scholarly journals Risk factors associated with the presence of Mycobacterium bovis in macroscopic lesions suspected as being caused by bovine tuberculosis detected in slaughterhouses

2022 ◽  
Vol 43 (2) ◽  
pp. 713-726
Author(s):  
Flávio Gomes Barcelos ◽  
◽  
Taís Ramalho dos Anjos ◽  
Leila Auxiliadora de Arruda Alencar ◽  
Vinicius Silva Castro ◽  
...  
Keyword(s):  
Risk Factors ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Statistical Significance ◽  
Control Measures ◽  
Epidemiological Surveillance ◽  
Nested Polymerase Chain Reaction ◽  
Mato Grosso ◽  
Molecular Tests

Mycobacterium bovis is a bacterium belonging to the Mycobacterium tuberculosis complex that causes tuberculosis in cattle and in other domestic and wild animals, as well as in humans. Disease control measures are carried out by slaughtering animals tested positive in the intradermal tuberculinization test and sanitation of their original living spaces, in addition to epidemiological surveillance carried out through the sanitary inspection of bovine carcasses in slaughterhouses. In the latter, official inspection services collect samples from macroscopic lesions suspected of bovine tuberculosis, which are then sent for laboratory analysis. Knowledge concerning the variables associated with the occurrence of M. bovis can aid in decision-making regarding control and disease eradication efforts. In this context, the aim of this study was to identify the risk factors for a positive M. bovis diagnosis in suspected bovine tuberculosis lesions obtained during epidemiological surveillance activities in the state of Mato Grosso, Brazil. A total of 105 suspicious lesions were analyzed using the Nested Polymerase Chain Reaction (nested q-PCR) method, of which 14 (13.33%) tested positive for M. bovis. Univariate and bivariate statistical analyses indicated that the variable “animal slaughter” was the only risk factor presenting statistical significance associated with the diagnosis of M. bovis (p < 0.05), demonstrating that macroscopic lesions suspected as being caused by bovine tuberculosis from animals with an in vivo diagnosis were 2.82 - fold more likely to result in a positive M. bovis diagnosis by molecular tests.

scholarly journals Risk Factors Associated With the Presence of Mycobacterium Bovis in Macroscopic Lesions Suspected as Being Caused by Bovine Tuberculosis Detected in Slaughterhouses

2021 ◽  
Author(s):  
Flávio Gomes Barcelos ◽  
Tais Ramalho dos Anjos ◽  
Leila Auxiliadora de Arruda Alencar ◽  
Maria Júlia Sudária de Freitas ◽  
Mariano Martinez Espinosa ◽  
...  
Keyword(s):  
Risk Factors ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Statistical Significance ◽  
Control Measures ◽  
Epidemiological Surveillance ◽  
Nested Polymerase Chain Reaction ◽  
Mato Grosso ◽  
Molecular Tests

Abstract Mycobacterium bovis is a bacterium belonging to the Mycobacterium tuberculosis complex that causes tuberculosis in cattle and in other domestic and wild animals, as well as in humans. Disease control measures are carried out by slaughtering animals tested positive in the intradermal tuberculinization test and sanitation of their original living spaces, in addition to epidemiological surveillance carried out through the sanitary inspection of bovine carcasses in slaughterhouses. In the latter, official inspection services collect samples from macroscopic lesions suspected of bovine tuberculosis, which are then sent for laboratory analysis. Knowledge concerning the variables associated with the occurrence of M. bovis can aid in decision-making regarding control and disease eradication efforts. In this context, the aim of this study was to identify the risk factors for a positive M. bovis diagnosis in suspected bovine tuberculosis lesions obtained during epidemiological surveillance activities in the state of Mato Grosso, Brazil. A total of 105 suspicious lesions were analyzed using the Nested Polymerase Chain Reaction (nested q-PCR) method, of which 14 (13.33%) tested positive for M. bovis. Univariate and bivariate statistical analyses indicated that the variable “animal slaughter” was the only risk factor presenting statistical significance associated with the diagnosis of M. bovis (p < 0.05), demonstrating that macroscopic lesions suspected as being caused by bovine tuberculosis from animals with an in vivo diagnosis were 2.82 - fold more likely to result in a positive M. bovis diagnosis by molecular tests.

scholarly journals Bovine Tuberculosis (Mycobacterium bovis) Outbreak Duration in Cattle Herds in Ireland: A Retrospective Observational Study

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 815
Author(s):  
Andrew W. Byrne ◽  
Damien Barrett ◽  
Philip Breslin ◽  
Jamie M. Madden ◽  
James O'Keeffe ◽  
...  
Keyword(s):  
Risk Factors ◽  
Observational Study ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Animal Health ◽  
Herd Size ◽  
Policy Formation ◽  
Nitrogen Loading ◽  
Management Policy ◽  
Retrospective Observational Study

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.

scholarly journals Risk factors associated with negative in-vivo diagnostic results in bovine tuberculosis-infected cattle in Spain

2014 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Julio Álvarez ◽  
Andrés Perez ◽  
Sergio Marqués ◽  
Javier Bezos ◽  
Anna Grau ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bovine Tuberculosis ◽  
Infected Cattle ◽  
Factors Associated

scholarly journals Epidemiology of Bovine Tuberculosis and Its Zoonotic Implication in Addis Ababa Milkshed, Central Ethiopia

2021 ◽  
Vol 8 ◽  
Author(s):  
Begna Tulu ◽  
Aboma Zewede ◽  
Mulugeta Belay ◽  
Miserach Zeleke ◽  
Mussie Girma ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bovine Tuberculosis ◽  
Addis Ababa ◽  
Public Awareness ◽  
Farm Management ◽  
Postmortem Examination ◽  
Control Measures ◽  
Cross Sectional ◽  
Central Ethiopia ◽  
Farm Type

Bovine tuberculosis (bTB) continues to be one of the most widely distributed chronic infectious diseases of zoonotic importance, which causes a significant economic loss in animal production. A cross-sectional study was conducted to estimate the prevalence of bTB and its associated risk factors and type the Mycobacterium bovis isolated in central Ethiopia. A total of 65 dairy farms and 654 cattle were tested for bTB using a single intradermal comparative cervical tuberculin (SICCT) test. Data on farm management, animal-related characteristics, and the owner's knowledge of the zoonotic importance of bTB were collected using a structured questionnaire. In addition, a total of 16 animals from different farms were identified for postmortem examination. Lowenstein Jensen (LJ) culture was also conducted, and spoligotyping was used to type the M. bovis strains isolated. Chi-square test and logistic regression models were used to analyze the herd- and animal-level risk factors. Herd- and animal-level prevalence rates of bTB were 58.5% (95% CI: 46.2%−69.2%) and 39.3% (95% CI: 35.5%−43.5%), respectively. At the herd level, poor farm management was the predictor for bTB positivity (p &lt; 0.05). Animal breed, poor BCS, farm type, and poor farm management conditions were significant predictors of bTB positivity (p &lt; 0.05) at an individual animal level. All animals identified for postmortem examination were found to have gross TB-like lesions. A total of 14 M. bovis strains were identified from 12 animals that were positive for LJ culture. The strain with the largest number of clusters (five isolates) was SB1176, followed by SB0134 (three isolates), SB0192 (two isolates), and SB2233 (two isolates), and two new strains, each consisting of only one isolate. The majority (58.5%) of the respondents did not know the zoonotic importance of bTB. The result of this study showed a high prevalence of bTB in the Addis Ababa milkshed and a low level of consciousness of the owners on its transmission to humans. Therefore, the launching of acceptable control measures of bTB and the creation of public awareness about its zoonotic transmission and prevention measures are required.

scholarly journals Performance of a Noninvasive Test for Detecting Mycobacterium bovis Shedding in European Badger (Meles meles) Populations

2015 ◽  
Vol 53 (7) ◽  
pp. 2316-2323 ◽  
Author(s):  
Hayley C. King ◽  
Andrew Murphy ◽  
Phillip James ◽  
Emma Travis ◽  
David Porter ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Meles Meles ◽  
Control Measures ◽  
Disease Spread ◽  
Economic Losses ◽  
Noninvasive Test ◽  
Content Type ◽  
Additional Information ◽  
European Badger

The incidence ofMycobacterium bovis, the causative agent of bovine tuberculosis, in cattle herds in the United Kingdom is increasing, resulting in substantial economic losses. The European badger (Meles meles) is implicated as a wildlife reservoir and is the subject of control measures aimed at reducing the incidence of infection in cattle populations. Understanding the epidemiology ofM. bovisin badger populations is essential for directing control interventions and understanding disease spread; however, accurate diagnosis in live animals is challenging and currently uses invasive methods. Here we present a noninvasive diagnostic procedure and sampling regimen using field sampling of latrines and detection ofM. boviswith quantitative PCR tests, the results of which strongly correlate with the results of immunoassays in the field at the social group level. This method allowsM. bovisinfections in badger populations to be monitored without trapping and provides additional information on the quantities of bacterial DNA shed. Therefore, our approach may provide valuable insights into the epidemiology of bovine tuberculosis in badger populations and inform disease control interventions.

scholarly journals Temporal and spatial Mycobacterium bovis prevalence patterns as evidenced in the All Wales Badgers Found Dead (AWBFD) survey of infection 2014–2016

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paul Schroeder ◽  
Beverley Hopkins ◽  
Jeff Jones ◽  
Terry Galloway ◽  
Ryan Pike ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Spatial Variations ◽  
Control Measures ◽  
Spatial Spread ◽  
Similar Survey ◽  
Temporal And Spatial ◽  
And Control

Abstract In order to better understand the spatial spread of bovine tuberculosis (bTB) in Wales, an All Wales Badgers Found Dead (AWBFD) survey was carried out from 2014–2016. For Wales, as a whole, there was a significant decrease (p < 0.001) in prevalence of bTB in badgers since a similar survey was carried out in 2005–2006, with a drop from 13.3% to 7.3%. The highest prevalence was observed for the High TB Area East (18.6%), which shares its border with England, and differed significantly (p < 0.001) from the High TB Area West (7.4%). The lowest proportion of carcases diagnosed with the disease (0.7%) was in the Low TB Area, followed by the two Intermediate TB Areas of Wales (2.7%). The M. bovis isolates from badgers tended to be similar to the genotypes of cattle in the same area, except in the Low TB Area. The direction of any cross species transmission and the drivers for this cannot be determined from this study. The spatial variations described here support the need for regionally adapted surveillance and control measures for bovine tuberculosis in Wales.

scholarly journals Tracing cross species transmission of Mycobacterium bovis at the wildlife/livestock interface in South Africa 

2020 ◽  
Author(s):  
Petronillah Rudo Sichewo ◽  
Tiny M. Hlokwe ◽  
Eric M.C. Etter ◽  
Anita L. Michel
Keyword(s):  
South Africa ◽  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
Variable Number ◽  
Control Measures ◽  
Economic Losses ◽  
African Buffalo ◽  
High Genetic Variability ◽  
Spoligotype Pattern ◽  
Public Health Threat

Abstract Background: Bovine tuberculosis (bTB) affects cattle and wildlife in South Africa with the African buffalo (Syncerus caffer) as the principal maintenance host. The presence of a wildlife maintenance host at the wildlife/livestock interface acting as spill-over host makes it much more challenging to control and eradicate bTB in cattle. Spoligotyping and mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) genotyping methods were performed to investigate the genetic diversity of Mycobacterium bovis (M. bovis) isolates from cattle and wildlife, their distribution and transmission at the wildlife/livestock interface in northern Kwa-Zulu Natal (KZN), South Africa. Results: SB0130 was identified as the dominant spoligotype pattern at this wildlife/livestock interface, while VNTR typing revealed a total of 29 VNTR profiles (strains) in the KZN province signifying high genetic variability. The detection of 5 VNTR profiles shared between cattle and buffalo suggests M. bovis transmission between species. MIRU-VNTR confirmed co-infection in one cow with three strains of M. bovis that differed at a single locus, with 2 being shared with buffalo, implying pathogen introduction from most probably unrelated wildlife sources. Conclusion: Our findings highlight inter and intra species transmission of bTB at the wildlife/livestock interface and the need for the implementation of adequate bTB control measures to mitigate the spread of the pathogen responsible for economic losses and a public health threat.

scholarly journals Molecular diagnosis and risk factors of canine ehrlichiosis in the municipality of Itabuna-Bahia, Brazil

2020 ◽  
Vol 41 (3) ◽  
pp. 897
Author(s):  
Jeane Martinha dos Anjos Cordeiro ◽  
Paula Elisa Brandão Guedes ◽  
Alexandre Dias Munhoz ◽  
Fabiana Lessa Silva
Keyword(s):  
Risk Factors ◽  
Nested Pcr ◽  
Clinical Signs ◽  
Rhipicephalus Sanguineus ◽  
Nested Polymerase Chain Reaction ◽  
Molecular Tests ◽  
Canine Ehrlichiosis ◽  
Non Governmental Organizations ◽  
Canine Monocytic Ehrlichiosis ◽  
The City

Ehrlichiosis is an emerging zoonosis worldwide and has had several adverse effects on public health. Canine monocytic ehrlichiosis (CME), caused by Ehrlichia canis, has the tick Rhipicephalus sanguineus as the vector. The main clinical signs in affected dogs are fever, apathy, anorexia, weight loss, and neurological signs. The diagnosis is made through the association of clinical signs with parasitological, serological, and molecular tests. The aim of this study was to evaluate the occurrence of E. canis infection in dogs from the city of Itabuna-Bahia, as well as to identify the risk factors related to infection. For this, 405 dogs from the Center for Zoonoses Control (CCZ), non-governmental organizations (NGOs), and dogs domiciled and semi-domiciled in the city of Itabuna, southern Bahia, were evaluated. After initial physical evaluation of the dogs, blood samples were collected by venipuncture for subsequent DNA extraction and E. canis testing using the nested Polymerase Chain Reaction (nested-PCR) technique. In addition, an epidemiological questionnaire that included questions related to the animals was administered to the dog owners to identify the risk factors for exposure to the etiological agent and to the vector. Approximately 17% of the dogs in the municipality of Itabuna-Bahia tested positive for E. canis by nested-PCR, a result higher than that found in other studies conducted in the same municipality. Among the factors associated with E. canis infection, contact with other dogs (p = 0.0226) was an important factor for the dissemination of CME, since dogs are reported to be reservoirs of E. canis. Male dogs (p = 0.0016) presented lower risk for E. canis infection. Other studies, however, describe no association between animal gender and infection by E. canis. Preventive measures to reduce exposure to the vector of ehrlichiosis are necessary.

scholarly journals Mycobacterium bovis DNA Detection in Colostrum as a Potential Indicator of Vaccination Effectiveness against Bovine Tuberculosis

2013 ◽  
Vol 20 (4) ◽  
pp. 627-633 ◽  
Author(s):  
Sara E. Herrera-Rodríguez ◽  
María Alejandra Gordiano-Hidalgo ◽  
Gonzálo López-Rincón ◽  
Luis Bojorquez-Narváez ◽  
Francisco Javier Padilla-Ramírez ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Nested Pcr ◽  
Bovine Tuberculosis ◽  
Dna Detection ◽  
Dairy Farms ◽  
Primary Vaccination ◽  
Content Type ◽  
Booster Immunization ◽  
Culture Filtrate Proteins

ABSTRACTBovine tuberculosis (bTB) remains a problem on many dairy farms in Mexico, as well as a public health risk. We previously found a high frequency ofMycobacterium bovisDNA in colostrum from dairy cows using a nested PCR to detectmpb70. Since there are no reliablein vivotests to determine the effectiveness of boosterMycobacterium bovisBCG vaccination against bTB, in this work we monitoredM. bovisDNA in colostrum by using this nested PCR. In order to decrease the risk of adverse reactions in animals likely containing viableM. bovis, a single application of BCG and a subunit vaccine (EEP-1) formulated withM. bovisculture filtrate proteins (CFP) and a copolymer as the adjuvant was performed in tuberculin skin test-negative cattle (TST−), while TST reactor animals (TST+) received EEP-1 only. Booster immunization using EEP-1 was applied to both groups, 2 months after primary vaccination to whole herds and 12 months later to lactating cows. Colostrum samples were collected from 6 farms where the cows were vaccinated over a 12-month period postvaccination and, for comparison, from one control farm where the cows were not vaccinated with comparable bTB prevalence. We observed an inverse relationship between the frequency ofM. bovisDNA detection and time postvaccination at the first (P< 0.001) and second (P< 0.0001) 6-month periods. Additionally, the concentration of gamma interferon (IFN-γ) was higher inmpb70PCR-positive colostrum samples (P= 0.0003). These results suggest thatM. bovisDNA frequency in colostrum could be a potentially useful biomarker for bTB vaccine efficacy on commercial dairy farms.

Population dynamics of the badger ( Meles meles ) and the epidemiology of bovine tuberculosis ( Mycobacterium bovis )

1985 ◽  
Vol 310 (1145) ◽  
pp. 327-381 ◽  
Keyword(s):  
Population Growth ◽  
Mycobacterium Bovis ◽  
Disease Transmission ◽  
Bovine Tuberculosis ◽  
Meles Meles ◽  
Control Measures ◽  
Low Density ◽  
Force Of Infection ◽  
Low Levels

A survey and analysis is presented of the population biology of the badger ( Meles meles ) and the epidemiology of bovine tuberculosis ( Mycobacterium bovis ) within badger populations. Simple mathematical models are used to further our understanding of Special attention is given to the identification of areas in which current knowledge is inadequate, and to future research needs. The badger is shown to have a low intrinsic population growth rate, a not insignificant maturation delay to first breeding, to produce small litters of cubs which experience high rates of mortality in their first year of life but low rates thereafter, and to exhibit limited powers of dispersal. Population abundance is largely determined by habitat type and long term stability appears to arise primarily as a consequence of density-dependent constraints on fecundity. Such constraints are thought to only operate at densities close to the carrying capacity of the habitat. Cyclic fluctuations in abundance, with a period of between six and eight years, may occur in areas of moderate to poor habitat. Such fluctuations will be most apparent with respect to cub abundance as opposed to adult density. Bovine tuberculosis is endemic within many badger populations throughout regions of Britain but is particularly prevalent in areas of good badger habitat in the southwest of England. Current evidence suggests that badgers play a significant role in disease transmission to cattle. It is argued that the infection is able to persist in high, moderate and low density badger populations. The observed stability of the disease appears to be a consequence of ‘pseudo-vertical’ transmission (from parent to new born offspring), the long duration of infectiousness of infected animals (low disease-induced mortality rate), the presence of carriers and inactive cases and the social organization and behaviour of the host species. Disease prevalence is likely to be related to badger density although in a nonlinear manner. Control measures based on the removal of infected social groups of badgers in the southwest of England appear to have reduced the force of infection within badger populations by approximately 50%. The disease, however, remains endemic but at low levels of prevalence. The reduction in the force of infection has reduced the frequency of disease transmission to cattle herds. Eradication of the infection within badger populations may not be necessary for the short-term control of the infection in cattle. The persistence of low levels of infection in low density badger populations (suppressed by control measures), in areas of intensive cattle farming activity, however, presents a continual threat to cattle health in the long term . The ability of badger populations to recover from substantive reductions in density is poor, with a return time (to the pre-control state) of approximately five years. Small reductions in abundance, however, are likely to enhance net population growth rates as a consequence of the relaxation of density-dependent constraints on fecundity (the natural population regulatory mechanism). As such, rapid population growth to precontrol levels is predicted, following small reductions in density. As a consequence of the requirement for continual and substantive suppression of badger abundance (a renewable resource) in areas of intensive cattle farming it is suggested that alternative methods of disease control should be actively sought with a view to the design of more effective long-term control policies.

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