scholarly journals Detection of Rickettsia rickettsii in the tick Amblyomma cajennense in a new Brazilian spotted fever-endemic area in the state of Minas Gerais

2005 ◽  
Vol 100 (8) ◽  
pp. 841-845 ◽  
Author(s):  
Elizângela Guedes ◽  
Romário C Leite ◽  
Márcia CA Prata ◽  
Richard C Pacheco ◽  
David H Walker ◽  
...  
Keyword(s):  
Endemic Area ◽  
Spotted Fever ◽  
Minas Gerais ◽  
The State ◽  
Amblyomma Cajennense ◽  
Rickettsia Rickettsii ◽  
Brazilian Spotted Fever

scholarly journals Serosurvey of Rickettsia spp. in dogs and humans from an endemic area for Brazilian spotted fever in the State of São Paulo, Brazil

2008 ◽  
Vol 24 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Adriano Pinter ◽  
Maurício C. Horta ◽  
Richard C. Pacheco ◽  
Jonas Moraes-Filho ◽  
Marcelo B. Labruna
Keyword(s):  
Human Serum ◽  
Endemic Area ◽  
Spotted Fever ◽  
Sao Paulo ◽  
The State ◽  
The Other ◽  
São Paulo ◽  
Human Sera ◽  
Antibody Titers ◽  
Brazilian Spotted Fever

The present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area for Brazilian spotted fever in the State of São Paulo, where the tick Amblyomma aureolatum is the main vector. Testing canine and human sera by indirect immunofluorescence against four Rickettsia antigens (R. rickettsii, R. parkeri, R. felis and R. bellii) showed that 16 (64%) of canine sera and 1 (2.8%) of human sera reacted to at least one of these rickettsial antigens with titers <FONT FACE=Symbol>³</FONT> 64. Seven canine sera and the single reactive human serum showed titers to R. rickettsii at least four times those of any of the other three antigens. The antibody titers in these 7 animals and 1 human were attributed to stimulation by R. rickettsii infection. No positive canine or human serum was attributed to stimulation by R. parkeri, R. felis, or R. bellii. Our serological results showed that dogs are important sentinels for the presence of R. rickettsii in areas where the tick A. aureolatum is the main vector of Brazilian spotted fever.

scholarly journals Rickettsiae-infected Ticks in an Endemic Area of Spotted Fever in the State of Minas Gerais, Brazil

1997 ◽  
Vol 92 (4) ◽  
pp. 477-481 ◽  
Author(s):  
Elba Regina Sampaio de Lemos ◽  
Raimundo Diogo Machado ◽  
Fernando Dias de Ávila Pires ◽  
Sérgio Lisboa Machado ◽  
Lígia Maria Cantarino da Costa ◽  
...  
Keyword(s):  
Endemic Area ◽  
Spotted Fever ◽  
Minas Gerais ◽  
The State

scholarly journals Rickettsial infection in Amblyomma cajennense ticks and capybaras (Hydrochoerus hydrochaeris) in a Brazilian spotted fever-endemic area

2014 ◽  
Vol 7 (1) ◽  
pp. 7 ◽  
Author(s):  
Felipe S Krawczak ◽  
Fernanda A Nieri-Bastos ◽  
Fernanda P Nunes ◽  
João F Soares ◽  
Jonas Moraes-Filho ◽  
...  
Keyword(s):  
Endemic Area ◽  
Spotted Fever ◽  
Amblyomma Cajennense ◽  
Rickettsial Infection ◽  
Hydrochoerus Hydrochaeris ◽  
Brazilian Spotted Fever

Rickettsia rickettsii (Rickettsiales: Rickettsiaceae) Infecting Amblyomma sculptum (Acari: Ixodidae) Ticks and Capybaras in a Brazilian Spotted Fever-Endemic Area of Brazil

2019 ◽  
Vol 57 (1) ◽  
pp. 308-311 ◽  
Author(s):  
Francisco B Costa ◽  
Monize Gerardi ◽  
Lina de C Binder ◽  
Hector R Benatti ◽  
Maria Carolina de Azevedo Serpa ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Infection Rate ◽  
Guinea Pigs ◽  
Endemic Area ◽  
Spotted Fever ◽  
Immunofluorescence Assay ◽  
Southeastern Brazil ◽  
Rickettsia Rickettsii ◽  
Brazilian Spotted Fever ◽  
Low Incidence

Abstract The bacterium Rickettsia rickettsii is the agent of Brazilian spotted fever (BSF), a highly fatal disease that is transmitted in Brazil mainly by the tick Amblyomma sculptum Berlese, which uses capybaras (Hydrochoerus hydrochaeris Linnaeus) as major hosts. In 2015, we captured nine capybaras in a BSF-endemic area of southeastern Brazil. From each capybara, we collected blood sera that were tested through the immunofluorescence assay using Rickettsia spp. antigens, and A. sculptum ticks, processed for isolation of R. rickettsii through guinea pig inoculation. All capybaras (100%) were seroreactive to Rickettsia spp., with highest titers to R. rickettsii. A total of 166 A. sculptum ticks were macerated and inoculated into nine guinea pigs, from which only one presented high fever and seroconverted to R. rickettsii. Blood from this febrile animal was inoculated into additional guinea pigs (guinea pig passages), which also became febrile and seroconverted, or when euthanized during the fever period, their internal organs (spleen, lung) were shown to contain R. rickettsii DNA. The present rickettsial isolate has been maintained cryopreserved as infected guinea pig organs. There was at least one R. rickettsii-infected tick among the 166 macerated ticks, giving a minimal infection rate of 0.6% (1/166). This infection rate is within the range of previous studies, which reported that only 0.05% to at most 1.28% A. sculptum ticks were infected by R. rickettsii in other BSF-endemic areas. These low infection rates support the low incidence of BSF, despite of A. sculptum being the most frequent human-biting tick in southeastern Brazil.

New Epidemiological Data on Brazilian Spotted Fever in an Endemic Area of the State of São Paulo, Brazil

2009 ◽  
Vol 9 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Jonas Moraes-Filho ◽  
Adriano Pinter ◽  
Richard C. Pacheco ◽  
Thais B. Gutmann ◽  
Sonia O. Barbosa ◽  
...  
Keyword(s):  
Endemic Area ◽  
Spotted Fever ◽  
Epidemiological Data ◽  
Sao Paulo ◽  
The State ◽  
São Paulo ◽  
Brazilian Spotted Fever

scholarly journals Rickettsial spotted fever in capoeirão Village, Itabira, Minas Gerais, Brazil

2008 ◽  
Vol 50 (5) ◽  
pp. 297-301 ◽  
Author(s):  
Manoella Campostrini Barreto Vianna ◽  
Maurício Claudio Horta ◽  
Luis Antônio Sangioni ◽  
Adriana Cortez ◽  
Rodrigo Martins Soares ◽  
...  
Keyword(s):  
Spotted Fever ◽  
Minas Gerais ◽  
Immunofluorescence Assay ◽  
Tick Population ◽  
Rickettsial Infection ◽  
Rickettsia Rickettsii ◽  
Minas Gerais State ◽  
Brazilian Spotted Fever ◽  
Polymerase Chain ◽  
Sfg Rickettsia

The present study investigated the infection by spotted fever rickettsia in an endemic area for Brazilian spotted fever (BSF; caused by Rickettsia rickettsii) in Minas Gerais State, Brazil. Human, canine and equine sera samples, and Amblyomma cajennense adult ticks collected in a rural area of Itabira City, Minas Gerais State were tested for rickettsial infection. Through Immunofluorescence Assay (IFA) we demonstrated the presence of antibodies anti-R. rickettsii in 8.2%, 81.3% and 100% of the human, canine and equine sera, respectively. None of the 356 tick specimens analyzed were positive for Rickettsia by the hemolymph test or Polymerase Chain Reaction technique (PCR) for the htrA and the gltA genes. Our serological results on horses and dogs (sentinels for BSF) appoint for the circulation of a SFG Rickettsia in the study area, however in a very low infection rate among the A. cajennense tick population.

scholarly journals DETECTION OF A Rickettsia GENOTYPE RELATED TO THE OLD WORLD INFECTING Amblyomma sculptum TICK IN AN ENDEMIC AREA OF BRAZILIAN SPOTTED FEVER

2019 ◽  
Vol 48 (3) ◽  
pp. 161-169 ◽  
Author(s):  
Gilberto Gazêta ◽  
Tayra Sato ◽  
Nicole Moura-Martiniano ◽  
Vinícius Vizzoni ◽  
Arannadia Silva ◽  
...  
Keyword(s):  
Endemic Area ◽  
Spotted Fever ◽  
Epidemiological Surveillance ◽  
Southeastern Brazil ◽  
Spotted Fever Group ◽  
Rickettsia Rickettsii ◽  
Rickettsia Monacensis ◽  
Minas Gerais State ◽  
Brazilian Spotted Fever ◽  
Spotted Fever Group Rickettsia

Brazilian Spotted Fever is an important tick-borne disease caused by Rickettsia rickettsii and transmitted mainly by the human-biting tick Amblyomma sculptum. During an epidemiological surveillance in Pedro Leopoldo, an endemic area of Minas Gerais State, southeastern Brazil, ectoparasites were collected from vertebrate hosts and from the environment. Rickettsial genes were obtained from a male A. sculptum and the resulting phylogenetic tree grouped this bacterium with Rickettsia sp. isolate Pampulha, a strain closely related to the pathogenic species Rickettsia tamurae and Rickettsia monacensis. This is the first report of sequencesphylogenetically related to R. tamurae and R. monacensis infecting A. sculptum in Brazil. KEY WORDS: Spotted Fever Group Rickettsia; Amblyomma sculptum; Spotted Fever focus;Ixodidae; Brazil.

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

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Ila Ferreira Farias ◽  
Eline Almeida Rodrigues de Souza ◽  
Maria Carolina de Azevedo Serpa ◽  
Flávio Silva Palha ◽  
Glauber Meneses Barboza de Oliveira ◽  
...  
Keyword(s):  
Central Region ◽  
Endemic Area ◽  
Spotted Fever ◽  
Immunofluorescence Assay ◽  
North Central Region ◽  
North Central ◽  
Rickettsia Rickettsii ◽  
The North ◽  
Tick Borne Disease ◽  
Brazilian Spotted Fever

Abstract 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. rickettsii antigens in horses from a non-endemic area in the north-central region of Bahia state, Brazil. Blood samples and ticks were collected from 70 horses from the municipalities of Senhor do Bonfim, Antônio Gonçalves, Pindobaçu, and Campo Formoso. The sera obtained were tested by an indirect immunofluorescence assay to detect anti-Rickettsia antibodies. Overall, 5.7% (4/70) of the horses reacted to R. rickettsii antigens. Ticks were collected from 18.6% (13/70) of the horses and were identified as A. sculptum and Dermacentor nitens. Despite being a non-endemic area, seropositive animals were identified in our study, suggesting circulation of rickettsial agents in the region. This is the first serological survey of this agent in horses from the north-central region of Bahia, and further studies are needed to understand the epidemiology of BSF in these locations.

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