ABSTRACT
Species distribution models (SDMs) are increasingly popular tools for profiling disease risk in ecology, particularly for infectious diseases of public health importance that include an obligate non-human host in their transmission cycle. SDMs can create high-resolution maps of host distribution across geographical scales, reflecting baseline risk of disease. However, as SDM computational methods have rapidly expanded, there are many outstanding methodological questions. Here we address key questions about SDM application, using schistosomiasis risk in Brazil as a case study. Schistosomiasis is transmitted to humans through contact with the free-living infectious stage of Schistosoma spp. parasites released from freshwater snails, the parasite's obligate intermediate hosts. In this study, we compared snail SDM performance across machine learning (ML) approaches (MaxEnt, Random Forest, and Boosted Regression Trees), geographic extents (national, regional, and state), types of presence data (expert-collected and publicly-available), and snail species (Biomphalaria glabrata, B. straminea, and B. tenagophila). We used high-resolution (1km) climate, hydrology, land-use/land-cover (LULC), and soil property data to describe the snails' ecological niche and evaluated models on multiple criteria. Although all ML approaches produced comparable spatially cross-validated performance metrics, their suitability maps showed major qualitative differences that required validation based on local expert knowledge. Additionally, our findings revealed varying importance of LULC and bioclimatic variables for different snail species at different spatial scales. Finally, we found that models using publicly-available data predicted snail distribution with comparable AUC values to models using expert-collected data. This work serves as an instructional guide to SDM methods that can be applied to a range of vector-borne and zoonotic diseases. In addition, it advances our understanding of the relevant environment and bioclimatic determinants of schistosomiasis risk in Brazil.
ABSTRACT
Despite the considerable morbidity and mortality of yellow fever virus (YFV) infections in Brazil, our understanding of disease outbreaks is hampered by limited viral genomic data. Here, through a combination of phylogenetic and epidemiological models, we reconstructed the recent transmission history of YFV within different epidemic seasons in Brazil. A suitability index based on the highly domesticated Aedes aegypti was able to capture the seasonality of reported human infections. Spatial modeling revealed spatial hotspots with both past reporting and low vaccination coverage, which coincided with many of the largest urban centers in the Southeast. Phylodynamic analysis unraveled the circulation of three distinct lineages and provided proof of the directionality of a known spatial corridor that connects the endemic North with the extra-Amazonian basin. This study illustrates that genomics linked with eco-epidemiology can provide new insights into the landscape of YFV transmission, augmenting traditional approaches to infectious disease surveillance and control.
Subject(s)
Yellow Fever , Yellow fever virus , Humans , Yellow fever virus/genetics , Phylogeny , Brazil/epidemiology , Yellow Fever/epidemiology , Disease Outbreaks , GenomicsABSTRACT
OBJECTIVE: to evaluate the completeness and timeliness of notifications of cases of spotted fever (SF) held on the Notifiable Health Conditions Information System (SINAN) in São Paulo State, Brazil, from 2007 to 2017. METHODS: this was a descriptive and ecological study of confirmed human cases of SF regarding completeness and timeliness of ten fields of the notification form (good if ≥ 90% for most variables); time series analysis was performed using the Prais-Winsten technique. RESULTS: we analyzed 736 records; among essential fields, only "Discharge date" showed poor completeness (68.5%). Timeliness was good for the "Investigation" and "Closure" fields; other time lapses were not adequate. CONCLUSION: in São Paulo state, data completeness was good for most variables, whereas timeliness was not adequate (except for "Closure" and "Investigation"), pointing to the need for health education and communication actions about SF.
Subject(s)
Population Surveillance , Spotted Fever Group Rickettsiosis , Humans , Population Surveillance/methods , Brazil/epidemiology , Disease Notification , Information SystemsABSTRACT
The objective was to study the composition of sand fly species, the seasonal activity of the dominant species and correlation with average rainfall, sex association of the dominant species with domicile habitats and analyze different landscape scenarios for the two study sites in the municipalities of Itapevi and Mogi of the Crosses. Sandflies were captured with CDC(s) traps installed in three households at each study site for a period of 24 hours, biweekly for two years. A total of 2970 specimens were collected. The dominant species were P.fischeri and M.migonei. A statistically significant difference was registered between males and females of the two species in relation to the intra and peridomicile. The seasonal activity of both species showed a weak significant positive correlation with rainfall. The species P.fischeri and M.migonei may be potential vectors of CVL in the studied sites.
Subject(s)
Dog Diseases , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Phlebotomus , Psychodidae , Male , Female , Animals , Dogs , Leishmaniasis, Visceral/veterinary , Cities , Brazil , Psychodidae/parasitology , Leishmaniasis, Cutaneous/veterinaryABSTRACT
Amblyomma is an important tick genus for animal and human health, with some species being the vectors of zoonotic pathogens, such as Rickettsia rickettsii, in the Neotropical region. Knowing their hosts may help to understand the distribution of these agents and decrease the occurrence of clinical cases. Primates are intelligent and adaptable animals that can get close to humans in the search for food. So, they may be an important epidemiological link for the spread of these ticks. Beyond that, primates also suffer from these infections, serving as sentinels for different diseases. Thus, the present study aims to report the parasitism by Amblyomma spp. on six species of Neotropical primates from different locations in Brazil. The 337 collected ticks were morphologically identified using stereomicroscopes and taxonomic keys, and six distinct species of ticks were identified. We report here the first record of nymphs of the tick species Amblyomma cajennense sensu stricto on Alouatta belzebul, a male of Amblyomma fuscum on Alouatta guariba clamitans, nymphs of Amblyomma sculptum on Leontopithecus chrysopygus and Callithrix aurita, as well as nymphs of Amblyomma geayi on Saimiri collinsi. Of the 337 tick specimens collected, 256 (75,96%) were nymphs. The importance of primates in the life cycle of these species remains to be elucidated.
Subject(s)
Ixodidae , Rickettsia , Ticks , Animals , Male , Humans , Ticks/microbiology , Amblyomma , Ixodidae/microbiology , Brazil/epidemiology , PrimatesABSTRACT
Objective: To evaluate the completeness and timeliness of notifications of cases of spotted fever (SF) in the National System of Information on Notifiable Diseases (Sinan) in the state of São Paulo, from 2007 to 2017. Methods: This is a descriptive and ecological study of confirmed human cases of SF for completeness and timeliness of ten form fields (good if ≥ 90% for most variables). Linear regression was performed to analyze trends in the time series. Results: Among essential fields, only "Discharge date" showed low completeness (68.5%). "Investigation" and "Closure" had good timeliness; other intervals were not adequate. Conclusion: In the state of São Paulo, data completeness was good for most variables, but not adequate in terms of timeliness, except for "Closing" and "Investigation", pointing to the need for health education and communication actions on SF.
Objetivo: Evaluar la integridad y oportunidad de las notificaciones de casos de fiebre maculosa (SF) en el Sistema Nacional de Información sobre Enfermedades de Declaración Obligatoria (Sinan) en el estado de São Paulo, de 2007 a 2017. Métodos: Se trata de un estudio descriptivo y ecológico. estudio de casos humanos confirmados de SF para la integridad y puntualidad de diez campos de formulario (bueno si ≥ 90% para la mayoría de las variables). Se realizó una regresión lineal para analizar las tendencias en la serie temporal. Resultados: Entre los campos esenciales, solo "Fecha de alta" mostró baja completitud (68,5%). "Investigación" y "Cierre" tuvieron buena oportunidad; otros intervalos no fueron adecuados. Conclusión: En São Paulo, la completitud fue buena para la mayoría de las variables, pero no adecuada en cuanto a la oportunidad, excepto para "Cierre" e "Investigación", lo que apunta a la necesidad de acciones de educación y comunicación en salud sobre SF.
Objetivo: avaliar completitude e oportunidade das notificações de casos de febre maculosa (FM) no Sistema de Informação de Agravos de Notificação (Sinan), no estado de São Paulo, Brasil, no período de 2007 a 2017. Métodos: estudo descritivo e ecológico dos casos humanos confirmados de FM, mediante análise dos atributos "completitude" e "oportunidade" de dez campos da ficha de notificação (boas quando ≥ 90% para a maioria das variáveis); realizou-se análise de regressão linear para avaliar as tendências das séries temporais. Resultados: foram analisados 736 registros; dos campos essenciais, apenas "Data da alta" demonstrou baixa completitude (68,5%); "Investigação" e "Encerramento" tiveram boa oportunidade; demais intervalos não foram adequados. Conclusão: no estado de São Paulo, a completitude dos dados foi boa na maioria das variáveis, porém não adequada quanto à oportunidade (exceto para "Encerramento" e "Investigação"), apontando para a necessidade de ações de educação e comunicação em saúde sobre FM.
ABSTRACT
Objetivo: avaliar completitude e oportunidade das notificações de casos de febre maculosa (FM) no Sistema de Informação de Agravos de Notificação (Sinan), no estado de São Paulo, no período de 2007 a 2017. Métodos: estudo descritivo e ecológico dos casos humanos confirmados de FM, mediante análise dos atributos completitude e oportunidade de dez campos da ficha de notificação (boas quando ≥ 90% para a maioria das variáveis); na análise das tendências das séries temporais, utilizou-se a técnica de Prais-Winsten. Resultados: foram analisados 736 registros; dos campos essenciais, apenas "Data da alta" demonstrou baixa completitude (68,5%); "Investigação" e "Encerramento" tiveram boa oportunidade; demais intervalos não foram adequados. Conclusão: no estado de São Paulo, a completitude dos dados foi boa na maioria das variáveis, porém não adequada quanto à oportunidade (exceto para "Encerramento" e "Investigação"), apontando para a necessidade de ações de educação e comunicação em saúde sobre FM.
Objective: to evaluate the completeness and timeliness of notifications of cases of spotted fever (SF) held on the Notifiable Health Conditions Information System (SINAN) in São Paulo State, Brazil, from 2007 to 2017. Methods: this was a descriptive and ecological study of confirmed human cases of SF regarding completeness and timeliness of ten fields of the notification form (good if ≥ 90% for most variables); time series analysis was performed using the Prais-Winsten technique. Results: we analyzed 736 records; among essential fields, only "Discharge date" showed poor completeness (68.5%). Timeliness was good for the "Investigation" and "Closure" fields; other time lapses were not adequate. Conclusion: in São Paulo state, data completeness was good for most variables, whereas timeliness was not adequate (except for "Closure" and "Investigation"), pointing to the need for health education and communication actions about SF.
Objetivo: evaluar la completitud y oportunidad de las notificaciones de casos de fiebre manchada (FM) en el Sistema Nacional de Información sobre Enfermedades de Declaración Obligatoria (Sinan) en el estado de São Paulo, Brasil, de 2007 a 2017. Métodos: estudio descriptivo y ecológico de casos humanos confirmados de FM para completitud y oportunidad de diez campos del formulario (bueno si ≥ 90% para la mayoría de las variables). Se realizó una regresión lineal para analizar las tendencias de las series temporales. Resultados: entre los campos esenciales, solo "Fecha de alta" mostró baja completitud (68,5%). "Investigación" y "Cierre" tuvieron buena oportunidad; otros intervalos no fueron adecuados. Conclusión: en São Paulo, la completitud fue buena para la mayoría de las variables, pero no adecuada en cuanto a la oportunidad, excepto para "Cierre" e "Investigación", lo que apunta a la necesidad de acciones de educación y comunicación en salud sobre FM.
Subject(s)
HumansABSTRACT
The bacterium Rickettsia rickettsii is the etiological agent of Brazilian spotted fever (BSF), and its most important vector to humans in Brazil is the tick Amblyomma sculptum. Capybaras are the main hosts of A. sculptum in many BSF-endemic areas and are considered valuable sentinels for BSF surveillance. This study aimed to assess the persistence of anti-R. rickettsii antibodies for long periods in capybaras and their passive transfer to offspring. For this purpose, three adult capybaras previously exposed to multiple infections with R. rickettsii were followed up until 3.1 years after their last exposure. During the study, one female delivered five cubs, of which three survived. Blood samples were collected monthly from adults and infants, and serum samples were titrated by indirect immunofluorescence assay (IFA) to determine endpoint titers of anti-R. rickettsii antibodies. All three adults remained seroreactive to R. rickettsii with high endpoint titers until the end of the study. All infants were seroreactive to R. rickettsii after birth and remained seroreactive for one to four months. This study showed that exposure of capybaras to R. rickettsii-infected A. sculptum ticks elicits a persistent antibody response. In addition, there was evidence of passive transfer of R. rickettsii-reactive antibodies to offspring.
Subject(s)
Ixodidae , Rocky Mountain Spotted Fever , Rodent Diseases , Ticks , Animals , Antigens, Bacterial , Brazil/epidemiology , Female , Humans , Ixodidae/microbiology , Rickettsia rickettsii , Rocky Mountain Spotted Fever/epidemiology , Rocky Mountain Spotted Fever/veterinary , Rodentia/parasitology , Ticks/microbiologyABSTRACT
Records of accidental parasitism by ticks in humans from Brazil are scarce, with most being reported by researchers who are parasitized during their research and by professionals who work with animals. In order to compile these records, an extensive literature review was carried out. Our revision includes studies published between 1909 and 2022, including nine species of the Argasidae family and 32 species of the Ixodidae family that were reported biting humans in the six biomes of the Brazilian territory. The species with the highest number of records of human parasitism was Amblyomma sculptum, followed by Amblyomma coelebs, Amblyomma cajennense sensu stricto, and Amblyomma brasiliense. The Atlantic Forest was the most frequent biome where human parasitism occurred, probably due to the greater number of inhabitants, universities, and researchers in the region; however, this does not mean that this biome is more conducive to the development of ticks and their parasitism in humans. In addition to Amblyomma ovale, a vector of Rickettsia parkeri in the country, two of the main species that act as vectors of Rickettsia rickettsii, A. sculptum, and Amblyomma aureolatum, have been reported, which is quite worrying considering that the wide distribution of the species and life stages most frequently mentioned in parasitism (i.e., nymphs and adults) are the ones that favour pathogen transmission. This research provides a significant contribution to the knowledge of tick species associated with human parasitism in Brazil; however, due to environmental change potentiated by deforestation and fires, it is expected that there will be a geographic expansion of some tick species and the pathogens that use them as a vector and an increase in human parasitism.
Subject(s)
Argasidae , Ixodidae , Rickettsia , Ticks , Animals , Brazil/epidemiology , Ecosystem , Humans , Ixodidae/microbiology , Ticks/microbiologyABSTRACT
In June 2012, a tick was found parasitizing a man in the city of São Paulo, who had recently returned from a visit to Pennsylvania, in the northeast of the United States. The tick was removed and sent to the São Paulo State Department of Health, where it was identified as a male of the species Dermacentor variabilis (Say, 1821), according to the literature and taxonomic keys. The tick was subjected to a PCR test to search for rickettsiae, but the result was negative. The fact that a human entered Brazilian territory unaware that he was parasitized by a hard tick not belonging to the national tick fauna is significant because of the possibility that an exotic species could be introduced and take hold in this country. Another major risk to public health is that this arthropod could be infected with the bacterium Rickettsia rickettsii, as this ectoparasite is the main vector of Spotted Fever on the East Coast of North America.
Subject(s)
Dermacentor , Rickettsia , Spotted Fever Group Rickettsiosis , Animals , Brazil , Humans , Male , Rickettsia/genetics , Rickettsia rickettsii , Spotted Fever Group Rickettsiosis/veterinaryABSTRACT
Abstract Alongside modernity, the human activity has been a key factor in global environmental risks, with worldwide anthropic modification being the cause of the emergence of diseases for wild and livestock animals, and even humans. In special, the increase in the spatial distribution and in the incidence of some emerging infectious diseases (EID) are directly associated to deforestation and global climate changes. Moreover, the arise of new EID agents, such as the SARS-COV-2 have been reported for the last 30 years. On the other hand, biodiversity has been shown to be a key indicator for ecosystem health, and to pose a role to increase the promotion of human public health. In neotropical regions, and in special, in Brazil, several infectious diseases have been demonstrated to be directly affected for the biodiversity loss, such as malaria, hantavirus pulmonary syndrome, yellow fever, urban arboviruses, spotted fever, amongst other. To better understand the ecosystem capacity of regulation of infectious diseases, FAPESP BIOTA program have supported researchers and research projects to increase knowledge about Brazilian biodiversity and the ecosystems, such as diversity of bird bioagents, venomous animals biodiversity, diversity of mosquitos species in forest patches inside urban areas, propagation of the yellow fever virus over fragmented forest territories, loss of ecological corridors and occurrence of spotted fever and malaria, amongst others. It is noteworthy that FAPESP BIOTA is a successful program and must be expanded as an important tool for present and future public health promotion.
Resumo Junto à modernidade, a atividade humana tem sido um fator chave ligada aos riscos ambientais globais, as modificações antrópicas em âmbito mundial têm sido causa do surgimento de doenças para os animais silvestres e domésticos, bem como para o ser humano. Em especial, o incremento na distribuição espacial e incidência de doenças infecciosas emergentes (DIE) estão diretamente associados ao desmatamento e às mudanças climáticas globais, além disso, o surgimento de novos agentes de DIE, como o SARS-COV-2, tem sido relatado nos últimos 30 anos. Por outro lado, a biodiversidade tem se mostrado um indicador chave para a saúde dos ecossistemas, além de representar um papel importante na promoção da saúde pública humana. Nas regiões neotropicais, e em especial, no Brasil, várias doenças infecciosas têm demonstrado ser diretamente afetadas pela perda de biodiversidade, como a malária, a síndrome pulmonar por hantavírus, a febre amarela, as arboviroses urbanas, a febre maculosa, entre outras. Para entender melhor a capacidade ecossistêmica de regulação de doenças infecciosas, o programa BIOTA FAPESP tem apoiado pesquisadores e projetos de pesquisa para aumentar o conhecimento sobre a biodiversidade e os ecossistemas brasileiros, como a diversidade de bioagentes de aves, a biodiversidade de animais peçonhentos, a diversidade de espécies de mosquitos em fragmentos florestais dentro de áreas urbanas, a propagação do vírus da febre amarela em território florestal fragmentado, perda e isolamento de remanescentes florestais e a ocorrência de febre maculosa e malária, entre outros. Ressalta-se que o BIOTA FAPESP é um programa de sucesso e deve ser ampliado como importante ferramenta de promoção da saúde pública presente e futura.
ABSTRACT
Abstract In June 2012, a tick was found parasitizing a man in the city of São Paulo, who had recently returned from a visit to Pennsylvania, in the northeast of the United States. The tick was removed and sent to the São Paulo State Department of Health, where it was identified as a male of the species Dermacentor variabilis (Say, 1821), according to the literature and taxonomic keys. The tick was subjected to a PCR test to search for rickettsiae, but the result was negative. The fact that a human entered Brazilian territory unaware that he was parasitized by a hard tick not belonging to the national tick fauna is significant because of the possibility that an exotic species could be introduced and take hold in this country. Another major risk to public health is that this arthropod could be infected with the bacterium Rickettsia rickettsii, as this ectoparasite is the main vector of Spotted Fever on the East Coast of North America.
Resumo Em junho de 2012, foi enviado ao serviço da Secretaria de Estado da Saúde de São Paulo um carrapato que foi encontrado em parasitismo sobre um homem adulto na cidade de São Paulo, que havia chegado recentemente de uma viagem de turismo aos Estados Unidos, onde visitou o estado da Pensilvânia, situado na região Nordeste Americana. O carrapato foi identificado como um macho da espécie Dermacentor variabilis, (Say, 1821), de acordo com a literatura e chaves taxonômicas, sendo submetido ao teste da PCR para pesquisa de riquétsias, porém o resultado foi negativo. O fato de um ser humano ter cruzado a fronteira do Brasil, parasitado, sem o seu prévio conhecimento, por um carrapato duro, não pertencente à ixodofauna nacional, é de grande importância pela chance de introdução e estabelecimento no território brasileiro de uma espécie exótica. Outro grande risco para a saúde pública é que esse artrópode poderia estar infectado com a bactéria Rickettsia rickettsii, pois esse ectoparasito é o principal vetor da Febre Maculosa na costa Leste Norte Americana.
Subject(s)
Humans , Animals , Male , Rickettsia/genetics , Dermacentor , Spotted Fever Group Rickettsiosis/veterinary , Rickettsia rickettsii , BrazilABSTRACT
Brazilian spotted fever (BSF) is an acute infectious disease caused by the bacterium Rickettsia rickettsii, which is transmitted by different tick species. Due to deleterious effects caused on ticks, the horizontal transmission of R. rickettsii through amplifying hosts is crucial for its maintenance in tick populations among BSF-endemic areas. The tick Amblyomma aureolatum is the main vector of R. rickettsii in the São Paulo metropolitan area; nevertheless, it is not known which vertebrate could act as an amplifying host for this tick species. Herein, we evaluated the potential of domestic dogs - primary hosts for A. aureolatum adults in BSF-endemic areas - to act as amplifying hosts. For this purpose, A. aureolatum non-infected adults were allowed to feed on two groups of dogs: the control group (G1), composed of one dog not exposed to R. rickettsii; and, the infected group (G2), composed of three dogs infected with R. rickettsii via tick parasitism. All G2-dogs became ill, seroconverted to R. rickettsii, and rickettsial DNA was detected in 87% of the engorged females that fed on them. Transovarial transmission rate was estimated to be 25% and infected larvae successfully transmitted R. rickettsii to guinea-pigs, confirming transovarial transmission and vector competence. No rickettsial DNA was detected in individual samples of eggs or larvae, which precluded the estimation of filial infection rate, but implies that it was low. Our results suggest that domestic dogs act as amplifying hosts of R. rickettsii for A. aureolatum ticks in BSF-endemic areas in Brazil.
Subject(s)
Amblyomma/microbiology , Bacterial Zoonoses/transmission , Dog Diseases/transmission , Host-Pathogen Interactions , Rickettsia Infections/veterinary , Rickettsia rickettsii/physiology , Animals , Bacterial Zoonoses/microbiology , Brazil , Dog Diseases/microbiology , Dogs , Female , Larva/growth & development , Larva/physiology , Male , Nymph/growth & development , Nymph/physiology , Rickettsia Infections/microbiology , Rickettsia Infections/transmissionABSTRACT
We investigated the sylvatic yellow fever (SYF) diffusion process in São Paulo (SP) between 2016 and 2019. We developed an ecological study of SYF through autochthonous human cases and epizootics of non-human primates (NHPs) that were spatiotemporally evaluated. We used kriging to obtain maps with isochrones representative of the evolution of the outbreak and characterized its diffusion pattern. We confirmed 648 human cases of SYF in SP, with 230 deaths and 843 NHP epizootics. Two outbreak waves were identified: one from West to East (2016 and 2017), and another from the Campinas region to the municipalities bordering Rio de Janeiro, Minas Gerais, and Paraná and those of the SP coast (2017-2019). The SYF outbreak diffusion process was by contagion. The disease did not exhibit jumps between municipalities, indicating that the mosquitoes and NHPs were responsible for transmitting the virus. There were not enough vaccines to meet the population at risk; hence, health authorities used information about the epizootic occurrence in NHPs in forest fragments to identify priority populations for vaccination.
Subject(s)
Yellow Fever/epidemiology , Animals , Brazil/epidemiology , Disease Outbreaks/prevention & control , Humans , Primates/virology , Vaccination/methods , Yellow Fever/immunology , Yellow Fever/virology , Yellow fever virus/immunology , Zoonoses/epidemiology , Zoonoses/immunology , Zoonoses/virologyABSTRACT
Avian malaria parasites are widespread parasites transmitted by Culicidae insects belonging to different genera. Even though several studies have been conducted recently, there is still a lack of information about potential vectors of Plasmodium parasites, especially in Neotropical regions. Former studies with free-living and captive animals in São Paulo Zoo showed the presence of several Plasmodium and Haemoproteus species. In 2015, a pilot study was conducted at the zoo to collect mosquitoes in order to find out (i) which species of Culicidae are present in the study area, (ii) what are their blood meal sources, and (iii) to which Plasmodium species might they be potential vectors. Mosquitoes were morphologically and molecularly identified. Blood meal source and haemosporidian DNA were identified using molecular protocols. A total of 25 Culicidae species were identified, and 6 of them were positive for Plasmodium/Haemoproteus DNA. Ten mosquito species had their source of blood meal identified, which were mainly birds, including some species that were positive for haemosporidian parasites in the former study mentioned. This study allowed us to expand the list of potential vectors of avian malaria parasites and to improve our knowledge of the evolutionary and ecological relationships between the highly diverse communities of birds, parasites, and vectors present at São Paulo Zoo.
ABSTRACT
This study aimed to evaluate the occurrence of diseases transmitted by Amblyomma ovale in 61 dogs monitored for three years through collections of ticks and blood, interviews, telemetry and camera traps in three areas of Serra do Mar State Park, Brazil. Blood samples were used to investigate infection by Rangelia vitalii by real-time TaqMan PCR and Rickettsia parkeri by IIFA. The collected ticks were submitted to conventional PCR to investigate the presence of R. parkeri . These data were compared with the monitoring results and interviews with the owners. Dogs considered as companion presented a risk of infection by R. parkeri strain Mata Atlantica 5.4 times higher than those not considered as companion (p = 0.009). Dogs that had at least one A. ovale collected during the campaigns had a 10 times higher risk of infection by R. parkeri strain Mata Atlantica than those who did not (p = 0.009). One dog positive for R. vitalii by real-time TaqMan PCR was parasitized by A. ovale frequently during monitoring. Sequenced ompaA - positive DNA samples had 100% identity of R. parkeri strain Mata Atlantica clone As106. From the findings, it is urgent to control domestic dogs around rainforests to reduce zoonoses transmission.
Subject(s)
Dog Diseases/epidemiology , Ixodidae/microbiology , Rickettsia Infections/veterinary , Rickettsia/isolation & purification , Animals , Brazil/epidemiology , DNA, Bacterial/analysis , Dog Diseases/diagnosis , Dog Diseases/microbiology , Dogs , Fluorescent Antibody Technique, Indirect , Polymerase Chain Reaction , Rainforest , Rickettsia/classification , Rickettsia/genetics , Rickettsia Infections/diagnosis , Rickettsia Infections/epidemiology , Sequence Analysis, DNA , TelemetryABSTRACT
Abstract This study aimed to evaluate the occurrence of diseases transmitted by Amblyomma ovale in 61 dogs monitored for three years through collections of ticks and blood, interviews, telemetry and camera traps in three areas of Serra do Mar State Park, Brazil. Blood samples were used to investigate infection by Rangelia vitalii by real-time TaqMan PCR and Rickettsia parkeri by IIFA. The collected ticks were submitted to conventional PCR to investigate the presence of R. parkeri . These data were compared with the monitoring results and interviews with the owners. Dogs considered as companion presented a risk of infection by R. parkeri strain Mata Atlantica 5.4 times higher than those not considered as companion (p = 0.009). Dogs that had at least one A. ovale collected during the campaigns had a 10 times higher risk of infection by R. parkeri strain Mata Atlantica than those who did not (p = 0.009). One dog positive for R. vitalii by real-time TaqMan PCR was parasitized by A. ovale frequently during monitoring. Sequenced ompaA - positive DNA samples had 100% identity of R. parkeri strain Mata Atlantica clone As106. From the findings, it is urgent to control domestic dogs around rainforests to reduce zoonoses transmission.
Resumo A ocorrência de doenças transmitidas por Amblyomma ovale em 61 cães monitorados por três anos através de coletas de carrapatos, sangue, entrevistas, telemetria e armadilhas fotográficas foi avaliada em três áreas do Parque Estadual da Serra do Mar - SP. Amostras de sangue foram utilizadas para investigação de Rangelia vitalii através de PCR TaqMan em tempo real e Rickettsia parkeri através da RIFI. Carrapatos coletados foram submetidos à PCR convencional para investigação de R. parkeri . Estes dados foram comparados considerando os resultados do monitoramento e entrevistas. Cães de companhia apresentaram risco de infecção pela R. parkeri cepa Mata Atlântica 5,4 vezes maior que os não considerados como de companhia (p = 0,009). Cães que tiveram pelo menos um A. ovale coletado apresentaram risco de infecção por R. parkeri cepa Mata Atlântica 10 vezes maior do que aqueles que não tiveram (p = 0,009). Um cão positivo para R. vitalii através de PCR TaqMan em tempo real foi parasitado por A. ovale durante o monitoramento. Amostras positivas para o gene ompaA possuíam 100% de identidade do clone As106 de R. parkeri cepa de Mata Atlântica. Assim, é urgente o controle de cães na Mata Atlântica para redução dos riscos de zoonoses.
Subject(s)
Animals , Dogs , Rickettsia/isolation & purification , Rickettsia Infections/veterinary , Ixodidae/microbiology , Dog Diseases/epidemiology , Rickettsia/classification , Rickettsia/genetics , Rickettsia Infections/diagnosis , Rickettsia Infections/epidemiology , Telemetry , Brazil/epidemiology , DNA, Bacterial/analysis , Polymerase Chain Reaction , Sequence Analysis, DNA , Fluorescent Antibody Technique, Indirect , Dog Diseases/diagnosis , Dog Diseases/microbiology , RainforestABSTRACT
O gênero Eutrombicula compreende ca. 80 espécies em todo o mundo, algumas das quais foram relatadas como agentes causadores de irritação severa na pele do hospedeiro, conhecidas como trombiculíase. Seis espécies de Eutrombicula foram registradas no Brasil até o presente, com dois relatos de humanos como hospedeiros. Neste estudo, Eutrombicula tinami (Oudemans) é redescrita e novos registros para os estados de Minas Gerais, Rio de Janeiro, Santa Catarina e São Paulo, bem como novas associações de parasitas-hospedeiros com Columbiformes, Cuculiformes, Passeriformes, Tinamiformes, Carnívoros, Didelphimorphia e Lagomorpha estão listados. Além disso, são apresentados dois casos detalhados de trombiculíase.
ABSTRACT
BACKGROUND: Rickettsia parkeri strain Atlantic rainforest has emerged in Brazil during the last 10 years, with three laboratory-confirmed human cases. While these cases were epidemiologically associated with the tick Amblyomma ovale, in none of them the tick specimens that bit the patients could be identified. RESULTS: We report a clinical case of spotted fever rickettsiosis that was acquired in an Atlantic forest area in Bahia state, northeast Brazil. The case was determined to be caused by R. parkeri strain Atlantic rainforest, based on molecular analysis of the crust removed from the tick bite site (inoculation eschar) of the patients' skin. DNA extracted from the crust yielded partial sequences of three rickettsial genes (gltA, ompA and ompB), which were 99-100% identical to R. parkeri strain Atlantic rainforest. The tick specimen that was attached to patient skin was identified as a female of A. ovale. CONCLUSIONS: We report the fourth confirmed case of spotted fever rickettsiosis caused by R. parkeri strain Atlantic rainforest, providing to our knowledge for the first time, direct evidence of R. parkeri strain Atlantic rainforest transmission by A. ovale.