Search

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.

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.

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

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.

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. Publisher PDF

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.

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.