the American continent. Rickettsia parkeri represents the second most important agent of eschar-associated spotted fever throughout the American continent. In Mexico, the presence of three strains of this bacterium (Black Gap, Maculatum and Atlantic Rainforest) has recently been reported in four species of ticks from five states (Baja California, Campeche, Sonora, Tabasco and Veracruz) and rickettsaemia was demonstrated in a dog from the state of Yucatán. Read More

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Pathogenic, but Not Nonpathogenic, spp. Evade Inflammasome-Dependent IL-1 Responses To Establish an Intracytosolic Replication Niche.

mBio 2022 Feb 8:e0291821. Epub 2022 Feb 8.

Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA.

species (spp.) are strict obligate intracellular bacteria, some of which are pathogenic in their mammalian host, including humans. One critical feature of these stealthy group of pathogens is their ability to manipulate hostile cytosolic environments to their benefits. Read More

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February 2022

Mediterranean spotted fever and peripheral facial nerve palsy: a rare neurological complication.

Int J Infect Dis 2022 Apr 30;117:15-17. Epub 2022 Jan 30.

Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France; IHU-Méditerranée Infection, Marseille, France. Electronic address:

Mediterranean spotted fever (MSF) caused by the bacterium Rickettsia conorii is one of the oldest known tick-borne diseases. It is transmitted by the brown dog tick Rhipicephalus sanguineus and occurs mainly in the Mediterranean area. MSF usually presents with a skin rash, high fever, and characteristic eschar at the site of the tick bite. Read More

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Rocky Mountain spotted fever, dengue and chikungunya, and other tropical vector borne infection.

Gac Med Mex 2021 Sep 1;157(5). Epub 2021 Sep 1.

Department of Community Medicine, Dr. DY Patil University, Pune, India.

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September 2021

Case Report: Rocky Mountain Spotted Fever with Adrenalectomy and a Hard-to-Find Tick.

Am J Case Rep 2022 Jan 31;23:e934505. Epub 2022 Jan 31.

Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.

BACKGROUND Rocky Mountain spotted fever (RMSF) is a potentially fatal infectious disease caused by the gram-negative intracellular bacterium Rickettsia rickettsii. The classic triad includes fever, rash, and history of tick exposure; however, the triad presents in only 3% to 18% of cases at the initial visit, and the tick bite is often painless and overlooked. RMSF can present with other manifestations, including hyponatremia, lymphopenia, thrombocytopenia, and coagulopathy. Read More

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January 2022

Fatal Case of Mediterranean Spotted Fever Associated with Septic Shock, Iran.

Emerg Infect Dis 2022 02;28(2):485-488

A fatal case of Mediterranean spotted fever associated with septic shock was reported in a 61-year-old man living in a village in southeastern Iran. The patient had a history of tick bite a few days before symptom onset. Phylogenetic analysis confirmed infection by Rickettsia conorii subspecies israelensis. Read More

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February 2022