Epidemiological analysis of Dirofilaria immitis (Spirurida: Onchocercidae) infecting pet dogs (Canis lupus familiaris, Linnaeus, 1758) in Baixada Fluminense, Rio de Janeiro.

Dirofilaria immitis infection is routinely detected in dogs during veterinary care in tropical and subtropical regions worldwide. Parasitological tests for the detection of this infection are routinely performed only in areas with a high prevalence. Baixada Fluminense, a region in Rio de Janeiro, was considered heartworm-free until local veterinarians began to receive blood exams results indicating the presence of microfilariae (MF). A laboratory database was hence used to collect data from 2017 to 2020 to understand the extent of spread of the parasite in this area. The results of complete blood count analysis and MF or heartworm antigen detection tests conducted on canine samples sent from veterinary clinics in Baixada Fluminense (Magé, Duque de Caxias, Guapimirim, Nova Iguaçu, and São João de Meriti municipalities) were included. In total, the results of 16,314 hematological tests were considered. The overall prevalence of D. immitis was 3.4% (554/16,314), considering that only one test result was obtained per animal on the same day. This study is highly relevant because it indicates the spreading geographic distribution of the worms, heightens awareness among local health professionals and the general population, and encourages compliance with prophylactic measures to prevent further spread of parasite.

Piroplasmid Infections Among Domestic Dogs in the Mountain City of Rio de Janeiro, Brazil.

PURPOSE: The aim of the present study was to analyze the frequency of the piroplasmids in blood from dogs and ticks recovered from these animals in Teresópolis city, located in the mountain region of Rio de Janeiro state, Brazil. In addition to the clinical and hematological profile. METHODS: A total of 400 dogs attended in a veterinary clinic in this city between 2020 and 2021 were included. The blood was collected from the dogs, along with ticks and information on these dogs was obtained through a questionnaire applied to the owners. Thin-smear analyses and complete blood counts were performed. All forms characteristic of piroplasmids were measured and classified morphologically. The blood was also subjected to PCR assays based on the genes 18S rRNA and hsp70. In addition, the ixodid ticks were classified morphologically and subjected to PCR for piroplasmids research. The amplified products were sent for gene sequencing. RESULTS: Piroplasmids were detected in 2.3% of the dogs. The variables statistically associated with infections in these animals were hemorrhage/bleeding, jaundice, anisocytosis, activated monocytes and macroplatelets (p ≤ 0.05). Piriform, ring-shaped, oval and aberrant structures were viewed in erythrocytes, neutrophils and monocytes, with lengths greater than and less than 2.5 µm. The nine positive samples from these dogs were characterized as due to Rangelia vitalii. However, one sequence from B. vogeli was detected in a single adult specimen of R. sanguineus. CONCLUSION: Although circulation of two species of piroplasmids potentially infective for domestic dogs has been observed in the mountain city of Rio de Janeiro, infection due to R. vitalii was mostly seen in the dogs of the present study.

Detection of Rickettsia tamurae-like and other spotted fever group rickettsiae in ticks (Acari: Ixodidae) associated with wild birds in the Western Amazon, Brazil.

Ticks are vectors for several pathogens, including bacteria belonging to the Rickettsia genus, such as Rickettsia rickettsii and Rickettsia parkeri, the causative agents of spotted fever. The aim of the present study was to investigate the tick species richness and rickettsial agents associated with wild birds captured in the Humaita Forest Reserve, Acre, in the Western Amazon region. Wild birds were captured with ornithological nets for visual inspection with the purpose of collecting ticks, which were identified through morphological analyses and molecular tests for several genes (12S rDNA, 16S rDNA, gltA, ompA, and sca4). A total of 607 wild birds were captured, 12% of which were parasitized by 268 ticks of the Amblyomma genus, with new host-parasite associations reported for Amblyomma calcaratum, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, and Amblyomma varium. Of the total ticks collected, 113 were tested for the presence of rickettsial DNA fragments, with 19 testing positive for R. parkeri in A. geayi, Rickettsia tamurae-like in Amblyomma sp., and Rickettsia amblyommatis in A. geayi, A. longirostre, and Amblyomma sp. We detected R. tamurae-like in Amblyomma larvae for the first time in the Western Brazilian Amazon biome, and registered spotted fever group rickettsiae, although the relevance of the detected species in a public health context should be further explored in South America, as well as new host-parasite interactions in this underexplored region.

Estudo descritivo de casos notificados de febre maculosa em São Paulo, Rio de Janeiro e Minas Gerais entre 2007 e 2016 / Descriptive study of reported cases of spotted fever in São Paulo, Rio de Janeiro and Minas Gerais between 2007 and 2016

Resumo Introdução A febre maculosa é uma doença infecciosa aguda causada por bactérias do gênero Rickettsia e transmitida por carrapatos que pode levar à hospitalização e, eventualmente, a óbito por causa de quadros mais graves. Objetivo O objetivo deste artigo foi descrever o cenário epidemiológico da doença nas três unidades federativas de maior número de notificações e óbitos pela doença no Brasil entre 2007 e 2016. Método Estudo epidemiológico descritivo com base nos dados das fichas de investigação para a doença, sendo analisados dados demográficos, geográficos, ambientais e de hospitalização, diagnóstico e desfecho dos casos na área de estudo. Resultados Foram confirmados 953 casos da doença, em sua maioria por critérios laboratoriais, sendo observada maior prevalência entre homens com idade média de 35 anos, pouco relacionados ao ambiente de trabalho, mas amplamente relacionados ao meio urbano. Do total de casos confirmados, 64% pacientes afirmaram ter tido algum contato com carrapato, assim como com cães (36%), capivaras (20%) e equinos (19%). Conclusão Existem questionamentos a respeito da doença que não foram elucidados neste artigo, entretanto abordagens criativas, validadas e ancoradas na associação de áreas de conhecimento distintas poderão dar bons resultados se objetivamente aplicadas em ações estratégicas da gestão da saúde.

Abstract Background Spotted fever is an acute infectious disease caused by bacteria of the genus Rickettsia and transmitted by ticks, which can lead to hospitalization and, eventually, death due to more severe conditions. Objective The purpose of this article was to describe the epidemiological scenario of the disease in the three federal states with the highest number of notifications and deaths due to the disease in Brazil between 2007 and 2016. Method A descriptive epidemiological study was carried out based on data from the investigation forms for the disease, with data being analyzed on demographic, geographic, environmental, and hospitalization, diagnosis, and outcome of cases in the study area. Results 953 cases of the disease were confirmed, mostly by laboratory criteria, with a higher prevalence being observed among men with an average age of 35 years, little related to the work environment, but largely related to the urban environment. Of the total confirmed cases, 64% of patients said that they had had some contact with ticks, as well as with dogs (36%), capybaras (20%), and horses (19%). Conclusion We believe that there are questions about the disease that were not elucidated in this article, however, creative approaches, validated and anchored in the association of different areas of knowledge can give good results if objectively applied in strategic health management actions.

Mapping potential risks for the transmission of spotted fever rickettsiosis: The case study from the Rio de Janeiro state, Brazil.

Spotted fever rickettsiosis is a zoonosis transmitted by ticks, having a varied clinical course that can lead to death if not managed properly. In Brazil it is more commonly observed in the Southeast, being an emerging public health problem. Hazard mapping models are common in different areas of knowledge, including public health, as a way of inferring reality and seeking to reduce or prevent damage. The aim of this study is to offer a spatial heuristic methodology for assessing the potential risk of transmission of spotted fever in the Rio de Janeiro state, located in the southeastern region of Brazil. For this, we used geospatial tools associated with eco-epidemiological data related to the clinical profile of the disease. The results achieved were substantially encouraging, considering that there are territories with greater or lesser expectation of risk for spotted fever in the study area. We observed that there are important distinctions between the two rickettsiosis scenarios in the same geographic space and that the areas where there is a greater potential risk of contracting rickettsiosis coincide with the administrative regions that concentrated the cases of hospitalization and deaths from the disease, concluding that the scenery found are relevant to the case series for the disease and that the planning of surveillance actions can gain in quality if the use of this spatial analysis tool is incorporated into the routine of local health management.

A new focus of spotted fever caused by Rickettsia parkeri in 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. The SF mild form is caused by Rickettsia parkeri strain Atlantic Rainforest, and this etiological agent has been reported in the South, Southeast and Northeast regions of the country, in areas of preserved or little antropized Atlantic Rainforest. Amblyomma ovale is the proven vector and dogs are the hosts associated with the bioagent cycle. During a SF case investigation in Paraty municipality, Rio de Janeiro State, an Atlantic Rainforest biome area in Southeastern Brazil, the human pathogen R. parkeri strain Atlantic Rainforest was detected by PCR in a sample of human skin inoculation eschar and in a female A. ovale tick collected from a dog. These results expand the known area of occurrence of this mild form rickettsiosis in Brazil. In addition, the results of the present study indicate the importance of implementing programs to control canine ectoparasites and to raise awareness of the risks of infection, signs and symptoms of SF caused by R. parkeri strain Atlantic Rainforest.

Molecular characterization of canine filarioids in a previously non-endemic area of Rio de Janeiro State, Brazil.

Dirofilaria immitis is the causative agent of canine heartworm disease, a severe health problem in dogs, especially in coastal areas of tropical and subtropical regions of the world. We employed molecular methods to investigate the occurrence of canine infection by filarioids in five municipalities of Baixada Fluminense (Magé, Duque de Caxias, Guapimirim, Nova Iguaçu, and São João de Meriti), a non-endemic area of Rio de Janeiro State, Southeast Brazil. A total of 110 canine blood samples collected from 2017 to 2018 and positive for microfilariae at the modified Knott's test were screened by cPCR targeting DNA fragments of the 12S rDNA gene for filarial nematodes. Seventy-seven samples (70%) tested positive at the molecular analysis. Of these, 72 were identified as D. immitis and 5 (4.5%) as Acanthocheilonema reconditum. Dirofilaria repens was not detected in the studied municipalities of Baixada Fluminense. This is the first record of D. immitis and A. reconditum in the Baixada Fluminense region, Rio de Janeiro State, Brazil. The prevalence of D. immitis cases in the five municipalities suggests the establishment and maintenance of its enzootic cycle in the studied region, which indicate vulnerability to the occurrence of epidemic cycles and, possibly, human cases.

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

ABSTRACT 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. The SF mild form is caused by Rickettsia parkeri strain Atlantic Rainforest, and this etiological agent has been reported in the South, Southeast and Northeast regions of the country, in areas of preserved or little antropized Atlantic Rainforest. Amblyomma ovale is the proven vector and dogs are the hosts associated with the bioagent cycle. During a SF case investigation in Paraty municipality, Rio de Janeiro State, an Atlantic Rainforest biome area in Southeastern Brazil, the human pathogen R. parkeri strain Atlantic Rainforest was detected by PCR in a sample of human skin inoculation eschar and in a female A. ovale tick collected from a dog. These results expand the known area of occurrence of this mild form rickettsiosis in Brazil. In addition, the results of the present study indicate the importance of implementing programs to control canine ectoparasites and to raise awareness of the risks of infection, signs and symptoms of SF caused by R. parkeri strain Atlantic Rainforest.

Amblyomma aureolatum Genetic Diversity and Population Dynamics Are Not Related to Spotted Fever Epidemiological Scenarios in Brazil.

Regional differences in tick-borne disease epidemiology may be related to biological variations between vector populations. Amblyomma aureolatum (Ixodida: Ixodidae), a neotropical tick, is known from several regions in Brazil. However, only in the metropolitan area of São Paulo (SP) state are there studies that establish its role as a vector of a pathogenic rickettsia (Rickettsia rickettsii). The aim of the study was to analyze the genetic diversity, population dynamics, and rickettsia infection in A. aureolatum populations from different spotted fever scenarios in Brazil. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D-loop mitochondrial markers for tick population analyses, and gltA, htrA, ompA, and ompB genes for rickettsia researches. Of the 7-17 tick haplotypes identified, 5-13 were exclusive to each population and 2-12 for each epidemiological scenario, as well as three haplotypes shared by all populations. Amblyomma aureolatum populations are expanding, and do not appear to be genetically structured vis-a-vis the different epidemiological scenarios studied. Rickettsia bellii (in SP) and Rickettsia felis (in Santa Catarina) were identified as infecting A. aureolatum. No relationship between tick haplotypes and rickettsia types were observed.

Microscopic Detection, Hematological Evaluation and Molecular Characterization of Piroplasms from Naturally Infected Dogs in Rio de Janeiro, Brazil.

PURPOSE: This study aimed to analyze the frequency of piroplasmids in the blood of dogs in Rio de Janeiro, compare the performance of microscopic techniques, assess the risk factors associated with infections and also molecularly and morphologically characterize the piroplasmids identified. METHODS: In all, 407 blood samples were collected from dogs between 2018 and 2019. These were subjected to microscopic parasitological techniques for thin and thick smears, stained with Giemsa and using a rapid staining kit. The slides were read under an optical microscope and the protozoa were characterized morphometrically. In addition, the blood samples were subjected to molecular characterization for diagnosing piroplasmid species using primers that amplified the gene 18S rRNA. RESULTS: Piroplasmids were detected in 38 (9.3%) samples. Of these, 33 samples presented nucleotide sequences compatible with Babesia vogeli. Most of the positive samples were young, male, defined breeds dogs that had been attended in clinics in São Gonçalo city. Thrombocytopenia and leukopenia were the hematological alterations more observed in positive samples, but positive samples without alterations were also detected. The sex was the only variable that showed statistical differences. Males dogs being more often infected than females (p < 0.05). The microscope slides mostly showed piriform and oval merozoites measuring greater than 2.5 µm in length, which were compatible with B. vogeli. However, smaller forms were also identified, thus demonstrating the polymorphic nature of this parasite. CONCLUSION: Babesia vogeli was detected in blood samples from dogs in the metropolitan cities of Rio de Janeiro by molecular techniques in different parasite morphotypes.

Biodiversity of Potential Vectors of Rickettsiae and Epidemiological Mosaic of Spotted Fever in the State of Paraná, Brazil.

Spotted Fever Rickettsioses (SFR) are diseases caused by bacteria of the genus Rickettsia, and are transmitted mainly by ticks. Its eco-epidemiological scenarios vary spatially, and may also vary over time due to environmental changes. It is the main disease transmitted by ticks to humans in Brazil, with the state of Paraná (PR) having the sixth highest number of notified incidences in the country. However, information is lacking regarding the SFR disease cycles at likely infection sites within PR. During case investigations or environmental surveillance in PR for SFR, 28,517 arthropods were collected, including species known or potentially involved in the SFR cycles, such as Amblyomma sculptum, Amblyomma aureolatum, Amblyomma ovale, Amblyomma dubitatum, Amblyomma parkeri, Ctenocephalides felis felis, and Rhipicephalus sanguineus sensu lato. From these Rickettsia asembonensis, Rickettsia bellii, Rickettsia felis, Rickettsia parkeri strain Atlantic Rainforest and Candidatus Rickettsia paranaensis were detected. Ectoparasite abundance was found to be related with specific hosts and collection environments. Rickettsiae circulation was observed for 48 municipalities, encompassing 16 Health Regions (HR). As for socio-demographic and assistance indicators, circulation occurred largely in the most urbanized HR, with a higher per capita Gross Domestic Product, lower Family Health Strategy coverage, and with a higher ratio of beds in the Unified Health System per thousand inhabitants. For environmental variables, circulation occurred predominantly in HR with a climatic classified as "subtropical with hot summers" (Cfa), and with forest type phytogeographic formations. In terms of land use, circulation was commonest in areas with agriculture, pasture and fields and forest cover. Rickettsiae were circulating in almost all hydrographic basins of PR state. The results of this study provide the first descriptive recognition of SFR in PR, as well as outlining its eco-epidemiological dynamics. These proved to be quite heterogeneous, and analyzed scenarios showed characteristics strongly-associated with the outbreaks, with cases presenting clinical variation in space, so illustrating the complexity of scenarios in PR state. Due to the diversity of the circumstances surrounding SFR infections in PR, public health initiatives are necessary to foster a better understanding of the dynamics and factors effecting vulnerability to SFR in this Brazilian state.

Molecular evaluation of piroplasms and hematological changes in canine blood stored in a clinical laboratory in Niterói, Rio de Janeiro.

Piroplasm species were analyzed by molecular tools in total 31 blood samples from positive dogs, previously checked by stained slides, stored until DNA extraction between 2016 to 2018 in the laboratory Clinical Analyzes in Niterói, Rio de Janeiro. The piroplasms were identified by PCR, targeting the 18S rRNA gene and sequencing. From the total number of samples only 24 (77.4%) were positive and show adequate nucleotide sequences for interpretation with identity between 93%-100% with Babesia vogeli in compared to the sequences isolated of infected dogs from other states in Brazil deposited on GenBank. Most of dogs infected with B. vogeli had anemia (62.5%) and thrombocytopenia (95.8%). The findings of this study are compatible with previous reports in the literature and highlight B. vogeli as the most incriminated species in canine piroplasmosis in Brazil, and thrombocytopenia the hematological alteration most frequently identified in this infection. It is important to note that this is the first study involving the molecular characterization of piroplasms in the metropolitan region of Rio de Janeiro, based on PCR followed by sequencing.

Rhizoglyphus echinopus (Acari: Acaridae) associated with Atta sexdens (Insecta: Formicidae) / Rhizoglyphus echinopus (Acari: Acaridae) associado a Atta sexdens (Insecta: Formicidae)

Four deutonymphs of bulb mites (hypopus) from Rhizoglyphus echinopus (Fumouze & Robin) (Acari: Acaridae) were found attached to the head of Atta sexdens in Rio de Janeiro, Brazil. This mite species is commonly associated with ornamental plants and trees with bulbs, corms and tubers. The results of this study provided an insight into the phoretic relationship between mites and ants, indicating the role of the latter in the dispersion of the first. Despite the abundant and diverse mite fauna existing in ants, little is known about their diversity, biology, ecology and the nature of their associations.(AU)

Quatro deutoninfas de ácaros do bulbo (hipopus) da espécie Rhizoglyphus echinopus (Fumouze & Robin) (Acari: Acaridae) foram encontradas fixadas na cabeça de formigas da espécie Atta sexdens no Rio de Janeiro, Brasil. Essa espécie de ácaro está comumente associada a plantas ornamentais e plantas com bulbos e tubérculos. Os resultados desse estudo fornecem uma visão sobre a relação forética entre ácaros e formigas, indicando o papel destas últimas na dispersão dos primeiros. Apesar da abundância e da fauna diversa do ácaro em formigas, pouco se sabe sobre a diversidade, a biologia, a ecologia e a natureza dessa associação.(AU)

Detection of a Rickettsia genotype related to the old world infecting Amblyomma sculptum tick in an endemic area of brazilian spotted fever

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 sequences phylogenetically related to R. tamurae and R. monacensis infecting A. sculptum in Brazil.

Human parasitism and toxicosis by Ornithodoros rietcorreai (Acari: Argasidae) in an urban area of Northeastern Brazil.

The soft tick, Ornithodoros rietcorreai, is a parasite of the rodent, Kerodon rupestris, and, to a lesser extent, of bats living in rock cavities in Northeastern Brazil. This report describes the first recorded episodes of human parasitism by this argasid tick, reported to the Brazilian Ministry of Health in September 2017. We assessed outdoor environments, roofs, animal nests and chicken coops in five houses located in an urban area of Russas City, Ceará State, Brazil. Our results confirmed the presence of the tick in two of the assessed houses. The collected specimens were molecularly identified as O. rietcorreai. Of the ten individuals living in the investigated properties, three reported being parasitized by ticks. Although O. rietcorreai ticks were recovered from the evaluated houses, the primary hosts for the ticks were not identified. The retrospective medical records of parasitized individuals reported the following: local pruritus 3/3, malaise 3/3, local edema and erythema 3/3, local rash 3/3, local pain 3/3, slow lesion healing 3/3 and paresthesia 1/3. One of the individuals reported four parasitism episodes (March, June, July and August 2017) and required medical attention and the administration of anti-allergy and anti-inflammatory drugs. The aforementioned reports were the first to address human parasitism, with subsequent toxicosis, by this tick species in Brazilian urban areas. Attention was drawn to the potential consequences of such episodes to the health of previously exposed individuals.

Fatal case of spotted fever in a patient from Northeastern Brazil.

Spotted fevers are diseases caused by bacterial agents belonging to the spotted-fever (SF) group of the genus Rickettsia. The first documented case of SF in Pernambuco State, Northeast Brazil, was reported here. Also, it is the first case described of fatal SF in Northeast region of Brazil. The patient was a resident of Arcoverde municipality and the probable site of infection lies in Sertania municipality, both in Pernambuco State, a semi-arid region of Brazil. The patient had not visited other areas where SF is endemic. The patient showed clinical manifestations and epidemiological exposure compatible with SF, and the infection was confirmed by molecular biology techniques.

Rickettsia amblyommatis infecting Amblyomma pseudoconcolor in area of new focus of spotted fever in northeast Brazil.

In Brazil, active infections of Rickettsia spp. is confirmed in all regions, involving various species of ticks. During investigation of a new focus of Spotted Fever (SF) incidence in the state of Pernambuco, northeastern Brazil, tick species Rhipicephalus sanguineus sensu lato (Latreille), and Amblyomma pseudoconcolor were collected from one Canis familiaris and four Euphractus sexcinctus, respectively, and analized for the presence of rickettsial genes. Ten A. pseudoconcolor ticks (90.9%) were found to be infected with Rickettsia, whereas no evidence of Rickettsia spp. was found in R. sanguineus s. l. Genetic analysis based of five rickettsial genes showed that the detected strain is most closely related to Rickettsia amblyommatis (formerly Candidatus Rickettsia amblyommii). R. amblyommatis was, for the first time, detected in Amblyomma pseudoconcolor and the results pointed to this tick like a potential vector in the enzootic cycle of R. amblyommatis in a typical semiarid Brazilian savannah region. In conclusion, despite the need for further studies to confirm if R. amblyommatis was responsible for the observed case in the state of Pernambuco, the presence of this bacterium during an SF focussed investigation should be a major concern in terms of public health due the capacity of SF for rapid and extensive dispersion within Brazilian territory.

Evaluating the Surveillance System for Spotted Fever in Brazil Using Machine-Learning Techniques.

This work analyses the performance of the Brazilian spotted fever (SF) surveillance system in diagnosing and confirming suspected cases in the state of Rio de Janeiro (RJ), from 2007 to 2016 (July) using machine-learning techniques. Of the 890 cases reported to the Disease Notification Information System (SINAN), 11.7% were confirmed as SF, 2.9% as dengue, 1.6% as leptospirosis, and 0.7% as tick bite allergy, with the remainder being diagnosed as other categories (10.5%) or unspecified (72.7%). This study confirms the existence of obstacles in the diagnostic classification of suspected cases of SF by clinical signs and symptoms. Unlike man-capybara contact (1.7% of cases), man-tick contact (71.2%) represents an important risk indicator for SF. The analysis of decision trees highlights some clinical symptoms related to SF patient death or cure, such as: respiratory distress, convulsion, shock, petechiae, coma, icterus, and diarrhea. Moreover, cartographic techniques document patient transit between RJ and bordering states and within RJ itself. This work recommends some changes to SINAN that would provide a greater understanding of the dynamics of SF and serve as a model for other endemic areas in Brazil.

Molecular and serological detection of Theileria equi, Babesia caballi and Anaplasma phagocytophilum in horses and ticks in Maranhão, Brazil / Detecção molecular e serológica de Theileria equi, Babesia caballi e Anaplasma phagocytophilum em equinos e carrapatos no Maranhão

Equine piroplasmosis is a tick-borne disease caused by the intraeytrhocytic protozoans Babesia caballi and Theileria equi. It has been reported as a main equine parasitic disease. In addition, Anaplasma phagocytophilum, the causative agent of granulocytic ehrlichiosis, causes a seasonal disease in horses. Both diseases, can be detrimental to animal health. In this sense, blood samples and ticks were collected from 97 horses raised in the microregion of Baixada Maranhense, Maranhão State, Brazil. Serum samples were subjected to Indirect Fluorescence Antibody Test (IFAT) and blood samples and ticks to Polymerase Chain Reaction (PCR) to evaluate the infection by Theileria equi, Babesia caballi and Anaplasma phagocytophilum. The overall seroprevalence was 38.14%, 18.55% and 11.34% for T. equi, B. caballi and A. phagocytophilum, respectively. The results of PCR from blood samples showed 13.40% and 3.09% positive samples to T. equi and B. caballi, respectively. A total of 170 tick specimens were collected and identified as Dermacentor nitens, Amblyomma cajennense sensu lato and Rhipicephalus (Boophilus) microplus. It was detected 2.35% (4/170) and 0.59% (1/170) positive tick samples by PCR for T. equi and B. caballi, respectively. All samples were negative to A. phagocytophilum. No statically difference (p>0.05) was observed when gender, age, use of ectoparasiticide and tick presence were analyzed. A BLASTn analysis of the sequenced samples indicated 97 to 100% similarity with T. equi 18S rRNA gene sequences in GenBank and 98 to 100% with B. caballi. Genetic analysis classified the obtained sequences as T. equi and B. caballi cluster, respectively. It can be concluded that these pathogens occur and are circulating in the studied area.(AU)

A piroplasmose equina é uma doença transmitida por carrapatos causada pelos protozoários intraeritrocitários Babesia caballi e Theileria equi. É relatada como uma doença parasitária comum em equinos. Além disso, Anaplasma phagocytophilum, o agente causal da ehrlichiose granulocítica, causa uma doença sazonal em equinos. Ambas as doenças, podem ser prejudiciais para a saúde animal. Nesse sentido, amostras de sangue e carrapatos foram coletadas de 97 cavalos criados na microrregião da Baixada Maranhense, estado do Maranhão, Brasil. As amostras de soro foram submetidas ao Teste de Imunofluorescência Indireta (RIFI) e amostras de sangue e os carrapatos a Reação da Polimerase em Cadeia (PCR) para avaliar a infecção por Theileria equi, Babesia caballi e Anaplasma phagocytophilum. A prevalência foi de 38,14%, 18,55% e 11,34% para T. equi, B. caballi e A. phagocytophilum, respectivamente. Os resultados da PCR para as amostras de sangue demonstraram 13,40% e 3,09% de positividade para T. equi e B. caballi, respectivamente. Um total de 170 specimens de carrapatos foi coletado e foram identificados Dermacentor nitens, Amblyomma cajennense sensu lato and Rhipicephalus (Boophilus) microplus. Obteve-se 2,35% (4/170) e 0,59% (1/170) positivos por PCR para T. equi e B. caballi, respectivamente. Todas as amostras foram negativas para A. phagocytophilum. Não houve diferença estatística significativa (p>0.05) em relação ao sexo, idade, uso de ectoparasiticida e presença de carrapatos. A análise BLASTn das amostras sequenciadas para gene 18S rRNA indicaram 97 a 100% de similaridade com T. equi e 98-100% com B. caballi no GenBank. Análises genéticas classificaram as sequencias obtidas no mesmo clado que T. equi e B. caballi, respectivamente. Podemos concluir que estes patógenos estão circulando na área de estudo.(AU)

Febre maculosa no Brasil: situação epidemiológica e a distribuição geográfica de carrapatos em cenários de mudanças climáticas / Spotted fever in Brazil: current epidemiological profile and the geographical distribuition of ticks in climate change scenarios / La fiebre manchada en Brasil: situacíon actual epidemiológica y distribuicíon geográfica de garrapatas en escenarios de cambio climático

No Brasil, os quadros clínicos da febre maculosa podem ser resultantes da infecção por duas espécies de riquétsias. Rickettsia rickettsii é registrada na região Sul e Sudeste e está relacionada a casos graves da doença. Rickettsia sp. cepa Mata Atlântica foi identificada no Sul, Sudeste e Nordeste, causando febre maculosa mais branda. Febre maculosa é doença de notificação compulsória ao Ministério da Saúde que promove ações de vigilância epidemiológica e assistência médica com o objetivo de reduzir a morbimortalidade. No entanto, a doença ainda é pouco conhecida. Sabe-se que os carrapatos do gênero Amblyomma atuam como vetores, podendo parasitar hospedeiros silvestres, domésticos e eventualmente o homem. O conhecimento da distribuição geográfica potencial desses vetores torna-se importante nas ações de vigilância epidemiológica. Dessa forma, o presente estudo tem os seguintes objetivos: 1) atualizar o perfil epidemiológico da febre maculosa no Brasil; 2) avaliar preditores de evolução fatal por febre maculosa; 3) analisar a distribuição geográfica potencial de carrapatos do Complexo Amblyomma cajennese em cenário atual e futuro sob influência das mudanças climáticas. Na primeira abordagem, verificamos o crescente número de registros da doença nos últimos anos e observamos a expansão espacial da febre maculosa no país com uma ascendente taxa de letalidade. Por meio desses registros, um estudo do tipo caso-controle avaliou fatores preditores de evolução fatal por febre maculosa. Neste, verificou-se que residir em área urbana, relatar a presença de carrapato e apresentar quadro clínico com presença de linfadenopatia são fatores protetores. Enquanto os sinais de gravidade como hipotensão, choque, estupor, coma e convulsão estão associados as maiores chances de morte. Quando analisamos a distribuição geográfica potencial de carrapatos do Complexo Amblyoma cajenennese utilizando a modelagem de nicho ecológico, verificamos que áreas do Cerrado, Amazônia, Pantanal e Mata Atlântica apresentam ampla adequabilidade para manutenção dessas espécies. No entanto, em cenários de mudanças climáticas, verificamos uma tendência de redução dessas áreas (nos anos de 2050 e 2070). Nossos dados indicam que a presença do vetor pode ser restringida (e consequentemente a doença), se considerarmos a não adaptação dos carrapatos aos novos climas. Os métodos empregados neste estudo buscam, de forma complementar, o entendimento epidemiológico da febre maculosa e poderão ser utilizados para predição, prevenção e, consequentemente, para redução da morbimortalidade desta importante doença no Brasil.

In Brazil, two species of rickettsiae are responsible for the clinical manifestations of spotted fever. Rickettsia rickettsii is registered in the South and Southeast region and is related to severe cases of the disease. Rickettsia sp. Strain Atlantic Forest was identified in the south, southeast and northeast causing milder spotted fever. Spotted fever is a notifiable disease to the Ministry of Health that promotes actions of epidemiological surveillance and medical assistance aimed at reducing morbidity and mortality. However, the disease is still poorly understood. It is known that the ticks of the genus Amblyomma act as vectors, able to parasitize wild, domestic and eventually man hosts. Knowledge of the potential geographical distribution of these vectors becomes important for epidemiological surveillance actions. Thus, the present study has the following objectives: 1) update the epidemiological profile of spotted fever in Brazil; 2) evaluate predictors of fatal evolution due to spotted fever; 3) analyze the potential geographic distribution of the Amblyomma cajennese Complex ticks in current and future scenarios under the influence of climate changes. In the first approach, we verified the increasing number of records of the disease in recent years and observed the spatial expansion of spotted fever in the country with an ascending lethality rate. From these records, a case-control study evaluated predictors of fatal spotted fever progression. In this study, it was verified that residing in urban areas, reporting the presence of ticks and presenting clinical features with presence of lymphadenopathy are protective factors. While signs of severity such as hypotension, shock, stupor, coma, and seizure, were strongly associated with the risk of death. When analyzing the potential geographic distribution of Amblyoma cajenennese Complex ticks using ecological niche modeling, we found that areas of Cerrado, Amazon, Pantanal and the Atlantic Forest present wide suitability for the maintenance of these species. However, in climate change scenarios we have seen a tendency to reduce these areas (in the years 2050 and 2070). Our data indicate that the presence of the vector may be restricted (and consequently the disease) if we consider the non-adaptation of ticks to the new climates. The methods used in this study seek to complement the epidemiological understanding of spotted fever and can be used for prediction, prevention and consequently to reduce the morbimortality of this important disease in Brazil.

Los cuadros clínicos de fiebre manchada en Brasil, pueden ser resultantes de infecciones producidas por dos especies de Rickettsia. Rickettsia rickettsii es registrada en la región Sur y Sureste y relacionada a casos clínicos más graves de la enfermedad. Rickettsia sp. cepa Mata Atlântica ha sido identificada en el Sur, Sureste y Noreste causando casos clínicos menos graves. La fiebre manchada es una enfermedad de notificación obligatoria al Ministerio de la Salud, que promueve acciones de vigilancia epidemiológica y atención médica a fin de reducir la morbimortalidad. Sin embargo, la enfermedad sigue siendo desconocida. Hay suficiente evidencia que las garrapatas del género Amblyomma son los principales vectores de los patógenos, parasitan hospederos silvestres, domésticos y en ocasiones a los humanos. El conocimiento de la potencial distribución geográfica de esos vectores es esencial en las acciones de vigilancia epidemiológica. Por lo tanto, este estudio tiene los siguientes objetivos: 1) actualizar el perfil epidemiológico de la fiebre manchada en Brasil; 2) evaluar los predictores que conducen a la evolución fatal de los casos de fiebre manchada; 3) analizar el potencial de distribución geográfica de las garrapatas del complejo Amblyomma cajennese en el escenario actual y futuro bajo la influencia del cambio climático. En el primer enfoque, evidenciamos el creciente número de registros de la enfermedad en los últimos años y observamos la expansión espacial de la fiebre manchada en el país, con tasa de aumento de la mortalidad. A partir de estos registros, un estudio caso-control evaluó los predictores de evolución fatal de los casos de fiebre manchada. Se ha verificado que residir en área urbana, relatar la presencia de garrapatas y manifestar cuadro clínico con presencia de adenopatía son factores de protección. Mientras que los signos de gravedad como hipotensión, shock, estupor, coma y convulsiones se asocian con la mayor probabilidad de muerte. Cuando se analiza el potencial de distribución geográfica de las garrapatas del complejo A. cajenennese utilizando el modelo de nicho ecológico, hemos encontrado que las áreas de los biomas: Cerrado, Amazonia, Pantanal y Mata Atlántica, son aptos para la manutención de esas especies. No obstante, también evidenciamos que en escenarios de cambio climático hay una tendencia de reducción de estos biomas (años 2050 y 2070). Nuestros resultados indican que la presencia del vector puede ser restringido y, por lo tanto, la enfermedad, teniendo en cuenta la falta de adaptación de las garrapatas a los nuevos escenarios climáticos. Los métodos empleados en el presente estudio buscan complementar el entendimiento epidemiológico de la fiebre manchada y pueden ser utilizados para la predicción, prevención y, consecuentemente, para la reducción de la morbimortalidad de esta enfermedad de interés en salud pública en Brasil.