Spatial dynamics of bovine tuberculosis in the Autonomous Community of Madrid, Spain (2010-2012)

Progress in control of bovine tuberculosis (bTB) is often not uniform, usually due to the effect of one or more sometimes unknown epidemiological factors impairing the success of eradication programs. Use of spatial analysis can help to identify clusters of persistence of disease, leading to the identification of these factors thus allowing the implementation of targeted control measures, and may provide some insights of disease transmission, particularly when combined with molecular typing techniques. Here, the spatial dynamics of bTB in a high prevalence region of Spain were assessed during a three year period (2010-2012) using data from the eradication campaigns to detect clusters of positive bTB herds and of those infected with certain Mycobacterium bovis strains (characterized using spoligotyping and VNTR typing). In addition, the within-herd transmission coefficient (β) was estimated in infected herds and its spatial distribution and association with other potential outbreak and herd variables was evaluated. Significant clustering of positive herds was identified in the three years of the study in the same location ("high risk area"). Three spoligotypes (SB0339, SB0121 and SB1142) accounted for >70% of the outbreaks detected in the three years. VNTR subtyping revealed the presence of few but highly prevalent strains within the high risk area, suggesting maintained transmission in the area. The spatial autocorrelation found in the distribution of the estimated within-herd transmission coefficients in herds located within distances <14 km and the results of the spatial regression analysis, support the hypothesis of shared local factors affecting disease transmission in farms located at a close proximity.

Tuberculosis in alpacas (Lama pacos) caused by Mycobacterium bovis

We report three cases of tuberculosis in alpacas from Spain caused by Mycobacterium bovis. The animals revealed two different lesional patterns. Mycobacterial culture and PCR assay yielded positive results for M. bovis. Molecular typing of the isolates identified spoligotype SB0295 and identical variable-number tandem repeat (VNTR) allele sizes.

Protection against Tuberculosis in Eurasian Wild Boar Vaccinated with Heat-Inactivated Mycobacterium bovis

Tuberculosis (TB) caused by Mycobacterium bovis and closely related members of the Mycobacterium tuberculosis complex continues to affect humans and animals worldwide and its control requires vaccination of wildlife reservoir species such as Eurasian wild boar (Sus scrofa). Vaccination efforts for TB control in wildlife have been based primarily on oral live BCG formulations. However, this is the first report of the use of oral inactivated vaccines for controlling TB in wildlife. In this study, four groups of 5 wild boar each were vaccinated with inactivated M. bovis by the oral and intramuscular routes, vaccinated with oral BCG or left unvaccinated as controls. All groups were later challenged with a field strain of M. bovis. The results of the IFN-gamma response, serum antibody levels, M. bovis culture, TB lesion scores, and the expression of C3 and MUT genes were compared between these four groups. The results suggested that vaccination with heat-inactivated M. bovis or BCG protect wild boar from TB. These results also encouraged testing combinations of BCG and inactivated M. bovis to vaccinate wild boar against TB. Vaccine formulations using heat-inactivated M. bovis for TB control in wildlife would have the advantage of being environmentally safe and more stable under field conditions when compared to live BCG vaccines. The antibody response and MUT expression levels can help differentiating between vaccinated and infected wild boar and as correlates of protective response in vaccinated animals. These results suggest that vaccine studies in free-living wild boar are now possible to reveal the full potential of protecting against TB using oral M. bovis inactivated and BCG vaccines

Infection of the central nervous system by Mycobacterium tuberculosis in patients infected with human immunodeficiency virus (the new neurotuberculosis)

Neurologic complications of HIV infection are numerous. This review focuses on the clinical presentation, diagnostic particularities and therapeutic issues of neurotuberculosis. The pertinent literature describing this important infection is succinctly summarized with a particular emphasis on the discussion of differences in clinical presentation between HIV-infected and -uninfected patients.

Epidemiological studies of Johne’s Disease in cattle from Scottish farms, with a focus on slaughterhouse investigations

The PARABAN project has been a Scotland-wide initiative to develop and deliver farm-specific ‘best practice’ for the control of Mycobacterium avium ssp. paratuberculosis (MAP) in cattle using ‘Knowledge Exchange’. A range of partners have been involved, including nine ‘Champion Farms’. With input from the farmer, his/her vet and PARABAN advisors, a tailored monitoring and control programme was devised for each ‘Champion Farm’, taking into account the history of the disease on the farm, the physical facilities available and farmer objectives. Culling decisions based on live animal test results were incorporated into each farm-specific programme to complement the management programme already in place to maintain each herd. Results were analysed and discussed with all the partners throughout the project and then offered for wider scrutiny at farm open days. Feedback and questions from these open days have been used to complete the ‘Knowledge Exchange’ cycle. As a major component of the PARABAN project the author collected samples from all adult animals culled from ‘Champion Farms’ at slaughter or as fallen stock, irrespective of in-life MAP test status. These were then subjected to histopathological examination by experienced veterinary pathologists and the results compared with the results from in-life MAP testing. This was intended to evaluate the contribution slaughterhouse sampling could make towards decision making for disease control on farm and formed the main aim of this thesis. In total, samples of terminal ileum and draining lymph node were collected from three-hundred and fifty-two animals. A positive result on histopathology was defined as the presence of lesions typical of MAP and also the presence of acid-fast bacteria within the sections. There was found to be fair agreement between the overall results from histopathology and serum ELISA (Kappa = 0.33), though there appeared to be some variation in agreement between the tests on the individual ‘Champion Farms’. The presence of MAP was confirmed in seven of the eight farms which contributed animals to this study, despite sometimes prolonged efforts at controlling the disease. A separate study was undertaken to make use of the archives of the Scottish Centre for Production Animal Health and Food Safety at the Veterinary School, University of Glasgow. The archive contained records of cases from across southern Scotland and northern England. Analysis of the data generated from examination of these records suggested that MAP is widespread within the Scottish cattle herd and may well be increasing

Development and application of a selenium speciation method in cattle feed and beef samples using HPLC-ICP-MS: evaluating the selenium metabolic process in cattle.

2016

Allele- and parent-of-origin-specific effects on expression of the KCNJ11 gene: a candidate for meat tenderness in cattle.

2016

Report ... 1910. Supplement, 1911.

Supplement entitled: Tuberculosis. A plain statement of facts regarding this disease.

Beiträge zur bakteriologischen Sputumuntersuchung bei der Lungentuberkulose des Rindes.

Mode of access: Internet.

Die ersten Veränderungen der Nierentuberkulose bei den Schlacht-Rindern.

Inaug.-diss. Berne, 1910

Über die Verwertbarkeit der Komplementbindungsreaktion bei Tuberkulose.

Inaug.-diss.--Hannover, 1912.

Untersuchungen über die Konjunktivalreaktion auf Tuberkulose beim Rind ...

Inaug.-diss.-Bern.

An inter-laboratory validation of a real time PCR assay to measure host excretion of bacterial pathogens, particularly of Mycobacterium bovis

Advances in the diagnosis of Mycobacterium bovis infection in wildlife hosts may benefit the development of sustainable approaches to the management of bovine tuberculosis in cattle. In the present study, three laboratories from two different countries participated in a validation trial to evaluate the reliability and reproducibility of a real time PCR assay in the detection and quantification of M. bovis from environmental samples. The sample panels consisted of negative badger faeces spiked with a dilution series of M. bovis BCG Pasteur and of field samples of faeces from badgers of unknown infection status taken from badger latrines in areas with high and low incidence of bovine TB (bTB) in cattle. Samples were tested with a previously optimised methodology. The experimental design involved rigorous testing which highlighted a number of potential pitfalls in the analysis of environmental samples using real time PCR. Despite minor variation between operators and laboratories, the validation study demonstrated good concordance between the three laboratories: on the spiked panels, the test showed high levels of agreement in terms of positive/negative detection, with high specificity (100%) and high sensitivity (97%) at levels of 10(5) cells g(-1) and above. Quantitative analysis of the data revealed low variability in recovery of BCG cells between laboratories and operators. On the field samples, the test showed high reproducibility both in terms of positive/negative detection and in the number of cells detected, despite low numbers of samples identified as positive by any laboratory. Use of a parallel PCR inhibition control assay revealed negligible PCR-interfering chemicals co-extracted with the DNA. This is the first example of a multi-laboratory validation of a real time PCR assay for the detection of mycobacteria in environmental samples. Field studies are now required to determine how best to apply the assay for population-level bTB surveillance in wildlife.

Cost-benefit analysis model of badger (Meles meles) culling to reduce cattle herd tuberculosis breakdowns in Britain, with particular reference to badger perturbation

Bovine tuberculosis (TB)is an important economic disease. Badgers (Meles meles) are the wildlife source implicated in many cattle outbreaks of TB in Britain, and extensive badger control is a controversial option to reduce the disease. A badger and cattle population model was developed, simulating TB epidemiology; badger ecology, including postcull social perturbation; and TB-related farm management. An economic cost-benefit module was integrated into the model to assess whether badger control offers economic benefits. Model results strongly indicate that although, if perturbation were restricted, extensive badger culling could reduce rates in cattle, overall an economic loss would be more likely than a benefit. Perturbation of the badger population was a key factor determining success or failure of control. The model highlighted some important knowledge gaps regarding both the spatial and temporal characteristics of perturbation that warrant further research.

Reducing the Public Health Impact of Bovine Tuberculosis by Controlling Disease Transmission Between Cattle and White-Tailed Deer in Northwestern Minnesota

Bovine tuberculosis, caused by infection with Mycobacterium bovis, is a re-emerging zoonotic disease. It has staged a comeback by establishing infections in wildlife and cattle, creating the potential for human disease in locations where it was thought to be under control. In northwestern Minnesota, infected cattle and white-tailed deer were first discovered in 2005. A major bovine tuberculosis eradication campaign is underway in the state, with multiple efforts employed to control M. bovis infection in both cattle and deer populations. In order to effectively eradicate bovine tuberculosis in Minnesota, there is a need for better understanding of the factors that increase the risk of deer and cattle interacting in a way that facilitates tuberculosis transmission. By reducing the risk of disease transmission within the animal populations, we will also reduce the risk that bovine tuberculosis will again become a common disease in human populations. The purpose of this study is to characterize the risk of interactions between cattle and white-tailed deer in northern Minnesota in order to prevent M. bovis transmission. A survey originally developed to assess deer-cattle interactions in Michigan was modified for use in Minnesota, introducing a scoring method to evaluate the areas of highest priority at risk of potential deer-cattle interaction. The resulting semi-quantitative deer-cattle interaction risk assessment was used at 53 cattle herds located in the region adjacent to the bovine tuberculosis “Core Area”. Two evaluators each scored the farm separately, and then created a management plan for the farm that prioritized the areas of greatest risk for deer-cattle interactions. Herds located within the “Management Zone” were evaluated by Minnesota Board of Animal Health staff, and results from these surveys were used as a point of comparison.