查看更多>>摘要：Phlebotomine sand flies are vectors of various diseases such as leishmaniasis making them a public health concern worldwide. To increase the tools available for the study of sand flies, we developed do it yourself (DIY) light traps made mainly from recycled materials and tested their effectiveness in the field. This new model is named Flebocollect light trap. In this report we describe how the DIY light traps are prepared and illustrate the process with a short video. Lowering costs makes this resource available for citizen science and educational projects, and for research groups with a low budget such as those in developing countries. Our preliminary results showed a capture rate increase of 37 % of DIY light traps over commercial CDC, although no statistical evidence has been obtained.
Jack, CorinHotchkiss, EmilySargison, Neil D.Toma, Luiza...
12页
查看更多>>摘要：Since 2003, the Sustainable Control Of Parasites in Sheep (SCOPS) group have provided the UK sheep farming industry with guidance on ways to mitigate the development and dissemination of anthelmintic resistance (AR). However our empirical understanding of sheep farmers' influences towards such 'best practice' parasite control approaches is limited, and therefore requires further assessment and evaluation to identify the potential factors influencing their implementation. In 2015, a telephone questionnaire was conducted in order to elicit Scottish sheep farmers' attitudes and behaviours regarding the SCOPS recommended practices, as well as gauging farmers' general attitudes to gastrointestinal nematodes (GIN; term roundworm used in questionnaire) control. A quantitative structural equation modelling (SEM) approach was employed to determine the influences of sociopsychological factors and the uptake of individual anthelmintic resistance mitigating practices including: the implementation of a quarantine strategy for parasite control and the use of parasite diagnostic testing for monitoring faecal egg counts (FEC) and detecting AR. The proposed models established a good fit with the observed data and explained 61%, 54% and 27% of the variance in the adoption of AR testing, FEC monitoring, and quarantine behaviours respectively. The results presented highlight a number of consistent and distinct factors significantly influencing the implementation of selected SCOPS recommended practices. The negative influences of topography and farmer experience was frequently demonstrated in relation to multiple GIN control practices, as well as the positive influences of social norms, worm control knowledge, AR risk perception and positive attitudes to the services provided by the veterinary profession. Factors that were shown to have the greatest relative effects on individual parasite control practices included: the perceived expectation of others (i.e. Social norms) for implementing a quarantine strategy, farmer's suspicions to the presence of AR on the holding for instigating AR testing and the confirmation of AR for adopting FEC monitoring. Determining the influences of behaviour-specific factors on farmers' decision making processes will help to identify and address positive and negative influences concerning implementation of AR mitigating practices, as well as contribute to the development of more evidence based intervention strategies in the future.
McNeilly, T.Ferguson, K. D.Skuce, P. J.Jonsson, N. N....
8页
查看更多>>摘要：We aimed to estimate 1) the marginal effect of liver fluke (Fasciola hepatica) infection on productivity of Scottish beef cattle, and 2) the associated greenhouse gas emissions intensity (GHG EI). Data comprised 240,065 abattoir records from NE Scotland from 2014 to 2017, including the presence or absence of lesions typical of liver fluke in the liver at the time of slaughter, from which we inferred liver fluke infection status. The retrospective analysis of abattoir records to estimate marginal effects of an exposure is complicated by the multi-dimensional, clustered nature of the datasets, which result in confounding of potential causal factors with the exposure. Causal inference methods are required to identify and correct for variation in background exposure. We constructed directed acyclic graphs (DAGs) of observed variables, including the potential confounders, breed, sex, breeder, finisher, season of birth and year of birth. We then applied inverse probability weighting (IPW) to adjust for variation among exposure risk and applied a doubly robust generalized linear model (DRGLM) to the weighted observations to estimate the marginal effect of fluke on the growth rate of animals and total days from birth until slaughter. We compared these estimates with the results of linear mixed effects (LME) models with the same variables, treating breeder and producer as random effects. To estimate GHG EI, we applied IPCC tier-2 type GHG calculations to the marginal effects estimated from IPW with DRGLM. The IPW with DRGLM model estimated that animals with active fluke lesions (adult fluke seen on postmortem inspection) gained 17 (95 % CI 12-22) g/ d less saleable beef than animals with no lesions and no visible fluke. Animals with active fluke lesions were 11 (95 % CI 6.5-15) d older at slaughter weight than animals with no lesions. Animals with historic lesions in which there was scarring of the liver but in which no adult fluke were seen showed a wide variation in effect estimates, consistent with some misclassification. The effect estimates from LME models suggested slightly lower effects of fluke on growth rate and days to slaughter but with overlapping 95 % confidence intervals. Calculation of the associated GHG emissions suggest the EI of meat from a herd with no fluke is approximately 1.5 % lower than the same herd with fluke. Sustainably controlling liver fluke would have additional production benefits not included in this estimate and could therefore have a much greater impact on GHG EI in practice than demonstrated here.
Kuczewski, AlessaAdams, CindyLashewicz, Bonnievan der Meer, Frank...
14页
查看更多>>摘要：A high herd and within-herd prevalence of Bovine Leukemia Virus (BLV) infections in the dairy herds of North America and the negative effects thereof caused the Alberta dairy industry to initiate the development of an on farm BLV control program. Because BLV control is dependent on the commitment of the farmer, potential barriers were identified and farmers' and veterinarians' points of view toward different control options were investigated to inform how the control program might be adjusted. Conversations with these stakeholders were sought and four focus groups with farmers and eleven interviews with veterinarians were conducted. Testing for BLV, the most common BLV control strategies (testing/culling/segregation/management), as well as on farm best management practices (BMP) to prevent the transmission of BLV, were discussed. The thematic analysis of these conversations resulted in the following findings: Testing of animals was considered important for BLV control, but the financial investment was prohibitive for farmers. Test and cull as well as test and segregation approaches of test positive animals were considered efficient BLV control measures, but impractical and not feasible due to the supply managed Alberta dairy industry (i.e. milk is produced based on demand), with a high prevalence. The management of test positive animals with BMP to prevent new infections and thereby decreasing the within-herd prevalence was considered the only realistic BLV control strategy. The most important barriers for suggested BMP were the cost for some BMP, the inconvenience of performing other BMP, as well as difficulties in performing some BMP consistently and well. Additionally, a lack of knowledge about BLV and its control were identified as an important barrier. On the contrary, farmers indicated being inclined to implement BMP they considered feasible or that were considered a standard within the industry. Further, if BMP increased convenience on farm, they were considered easy to implement. Farmers and veterinarians agreed in many, but not all cases. For example, the single use of examination sleeves was met with differing opinions (i.e. considered doable by farmers while veterinarians assumed it to be too costly). In conclusion, stakeholders' awareness and communication amongst each other (e.g. veterinarians and farmers) about BLV and its control has to be highlighted in order to manage BLV infection successfully. In addition, by communicating and understanding barriers and motivators for specific BMP, important barriers could be identified (e.g. difficulties while changing needles), and solutions found (e.g. tool belt for needles), thereby improving BLV control efforts on farm.
查看更多>>摘要：Chlamydia psittaci is a highly zoonotic bacteria distributed worldwide; it is responsible for psittacosis, one of the most important infectious diseases affecting the Psittacidae, mostly parrots. This work was aimed at determining C. psittaci prevalence and genotype in 177 parrots confiscated in Colombia; cloacal swab (166) and faecal (177) samples were analysed from birds confiscated and housed in a Tempora r y Wildlife Reception Centre (Centro de Reception de Fauna Temporal). Conventional PCR was r u n on the samples for amplifying the MOMP gene and then the ompA gene. The C. psittaci genotype A was found in 81.3 % (144/177) of the birds analysed. Cloacal swabs accounted for 129/166 (77.7 %) positive samples and faecal matter for 53/177 (29.9 %), 38 birds proving positive for both types of sample; there was an 8.15 times greater probability of detection for cloacal swabs compared to faecal swabs (p < 0.05). Clinical examination findings were correlated with the animals' positivit y for cloacal swabs, faecal matter or both, finding a statistically significant relationship with low respirator y rate (p < 0.05) and broken plumage for cloacal swab sample results (p < 0.1). Even though 85 % seroprevalence has previously been reported in Colombia using indirect ELISA , this study reports for the first time C. psittaci ge-notype A endemicity in psittacines in captivity in Colombia using molecular techniques, considering the zoonotic risk involved in having these birds as pets.
Souza, Marcio Rodrigues dos SantosSoares Filho, Paulo MartinsHodon, Mikael Arraisde Souza, Patricia Gomes...
8页
查看更多>>摘要：Cervical bursitis is a suggestive lesion of bovine brucellosis. Diagnostic sensitivity and specificity of two brucellosis serological tests, Rose Bengal (RB) and serum agglutination test with 2-mercaptoethanol (SAT/2-ME), and of isolation and identification (bacteriology) were evaluated through Bayesian latent class analysis (BLCA). A total of 165 paired serum and cervical bursitis samples detected at inspection by Brazilian federal meat in-spection services were analyzed. The best model fit to the data occurred when accounting for the conditional dependence between serological tests. According to this model, RB and SAT/2-ME had almost the same sensi-tivity, 0.960 [0.903 - 0.992] and 0.963 [0.906 - 0.994] with 95 % Credible Interval (95 %CrI), respectively. Specificities were 0.9068 [0.562 - 0.997] and 0.875 [0.546 - 0.990] for RB and SAT/2-ME, respectively, also with 95 %CrI. Bacteriology had lower sensitivity than serological tests, 0.594 (95 %CrI: [0.525 - 0.794]) and the highest specificity of all evaluated tests, 0.992 (95 %CrI: [0.961-1.00]). Prevalence of infected animals was 0.829 (95 %CrI: [0.700-0.900]). BLCA showed that both RB and SAT/2-ME fitted to the purpose of initial screening the brucellosis suspect in carcasses with cervical bursitis in a reliable way. The results of RB or SAT/2-ME can guide the sanitary actions for brucellosis control and help the implementation of a risk-based surveillance system in the meat production chain. This strategy is especially true in remote areas with large beef cattle herds, raised extensively, where in vivo tests are rarely performed due to logistic and management constraints, as in the Northern region of Brazil.
Mercat, M.van Roon, A. M.Santman-Berends, Ivan Schaik, G....
13页
查看更多>>摘要：Control programmes against non-regulated infectious diseases of farm animals are widely implemented. Different control programmes have different definitions of "freedom from infection" which can lead to difficulties when trading animals between countries. When a disease is still present, in order to identify herds that are safe to trade with, estimating herd-level probabilities of being infected when classified "free from infection" using field data is of major interest. Our objective was to evaluate the capacity of a Bayesian Hidden Markov Model, which computes a herd-level probability of being infected, to detect infected herds compared to using test results only. Herd-level risk factors, infection dynamics and associated test results were simulated in a population of herds, for a wide range of realistic infection contexts and test characteristics. The model was used to predict the infection status of each herd from longitudinal data: a simulated risk factor and a simulated test result. Two different indexes were used to categorize herds from the probability of being infected into a herd predicted status. The model predictive performances were evaluated using the simulated herd status as the gold standard. The model detected more infected herds than a single final test in 85 % of the scenarios which converged. The proportion of infected herds additionally detected by the model, compared to test results alone, varied depending on the context. It was higher in a context of a low herd test sensitivity. On average, around 20 %, for high test sensitivity scenarios, and 40 %, for low test sensitivity scenarios, of infected herds that were undetected by the test were accurately classified as infected by the model. Model convergence did not occur for 39 % of the scenarios, mainly in association with low herd test sensitivity. Detection of additional newly infected herds was always associated with an increased number of false positive herds (except for one scenario). The number of false positive herds was lower for scenarios with low herd test sensitivity and moderate to high incidence and prevalence. These results highlight the benefit of the model, in particular for control programmes with infection present at an endemic level in a population and reliance on test(s) of low sensitivity.
Roessler, Anne S.Oehm, Andreas W.Knubben-Schweizer, GabrielaGroll, Andreas...
9页
查看更多>>摘要：Fasciolosis caused by the trematode Fasciola hepatica is an important parasitosis in both livestock and humans across the globe. Chronic infections in cattle are associated with considerable economic losses. As a prerequisite for an effective control and prevention of fasciolosis in cattle fine-scale predictive models on farm-level are needed. Since disease transmission will only occur where the mollusc intermediate host is present, the objective of our research was to develop a regression model that allows to predict the local presence or absence of Galba truncatula as principal intermediate host for Fasciola hepatica in Switzerland. By implementing generalized linear mixed models (GLMMs) a total amount of 70 variables were analysed for their potential influence on the likelihood pi(i) of finding Galba truncatula at a certain site. Important site-specific features could be considered by selecting suitable modelling procedures. The statistical software R was used to conduct regression analysis, performing the grplasso and the glmmLasso method. The selection of parameters was based on 10-fold cross validation and the Bayesian Information Criterion (BIC). This yielded a total number of 19 potential predictor variables for the grplasso and 13 variables for the glmmLasso model, which also included random effects. Nine variables appeared to be relevant predictors for the occurrence of Galba truncatula in both models. These included reed/humid area, spring water, water bodies within a 100 m radius, and trees/bushes as powerful positive predictors. High soil depth, temperatures frequently exceeding 30 degrees C in the year preceding the search for snails and temperatures below 0 degrees C especially in the second year before were identified to exert an adverse effect on the occurrence of Galba truncatula. Temperatures measured near ground level proved to be more powerful predictors than macroclimatic parameters. Precipitation values seemed to be of minor impact in the given setting. Both regression models may be convenient for a fine-scale prediction of the occurrence of Galba truncatula, and thus provide useful approaches for the development of future spatial transmission models, mapping the risk of fasciolosis in Switzerland on farm-level.
查看更多>>摘要：Microsporidiosis, caused by the zoonotic eukaryote microsporidia spp. have serious health threat in high-risk groups, including immunocompromised individuals. Cattle plays a major role as reservoirs of microsporidia among the animals because of close-contact with humans. Hence, we aimed to evaluate the prevalence and genetic diversity of cattle microsporidiosis at a global scale through systematic review and meta-analysis approach. A comprehensive literature searches of published articles related to the molecular distribution of microsporidiosis in cattle was conducted between 1 January 1990 and 20 December 2020. The confidence intervals (95 %) and point estimates were calculated using the random-effects model. A total of 1809 was retrieved from the initial search, after exclusion of irrelevant articles 37 articles met inclusion criteria to be included for final analysis. The estimated pooled prevalence of cattle microsporidiosis was 14 % (CI: 11.5-17 %) worldwide. Accordingly, the calves had the highest prevalence 20 % (CI: 14.8-26.5 %). According to internal transcribed spacer (ITS) gene, Enterocytozoon bieneusi with genotypes BEB4 (22 studies), J (21 studies), and I (17 studies) were the highest reported genotypes. The present results highlight the role of cattle as reservoir hosts for human infecting microsporidia. Strategies for control and prevention of these pathogens should be designed to mitigate the risk of cattle to human transmission.
查看更多>>摘要：China launched a H7N9 vaccination program in poultry, starting from the Guangxi and Guangdong provinces in July 2017, followed by other provinces in September 2017, as a response to a steep increase of H7N9 influenza human infections from September 2016. Since then, H5-H7 bivalent vaccine has been used in the nationwide avian influenza compulsory vaccination program to replace the existing H5N1 vaccine. However, the economic returns of the H7N9 vaccination program in China have never been adequately assessed. This study was designed to evaluate the economic value of the H7N9 vaccination program in Guangxi by assessing the benefits and costs of the program compared to not vaccinating against H7N9. A benefit-cost analysis (BCA) was undertaken to evaluate the adoption of a vaccination program against H7N9 in each of three consecutive years from July 2017 to June 2020 with the baseline scenario (the absence of H7N9 vaccination in the 12-month period July 2016 to June 2017). Both animal and public health perspectives were included in the BCA framework and took account of both the private and public sectors. Benefit-Cost Ratio (BCR) of the three-year H7N9 vaccination program was 18.6 (90 %PI: 15.4; 21.8), and total Net Present Values reached to CNY 1.63 billion (90 %PI: 1.37 billion; 1.89 billion). The extra revenue generated by the yellow broiler industry comprised 93.8 % of the total benefits after adoption of H7N9 vaccination program in Guangxi. While cost-savings in public health and animal health expenditure avoided were 3.6 % and 2.6 %, respectively. Total costs arising from adoption of the revised vaccination program over the three years were CNY 12.46 million (90 %PI: 11.49 million; 14.14 million), CNY 34.87 million (90 %PI: 31.88 million; 40.06 million), and CNY 44.28 million (90 %PI: 39.66 million; 52.27 million), respectively. Sensitivity analysis found the yellow broiler wholesale prices contributed 97.7 % of the variance of the total NPV of three vaccination years. The study results demonstrate the significant economic advantage of implementing a vaccination program against H7N9 in Guangxi. It also offers a new set of evidence to China's H7N9 vaccination policy and debates around economic values of conducting routine avian influenza vaccination.
NSTL
Elsevier