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Abstract: Bovine TB is a disease that affects cattle and the wildlife badger, species Meles meles, in Ireland and the UK, and badgers have been implicated in the spread of the disease in cattle. Efforts to eradicate the disease that have included localized badger culling, have not been successful. In a study to understand how the disease spreads, Kelly and More [1] determined that the disease spatially clusters in cattle herds and estimated the practical spatial ranges at which this occurs. We extend this work by examining possible anisotropy in clustering and the consequences for TB control policy. [Copyright &y& Elsevier]

Abstract: An enzyme-linked immunosorbent assay (ELISA) using bulk tank milk samples was evaluated as a screening test for bovine tuberculosis (TB), a contagious chronic disease of cattle. An ELISA with MPB70, a major antigen of Mycobacterium bovis was performed using paired sets of milk and sera samples from 33 tuberculin-positive and 43 tuberculin-negative cattle. Anti-MPB70 antibodies were detected in milk samples and there was a significant correlation between seroreactivities of milk and sera samples (R2 =0.83). Using the tuberculin skin test as the reference test, the sensitivities of ELISA using milk and sera samples were 87.8% and 81.8%, respectively, and the specificities were 97.7% and 100%, respectively. In the screening test using bulk tank milk samples from 931 dairy herds in Whasung, Gyeonggi-do, Korea, the positive rate for anti-MPB70 antibody was 4.5% (42/931) and the tuberculin-positive rate was 2.8% (26/931). Individual milk samples (n =253) were collected from randomly selected 8 problematic and 3 negative herds (positive and negative in the screening test by MPB70 ELISA using bulk tank milk samples, respectively) and tested by MPB70 milk ELISA. In the problematic herds, positive rates were 10.5% (20/190) for anti-MPB70 antibodies in milk ELISA and 2.1% (4/190) in the tuberculin skin test. More than one dairy cows were positive by milk ELISA among the problematic herds, and all tuberculin-positive dairy cows were positive in the milk ELISA. Further, no positive cows were detected in negative herds both by milk ELISA and tuberculin skin test. These results suggest that an ELISA, using bulk tank milk samples, might be a potential efficient screening test for bovine TB of dairy cows. [Copyright &y& Elsevier]

An editorial is presented in which the editor discusses role of Mycobacterium bovis in causing bacteraemia in cattle. Topics discussed include risk factors of the disease such as reduced productivity in affected animals, culling of affected animals; challenges associated in diagnosing due to its slow growth; and development of a sensitive and rapid method for detection of Mycobacterium tuberculosis complex (MTC) in bovine peripheral blood mononuclear cells (PMBC).

Abstract: Zoonotic diseases such as bovine tuberculosis (TB) that infect wildlife and livestock are particularly difficult to eradicate where wild animals make extensive use of agricultural landscapes. Transmission of TB between cattle (Bos taurus) and wild elk (Cervus elaphus) in southwestern Manitoba, Canada remains poorly understood but there is a risk when comingling occurs on summer pasture. Elk use of cattle summer pastures was assessed using ecological data (187 VHF and 25 GPS collared elk monitored over four years representing 8% of the elk population). Local knowledge was documented by conducting interviews and participatory mapping exercises with 86 cattle producers (98% of those within the study area). Of the 294 cattle pastures mapped by farmers, 13% were used by radio-collared elk, 38% were reported by farmers as being used by elk, and 42% were identified as used by elk when both when all datasets were combined. Cattle pastures that had been used by elk and those that had no elk were compared using binary logistic regression based on each of the three datasets (i.e. farmer observations, radio-collared elk on pasture, and combined dataset). For all three datasets, distance to protected area and proportion of forest cover on the cattle pasture were identified as the most and second most important predictor variables, respectively. There was strong agreement among the relative probabilities of elk occurrence on each pasture derived from the resource selection function (RSF) models developed using farmer interviews and elk collaring data. The farmer interview and collar datasets were then combined to generate a final integrated RSF map summarizing the probability of elk–cattle comingling and were contrasted over each of four cattle grazing seasons (spring, early summer, late summer, and autumn). These predictive maps indicate that use of cattle pastures by elk is extensive, particularly in spring and early summer. Farmer observations indicate that elk and cattle share water sources and livestock mineral supplements on pasture. Local knowledge and conventional ecological data complement and validate one another and help us better understand the temporospatial aspects of shared space use among wildlife and livestock and more generally the risks of disease transmission in agricultural landscapes. [Copyright &y& Elsevier]

Summary: Background: The effective control of human and livestock diseases is challenging where infection persists in wildlife populations. The Randomised Badger Culling Trial (RBCT) demonstrated that, while it was underway, proactive badger (Meles meles) culling reduced bovine tuberculosis (TB) incidence inside culled areas but increased incidence in neighboring areas, suggesting that the costs of such culling might outweigh the benefits. Objectives and design: The objective of this study was to investigate whether culling impacts persisted more than one year following the cessation of culling (the ‘post-trial’ period). We compared TB incidence in and around RBCT proactive culling areas with that in and around matched unculled areas. Results: : During the post-trial period, cattle TB incidence inside culled areas was reduced, to an extent significantly greater (p =0.002) than during culling. In neighboring areas, elevated risks observed during culling were not observed post-trial (p =0.038). However, the post-trial effects were comparable to those observed towards the end of the trial (inside RBCT areas: p =0.18 and neighboring areas: p =0.14). Conclusions: Although to-date the overall benefits of culling remain modest, they were greater than was apparent during the culling period alone. Continued monitoring will demonstrate how long beneficial effects last, indicating the overall capacity of such culling to reduce cattle TB incidence. [Copyright &y& Elsevier]

This paper applies an attribute-based stated choice experiment approach to estimate the value that society places on changes to the size of the badger population in England and Wales. The study was undertaken in the context of a rising incidence of bovine tuberculosis (bTB) in cattle and the government's review of current bTB control policy. This review includes consideration of culling badgers to reduce bTB in cattle, since badgers are thought to be an important wildlife reservoir for the disease. The design of the CE involved four attributes (size of badger population, cattle slaughtered due to bTB, badger management strategy and household tax) at four levels with eight choice sets of two alternatives presented to respondents. Telephone interviews were undertaken with over 400 respondents, which elicited their attitudes and preferences concerning badgers, bTB in cattle and badger management strategies. The study estimated a willingness to pay of £0.10 per household per year per 100,000 badgers and £1.52 per household per year per 10,000 cattle slaughtered due to bTB which aggregated to £22 per badger and £3298 per bTB slaughtered animal for all households in England and Wales. Management strategy toward badgers had a very high valuation, highlighting the emotive issue of badger culling for respondents and the importance of government policy towards badgers. [ABSTRACT FROM AUTHOR]

Summary: Background: Bovine tuberculosis (TB) has re-emerged as a major problem for British cattle farmers. Failure to control the infection has been linked to transmission from European badgers; badger culling has therefore formed a component of British TB control policy since 1973. Objectives and design: To investigate the impact of repeated widespread badger culling on cattle TB, the Randomised Badger Culling Trial compared TB incidence in cattle herds in and around ten culling areas (each 100km2) with those in and around ten matched unculled areas. Results: Overall, cattle TB incidence was 23.2% lower (95% confidence interval (CI) 12.4–32.7% lower) inside culled areas, but 24.5% (95% CI 0.6% lower–56.0% higher) higher on land ≤2km outside, relative to matched unculled areas. Inside the culling area boundary the beneficial effect of culling tended to increase with distance from the boundary (p =0.085) and to increase on successive annual culls (p =0.064). In adjoining areas, the detrimental effect tended to diminish on successive annual culls (p =0.17). On the basis of such linear trends, the estimated net effect per annum for culling areas similar to those in the trial was detrimental between the first and second culls, but beneficial after the fourth and later culls, for the range of analyses performed. Conclusions: Careful consideration is needed to determine in what settings systematic repeated culling might be reliably predicted to be beneficial, and in these cases whether the benefits of such culling warrant the costs involved. [Copyright &y& Elsevier]

Summary: Amongst the members of the Mycobacterium tuberculosis complex (MTBC), M. tuberculosis is mainly a human pathogen, whereas M. bovis has a broad host range and is the principal agent responsible for tuberculosis (TB) in domestic and wild mammals. M. bovis also infects humans, causing zoonotic TB through ingestion, inhalation and, less frequently, by contact with mucous membranes and broken skin. Zoonotic TB is indistinguishable clinically or pathologically from TB caused by M. tuberculosis. Differentiation between the causative organisms may only be achieved by sophisticated laboratory methods involving bacteriological culture of clinical specimens, followed by typing of isolates according to growth characteristics, biochemical properties, routine resistance to pyrazinamide (PZA) and specific non-commercial nucleic acid techniques. All this makes it difficult to accurately estimate the proportion of human TB cases caused by M. bovis infection, particularly in developing countries. Distinguishing between the various members of the MTBC is essential for epidemiological investigation of human cases and, to a lesser degree, for adequate chemotherapy of the human TB patient. Zoonotic TB was formerly an endemic disease in the UK population, usually transmitted to man by consumption of raw cows’ milk. Human infection with M. bovis in the UK has been largely controlled through pasteurization of cows’ milk and systematic culling of cattle reacting to compulsory tuberculin tests. Nowadays the majority of the 7000 cases of human TB annually reported in the UK are due to M. tuberculosis acquired directly from an infectious person. In the period 1990–2003, between 17 and 50 new cases of human M. bovis infection were confirmed every year in the UK. This represented between 0.5% and 1.5% of all the culture-confirmed TB cases, a proportion similar to that of other industrialized countries. Most cases of zoonotic TB diagnosed in the UK are attributed to (i) reactivation of long-standing latent infections acquired before widespread adoption of milk pasteurization, or (ii) M. bovis infections contracted abroad. Since 1990, only one case has been documented in the UK of confirmed, indigenous human M. bovis infection recently acquired from an animal source. Therefore, for the overwhelming majority of the population, the risk of contracting M. bovis infection from animals appears to be extremely low. However, bovine TB is once again a major animal health problem in the UK. Given the increasing numbers of cattle herds being affected each year, physicians and other public health professionals must remember that zoonotic TB is not just a disease of the past. A significant risk of M. bovis infection remains in certain segments of the UK population in the form of (i) continuing on-farm consumption of unpasteurized cows’ milk, (ii) retail sales by approved establishments of unpasteurized milk and dairy products and (iii) occupational exposure to infectious aerosols from tuberculous animals and their carcases. [Copyright &y& Elsevier]

1. The incidence of bovine tuberculosis (TB) in British cattle has risen markedly over the last two decades. Failure to control the disease in cattle has been linked to the persistence of a reservoir of infection in European badgers Meles meles, a nationally protected species. Although badger culling has formed a component of British TB control policy for many years, a recent large-scale randomized field experiment found that TB incidence in cattle was no lower in areas subject to localized badger culling than in nearby areas where no experimental culls occurred. Indeed, analyses indicated that cattle incidence was higher in culled areas. 2. One hypothesis advanced to explain this pattern is that localized culling disrupted badgers’ territorial behaviour, potentially increasing the rate of contact between cattle and infected badgers. This study evaluated this hypothesis by investigating badger activity and spatial organization in 13 study areas subjected to different levels of culling. Badger home ranges were mapped by feeding colour-marked baits at badger dens and measuring the geographical area in which colour-marked faeces were retrieved. 3. Badger home ranges were consistently larger in culling areas. Moreover, in areas not subjected to culling, home range sizes increased with proximity to the culling area boundary. Patterns of overlap between home ranges were also influenced by culling. 4. Synthesis and applications. This study demonstrates that culling badgers profoundly alters their spatial organization as well as their population density. These changes have the potential to influence contact rates between cattle and badgers, both where culls occur and on adjoining land. These results may help to explain why localized badger culling appears to have failed to control cattle TB, and should be taken into account in determining what role, if any, badger culling should play in future control strategies. [ABSTRACT FROM AUTHOR]

1. Control of zoonotic disease is difficult to achieve when populations of multiple hosts, particularly wildlife, become persistently infected. Bovine tuberculosis (TB) is one such disease: its causative agent, Mycobacterium bovis, infects cattle, humans and multiple wildlife species including European badgers Meles meles. 2. In Britain, from 1974 to 1998 various strategies for the control of cattle TB involved culling badgers in the immediate vicinity of TB-affected herds. However, patterns of association between cattle and badgers had not been investigated at a local scale. 3. Using data from the Randomized Badger Culling Trial, an ongoing large-scale study of TB dynamics and control, we investigated local geographical associations between M. bovis infection in badgers and cattle. 4. Mycobacterium bovis infections were locally clustered within both badger and cattle populations. 5. We show, for the first time, that M. bovis infections in badgers and cattle are spatially associated at a scale of 1–2 km. Badgers and cattle infected with the same strain type of M. bovis are particularly closely correlated. These observational data support the hypothesis that transmission occurs between the two host species; however, they cannot be used to evaluate the relative importance of badger-to-cattle and cattle-to-badger transmission. 6. Synthesis and applications. The close associations between M. bovis infections in cattle and badgers suggest that localized badger culling could reasonably be expected to reduce the risks of cattle TB infection; however, experimental culls have found no such beneficial effects over the time-scale on which they were tested. This demonstrates the difficulty of predicting the outcome of management interventions, and reinforces the need for well-designed empirical assessments of future control strategies. [ABSTRACT FROM AUTHOR]

Summary The objective of the investigation was to provide data on how a prior exposure of cattle to Mycobacterium avium , used here as a model of exposure to an environmental mycobacterium, affected the cellular immune response that follows vaccination with Mycobacterium bovis BCG. The assessment of cellular immune responses included lymphocyte proliferation assays, the delayed hypersensitivity skin test and IFN-γ synthesis in whole blood cultures. One group of calves was inoculated subcutaneously with M. avium followed 12 weeks later by M. bovis -BCG. The other group was vaccinated subcutaneously with BCG alone. Calves previously exposed to M. avium responded more rapidly, as assessed in the in vitro assays, to purified protein derivative (PPD) from M. avium (PPD-A) or M. bovis (PPD-B) than did calves inoculated with BCG only, indicating that the exposure to M. avium had primed the immune response in these calves. Following inoculation of BCG the intensity of the in vitro responses and the delayed hypersensitivity skin test to PPD-A was higher for the M. avium- primed animals while the responses to PPD-B were similar in the M. avium -primed and BCG-only groups. The results are consistent with a model in which prior exposure to environmental mycobacteria does not necessarily inhibit the immune response to the vaccine strain, BCG. They suggest that M. avium infection primes the immune system of calves and that the detection of an immune response specific for M. bovis BCG is masked by reactivity to antigens also present in M. avium. [ABSTRACT FROM AUTHOR]

Recent advances have permitted the red fox (Vulpes vulpes) to be vaccinated against rabies in order to control the European epidemic. Vaccination is also the preferred long-term strategy for controlling bovine tuberculosis (Mycobacterium bovis) (TB) in the European badger (Meles meles) in England. We discuss a model to compare the efficacy of various disease control strategies, including temporary and permanent sterilisation. By using rabies and TB as examples of acute and chronic diseases, the model shows that lethal control can be more effective at disease eradication in an isolated population than vaccination. This is due to the birth of larger numbers of susceptible individuals during a vaccination campaign, which makes it harder to keep the population below the critical threshold density. This difference was very marked for the progressive disease of tuberculosis. The inclusion of an abortifacient increased the chances of disease control to levels close to that of lethal control. If the abortifacient is replaced by a permanent contraceptive then the chances of disease eradication and population extinction were very similar to that of lethal control, since the birth of susceptibles is now much reduced. These results are also of relevance in the control of wildlife diseases in threatened populations or species. [Copyright &y& Elsevier]

Simple disease/host models are used to identify the ecological criteria governing the likely relative effectiveness of culling, sterilization and vaccination as methods of wildlife disease control. The models include non-linear host death or birth rate/density relationships, and non-linear disease contact rate/density relationships. The following conclusions are based on these simple homogeneous-mixing models, and may be modified by certain spatial effects such as territoriality and density-dependent settlement of dispensing hosts. The threshold density of susceptible and density-dependent settlement of dispersing hosts. The threshold density of susceptible host for elimination or a disease, relative to the disease-free carrying capacity, is largely determined by characteristics of the disease. For any given threshold, relative to the carrying capacity, the degree of control required to maintain the host density at this threshold is solely determined by ecological characteristics of the host. The sustained rate of control required to eliminate disease can be expressed, exactly or to a good approximation, in terms of the basic reproductive rate of the disease, Ro the host density-independent birth and death rates, and the parameters describing non-linearities in the host density dependence and disease contact rate/density functions. In terms of the sustained rates of control (e.g. percentage per year) necessary to eliminate disease, sterilization is as effective as culling (i.e. it requires the same level of control effort). Culling is likely to be more effective than vaccination (i.e. requires a lower rate of control) when Ro is high (> 3) or host density dependence acts on mortality rather than recruitment. When Ro is low (< 3) and density dependence and/or the disease contact rate/density relationship; vaccination is favoured by a low death rate relative to r, the host intrinsic rate of increase, and by non-linear density relationships. For a combined strategy of culling and vaccination, the total rate of control required to eliminate disease exceeds that for at lest one of the strategies in isolation; to this extent the combined control is less effective. Using the above criterion for comparison, for all six published case studies considered as examples, culling is theoretically the most effective control strategy given the authors' assumptions in the original models. More recent data for possum density dependence suggests that vaccination could more closely match culling in effectiveness. The extent to which vaccination appears more effective in practice, in cases like fox rabies in Europe, probably reflects the spatial behavior of the host not considered in these simple models. Comparing strategies on the basis of the relative rates at which they reduce endemic disease or the density of susceptible hosts, gives different results. In particular, sterilization is less effective than vaccination, and very much less effective than culling. Non-linearities in the density relationships greatly increase the effectiveness of vaccination relative to culling and sterilization, but the distinction between host density-dependent mortality or recruitment is no longer important. The biological reasons for these conclusions are discussed. [ABSTRACT FROM AUTHOR]

A mixed deterministic/stochastic model is described for the epidemic spread of bovine Tb in New Zealand possum populations. The model is a modified Sl one with birth and dispersal pulses, equations replicated over a spatial grid and with disease transmission between as well as within grid squares. An explanation is proposed for the assumption in this and previous models, based on observations, that the disease contact rate (potentially infectious contacts per infectious animal per year) is independent of the equilibrium density (K) but is dependent on manipulations of density below K. The explanation is the dependence of contact rate on the extent of den site sharing and use. Since K largely reflects that abundance of den sites in the habitat, den site use per possum, hence contact rate, is independent of K. The predicted rate of spread of the disease was sensitive to the assumptions about endemic disease behaviour. It varied from 0.6km year-1 for a chronic disease with long infectious period to 3 km year-1 for an acute disease with short latent and infectious periods. The model suggests that a 3 km ‘buffer zone’ around an endemic area, in which possums are effectively eliminated, reduces the number of diseased possums leaving the zone by the about 70%. However, in practice and with the less intensive control currently recommended, a buffer zone alone has little ultimate effect on disease spread unless its width approximates the maximum likely juvenile dispersal distance (12km). This is because some infected juveniles cross the buffer, and because the remaining possums within the buffer allow the presence of a stable level of Tb in the face of immigration of diseased animals. Control regimes were based on an earlier model for edemic disease, involving a 75% kill followed by a 50% kill when possum densities reached 40% of their pre-control level. Combining a buffer zone, routinely controlled in this way, with localized control operations, in which possums are controlled for 5 years beyond the buffer zone where cattle test positive for Tb, successfully prevents the spread of disease if the probability of possum-to-cattle transmission in sufficiently high. The most cost-effective option involved the widest buffer (12km), giving an average of about 3 km2 controlled per year per km of the Tb front. Localized control alone, without a buffer, was the most expensive option, requiring an average of 9.2km2 of annual control. Increasing the follow-up kill from 50% to 75% and decreasing the threshold density from 40% to 25% of pre-control levels both increased the cost-effectiveness of control. The level of control required to prevent Tb spread was sensitive to the possum carrying capacity (disease-free equilibrium density). At 3 ha-1 rather than 10 ha-1 the annual area controlled was reduced by 50%. Possum control operations within an endemic zone must be carried out over a wide area (>50 km2) to prevent immigration of diseased animals from seriously reducing control effectiveness. Immigration per unit area is a non-linearly decreasing function of the total area controlled. The model identifies a need for more data on possum/cattle transmission of disease and on short-range dispersal behaviour of adult possums. [ABSTRACT FROM AUTHOR]

Bovine tuberculosis (bTB) outbreaks, caused by Mycobacterium bovis infection, are a costly animal health challenge. Understanding factors associated with the duration of outbreaks, known as breakdowns, could lead to better disease management policy development. We undertook a retrospective observational study (2012–2018) and employed Finite Mixture Models (FMM) to model the outcome parameter, and to investigate how factors were associated with duration for differing subpopulations identified. In addition to traditional risk factors (e.g., herd size, bTB history), we also explored farm geographic area, parcels/farm fragmentation, metrics of intensity via nitrogen loading, and whether herds were designated controlled beef finishing units (CBFU) as potential risk factors for increased duration. The final model fitted log-normal distributions, with two latent classes (k) which partitioned the population into a subpopulation around the central tendency of the distribution, and a second around the tails of the distribution. The latter subpopulation included longer breakdowns of policy interest. Increasing duration was positively associated with recent (<3 years) TB history and the number of reactors disclosed, (log) herd size, beef herd-type relative to other herd types, number of land parcels, area, being designated a CBFU ("feedlot") and having high annual inward cattle movements within the "tails" subpopulation. Breakdown length was negatively associated with the year of commencement of breakdown (i.e., a decreasing trend) and non-significantly with the organic nitrogen produced on the farm (N kg/hectare), a measure of stocking density. The latter finding may be due to confounding effects with herd size and area. Most variables contributed only moderately to explaining variation in breakdown duration, that is, they had moderate size effects on duration. Herd-size and CBFU had greater effect sizes on the outcome. The findings contribute to evidence-based policy formation in Ireland. [ABSTRACT FROM AUTHOR]

Bovine tuberculosis (bTB) is a chronic illness in animals, especially in cattle, leading to loss in the productivity and signifies a crucial public health risk. Regardless of the zoonotic threat and significant economic costs associated with the disease, precise estimates of bTB prevalence are deficient in many countries, including India, where national control programs are yet to be instigated. The true burden of the disease remains unknown due to lack of routine surveillance data from most of the developing countries. India is progressing well towards attaining the End TB goal, yet bTB continues to remain largely hidden. Moreover, the paucity of literature on bTB in India might lead to undue complacency and hence has to be scrupulously guarded and prevented from gaining any misconceptions in the minds of the common people. Preventing and controlling bTB at the animal interface is pivotal to evade transmission to human, increase food safety and guard the livelihood of the people. To attain this goal, implementation of strategies based on international norms and a multi-sectoral approach will empower enhanced surveillance and diagnosis of disease in animals and subsequently reduce the risk for humans. As an initiative, we step forward to address this review which briefly summarizes the available data in the literature from early 20th century to date to assess the status of bTB in India. We have discussed in detail, the epidemiology, transmission and diagnosis pertaining to bTB. The review also focuses on the interconnection between the health of people and animal, discuss the preventions and control strategies and recommend the use of vaccination in cattle to reduce the spread of infection among other animals and humans. Implementing One Health approach in India, which recognizes the interdependence of the health of people and animals will help the nation in the fight against TB. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a re-emerging disease occurring worldwide, resulting in multi-billion-dollar loss and human death annually. The situation is worse in developing countries like Ethiopia, where lower knowledge, attitude, and practice (KAP) of the people is poor about the disease. A questionnaire-based cross-sectional study was conducted to assess livestock owners' KAP level towards human and bovine Tuberculosis in Gondar, Ethiopia. A total of 349 study participants were addressed through a face-to-face interview. Descriptive statistics and Pearson's chi-squares analysis were used to analyze the data and observe the association between outcome (KAP level) and predictor variables (sociodemographic characteristics). Out of the 349 respondents, 223 (63.9%) were males, while 126 (36.1%) were females. The KAP measuring interview indicated that 97.4% of the participants are aware of human tuberculosis, while only 84 (24.1%) know about bovine tuberculosis cause and mode of transmission. Inhalation was reported as the main route of transmission for human TB (41.1%) whereas, 50% of the respondent mentioned inhalation, contact, and ingestion of raw animal products as the main route of TB transmission from animal to human. Among those who have heard of bovine tuberculosis, only 56 (66.7%) of respondents consider bovine tuberculosis as a significant threat to public health. The study showed there is a lower KAP on bovine TB among cattle owners in the study area. Therefore, community health education about the impact of the disease, transmission, control, and prevention should be integrated with one health-oriented education and research to eradicate the disease from the country., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors.)

The contribution of Mycobacterium bovis to the proportion of tuberculosis cases in humans is unknown. A retrospective study was undertaken on archived Mycobacterium tuberculosis complex (MTBC) isolates from a reference laboratory in Uganda to identify the prevalence of human M. bovis infection. A total of 5676 isolates maintained in this repository were queried and 136 isolates were identified as pyrazinamide resistant, a hallmark phenotype of M. bovis. Of these, 1.5% (n = 2) isolates were confirmed as M. bovis by using regions of difference PCR analysis. The overall size of whole genome sequences (WGSs) of these two M. bovis isolates were ~4.272 Mb (M. bovis Bz_31150 isolated from a captive chimpanzee) and 4.17 Mb (M. bovis B2_7505 from a human patient), respectively. Alignment of these genomes against 15 MTBC genome sequences revealed 7248 single nucleotide polumorphisms (SNPs). Theses SNPs were used for phylogenetic analysis that indicated a strong relationship between M. bovis and the chimpanzee isolate (Bz_31150) while the other M. bovis genome from the human patient (B2_7505) analyzed did not cluster with any M. bovis or M. tuberculosis strains. WGS analysis also revealed multidrug resistance genotypes; these genomes revealed pncA mutations at positions H57D in Bz_31150 and B2_7505. Phenotypically, B2_7505 was an extensively drug-resistant strain and this was confirmed by the presence of mutations in the major resistance-associated proteins for all anti-tuberculosis (TB) drugs, including isoniazid (KatG (S315T) and InhA (S94A)), fluoroquinolones (S95T), streptomycin (rrs (R309C)), and rifampin (D435Y, a rare but disputed mutation in rpoB). The presence of these mutations exclusively in the human M. bovis isolate suggested that these occurred after transmission from cattle. Genome analysis in this study identified M. bovis in humans and great apes, suggesting possible transmission from domesticated ruminants in the area due to a dynamic and changing interface, which has created opportunity for exposure and transmission. [ABSTRACT FROM AUTHOR]

Pastoralism is a way of life in which food supply is produced from animals by using a variety of herding practices based on constant or partial herd mobility in the low land areas of Ethiopia. It covers 12% of the total livestock population and 61% of the total area of land in the country. As a result of their mobile lifestyle, pastoralists are almost completely excluded from the available health services. This review article focuses on bovine tuberculosis in the Ethiopian Somali Pastoralist. It describes Mycobacterium bovis in humans, livestock, and wildlife, and how the disease can be controlled by using One Health approach. Bovine tuberculosis is a chronic bacterial disease caused by Mycobacterium bovis . A study done from 2006 to 2008 on the prevalence of BTB in Ethiopian wildlife showed that sera from 20 of 87 animals (23%) were positive for BTB. In Ethiopia there is no comprehensive report about the status of M. bovis in wildlife populations that often share habitat with livestock . A study done on bovine tuberculosis in Somali pastoral livestock showed low prevalence of the disease. An individual animal prevalence of 2.0%, 0.4%, and 0.2% was reported in cattle, camels, and goats, respectively. In a simultaneous human and cattle study in a pastoralist areas of south-eastern Ethiopia, out of 163 human Mycobacterium tuberculosis complex isolates three were M. bovis . Due to the moderate resistance of the etiological agent to the environmental conditions in one hand and the capacity of its survival in acid milk for not less than 15 days on the other and the habitual consumption of unpasteurized milk by humans make this disease a vital zoonosis in Somali pastoralists in Ethiopia. M. bovis is a pathogen at the human-livestock-wildlife interface. Diseases transmitted between humans, livestock, and wildlife are increasingly challenging public and veterinary health systems. Therefore, studies concerning the burden of the diseases in wildlife, livestock and human beings in Somali Pastoralists should be undertaken. A One Health approach that takes the wellbeing of the pastoralists, the health of their livestock and environment into consideration is also necessary for the control of BTB., (© 2019 The Author.)

Culling wildlife to control disease can lead to both decreases and increases in disease levels, with apparently conflicting responses observed, even for the same wildlife-disease system. There is therefore a pressing need to understand how culling design and implementation influence culling's potential to achieve disease control. We address this gap in understanding using a spatial metapopulation model representing wildlife living in distinct groups with density-dependent dispersal and framed on the badger-bovine tuberculosis (bTB) system. We show that if population reduction is too low, or too few groups are targeted, a 'perturbation effect' is observed, whereby culling leads to increased movement and disease spread. We also demonstrate the importance of culling across appropriate time scales, with otherwise successful control strategies leading to increased disease if they are not implemented for long enough. These results potentially explain a number of observations of the dynamics of both successful and unsuccessful attempts to control TB in badgers including the Randomized Badger Culling Trial in the UK, and we highlight their policy implications. Additionally, for parametrizations reflecting a broad range of wildlife-disease systems, we characterize 'Goldilocks zones', where, for a restricted combination of culling intensity, coverage and duration, the disease can be reduced without driving hosts to extinction.

Background: Bovine tuberculosis (bTB; Mycobacterium bovis ) remains a significant problem in a number of countries, and is often found where M. avium subsp. paratuberculosis (MAP) is also present. In the United Kingdom, bTB has been difficult to eradicate despite long-term efforts. Co-infection has been proposed as one partial mechanism thwarting eradication. Methods: A retrospective case-control study of 4,500 cattle herds in Northern Ireland, where serological testing of cattle for MAP, was undertaken (2004-2015). Blood samples were ELISA tested for MAP; infection of M. bovis was identified in herds by the comparative tuberculin test (CTT) and through post-mortem evidence of infection. Case-herds were those experiencing a confirmed bTB breakdown; control-herds were not experiencing a breakdown episode at the time of MAP testing. A second model included additional testing data of feces samples (culture and PCR results) to better inform herd MAP status. Multi-level hierarchical models were developed, controlling for selected confounders. A sensitivity analysis of the effect of MAP sample numbers per event and the prior timing of tuberculin-testing was undertaken. Results: 45.2% ( n = 250) of case observations and 36.0% (3,480) of control observations were positive to MAP by ELISA (45.8% and 36.4% when including ancillary fecal testing, respectively). Controlling for known confounders, the adjusted odds ratio (aOR) for this association was 1.339 (95%CI:1.085-1.652; including ancillary data aOR:1.356;95%CI:1.099-1.673). The size-effect of the association increased with the increasing number of samples per event used to assign herd MAP status (aOR:1.883 at >2 samples, to aOR:3.863 at >10 samples), however the estimated CI increased as N decreased. 41.7% of observations from chronic herds were MAP serology-positive and 32.2% from bTB free herds were MAP positive (aOR: 1.170; 95%ci: 0.481-2.849). Discussion: Cattle herds experiencing a bTB breakdown were associated with increased risk of having a positive MAP status. Chronic herds tended to exhibit higher risk of a positive MAP status than bTB free herds, however there was less support for this association when controlling for repeated measures and confounding. MAP co-infection may be playing a role in the success of bTB eradiation schemes, however further studies are required to understand the mechanisms and to definitively establish causation.

Mycobacterium tuberculosis ( M. tb ) remains one of the most globally serious infectious agents for human morbidity and mortality, but with significant differences in prevalence across the globe. In many countries, the incidence is now low and declining, but control and eradication remain a distant view. Similarly, the prevalence of bovine TB caused by Mycobacterium bovis (M. bovis) , varies significantly across regions, although unlike for M. tuberculosis , data are sparse. The reduction in incidence and prevalence and control of both human and bovine TB is difficult and costly, yet some countries have managed to do this with some success. This perspective will consider some of the critical control steps we now know to be important for the control of TB from M. tuberculosis in humans living in South Africa, where the incidence of TB is the highest currently experienced. Despite the high incidence of human TB, South Africa has been able to reduce this incidence remarkably in the past few years, despite limited resources and high HIV prevalence. We draw from our experience to ascertain whether we may learn useful lessons from control efforts for both diseases in order to suggest effective control measures for bovine TB.

In 2017, Public Health England South East Health Protection Team (HPT) were involved in the management of an outbreak of Mycobacterium bovis (the causative agent of bovine tuberculosis) in a pack of working foxhounds. This paper summarises the actions taken by the team in managing the public health aspects of the outbreak, and lessons learned to improve the management of future potential outbreaks. A literature search was conducted to identify relevant publications on M. bovis. Clinical notes from the Public Health England (PHE) health protection database were reviewed and key points extracted. Animal and public health stakeholders involved in the management of the situation provided further evidence through unstructured interviews and personal communications. The PHE South East team initially provided 'inform and advise' letters to human contacts whilst awaiting laboratory confirmation to identify the infectious agent. Once M. bovis had been confirmed in the hounds, an in-depth risk assessment was conducted, and contacts were stratified in to risk pools. Eleven out of 20 exposed persons with the greatest risk of exposure were recommended to attend TB screening and one tested positive, but had no evidence of active TB infection. The number of human contacts working with foxhound packs can be large and varied. HPTs should undertake a comprehensive risk assessment of all potential routes of exposure, involve all other relevant stakeholders from an early stage and undertake regular risk assessments. Current guidance should be revised to account for the unique risks to human health posed by exposure to infected working dogs.

Tuberculosis (TB) is more than 3 million years old thriving in multiple species. Ancestral Mycobacterium tuberculosis gave rise to multiple strains including Mycobacterium bovis now distributed worldwide with zoonotic transmission happening in both directions between animals and humans. M. bovis in milk caused problems with a significant number of deaths in children under 5 years of age due largely to extrapulmonary TB. This risk was effectively mitigated with widespread milk pasteurization during the twentieth century, and fewer young children were lost to TB. Koch developed tuberculin in 1890 and recognizing the possibility of using tuberculin to detect infected animals the first tests were quickly developed. Bovine TB (bTB) control/eradication programmes followed in the late nineteenth century/early twentieth century. Many scientists collaborated and contributed to the development of tuberculin tests, to refining and optimizing the production and standardization of tuberculin and to determining test sensitivity and specificity using various methodologies and injection sites. The WHO, OIE, and EU have set legal standards for tuberculin production, potency assay performance, and intradermal tests for bovines. Now, those using tuberculin tests for bTB control/eradication programmes rarely, see TB as a disease. Notwithstanding the launch of the first-ever roadmap to combat zoonotic TB, many wonder if bTB is actually a problem? Is there a better way of dealing with bTB? Might alternative skin test sites make the test "better" and easier to perform? Are all tuberculins used for testing equally good? Why have alternative "better" tests not been developed? This review was prompted by these types of questions. This article attempts to succinctly summarize the data in the literature from the late nineteenth century to date to show why TB, and zoonotic TB specifically, was and still is important as a "One Health" concern, and that the necessity to reduce the burden of zoonotic TB, to save lives and secure livelihoods is far too important to await the possible future development of novel diagnostic assays for livestock before renewing efforts to eliminate it. Consequently, it is highly probable that the tuberculin skin test will remain the screening test of choice for farmed livestock for the considerable future.

Khuzestan is a southwestern province of Iran with proximity to the Persian Gulf and the international border with Iraq where harsh climate seriously affects this oil-rich region. In a search for causative agents of bovine tuberculosis (bTB), slaughterhouse specimens (lymph nodes) from 32 tuberculin-positive cows originating from 17 farms were cultured on Lowenstein–Jensen slopes. This was further extended with bacterial culture of postmortem material from 6 trapped feral mice straying on the same farm premises. Twenty-five bovine and 2 murine acid-fast isolates were consequently obtained with all of them confirmed as Mycobacterium tuberculosis (MTB) complex bacteria by IS6110-PCR experiment. Spoligotyping and RD4 typing of the 2 murine and some of the collected bovine isolates left no doubt that Mycobacterium bovis is the principle and possibly the single culprit in bTB in this region. It does not come as a surprise as previous exhaustive works have shown in the Iranian environment other members of MTB complex than M. bovis are very unlikely to have any role in the epidemiology of bTB. [ABSTRACT FROM AUTHOR]

The neglected zoonotic diseases (NZDs) have been all but eradicated in wealthier countries, but remain major causes of ill-health and mortality across Africa, Asia, and Latin America. This neglect is, in part, a consequence of under-reporting, resulting in an underestimation of their global burden that downgrades their relevance to policy-makers and funding agencies. Increasing awareness about the causes of NZDs and how they can be prevented could reduce the incidence of many endemic zoonoses. Addressing NZDs by targeting the animal reservoir can deliver a double benefit, as enhanced animal health means a reduced risk of infection for humans, as well as improved livelihoods through increased animal productivity. Advocacy for NZD control is increasing, but with it comes a growing awareness that NZD control demands activities both in the short term and over a long period of time. Moreover, despite the promise of cheap, effective vaccines or other control tools, these endemic diseases will not be sustainably controlled in the near future without long-term financial commitment, particularly as disease incidence decreases and other health priorities take hold. NZD intervention costs can seem high when compared with the public health benefits alone, but these costs are easily outweighed when a full cross-sector analysis is carried out and monetary/non-monetary benefits--particularly regarding the livestock sector--are taken into account. Public-private partnerships have recently provided advocacy for human disease control, and could prove equally effective in addressing endemic zoonoses through harnessing social impact investments. Evidence of the disease burdens imposed on communities by the NZDs and demonstration of the cost-effectiveness of integrated control can strengthen the case for a One Health approach to endemic zoonotic disease control., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Summary: Objectives: We present the results of a 2005 case–control study of bovine tuberculosis (bTB) breakdowns in English and Welsh herds. The herd management, farming practices, and environmental factors of 401 matched pairs of case and control herds were investigated to provide a picture of herd-level risk factors in areas of varying bTB incidence. Methods: A global conditional logistic regression model, with region-specific variants, was used to compare case herds that had experienced a confirmed bTB breakdown to contemporaneous control herds matched on region, herd type, herd size, and parish testing interval. Results: Contacts with cattle from contiguous herds and sourcing cattle from herds with a recent history of bTB were associated with an increased risk in both the global and regional analyses. Operating a farm over several premises, providing cattle feed inside the housing, and the presence of badgers were also identified as significantly associated with an increased bTB risk. Conclusions: Steps taken to minimize cattle contacts with neighboring herds and altering trading practices could have the potential to reduce the size of the bTB epidemic. In principle, limiting the interactions between cattle and wildlife may also be useful; however this study did not highlight any specific measures to implement. [Copyright &y& Elsevier]

The incidence of bovine tuberculosis (TB) in Great Britain has generally been increasing in recent decades. Routine ante-mortem testing of cattle herds is required for disease surveillance and control, due to the asymptomatic nature of the infection. The Department for Environment, Food and Rural Affairs (Defra) publishes TB incidence trends as the percentage of officially TB-free (OTF) herds tested per month with OTF status withdrawn due to post-mortem evidence of infection. This method can result in artefactual fluctuations. We have previously demonstrated an alternative method, that distributes incidents equally over the period of risk, provides a more accurate representation of underlying risk. However, this method is complex and it may not be sufficiently straightforward for use in the national statistics. Here we present a simple incidence-based method that adjusts for the time between tests and show it can provide a reasonable representation of the underlying risk without artefactual fluctuations.

Science is an essential component of policy-making in most areas of government, but the scientific community does not always understand its role in this process.

The Belfast blitzes of 1941 are blamed in our family for the scrofula of my younger brother and sister and myself. Guinea pigs and rabbits at Musgrave Park proved that each of us had bovine derived TB infection caused by failure to pasteurize milk when tuberculin-tested milk was not available. The clinical head of Harvard Medical School’s anti-tuberculosis effort contacted his boss, Professor Maxwell Finland, who ascertained from Selman A. Waksman that his antibiotic streptothricin was bacteriostatic against TB but too toxic for humans. Finland, born 1902, knew Waksman (born 1888) well, each having emigrated from the Czarist-ruled Ukraine. Waksman , in 1942, had hopes for an analog to streptothricin he intended to name streptomycin: an antibiotic from Actinomyces griseus which had been culture-isolated in 1916 for his M.Sc. thesis. Streptomycin was still 6-9 months away from animal testing. The same Actinomyces species was also able to produce actinomycin C and D which was later supplied to Professor Sidney Farber of Harvard to start successful human cancer chemotherapy.