BackgroundUntil recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known.MethodsThe distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens.ResultsFrom the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum.ConclusionOur results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some transition areas. The current distribution of A. cajennense (s.l.) has important implications to public health, since in Brazil A. sculptum is the most important vector of the bacterium Rickettsia rickettsii, the etiological agent of Brazilian spotted fever.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1460-2) contains supplementary material, which is available to authorized users.
In the first part of this study, monthly infestation by ticks was evaluated on dogs from December 2000 to November 2002 in the rural area of Taiaçupeba, São Paulo. Adults of Amblyomma aureolatum (Pallas) were found on dogs in all months, with a mean prevalence per month of 46.9 +/- 15.7% (range, 25-80%). The mean tick relative abundance per month was 2.4 +/- 2.7 ticks (range, 0.5-14 ticks), and the mean tick mean intensity per month was 4.7 +/- 4.2 ticks (range, 1.5-23.3 ticks). No A. aureolatum immature ticks were found on dogs. In the second part of this study, we studied the life cycle of A. aureolatum in the laboratory. We tested the suitability of six host species for the immature stages and dogs for the adult stage. Tick developmental periods were observed at different temperatures (23, 25, or 27 degrees C), always with RH >95%, which were satisfactory for all free-living developmental stages of the tick life cycle. Chickens and guinea pigs were the most suitable hosts for larvae and nymphs (recovery rates, 18.4-52.2%). Dogs were highly suitable for adult ticks (all females exposed to them were recovered and laid eggs) but were unsuitable for the immature ticks (recovery rates, 0-10%). Based on published host records for A. aureolatum, our results indicate that dogs and birds are primary hosts for adult and immature stages, respectively, of A. aureolatum in nature. In addition, wild guinea pigs are indicated as another potential primary host for immature ticks.
With the aim of supporting the strategic planning of the National Program for Control and Eradication of Brucellosis and Tuberculosis, different Brazilian states have been conducting cross-sectional studies, coordinated by the Ministry of Agriculture, Livestock, and Supply and with scientific support from the University of São Paulo and the University of Brasilia. In Santa Catarina, the State Animal Health Agency (CIDASC) conducted a study on bovine tuberculosis (TB) prevalence and assessment of risk factors in 2012. The state was divided into five regions and, in each region, independent sampling was performed in two steps: (i) cattle herds with reproductive activity were randomly selected; and (ii) in each herd, a sample of females aged 24 months or older underwent the intradermal comparative tuberculin test. A questionnaire was used to collect data on production characteristics and management practices that could be associated with the tuberculosis infection. Herd prevalence of bovine TB was 0.50% (95% confidence interval [CI]: 0.074-0.93%) while the prevalence of TB in adult females was 0.06% (95% CI: 0-0.12%). No significant difference in the prevalence of infected herds and of positive females was observed among the five regions. The logistic regression model revealed that herds with 19 or more females showed an odds ratio (OR) of 7.68 (95% CI: 1.22-48.39) compared to smaller herds, while dairy herds presented an OR of 10.43 (95% CI: 2.00-54.25) relative to beef or dual-purpose herds. The results suggest that dairy herds, in which animals are kept in partial or total confinement, and larger herds, which tend to acquire animals more often, are at a higher risk of bovine TB. Given the low prevalence and the type of higher-risk properties, a bovine TB surveillance system should be targeted at the state's dairy basins, particularly the western region that accounts for the major industries and more intensive dairy farms. (TB). O Estado foi dividido em cinco regiões e, em cada uma delas, foi realizada uma amostragem independente em duas etapas: (i) propriedades com atividade reprodutiva foram selecionadas aleatoriamente; (ii) em cada propriedade, uma amostra de fêmeas com idade igual ou superior a 24 meses foi submetida ao teste tuberculínico intradérmico comparativo. Um questionário foi utilizado para recolher dados sobre as características de produção e práticas de gestão que poderiam estar associados com a infecção tuberculosa. A prevalência de focos de tuberculose bovina foi de 0,50% (95% intervalo de confiança [CI]: 0,074-0,93%), enquanto a prevalência de TB em animais foi de 0,06% (IC 95%: 0-0,12%). Não foi observada diferença significativa na prevalência de focos ou animais entre as cinco regiões. O modelo de regressão logística revelou que rebanhos com 19 ou mais vacas apresentaram um odds ratio (OR) de 7,68 (IC 95%: 1,22-48,39) em comparação com rebanhos menores, enquanto rebanhos leiteiros apresentaram um OR de CI 10,43 (95%: 2.00-54,25) em relação aos rebanhos de corte ou de duplo propósito. ...
An epidemiological study was carried out in order to characterize the bovine tuberculosis situation and to support the planning and implementation of the National Program for the Control and Eradication of Bovine Tuberculosis in the State of Bahia, owing to the importance of the disease in causing economic burdens and its impact on public health. The State was divided into four regions. In each region, properties were randomly chosen and, a pre-established number of animals was also randomly selected; these animals then subjected to the intradermal comparative cervical tuberculin diagnostic test. Animals with inconclusive test results were retested with the same diagnostic procedure within a minimum interval of 60 days. Within each sampled property, a questionnaire was administered to verify possible risk factors for the disease. In the State, the prevalence of infected herds was 1.6% [1.0-2.6] and that of infected animals 0,21% [0,07; 0,60]. In the regions, the prevalence of infected herds and infected animals were, respectively, 2,0% [1,0; 4,2%] and 2,0% [1,0; 4,2%] In conclusion, it is recommended that the State of Bahia implement a surveillance system for the detection of herds with bovine tuberculosis to certifying them in free herds, with special attention to dairy properties, and develop a solid program of health education so that producers test animals for bovine tuberculosis before introducing them into their herds. para caracterizar a situação da enfermidade no estado. O Estado foi estratificado em quatro regiões. Em cada região, propriedades foram sorteadas aleatoriamente e, dentro dessas, escolheu-se de forma também aleatória um número pré-estabelecido de animais, os quais foram submetidos ao teste tuberculínico Cervical Comparativo. Os animais que resultaram inconclusivos foram retestados com o mesmo procedimento diagnóstico em intervalo mínimo de 60 dias. Em cada propriedade amostrada aplicou-se um questionário para se verificar possíveis fatores de risco para a doença. No Estado, a prevalência de focos foi de 1,6% [1,0; 2,6%] e a de animais 0,21% [0,07; 0,60]. Nas regiões, as prevalências de focos e de animais foram, respectivamente de 2,0% [1,0; 4,2%] e 0,08% [0,035; 0,17] (OR= 9,72), ser propriedade mista (OR= 6,66) e tamanho do rebanho ≥ 18 fêmeas ≥ 24 meses (OR= 8,44). Concluindo, recomenda-se que o Estado da Bahia implemente um sistema de vigilância para detecção e saneamento dos focos de tuberculose bovina, com especial atenção para as propriedades produtoras de leite, e que desenvolva uma sólida ação de educação sanitária para que seus produtores passem a testar os animais para tuberculose bovina antes de introduzi-los em seus plantéis. Palavras-chave: Tuberculose bovina. Prevalência. Fatores de risco. Bahia. Brasil.
A cross sectional study was performed to assess the epidemiological status of bovine tuberculosis in the state of Minas Gerais, Brazil, in 2013. The state was divided into seven regions, and a preset number of herds was randomly sampled in each region. From each farm, female cattle aged 24 months or older were randomly sampled and subjected to the comparative cervical tuberculin test (CCTT). Animals with inconclusive test results were re-tested with the same diagnostic procedure after a minimum interval of 60 days. A total of 31 832 animals were tested from 2 182 farms. An epidemiological questionnaire was administered in the farms to identify risk factors associated with bovine tuberculosis. Prevalence in the state was estimated at 4.25% (95% CI: 3.36% -5.15%) for herds and at 0.56% (95% CI: 0.46% -0.66%) for animals. Data on herd prevalence for bovine tuberculosis for each stratum showed the highest prevalences at region Sul e Sudoeste (stratum 5) and region Central (stratum 3) which were significantly different from the lowest prevalences found at regions Noroeste, Norte e Nordeste (stratum 1) and region Leste (stratum 2). The highest animal prevalences observed for the region Sul e Sudoeste (stratum 5), region Zona da Mata (stratum 4) and region Central (stratum 3) were significantly different from the lowest ones at region Triângulo Mineiro (stratum 7), region Noroeste, Norte, e Nordeste (stratum 1) and region Leste (stratum 2). The presence of bovine tuberculosis was associated with animal purchase from cattle traders ResumoFoi realizado um estudo transversal para avaliar a situação epidemiológica da tuberculose bovina no estado de Minas Gerais em 2013. O Estado foi dividido em sete regiões e um número predefinido de fazendas foi amostrado aleatoriamente em cada região. Dentro de cada propriedade, fêmeas com idade igual ou superior a 24 meses foram escolhidas aleatoriamente e submetidas ao Teste Tuberculínico Cervical Comparativo (CCTT). Os animais com resultados inconclusivos foram retestados com o mesmo procedimento diagnóstico após um intervalo mínimo de 60 dias. Um total de 31832 animais foram testados provenientes de 2182 propriedades. Um questionário epidemiológico foi aplicado em cada fazenda para identificar fatores de risco associados à tuberculose bovina. A prevalência de focos no estado foi de 4,25% (IC 95%: 3,36 -5,15) e 0,56% (IC 95%: 0,46 -0,66) de animais. Em relação a prevalência de rebanho com tuberculose bovina para cada estrato, as maiores prevalências foram observadas nas regiões Sul e Sudoeste (estrato 5) e Central (estrato 3), que foram significativamente diferentes das menores prevalências encontradas nas regiões Noroeste, Norte e Nordeste (estrato 1) e Leste (estrato 2). As maiores prevalências de animais observadas nas regiões Sul e Sudoeste (estrato 5), Zona da Mata (estrato 4) e Central (estrato 3) foram significativamente diferentes das menores encontradas nas regiões do Triângulo Mineiro (estrato 7), Noroeste, Norte, e Nordeste (estrato 1) e Leste (estrato 2). A prese...
This study integrated accessibility and location-allocation models in geographic information systems as a proposed strategy to improve the spatial planning of public health services. To estimate the spatial accessibility, we modified the two-step floating catchment area (2SFCA) model with a different impedance function, a Gaussian weight for competition among service sites, a friction coefficient, distances along a street network based on the Dijkstra’s algorithm and by performing a vectorial analysis. To check the accuracy of the strategy, we used the data from the public sterilization program for the dogs and cats of Bogot´a, Colombia. Since the proposed strategy is independent of the service, it could also be applied to any other public intervention when the capacity of the service is known. The results of the accessibility model were consistent with the sterilization program data, revealing that the western, central and northern zones are the most isolated areas under the sterilization program. Spatial accessibility improvement was sought by relocating the sterilization sites using the maximum coverage with finite demand and the p-median models. The relocation proposed by the maximum coverage model more effectively maximized the spatial accessibility to the sterilization service given the non-uniform distribution of the populations of dogs and cats throughout the city. The implementation of the proposed strategy would provide direct benefits by improving the effectiveness of different public health interventions and the use of financial and human resources.
A study was conducted to determine the epidemiological status of bovine tuberculosis in the state of Rio Grande do Sul. The state was divided in seven regions, and in each of them, a pre-established number of farms was randomly sampled. In each farm, cows with age equal to or greater than 24 months were selected at random and submitted to the comparative cervical tuberculin test. The animals whose tests were inconclusive were retested with the same diagnostic procedure within a minimum interval of 60 days. In all, 9,895 animals from 1,067 farms were tested. An epidemiological questionnaire was applied in the farms in order to identify risk factors associated with bovine tuberculosis. The prevalence of infected herds in the state was 2.8% [1.8; 4.0] and that of infected animals was 0.7% [0.4; 1.0]. There was a trend towards a concentration of infected herds in the northern part of the state, with a predominance of dairy and mixed herds. The risk factors associated with the condition of infected herds were being a dairy herd (OR = 2.90 [1.40; 6.13]) and herds with 16 or more cows (OR = 2.61 [1.20; 5.49]). Thus, the best strategy to be adopted by the state is the implementation of surveillance systems to detect and remediate the infected herds, preferably incorporating elements of risk-based surveillance. In addition, the state must carry out a solid action of health education so that the producers test animals for bovine tuberculosis before introducing them in their herds. Key words: Bovine tuberculosis. Brazil. Mycobacterium bovis. Prevalence. Rio Grande do Sul. Risk factors. ResumoUm estudo foi realizado para determinar a situação epidemiológica da tuberculose bovina no Estado de Rio Grande do Sul. O Estado foi dividido em sete regiões e em cada uma delas foi aleatoriamente amostrado um número pré-estabelecido de propriedades. Dentro de cada propriedade, fêmeas com idade igual ou superior a 24 meses foram escolhidas aleatoriamente e submetidas ao teste tuberculínico 20; 5.49]). Assim, a melhor estratégia a ser adotada pelo estado é a implementação de sistema de vigilância para detecção e saneamento dos focos, de preferência incorporando elementos de vigilância baseada em risco. Além disso, o estado deve realizar uma sólida ação de educação sanitária para que seus produtores passem a testar os animais para tuberculose bovina antes de introduzi-los em seus plantéis. Palavras-chave: Brasil. Fatores de risco. Mycobacterium bovis. Prevalência. Rio Grande do Sul. Tuberculose bovina.
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