Seroprevalence of Rickettsia rickettsii and Rickettsia parkeri in dogs during a Brazilian Spotted Fever outbreak in the State of Rio de Janeiro / Soroprevalência de Rickettsia rickettsii e Rickettsia parkeri em cães durante um surto de Febre Maculosa Brasileira no Estado do Rio de Janeiro

The present paper is the first to perform this evaluation in dogs from the cities of Natividade, Porciuncula and Varre-Sai. The aim of this study is to search for Spotted Fever Group Rickettsia in canine sera using indirect immunofluorescence assay and to identify the probable causative agent of sera reactions in animals. Of the 253 sampled canines, 67.59% (171/253) were seroreactive for Rickettsia rickettsii and 11.07% (28/253) for Rickettsia parkeri, both in dilution 1:64. Titration of tested sera against R. rickettsii antigens reached 1:131.072 and, for R. parkeri, 1:4.096. We conclude that dogs are important sentinels for R. rickettsii infection, and can be infected regardless of sex, age, the habit of visiting woodlands or being in direct contact with equines and capybaras. Serological diagnosis has highlighted many dogs infected by R. rickettsii, and ambient conditions, such as the presence of flowing water bodies, was important for the occurrence of Brazilian Spotted Fever in the northwestern of Rio de Janeiro State.(AU)

O presente trabalho é o primeiro a ser realizado com cães nos municípios de Natividade, Porciúncula e Varre-Sai e tem por objetivo pesquisar Rickettsias do Grupo da Febre Maculosa em soros de cães, por meio da reação de imunofluorescência indireta, e identificar o provável agente causador da reação sorológica nos animais. Dos caninos amostrados, 67,59% (171/253) foram sororreativos para Rickettsia rickettsii e 11,07% (28/253) para Rickettsia parkeri, ambos em diluição de 1:64. A titulação dos soros testados contra antígenos de R. rickettsii chegou a 1:131.072, e para R. parkeri, 1:4.096. Conclui-se que cães são importantes sentinelas para a infecção por R. rickettsii, independente de sexo, idade, hábito de visitar ambientes florestais ou de estarem em contato direto com equinos e capivaras. O diagnóstico sorológico permitiu evidenciar muitos cães infectados por R. rickettsii, e condições ambientais, como a presença de áreas ribeirinhas, foram importantes para a ocorrência de Febre Maculosa Brasileira na região noroeste do Estado do Rio de Janeiro.(AU)

Fluorescent membrane markers elucidate the association of Borrelia burgdorferi with tick cell lines.

This study aimed to describe the association of Borrelia burgdorferi s.s. with ixodid tick cell lines by flow cytometry and fluorescence and confocal microscopy. Spirochetes were stained with a fluorescent membrane marker (PKH67 or PKH26), inoculated into 8 different tick cell lines and incubated at 30°C for 24 h. PKH efficiently stained B. burgdorferi without affecting bacterial viability or motility. Among the tick cell lines tested, the Rhipicephalus appendiculatus cell line RA243 achieved the highest percentage of association/internalization, with both high (90%) and low (10%) concentrations of BSK-H medium in tick cell culture medium. Treatment with cytochalasin D dramatically reduced the average percentage of cells with internalized spirochetes, which passed through a dramatic morphological change during their internalization by the host cell as observed in time-lapse photography. Almost all of the fluorescent bacteria were seen to be inside the tick cells. PKH labeling of borreliae proved to be a reliable and valuable tool to analyze the association of spirochetes with host cells by flow cytometry, confocal and fluorescence microscopy.

Fluorescent membrane markers elucidate the association of Borrelia burgdorferi with tick cell lines

This study aimed to describe the association of Borrelia burgdorferi s.s. with ixodid tick cell lines by flow cytometry and fluorescence and confocal microscopy. Spirochetes were stained with a fluorescent membrane marker (PKH67 or PKH26), inoculated into 8 different tick cell lines and incubated at 30°C for 24 h. PKH efficiently stained B. burgdorferi without affecting bacterial viability or motility. Among the tick cell lines tested, the Rhipicephalus appendiculatus cell line RA243 achieved the highest percentage of association/internalization, with both high (90%) and low (10%) concentrations of BSK-H medium in tick cell culture medium. Treatment with cytochalasin D dramatically reduced the average percentage of cells with internalized spirochetes, which passed through a dramatic morphological change during their internalization by the host cell as observed in time-lapse photography. Almost all of the fluorescent bacteria were seen to be inside the tick cells. PKH labeling of borreliae proved to be a reliable and valuable tool to analyze the association of spirochetes with host cells by flow cytometry, confocal and fluorescence microscopy.

Primary embryonic cells of Rhipicephalus microplus and Amblyomma cajennense ticks as a substrate for the development of Borrelia burgdorferi (strain G39/40).

Borrelia burgdorferi, the agent of Lyme borreliosis, is a spirochetes transmitted by ticks to humans and animals. Its cultivation in vitro in tick cells allows studies of its biology and provides methodology for future research in Brazil, and for the isolation of Borrelia spp. We examined in vitro the characteristics of embryonic cells of Rhipicephalus microplus and Amblyomma cajennense in cell culture and investigated the suitability of embryonic cells as a substrate for cultivation of B. burgdorferi. Subcultures were prepared from primary cultures of embrionary cells of R. microplus and A. cajennense maintained in Leibovitz's (L-15) complete medium at 28 ºC and 31 ºC, respectively. When a monolayer had formed, the L-15 was replaced with Barbour-Stoener-Kelly medium for experiments to infect cell cultures with B. burgdorferi. After 72 hours of cultivation, the spirochetes were counted using an inverted phase contrast microscope and dark-field illumination (400×). Survival, multiplication and the adherence of B. burgdorferi for embryonic cells of R. microplus and A. cajennense were observed. B. burgdorferi cultured with embryonic cells of R. microplus grew on average to a density (final count) of 2.4 × 10(7) spirochetes/mL, whereas in cell-free culture, an average of 2.5 × 10(7) spirochetes/mL were counted. When cultivated with A. cajennense cells, the final count of spirochetes was on average 1.7 × 10(7) spirochetes/mL, while spirochetes cultured under cell-free conditions replicated on average of 2.2 × 10(7) spirochetes/mL. Similar results were observed in the final count of Spirochetes cultivated in cells of R. microplus and A. cajennense, when compared with cell-free control. These results demonstrated that cells of R. microplus and A. cajennense have the potential to be used as growth substrate for B. burgdorferi in the study of its interaction with host cells.

Análise retrospectiva dos fatores associados à distribuição da tuberculose bovina no estado do Rio de Janeiro / Retrospective analysis of the factors associated to the distribution of bovine tuberculosis in the State of Rio de Janeiro

Fatores associados à ocorrência da tuberculose bovina (TB), em dados de 209 fazendas, foram avaliados por meio de análise de variância. Os dados utilizados foram provenientes do levantamento epidemiológico por demanda, realizado nos rebanhos do estado do Rio de Janeiro, no período de 1959 até 1989. As variáveis significativas na análise bivariada foram incluídas no modelo e analisadas conjuntamente pelo método do modelo linear generalizado. A taxa de prevalência da TB nos rebanhos foi de 49,8 por cento. As variáveis detectadas no estudo como as mais importantes para a ocorrência de TB foram: aleitamento (P=0,03) e as interações densidade x aleitamento (P=0,04) e produtividade x período (P=0,02). A importância da organização econômica da produção pecuária na ocorrência da TB pode ser evidenciada pelos resultados obtidos neste estudo. Este é um fator relevante em decorrência dos danos à saúde humana e animal.

The factors associated to the occurrence of bovine tuberculosis (TB) in 209 farms were evaluated by variance analysis. Data came were colleted in an epidemiological investigation from herds in the State of Rio de Janeiro, examined from 1959 to 1989. The significant variables were analyzed and submitted to generalized linear model. The prevalence rate of TB in herds was 49.8 percent. The most important variations detected in this study for occurrence of TB were: sucking (P=0.03) and interactions density vs. sucking system (P=0.04) and productivity vs. sucking period (P=0.02). The influence of the economical aspects of the farming systems on the occurrence of TB was confirmed by the results of this study. This is an important factor due to human and animal health hazards.

Geoprocessamento aplicado à observação da sazonalidade das larvas da mosca Dermatobia hominis no município de Seropédica - RJ / Geoprocessing applied to the seasonality of Dermatobia hominis larvae in the municipality of Seropédica, Rio de Janeiro

Associações espaço-temporais entre os fatores envolvidos na distribuição sazonal das larvas da mosca do berne - Dermatobia hominis (Linnaeus Jr., 1781) (Diptera: Cuterebridae) - em bovinos foram analisadas por geoprocessamento, utilizando-se o sistema de análise geoambiental da Universidade Federal do Rio de Janeiro, no município de Seropédica, RJ. Na primavera, 50 por cento da área do município foi muito favorável ao desenvolvimento dessa miíase. Esse grau de favorabilidade reduziu-se para 35 por cento, 23 por cento e 12 por cento no verão, outono e inverno, respectivamente

Space-temporal associations between factors involved in the seasonal distribution of Dermatobia hominis (Linnaeus Jr., 1781) (Diptera: Cuterebridae) fly larvae in cattle were analyzed by geoprocessing using the geo-environment system of the Universidade Federal do Rio de Janeiro, in the municipality of Seropédica, RJ. In the spring, 50 percent of the area was favorable, reducing its extension to 35 percent in the summer, to 23 percent in the fall and to 12 percent in the winter

All-terrain vehicle injuries: are they dangerous? A 6-year experience at a level I trauma center after legislative regulations expired.

All-terrain vehicles (ATVs) have increased in popularity and sales since 1971. This rise in popularity led to an increase in injuries resulting in voluntary industry rider safety regulations in 1988, which expired without renewal in 1998. Our purpose was twofold, to determine the incidence and severity of ATV injuries in our patient population and what, if any impact the safety regulations had. To further characterize the risk of ATV use, we compared them to a vehicle generally recognized as dangerous, the motorcycle (MC). Our trauma registry was reviewed from January 1998 through August 2004 for ATV or MC injured. Data collected included age, gender, mortality, Injury Severity Score (ISS), helmet use, and injury distribution. These were compared to our data from the decade of regulation. There were 352 MC and 221 ATV patients. ATV injured demonstrated a higher proportion of pediatric and female patients (P < 0.001 and P < 0.01, respectively), a decrease in helmet use (8.6% vs 64.7%, P < 0.001), and increased closed head injuries (CHI) (54.2% vs 44.9%, P < 0.05) compared with MC injured. ISS and mortality were similar. The average number of patients from 1988 to 1998 was 6.9/yr compared to 31.6/yr (P < 0.001) during 1998-2004 with equal ISS. Our data show that there has been a dramatic and progressive increase in the number of ATV crashes since expiration of industry regulations. ATVs are as dangerous as MCs based on patient ISS and mortality. There are significantly more children and women injured on ATVs. The lower rate of helmet use in ATVs may account for the significantly greater incidence of CHI. These data mandate the need for injury prevention efforts for ATV riders, in particular children, through increased public awareness and new legislation.

Desempenho do programa BABSIM no estudo epidemiológico de Boophilus microplus (Canestrini, 1889) (Acari: Ixodidae)

Simulation models are useful tools in the analysis of bio-ecological interrelations of ticks. The purpose of the present work was to evaluate the performance of the BABSIM program, in epidemiological studies on B. microplus in the State of Minas Gerais, Brazil. Adjustments were made in the program by comparative analysis of B. microplus population curves observed and simulated in Pedro Leopoldo and São Miguel do Anta, State of Minas Gerais. Two sets of simulation were carried out. One used the original parameters of BABSIM, whereas in the other adjustments were made to the minimum temperature threshold for preoviposition, incubation host-finding and survival rate factors of B. microplus. The adjustments to biological parameters were able to increase the simulated infestation levels of ticks, but unable to improve the prediction of population dynamic in the São Miguel do Anta ecosystem. The simulation results with adjustments and original parameters, showed variability through the years, in comparison to experimental field results of Pedro Leopoldo. Despite the contribution of the simulation results to the analysis of variables determining changes on ticks population size in the studied ecosystems, they showed that BABSIM needs new submodels that represent the interconnection between parasite and ecological conditions. Besides, there is a need to modify the program making possible changes in the animal management within the same year of simulation and, therefore, justifying the population dynamic in different ecosystems with higher accuracy.

Os modelos de simulação são ferramentas úteis na análise das inter-relações bioecológicas dos carrapatos. Partindo dessa premissa, objetivou-se avaliar o desempenho do programa BABSIM como auxiliar no estudo epidemiológico de B. microplus para o Estado de Minas Gerais, validando-se os ajustes no programa pela análise comparativa das curvas populacionais observadas e simuladas em Pedro Leopoldo e São Miguel do Anta, MG. As simulações foram realizadas com o programa BABSIM utilizando-se os parâmetros biológicos originais do programa e com ajustes nas temperaturas mínimas para oviposição e incubação dos ovos, no índice de encontro do hospedeiro pelas larvas, e no índice de sobrevivência dos estádios de vida livre. Os ajustes nos parâmetros biológicos propiciaram aumento na intensidade da carga parasitária, porém não foram suficientes para representar com maior precisão a dinâmica populacional no ecossistema em São Miguel do Anta. As simulações procedidas com os parâmetros biológicos originais e ajustados apresentaram comportamento variável para os diferentes anos em relação aos observados no estudo experimental de Pedro Leopoldo. Apesar de os resultados das simulações terem contribuído para a análise do conjunto de variáveis que interagem para determinar as variações do tamanho das populações de carrapatos nos ecossistemas estudados, eles indicaram, também, a necessidade de introduzir modificações nos submodelos que representam as inter-relações parasito-ambiente antrópico, assim como a necessidade de modificar o programa para permitir alterações de manejo dos animais, dentro de um mesmo ano de simulação, e, dessa maneira, justificar com maior precisão a dinâmica populacional em diferentes tipos de ecossistemas.

Desempenho do programa BABSIM no estudo epidemiológico de Boophilus microplus (Canestrini, 1889) (Acari: Ixodidae) / Performance of the BABSIM program in epidemiological studies on Boophilus microplus (Canestrini, 1889) (Acari: Ixodidae)

Os modelos de simulaçäo säo ferramentas úteis na análise das inter-relaçöes bioecológicas dos carrapatos. Partindo dessa premissa, objetivou-se avaliar o desempenho do programa BABSIM como auxiliar no estudo epidemiológico de B. microplus para o Estado de Minas Gerais, validando-se os ajustes no programa pela análise comparativa das curvas populacionais observadas e simuladas em Pedro Leopoldo e Säo Miguel do Anta, MG. As simulaçöes foram realizadas com o programa BABSIM utilizando-se os parâmetros biológicos originais do programa e com ajustes nas temperaturas mínimas para oviposiçäo e incubaçäo dos ovos, no índice de encontro do hospedeiro pelas larvas, e no índice de sobrevivência dos estádios de vida livre. Os ajustes nos parâmetros biológicos propiciaram aumento na intensidade da carga parasitária, porém näo foram suficientes para representar com maior precisäo a dinâmica populacional no ecossistema em Säo Miguel do Anta. As simulaçöes procedidas com os parâmetros biológicos originais e ajustados apresentaram comportamento variável para os diferentes anos em relaçäo aos observados no estudo experimental de Pedro Leopoldo. Apesar de os resultados das simulaçöes terem contribuído para a análise do conjunto de variáveis que interagem para determinar as variaçöes do tamanho das populaçöes de carrapatos nos ecossistemas estudados, eles indicaram, também, a necessidade de introduzir modificaçöes nos submodelos que representam as inter-relaçöes parasito-ambiente antrópico, assim como a necessidade de modificar o programa para permitir alteraçöes de manejo dos animais, dentro de um mesmo ano de simulaçäo, e, dessa maneira, justificar com maior precisäo a dinâmica populacional em diferentes tipos de ecossistemas

Desempenho do programa BABSIM no estudo epidemiológico de Boophilus microplus (Canestrini, 1889) (Acari: Ixodidae)

Simulation models are useful tools in the analysis of bio-ecological interrelations of ticks. The purpose of the present work was to evaluate the performance of the BABSIM program, in epidemiological studies on B. microplus in the State of Minas Gerais, Brazil. Adjustments were made in the program by comparative analysis of B. microplus population curves observed and simulated in Pedro Leopoldo and São Miguel do Anta, State of Minas Gerais. Two sets of simulation were carried out. One used the original parameters of BABSIM, whereas in the other adjustments were made to the minimum temperature threshold for preoviposition, incubation host-finding and survival rate factors of B. microplus. The adjustments to biological parameters were able to increase the simulated infestation levels of ticks, but unable to improve the prediction of population dynamic in the São Miguel do Anta ecosystem. The simulation results with adjustments and original parameters, showed variability through the years, in comparison to experimental field results of Pedro Leopoldo. Despite the contribution of the simulation results to the analysis of variables determining changes on ticks population size in the studied ecosystems, they showed that BABSIM needs new submodels that represent the interconnection between parasite and ecological conditions. Besides, there is a need to modify the program making possible changes in the animal management within the same year of simulation and, therefore, justifying the population dynamic in different ecosystems with higher accuracy.

Os modelos de simulação são ferramentas úteis na análise das inter-relações bioecológicas dos carrapatos. Partindo dessa premissa, objetivou-se avaliar o desempenho do programa BABSIM como auxiliar no estudo epidemiológico de B. microplus para o Estado de Minas Gerais, validando-se os ajustes no programa pela análise comparativa das curvas populacionais observadas e simuladas em Pedro Leopoldo e São Miguel do Anta, MG. As simulações foram realizadas com o programa BABSIM utilizando-se os parâmetros biológicos originais do programa e com ajustes nas temperaturas mínimas para oviposição e incubação dos ovos, no índice de encontro do hospedeiro pelas larvas, e no índice de sobrevivência dos estádios de vida livre. Os ajustes nos parâmetros biológicos propiciaram aumento na intensidade da carga parasitária, porém não foram suficientes para representar com maior precisão a dinâmica populacional no ecossistema em São Miguel do Anta. As simulações procedidas com os parâmetros biológicos originais e ajustados apresentaram comportamento variável para os diferentes anos em relação aos observados no estudo experimental de Pedro Leopoldo. Apesar de os resultados das simulações terem contribuído para a análise do conjunto de variáveis que interagem para determinar as variações do tamanho das populações de carrapatos nos ecossistemas estudados, eles indicaram, também, a necessidade de introduzir modificações nos submodelos que representam as inter-relações parasito-ambiente antrópico, assim como a necessidade de modificar o programa para permitir alterações de manejo dos animais, dentro de um mesmo ano de simulação, e, dessa maneira, justificar com maior precisão a dinâmica populacional em diferentes tipos de ecossistemas.

Artificial feeding of Amblyomma cajennense (Fabricius, 1787) (Acari:Ixodidae) through silicone membrane.

An artificial feeding system was used where citrated bovine blood was offered to male and female Amblyomma cajennense. Vestiges of blood, sweat, hair and exfoliated skin were used as phago-stimulants placed on the surface of the silicone membrane. The ticks were collected, as engorged nymphs, from naturally infested equines, with the ecdysis occurring in the laboratory. Four hundred ticks were used, 50% being female, at three to four weeks post-ecdysis. Vestiges of blood on the silicone membrane were the most efficient phago-stimulant and the association of vestiges of blood and sweat residue smears yielded better results compared to the other phago-stimulants used.

[Development of Rhodnius pictipes Stal, 1872 fed on mice and through a silicone membrane (Hemiptera, Reduviidae, Triatominae)]. / Desenvolvimento de Rhodnius pictipes Stal, 1872 alimentado através de membrana de silicone e em camundongos (Hemiptera, Reduviidae, Triatominae).

Rhodnius pictipes (Hemiptera, Reduviidae) from Serra Norte, State of Pará, Brazil, acclimatized in an insectary at the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz, were fed through a silicone membrane. In order to know the viability and the efficiency of this membrane compared with insects fed on mice, the number of bloodmeals taken, period of development of the five nymphal instars, longevity of adults, average amount of blood intake in each meal and percent of mortality were observed. A total of 310 insects, were used, comprising 50 nymphs of each instar, as well as 30 male and 30 female adults. Insects fed artificially had reduced minimal and maximal periods of development than the group fed on mice. The largest relative increase of body weight was observed in the 2nd instar followed by the 1st, and the amount of blood ingested increased during the development, to the 5th instar for both groups. There were no significant differences between the groups fed artificially and in vivo according to Tukey's test for p > 0.05. The percent of mortality in the 1st instar was 18% for artificially fed and 16% for the group fed on mice; these percentages decreased as insects developed until the 4th instar, without mortality, returning to increase in the 5th instar. R. pictipes was shown to be easily adaptable to artificial feeding, and could be considered as an important and viable experimental model.

[Outline of Lyme borreliosis in Brazil]. / Perfil da borreliose de Lyme no Brasil.

Since 1989, we have identified 25 patients with Lyme disease, 15 in early and 10 in latent stage, supporting its existence in Brazil, according to following reasons: 1) presence of clinical manifestations compatible with Lyme disease, with cutaneous, articular, nervous system and rarely cardiac envolvement; 2) presence of antibodies against Borrelia burgdorferi; 3) follow up of acute cases show sorologycal changes; 4) good antibiotic response at early stage of disease and only satisfactory in latent form; 5) mapping of risk areas, according to geographycal distribution of patients; 6) presence and identification of Ixodid ticks; 7) identification of micro-organism like borrelias in human, wild animals and ticks cultures, seen by dark field microscope; 8) sorology done in dogs and oxes, confirm existence of risk areas for Lyme disease.

Effect of vaccination with a recombinant Bm86 antigen preparation on natural infestations of Boophilus microplus in grazing dairy and beef pure and cross-bred cattle in Brazil.

Current methods for the control of the cattle tick Boophilus microplus infestations are not effective and the parasite remains a serious problem for the cattle industry in tropical and sub-tropical areas. Recent advances have introduced the possibility for the immunological control of the parasite through the use of recombinant vaccines. Recently, it was shown that the recombinant vaccine Gavac (Heber Biotec S.A.) is able to control B. microplus populations in artificially infected grazing dairy cattle in Cuba. To assay the effect of the vaccine on a different B. microplus strain and under different ecological conditions, we conducted a trial in Brazil on grazing dairy and beef pure and cross-bred cattle under natural infestation conditions. A farm in the northeast of the state of Sao Paulo was selected and two groups of animals per breed were included in the experiment and were maintained grazing on separate but similar pastures. For each breed, one group was vaccinated with the vaccine Gavac and the second group was not vaccinated and was employed as a control. In vaccinated cattle, during 36 weeks of experiment, the average infestation rate was maintained below 78 ticks per animal while average infestation peaks (mean +/- S.E.) of 144 +/- 44 ticks per animal (for dairy cross-bred cattle) and 195 +/- 42 ticks per animal (for beef cross-bred cattle) were recorded in the control groups. Tick infestation rates showed statistical significant differences (p = 0.04) between both experimental groups throughout the experiment. These results clearly showed, as in the Cuban study, that the vaccine controlled tick numbers in successive generations in the field.

Funçöes da saliva dos ixodídeos / Functions of spittle of ixodideos

Durante a fase de alimentaçäo dos ixodídeos ocorre intensa inoculaçäo de saliva na circulaçäo sangüínea do hospedeiro. O autor analisa as principais funçöes dessa saliva e alerta que os antígenos ali presentes têm demonstrado eficiência promissora na imunizaçäo de animais contra o carrapato, assim como os antígenos das células intestinais. Recomenda, baseado na bibliografia, as condiçöes básicas que uma vacina deve ter para ser eficiente contra o carrapato