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8 páginas, 4 figuras, 2 tablas. Contains public sector information licensed under the Open Government Licence v3.0., In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely., This work was funded by Department for Environment, Food and Rural Affairs(Defra), UK [project SE3325].

Mycobacterium tuberculosis variant bovis (MBO) has one of the widest known mammalian host ranges, including humans. Despite the characterization of this pathogen in the 1800s and whole genome sequencing of a UK strain (AF2122) nearly two decades ago, the basis of its host specificity and pathogenicity remains poorly understood. Recent experimental calf infection studies show that MBO strain Ravenel (MBO Ravenel) is attenuated in the cattle host compared to other pathogenic strains of MBO. In the present study, experimental infections were performed to define attenuation. Whole genome sequencing was completed to identify regions of differences (RD) and single nucleotide polymorphisms (SNPs) to explain the observed attenuation. Comparative genomic analysis of MBO Ravenel against three pathogenic strains of MBO (strains AF2122-97, 10-7428, and 95-1315) was performed. Experimental infection studies on five calves each, with either MBO Ravenel or 95-1315, revealed no visible lesions in all five animals in the Ravenel group despite robust IFN-γ responses. Out of 486 polymorphisms in the present analysis, 173 were unique to MBO Ravenel among the strains compared. A high-confidence subset of nine unique SNPs were missense mutations in genes with annotated functions impacting two major MBO survival and virulence pathways: (1) Cell wall synthesis & transport [espH (A103T), mmpL8 (V888I), aftB (H484Y), eccC5 (T507M), rpfB (E263G)], and (2) Lipid metabolism & respiration [mycP1(T125I), pks5 (G455S), fadD29 (N231S), fadE29 (V360G)]. These substitutions likely contribute to the observed attenuation. Results from experimental calf infections and the functional attributions of polymorphic loci on the genome of MBO Ravenel provide new insights into the strain’s genotype-disease phenotype associations.

Background Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a significant problem for livestock industries in many countries worldwide including Northern Ireland, where a test and slaughter regime has utilised the Single Intradermal Comparative Cervical Tuberculin (SICCT) test since 1959. We investigated the variation in post-mortem confirmation based on bTB visible lesion (VL) presence during herd breakdowns using two model suites. We investigated animal-level characteristics, while controlling for herd-level factors and clustering. We were interested in potential impacts of concurrent infection, and therefore we assessed whether animals with evidence of liver fluke infection (Fasciola hepatica; post-mortem inspection), M. avium reactors (animals with negative M. bovis-avium (b-a) tuberculin reactions) or Bovine Viral Diarrhoea Virus (BVDV; RT-PCR tested) were associated with bTB confirmation. Results The dataset included 6242 animals removed during the 14 month study period (2013–2015). bTB-VL presence was significantly increased in animals with greater b-a reaction size at the disclosing SICCT test (e.g. b-a = 5-9 mm vs. b-a = 0 mm, adjusted Odds ratio (aOR): 14.57; p 0.1). Conclusions Our results suggest that neither co-infection of liver fluke nor BVDV had a significant effect on the presence of VLs in this high-risk cohort. M. avium tuberculin reactors had a significantly increased risk of disclosing with a bTB lesion, which could be related to the impact of co-infection with M. avium subsp. paratuberculosis (MAP) affecting the performance of the SICCT however further research in this area is required. Movements, test history, breed and age were important factors influencing confirmation in high-risk animals. Electronic supplementary material The online version of this article (10.1186/s12917-017-1321-z) contains supplementary material, which is available to authorized users.

In this study we investigated whether oral uptake of a heat inactivated M. bovis wildlife vaccine by domestic cattle induced systemic immune responses that compromised the use of tuberculin or defined antigens in diagnostic tests for bovine TB. Positive skin test and blood-based IFN-γ release assay (IGRA) results were observed in all calves vaccinated via the parenteral route (i.e. intramuscular). In contrast, no positive responses to tuberculin or defined antigens were observed in either the skin test or IGRA test when performed in calves vaccinated via the oral route. In conclusion, our results suggest that the heat inactivated M. bovis vaccine could be used to vaccinate wildlife in a baited form in conjunction with the following in cattle: (i) continuation of existing tuberculin skin testing or novel skin test formats based on defined antigens; and (ii) the use of IGRA tests utilizing tuberculin or defined antigens.

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.

Bacillus Calmette Guérin (BCG) is the only currently available vaccine against tuberculosis (TB), but it confers incomplete and variable protection against pulmonary TB in humans and bovine TB (bTB) in cattle. Insights into the immune response induced by BCG offer an underexploited opportunity to gain knowledge that may inform the design of a more efficacious vaccine, which is urgently needed to control these major global epidemics. Humoral immunity in TB and bTB has been neglected, but recent studies supporting a role for antibodies in protection against TB has driven a growing interest in determining their relevance to vaccine development. In this manuscript we review what is known about the humoral immune response to BCG vaccination and re-vaccination across species, including evidence for the induction of specific B cells and antibodies; and how these may relate to protection from TB or bTB. We discuss potential explanations for often conflicting findings and consider how factors such as BCG strain, manufacturing methodology and route of administration influence the humoral response. As novel vaccination strategies include BCG prime-boost regimens, the literature regarding off-target immunomodulatory effects of BCG vaccination on non-specific humoral immunity is also reviewed. Overall, reported outcomes to date are inconsistent, but indicate that humoral responses are heterogeneous and may play different roles in different species, populations, or individual hosts. Further study is warranted to determine whether a new TB vaccine could benefit from the targeting of humoral as well as cell-mediated immunity.

Bacillus Calmette Guérin (BCG) is the only currently available vaccine against tuberculosis (TB), but it confers incomplete and variable protection against pulmonary TB in humans and bovine TB (bTB) in cattle. Insights into the immune response induced by BCG offer an underexploited opportunity to gain knowledge that may inform the design of a more efficacious vaccine, which is urgently needed to control these major global epidemics. Humoral immunity in TB and bTB has been neglected, but recent studies supporting a role for antibodies in protection against TB has driven a growing interest in determining their relevance to vaccine development. In this manuscript we review what is known about the humoral immune response to BCG vaccination and re-vaccination across species, including evidence for the induction of specific B cells and antibodies; and how these may relate to protection from TB or bTB. We discuss potential explanations for often conflicting findings and consider how factors such as BCG strain, manufacturing methodology and route of administration influence the humoral response. As novel vaccination strategies include BCG prime-boost regimens, the literature regarding off-target immunomodulatory effects of BCG vaccination on non-specific humoral immunity is also reviewed. Overall, reported outcomes to date are inconsistent, but indicate that humoral responses are heterogeneous and may play different roles in different species, populations, or individual hosts. Further study is warranted to determine whether a new TB vaccine could benefit from the targeting of humoral as well as cell-mediated immunity.

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.

Zoonotic diseases accounts for about 75% of emerging infectious disease and can be devastating to both human and animal health globally. A subset of zoonotic diseases is referred to as "neglected zoonotic diseases - NZDs" as they mainly affect poor populations who live in close proximity to domestic or wild animals often in areas where access to health and adequate sanitary facilities are not available. Furthermore, underestimation of the burden of NZD has continually led to its further neglect in least developed countries such as Nigeria. Controlling zoonotic infections including NZDs in animals is crucial in reducing human infections. Veterinarians provides an understanding of the epidemiology of infectious diseases in animal population and are therefore integral for the overall reduction in global burden of NZDs worldwide. Due to the current lack of and in some cases weak involvement of Veterinarians in policy issues related to zoonotic diseases, there is need to elucidate their importance in NZDs control in Nigeria. This review therefore summarises the neglected zoonotic diseases so far documented in Nigeria and also highlight the important role of the Veterinarian in their prevention and control within both human and animal population. Important recommendations to strengthen the role of the public health Veterinarian for sustainable control of NZDs were made.

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., Cattle; Ethiopia; Gondar; KAP; Human TB; Bovine TaB

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&ndash, 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 (&lt, 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 (&ldquo, feedlot&rdquo, ) and having high annual inward cattle movements within the &ldquo, tails&rdquo, 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.

Background Despite rigorous controls placed on herds which disclose ante-mortem test positive cattle to bovine tuberculosis, caused by the infection of Mycobacterium bovis, many herds in Northern Ireland (NI) experience prolonged breakdowns. These herds represent a considerable administrative and financial burden to the State and farming community. Methods A retrospective observational study was conducted to better understand the factors associated with breakdown duration, which was modelled using both negative binomial and ordinal regression approaches. Results Six explanatory variables were important predictors of breakdown length in both models; herd size, the number of reactors testing positive in the initial SICCT test, the presence of a lesioned animal at routine slaughter (LRS), the count of M. bovis genotypes during the breakdown (MLVA richness), the local herd-level bTB prevalence, and the presence of herds linked via management factors (associated herds). We report that between 2008 and 2014, mean breakdown duration in NI was 226 days (approx. seven months; median: 188 days). In the same period, however, more than 6% of herds in the region remained under movement restriction for more than 420 days (13 months); almost twice as long as the mean. The MLVA richness variable was a particularly important predictor of breakdown duration. We contend that this variable primarily represents a proxy for beef fattening herds, which can operate by purchasing cattle and selling animals straight to slaughter, despite prolonged trading restrictions. For other herd types, the model supports the hypothesis that prolonged breakdowns are a function of both residual infection within the herd, and infection from the environment (e.g. infected wildlife, contiguous herds and/or a contaminated environment). The impact of badger density on breakdown duration was assessed by including data on main sett (burrow) density. Whilst a positive association was observed in the univariate analysis, confounding with other variables means that the contribution of badgers to prolonged breakdowns was not clear from our study. We do not fully reject the hypothesis that badgers are implicated in prolonging bTB breakdowns via spillback infection, but given our results, we posit that increased disease risk from badgers is unlikely to simply be a function of increasing badger density measured using sett metrics.

In 2017, Public Health England South East Health Protection Team (HPT) were involved in the management of an outbreak ofMycobacterium 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 onM. 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. OnceM. bovishad 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.

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.

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.

Tuberculosis (TB) is one of the most ancient diseases of mankind, with molecular evidence going back to over 17,000 years. In spite of newer modalities for diagnosis and treatment of TB, unfortunately, people are still suffering, and worldwide it is among the top 10 killer infectious diseases, second only to HIV. According to World Health Organization (WHO), TB is a worldwide pandemic. It is a leading cause of death among HIV-infected people. In India, historically speaking, fight against TB can be broadly classified into three periods: early period, before the discoveries of x-ray and chemotherapy; post-independence period, during which nationwide TB control programs were initiated and implemented; and the current period, during which the ongoing WHO-assisted TB control program is in place. Today, India's DOTS (directly observed treatment-short course) program is the fastest-expanding and the largest program in the world in terms of patients initiated on treatment; and the second largest, in terms of population coverage. Major challenges to control TB in India include poor primary health-care infrastructure in rural areas of many states; unregulated private health care leading to widespread irrational use of first-line and second-line anti-TB drugs; spreading HIV infection; lack of political will; and, above all, corrupt administration. Multidrug-resistant TB (MDR-TB) is another emerging threat to TB eradication and is a result of deficient or deteriorating TB control program. WHO with its "STOP TB" strategy has given a vision to eliminate TB as a public health problem from the face of this earth by 2050. For this review article, data available at the official websites of WHO; and from the Ministry of Health, Government of India, were consulted, and search engines PubMed(®) and Google Scholar(®) were used.

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. Clinical Microbiology and Infection (C) 2015 The Authors. Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases.

Aim: This study was aimed to determine the prevalence of bovine tuberculosis (bTB) in slaughtered cattle in Bauchi State, Nigeria. The cause (s) of grossly suspected bTB lesions encountered at the abattoirs during post-mortem (PM), as whether due to Mycobacterium bovis alone or together with other acid fast bacilli (AFB). Materials and Methods: A cross-sectional abattoir based study was conducted on 800 cattle slaughtered in the Northern, Central and Southern zonal abattoirs of Bauchi State, Nigeria, from June to August 2013; using PM meat inspection, Ziehl- Neelsen staining (ZN) and confirmatory polymerase chain reaction (PCR) techniques. Results: The occurrence of bTB lesions from the organs of slaughtered cattle in Bauchi State, showed that the lungs had the highest number of suspected tissues 65 (54.20%), followed by the lymph nodes 28 (23.30%) while the heart, liver, spleen, intestines and mammary glands had the other 8.3%, 6.7%, 5.0%, 1.7%, and 0.8%, suspected tissues respectively. By ZN microscopic staining all 100% (2/2) of the intestines were positive for bTB, followed by the heart with 50% (5/10), then the lungs 29.23% (19/65); while the liver, lymph nodes, and spleen had 25%, 21.43% and 16.67% respectively were tested positive for bTB. It was only the mammary gland that tested negative for bTB in all the suspected tissues sampled. By PCR, the intestines had the highest positive bTB with 100% (2/2), followed by the liver with 12.5% (1/8), and then the lungs with 7.8% (5/65). The lymph nodes had 7.14% (2/28) tissues that tested positive for bTB. However, the spleen, heart and mammary gland were all tested negative with 0%; indicating that the false positive for bTB detected by ZN were confirmed by PCR. While based on the location of the abattoirs in the three senatorial zones of Bauchi State, Bauchi zonal abattoir had the highest number of suspected bTB cases 75 (62.50%), followed by Katagum zonal slaughter house with 32 (26.7%) and then Misau with 13 (10.8%). By the ZN staining technique, there were 25 (33.33%) positivity in Bauchi Zonal abattoir, while Katagum and Misau abattoirs had 9 (28.13%) and 1 (7.72%) positive respectively. By the PCR technique, 9 (12.00%), 1 (3.13%) and 0 (0.00%) positive cases were recorded for Bauchi, Katagum and Misau abattoirs respectively. Conclusion: The present study estimated the prevalence rate of bTB in Bauchi State, using PM, ZN and PCR techniques at 15.0%, 29.16% and 8.33%, respectively. Bovine TB lesions found at PM were not all due to M. bovis alone, as other MTBC and AFB organisms may cause bTB-like lesions that were excluded by PCR specific primers. The prevalence of bTB was higher in Bauchi abattoir that supplies larger population of the state with beef. These findings also demonstrate the urgent need for public health authorities in the state to intervene in the control of the zoonotic bTB.

Mycobacterium bovis is the causative agent of bovine tuberculosis (TB), a disease that affects approximately 5% of Argentinean cattle. Among the molecular methods for genotyping, the most convenient are spoligotyping and variable number of tandem repeats (VNTR). A total of 378 samples from bovines with visible lesions consistent with TB were collected at slaughterhouses in three provinces, yielding 265 M. bovisspoligotyped isolates, which were distributed into 35 spoligotypes. In addition, 197 isolates were also typed by the VNTR method and 54 combined VNTR types were detected. There were 24 clusters and 27 orphan types. When both typing methods were combined, 98 spoligotypes and VNTR types were observed with 27 clusters and 71 orphan types. By performing a meta-analysis with previous spoligotyping results, we identified regional and temporal trends in the population structure of M. bovis. For SB0140, the most predominant spoligotype in Argentina, the prevalence percentage remained high during different periods, varying from 25.5-57.8% (1994-2011). By contrast, the second and third most prevalent spoligotypes exhibited important fluctuations. This study shows that there has been an expansion in ancestral lineages as demonstrated by spoligotyping. However, exact tandem repeat typing suggests dynamic changes in the clonal population of this microorganism. Fil: Shimizu, Ernesto. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentina Fil: Macías, Analía. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina Fil: Paolicchi, Fernando Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; Argentina Fil: Magnano, Gabriel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina Fil: Zapata, Laura. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina Fil: Fernández, Analía. Provincia de Entre Ríos. Secretaría de Producción. Dirección General de Producción Animal; Argentina Fil: Canal, Ana. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentina Fil: Garbaccio, Sergio. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina Fil: Cataldi, Ángel Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Caimi, Karina Cynthia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina Fil: Zumárraga, Martín José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina

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.

A Espanya, la prevalença de ramats amb tuberculosi ha disminuït del 11,1% el 1986 a 1,3% el 2011. Malgrat aquesta reducció en la prevalença, en els últims anys s'ha moderat el descens i l'actual situació epidemiològica de bTB planteja un desafiament cara a la consecució del estatus de país oficialment indemne de tuberculosi. Entre el 50 i el 60% dels ramats positius detecta cada any, són nous ramats positius, i la resta són ramats on la infecció persisteix des de l'any anterior. No es coneixen quines circumstàncies epidemiològiques condueixen a la introducció o la persistència de la infecció. Per tant, l'objectiu d'aquesta tesi és millorar el coneixement de l'epidemiologia de la bTB a Espanya mitjançant l'avaluació de les causes més probables d'infecció i els factors relacionats amb els ramats infectats de manera persistents. Per a l'estimació de les causes més probables d'introducció de la infecció en un ramat hem desenvolupat una metodologia basada en les diferents vies de transmissió de la bTB entre els ramats. S’han considerat set vies i per cada una s’ha realitzat un arbre de decisió sobre possibles riscos. A cada risc se l’hi ha assignat una probabilitat basada en opinió d'experts. Per a la gestió de dades i per al càlcul de les probabilitats de cada una de les diferents causes possibles s’han creat un parell de macros. D'acord amb els resultats dels 816 ramats estudiats (casos detectades principalment els anys 2010 i 2011), la majoria dels casos serien deguts al ressorgiment d'infeccions residuals que havien afectat anteriorment al ramat (39%, n = 316). La introducció de la infecció es va produir pel contacte amb animals silvestres en el 12% dels casos (n = 98), i a través de ramats veïns en el 10% (n = 85). En el 28% (n = 225) dels brots, no s’ha pogut determinar l'origen de la infecció. En 309 ramats, la diferència entre les dues causes amb la probabilitat més alta era petita (menys d'u), de manera, que per a aquestes granges tant la primera com la segona causa serien possibles. Dins d'aquest grup, la primera opció més freqüent va ser la infecció residual (69%, n = 214) i la segona de les opcions més freqüents era compartir les pastures amb altres granges (36%, n = 112) i la interacció amb la fauna silvestre (30%, n = 94). En comparar aquestes conclusions amb les dels veterinaris oficials que havien fet la investigació epidemiològica sobre el terreny, s’obté una concordança baixa; especialment en el cas de fauna silvestre. Dins del grup dels ramats on el veterinari només considerava una causa (és a dir, 309 ramats), en 124 la fauna silvestre va ser considerada com la causa més probable, mentre que nosaltres només ho varem concloure en 33 granges. Aquestes discordances podrien estar relacionades amb un diferent accés a les dades i també a percepcions diferents sobre la importància atribuïda a cada causa. Per tal d'avaluar els factors relacionats amb la persistència de bTB en granges es va realitzar un estudi de casos i controls on es va comparar granges infectades que es va eliminar fàcilment la bTB amb altres on es va tardar més de 5 anys. Totes les granges eren del sud d'Espanya i es van estratificar per grandària del ramat i la ubicació geogràfica (comarca). Es va omplir un qüestionari mitjançant entrevista personal en 150 ramats (80 controls i 70 casos) de les Comunitats d'Andalusia i de Castilla‐la Mancha. D'acord amb els resultats d'aquest estudi, les granges amb més superfície de pastures i amb veïns positius, tenien més dificultats per eradicar la infecció, per tant, eren més propenses a patir un brot de bTB persistent. Les probabilitats de persistència eren entre 1,1 i 5,0 vegades més gran en aquells ramats amb possible contacte amb el bestiar d'un ramat positiu veí. La probabilitat de persistència també es va associar amb la superfície de pastures. Les finques amb àrees de pastura més grans tenien una probabilitat entre 1,2 i 12,7 vegades més alta de tenir dificultats en l’eliminació que les finques amb àrees de pastures més petits. El maneig dels animals positius, com ara utilitzar vedelles de reposició de mares positives o no aïllar els animals positius, així com la presència de cabres dins de la granja semblen tenir també una influència en la persistència de bTB., En España, la prevalencia de rebaños con tuberculosis ha disminuido del 11,1% en 1986 a 1,3% en 2011. A pesar de esta reducción, en los últimos años se ha moderado el descenso de la prevalencia y la situación epidemiológica actual de bTB plantea un desafío cara a la consecución del estatus de país oficialmente indemne de tuberculosis. Entre el 50 y el 60% de los rebaños positivos detectados cada año, son nuevos rebaños positivos, y el resto son rebaños donde la infección persiste desde el año anterior. No se sabe qué circunstancias epidemiológicas están implicadas en la introducción o la persistencia de la infección. Por tanto, el objetivo de esta tesis es mejorar el conocimiento de la epidemiología de la bTB en España mediante la evaluación de las causas más probables de infección y los factores relacionados con los rebaños infectados de forma persistente. Para la estimación de las causas más probables de introducción de la infección en un rebaño hemos desarrollado una metodología basada en las diferentes vías de transmisión de la bTB entre los rebaños. Se han considerado siete vías y por cada una de ellas se ha realizado un árbol de decisión sobre posibles riesgos. A cada riesgo se le ha asignado una probabilidad basada en opinión de expertos. Para la gestión de datos y para el cálculo de las probabilidades de cada una de las diferentes causas posibles se han creado dos macros. De acuerdo con los resultados de los 816 rebaños estudiados (casos detectados principalmente en los años 2010 y 2011), la mayoría de las nuevas infecciones en realidad son debidas al resurgimiento de infecciones que habían afectado anteriormente al rebaño (39%, n = 316). La introducción de la infección se produjo por el contacto con animales silvestres en el 12% de los casos (n = 98), y a través de rebaños vecinos en el 10% (n = 85). En el 28% (n = 225) de los brotes, no se ha podido determinar el origen de la infección. En 309 rebaños, la diferencia entre las dos causas con la probabilidad más alta era escasa (menos de uno), de manera que para estas granjas tanto la primera como la segunda causa serían posibles. Dentro de este grupo, la primera opción más frecuente fue la infección residual (69%, n = 214) y la segunda de las opciones más frecuentes era compartir los pastos con otras granjas (36%, n = 112) y la interacción con la fauna silvestre (30%, n = 94). Al comparar las conclusiones de nuestro estudio con las de los veterinarios oficiales que habían hecho la investigación epidemiológica sobre el terreno, se obtiene una concordancia baja, especialmente en el caso de fauna silvestre. Dentro del grupo de los rebaños donde el veterinario sólo consideraba una causa (es decir, 309 rebaños), en 124 la fauna silvestre fue la causa considerada como más probable para el veterinario, mientras que nosotros sólo lo concluimos en 33 granjas. Estas discordancias podrían estar relacionadas con diferencias en los datos a los que hemos tenido acceso así como a diferentes percepciones sobre la importancia atribuida a cada causa. Para evaluar los factores relacionados con la persistencia de BTB en granjas se realizó un estudio de casos y controles donde se compararon granjas infectadas donde se eliminó fácilmente la bTB con otras donde se tardó más de 5 años. Todas las granjas eran del sur de España y se estratificaron por tamaño del rebaño y ubicación geográfica (comarca). Se rellenó un cuestionario mediante entrevista personal en 150 rebaños (80 controles y 70 casos) de las Comunidades de Andalucía y de Castilla‐La Mancha. De acuerdo con los resultados de este estudio, las granjas con más superficie de pastos y con vecinos positivos, tenían más dificultades para erradicar la infección, por lo tanto, eran más propensas a sufrir un brote de BTB persistente. Las probabilidades de persistencia eran entre 1,1 y 5,0 veces mayor en aquellos rebaños con posible contacto con un rebaño positivo vecino. La probabilidad de persistencia también se asoció con la superficie de pastos. Las fincas con áreas de pasto mayores tenían una probabilidad entre 1,2 y 12,7 veces más alta de tener dificultades en la eliminación que las fincas con áreas de pastos más pequeños. El manejo de los animales positivos, tales como utilizar terneras de reposición de madres positivas o no aislar los animales positivos, así como la presencia de cabras dentro de la granja parecen tener también una influencia en la persistencia de la bTB., In Spain, herd prevalence has decreased from 11.1% on 1986 to 1.3% on 2011. Despite this reduction on the prevalence, in the last years there has been just a moderate decline and the current bTB epidemiological situation poses a serious challenge towards the achievement of a national official tuberculosis free (OTF) status. In the country, approximately between 50 and 60% of the total bTB positive herds detected each year, are new positive herds, and the rest of the positives are herds that persist from the previous year. There is not a clear knowledge of the epidemiological circumstances that lead to the introduction or persistence of the infection. Therefore, the aim of this PhD was to improve the understanding of bTB epidemiology in Spain by assessing the most likely causes of infection and factors related with bTB persistent herds. To estimate the most likely causes of introduction of the infection on a herd we developed a methodology based on bTB routes of transmission between herds using decision trees. We considered seven routes as a possible cause of herd breakdown. In order to discriminate among them, probabilities were assigned within each decision tree based on expert opinion. Macros were used for data management and to calculate the probabilities of the different possible causes. According to the results of the 816 studied breakdowns (detected mainly in 2010 and 2011) most of the cases could be resurgence of residual infections that had previously affected the herd (39%, n=316). New introductions of the infection were produced by contact with wildlife in 12% of cases (n=98), and by neighboring herds in 10% of them (n=85). In 28 % (n=225) of the breakdowns, the origin of the infection remained unknown. In 309 herds, the difference between the first and the second cause with the higher probability was small (i.e., less than 1) so, for these herds, first and second possible causes of infection could be considered. Within this group the most frequent first option was residual infection (69%, n=214) and the most frequent second options were sharing pastures with other herds (36%, n=112) and interaction with wildlife (30%, n=94). The results of the comparisons between our conclusions and the ones of the veterinary officers conducting the epidemiological investigation on the field evidenced a low agreement. The lowest agreement was in the case of “wildlife”. Within the group of herds where the veterinary officer just considered one cause (i.e., 309 herds) in 124 Wildlife was considered as the most likely cause, while we just found evidences to suspect of this in 33 farms. These discrepancies could be related to differences on access to data and perception about the importance attributed to the different causes. In order to assess factors related to bTB persistence we conducted a case‐control study and compared persistent versus transient bTB infected farms from southern Spain. Farms were matched by herd size and geographical location (county). A questionnaire by personal interview was carried on 150 herds (80 controls and 70 cases) from Andalusia and Castilla La Mancha regions. According to the results of this study, farms with large pasture areas and positive neighbors had more difficulties in eradicating the disease and therefore, were more likely to suffer a persistent bTB outbreak. The odds of bTB persistence were between 1.1 and 5.0 times higher in those herds that had the possibility of contact with cattle from a neighbor positive herd. The probability of bTB persistence was also associated with the area of the pasture. Farms with larger pasture areas had odds between 1.2 and 12.7 times higher of having a persistent bTB episode than farms with smaller pasture areas. Management of positive animals such as making replacement from positive herds or not isolating positive animals and the presence of goats within the farm seem to have also an influence on bTB persistence.

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. Publisher PDF

We examine spatial association of bovine TB in cattle herds using data from Ireland. Badgers (Meles meles), a protected species under the Wildlife Act 1976 (OAG 2012), have been implicated in the spread of the disease in cattle. Current disease control policies include reactive culling (in response to TB outbreaks) of badgers in the index and neighbouring farms. Kelly and More (2011) using generalized linear geostatistical models, established that TB clusters in cattle herds and estimated the practical spatial ranges at which this occurs. Here this work is extended by taking into account possible anisotropy. Changes in spatial association over two time periods are also examined. The results have direct implications for establishing scale and direction in reactive culling. They are also of import regarding the evaluation of vaccines for badgers and cattle. Author has checked copyright TS 24.04.13

We examine spatial association of bovine TB in cattle herds using data from Ireland. Badgers (Meles meles), a protected species under the Wildlife Act 1976 (OAG 2012), have been implicated in the spread of the disease in cattle. Current disease control policies include reactive culling (in response to TB outbreaks) of badgers in the index and neighbouring farms. Kelly and More (2011) using generalized linear geostatistical models, established that TB clusters in cattle herds and estimated the practical spatial ranges at which this occurs. Here this work is extended by taking into account possible anisotropy. Changes in spatial association over two time periods are also examined. The results have direct implications for establishing scale and direction in reactive culling. They are also of import regarding the evaluation of vaccines for badgers and cattle. Not applicable ti, ke, ab - kpw26/6/12

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.

The present study was carried out for the detection and identification of bovine tuberculosis (bTB) using polymerase chain reaction (PCR). A total of 10 suspected cattle of Savar and BAU dairy farm were examined. Lymphnode biopsy, nasal swabs and blood were collected. Smears from lymphnode biopsy and nasal swabs were made onto clear slides and stain with acid fast staining. Portion of lymohnodes were preserved at -200 C and extracted DNA for PCR analysis. Portion of lymphnodes and other tissues were also collected in 10% neutral buffered formalin for routine Hematoxilin and Eosin staining and acid fast staining. In this study, acid fast staining of lymphnodes and nasal smears failed to detect acid fast Mycobacterium. The genome of bovine Mycobacterium in the extracted DNA of lymphnodes which used in PCR reaction was amplified and yielded 600 bp amplicon. This study suggests that, the PCR technique is a useful and rapid diagnostic tool for the identification of bovine TB in dairy cattle. Amplification technology offers the potential for the diagnosis of TB in a few hours with a high degree of sensitivity and specificity.

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.

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 100km 2 ) 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.

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.

peer-reviewed This work was supported by Science Foundation Ireland Principal Investigator award grant number 09/IN.1/B2642. Background Infection of livestock with bovine tuberculosis (bTB; Mycobacterium bovis) is of major economical concern in many countries; approximately 15 000 to 20 000 cattle are infected per year in Ireland. The objective of this study was to quantify the genetic variation for bTB susceptibility in Irish dairy and beef cattle. Methods A total of 105 914 cow, 56 904 heifer and 21 872 steer single intra-dermal comparative tuberculin test records (i.e., binary trait) collected from the years 2001 to 2010 from dairy and beef herds were included in the analysis. Only animal level data pertaining to periods of herd bTB infection were retained. Variance components for bTB were estimated using animal linear and threshold mixed models and co-variances were estimated using sire linear mixed models. Results Using a linear model, the heritability for susceptibility to bTB in the entire dataset was 0.11 and ranged from 0.08 (heifers in dairy herds) to 0.19 (heifers in beef herds) among the sub-populations investigated. Differences in susceptibility to bTB between breeds were clearly evident. Estimates of genetic correlations for bTB susceptibility between animal types (i.e., cows, heifers, steers) were all positive (0.10 to 0.64), yet different from one. Furthermore, genetic correlations for bTB susceptibility between environments that differed in herd prevalence of bTB ranged from 0.06 to 0.86 and were all different from one. Conclusions Genetic trends for bTB susceptibility observed in this study suggest a slight increase in genetic susceptibility to bTB in recent years. Since bTB is of economic importance and because all animals are routinely tested at least once annually in Ireland and some other countries, the presence of genetic variation for bTB susceptibility suggests that bTB susceptibility should be included in a national breeding program to halt possible deterioration in genetic susceptibility to bTB infection. Science FOundation IReland

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.