Seroprevalence and risk factors associated to Mycobacterium bovis in wild artiodactyl species from southern Spain, 2006-2010

Bovine Tuberculosis in Wild Boar (Sus scrofa) in Slovenia

Mycobacteria of the Mycobacterium tuberculosis complex (MTC) are capable of infecting a wide variety of animals. Wild boar (Sus scrofa) has been recognized as an important wildlife reservoir for bovine tuberculosis. We screened wild boar in Slovenia for the presence of (1) Mycobacterium bovis in tissues and (2) antibodies to M. bovis in blood samples. In 2016 and 2017, 1284 tissue samples from 676 wild boar were subjected to cultivation. In 2018 and 2019, blood samples from 132 wild boar were examined using an ELISA kit. None of the MTC species were isolated from the tissue samples, and no antibodies to M. bovis were detected in the blood samples. Several nontuberculous mycobacteria (NTM), identified by 16S rRNA sequencing and/or matrix-assisted laser desorption ionization time-of-flight mass spectrometry, were found in the tissues of 9.8% of the wild boar: Mycobacterium nonchromogenicum, Mycobacterium peregrinum/Mycobacterium septicum, Mycobacterium avium, Mycobacterium engbaekii, Mycobacterium arupense, Mycobacterium algericum, Mycobacterium bohemicum, Mycobacterium confluentis, Mycobacterium flavescens, Mycobacterium fortuitum, Mycobacterium thermoresistibile, and Mycobacterium vaccae. Species-level identification was not possible for 21.2% of the isolates. At the time of the study, wild boar in Slovenia were not at risk from bTB; the significance of the presence of NTM in wild boar remains to be clarified and evaluated from a One Health perspective.

Monitoring the dynamics of consumption of ungulate game by-products in vulture feeding stations in Iberian Mediterranean ecosystems

Vulture feeding stations (VFS) are strategic sites for the management of ungulate game by-products, with major implications for the conservation of obligate avian scavengers. These feeding points are designed to prevent access by facultative mammalian scavengers and to reduce the risk of trophically transmitted pathogen infection through scavenging behaviour. The aim of this study, using camera trap video recordings, was to evaluate the feeding dynamics around 32 lots of ungulate game by-products deposited in VFS in southern Spain. During the study period (2017-2022), 11 different avian and mammal scavenger species was detected. Also, many feeding events involving all scavenger species (51.1%; 362/709) and mammal scavenger species (23.4%; 166/709) was recorded. A significantly earlier presence of major obligate scavengers (Gyps fulvus and Aegypius monachus) (P = 0.023) and a lower persistence of by-products deposited (P < 0.001) were detected during October-December compared to January-March. Our results confirm that VFS play an important role in vulture conservation in Iberian Mediterranean ecosystems. However, we also point out the potential risk of VFS as hotspots of foodborne pathogens for mammal scavengers, particularly when the hunting offal persists longer. Consequently, we urge the competent authorities to update the regulations affecting VFS management, and hunting estate managers to make every effort to correctly apply those preventing scavenging mammals from gaining access to VFS. Further studies tackling access of non-target species to VFS are also warranted to properly assess the sanitary implications and geographical extent of these problems for mammal species inhabiting areas where VFS are installed.

Diseases of Iberian ibex (Capra pyrenaica)

Iberian ibex (Capra pyrenaica) is an ecologically and economically relevant medium-sized emblematic mountain ungulate. Diseases participate in the population dynamics of the species as a regulating agent, but can also threaten the conservation and viability of vulnerable population units. Moreover, Iberian ibex can also be a carrier or even a reservoir of pathogens shared with domestic animals and/or humans, being therefore a concern for livestock and public health. The objective of this review is to compile the currently available knowledge on (1) diseases of Iberian ibex, presented according to their relevance on the health and demography of free-ranging populations; (2) diseases subjected to heath surveillance plans; (3) other diseases reported in the species; and (4) diseases with particular relevance in captive Iberian ibex populations. The systematic review of all the information on diseases affecting the species unveils unpublished reports, scientific communications in meetings, and scientific articles, allowing the first comprehensive compilation of Iberian ibex diseases. This review identifies the gaps in knowledge regarding pathogenesis, immune response, diagnostic methods, treatment, and management of diseases in Iberian ibex, providing a base for future research. Moreover, this challenges wildlife and livestock disease and wildlife population managers to assess the priorities and policies currently implemented in Iberian ibex health surveillance and monitoring and disease management.

Presence of Foodborne Bacteria in Wild Boar and Wild Boar Meat-A Literature Survey for the Period 2012-2022

The wild boar is an abundant game species with high reproduction rates. The management of the wild boar population by hunting contributes to the meat supply and can help to avoid a spillover of transmissible animal diseases to domestic pigs, thus compromising food security. By the same token, wild boar can carry foodborne zoonotic pathogens, impacting food safety. We reviewed literature from 2012-2022 on biological hazards, which are considered in European Union legislation and in international standards on animal health. We identified 15 viral, 10 bacterial, and 5 parasitic agents and selected those nine bacteria that are zoonotic and can be transmitted to humans via food. The prevalence of Campylobacter, Listeria monocytogenes, Salmonella, Shiga toxin-producing E. coli, and Yersinia enterocolitica on muscle surfaces or in muscle tissues of wild boar varied from 0 to ca. 70%. One experimental study reported the transmission and survival of Mycobacterium on wild boar meat. Brucella, Coxiella burnetii, Listeria monocytogenes, and Mycobacteria have been isolated from the liver and spleen. For Brucella, studies stressed the occupational exposure risk, but no indication of meat-borne transmission was evident. Furthermore, the transmission of C. burnetii is most likely via vectors (i.e., ticks). In the absence of more detailed data for the European Union, it is advisable to focus on the efficacy of current game meat inspection and food safety management systems.

Genetic Diversity and Population Structure of Mycobacterium bovis at the Human-Animal-Ecosystem Interface in France: “A One Health Approach”

Mycobacterium bovis infects cattle and wildlife, and also causes a small proportion of tuberculosis cases in humans. In most European countries, M. bovis infections in cattle have been drastically reduced, but not eradicated. Here, to determine the M. bovis circulation within and between the human, cattle, and wildlife compartments, we characterized by spoligotyping and mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing the genetic diversity of M. bovis isolates collected from humans, cattle, and wildlife in France from 2000 to 2010. We also assessed their genetic structure within and among the different host groups, and across time and space. The M. bovis genetic structure and its spatiotemporal variations showed different dynamics in the human and animal compartments. Most genotypes detected in human isolates were absent in cattle and wildlife isolates, possibly because in patients, M. bovis infection was contracted abroad or was the reactivation of an old lesion. Therefore, they did not match the genetic pool present in France during the study period. However, some human-cattle exchanges occurred because some genotypes were common to both compartments. This study provides new elements for understanding M. bovis epidemiology in France, and calls for increased efforts to control this pathogen worldwide.

Tuberculosis caused by Mycobacterium orygis in wild ungulates in Chennai, South India

We report the isolation of Mycobacterium orygis, a member of Mycobacterium tuberculosis complex (MTBC), from two black bucks (Antelope cervicapra) and one spotted deer (Axis axis) from the Guindy National Park forest range in Chennai, India. Lung tissue and lymph node samples collected during post-mortem examination were processed using NaOH method and cultured in solid and liquid media. DNA extracted from the cultured isolates was used to amplify the mpt64 gene by specific primers and the band visualized at 240 bps confirmed the isolates as a member of MTBC. Further examination of these isolates by spoligotyping and whole-genome sequencing confirmed the isolates as M. orygis and the phylogenetic tree revealed their well-clustered position with other M. orygis isolates around the globe. The deletion of RD7-RD10, RDOryx_1, RDOryx_4, RD12Oryx, RD301 and RD315 further substantiated these isolates as M. orygis. The exact source of infection in animals was untraceable and the pairwise comparison of the genomes based on single-nucleotide polymorphisms difference did not detect any events of transmission within the affected animals. Nevertheless, it would be wise to take into account the environment where there exists a high chance of transmission due to the increased human-animal interaction. Since it is well known that the pathogen is capable of causing infection in both human and animal hosts, systematic surveillance and screening of spotted deer, black buck as well as humans in the vicinity is essential for successful implementation of the One Health approach.

Serological detection of Mycobacterium Tuberculosis complex infection in multiple hosts by One Universal ELISA

Tuberculosis (TB), a contagious disease mainly caused by Mycobacterium tuberculosis (M. tb), Mycobacterium bovis (M. bovis), and Mycobacterium caprae (M. caprae), poses a major global threat to the health of humans and many species of animals. Developing an ante-mortem detection technique for different species would be of significance in improving the surveillance employing a One Health strategy. To achieve this goal, a universal indirect ELISA was established for serologically detecting Mycobacterium tuberculosis complex infection for multiple live hosts by using a fusion protein of MPB70, MPB83, ESAT6, and CFP10 common in M. tb, M. bovis, and M. caprae as the coating antigen (MMEC) and HRP-labeled fusion protein A and G as a secondary antibody. After testing the known positive and negative sera, the receiver operating characteristic curves were constructed to decide the cut-off values. Then, the diagnostic sensitivity and specificity of MMEC/AG-iELISA were determined as 100.00% (95% CI: 96.90%, 100.00%) and 100.00% (95% CI: 98.44%, 100.00%) for M. bovis infection of cattle, 100.00% (95% CI: 95.00%, 100.00%) and 100.0% (95% CI: 96.80%, 100.00%) for M. bovis infection of sheep, 90.74% (95% CI: 80.09%, 95.98%) and 98.63% (95% CI: 95.14%, 99.76%) for M. bovis infection of cervids, 100.00% (95% CI: 15.81%, 100.00%) and 98.81% (95% CI: 93.54%, 99.97%) for M. bovis infection of monkeys, 100.00% (95% CI: 86.82%, 100.00%) and 94.85% (95% CI: 91.22%, 97.03%) for M. tb infection of humans. Furthermore, this MMEC/AG-iELISA likely detects M. caprae infection in roe deer. Thus this method has a promising application in serological TB surveillance for multiple animal species thereby providing evidence for taking further action in TB control.

Host Genetic Diversity and Infectious Diseases. Focus on Wild Boar, Red Deer and Tuberculosis

Host genetic diversity tends to limit disease spread in nature and buffers populations against epidemics. Genetic diversity in wildlife is expected to receive increasing attention in contexts related to disease transmission and human health. Ungulates such as wild boar (Sus scrofa) and red deer (Cervus elaphus) are important zoonotic hosts that can be precursors to disease emergence and spread in humans. Tuberculosis is a zoonotic disease with relevant consequences and can present high prevalence in wild boar and red deer populations. Here, we review studies on the genetic diversity of ungulates and determine to what extent these studies consider its importance on the spread of disease. This assessment also focused on wild boar, red deer, and tuberculosis. We found a disconnection between studies treating genetic diversity and those dealing with infectious diseases. Contrarily, genetic diversity studies in ungulates are mainly concerned with conservation. Despite the existing disconnection between studies on genetic diversity and studies on disease emergence and spread, the knowledge gathered in each discipline can be applied to the other. The bidirectional applications are illustrated in wild boar and red deer populations from Spain, where TB is an important threat for wildlife, livestock, and humans.

Retrospective analysis of the control and prevention of tuberculosis among cattle in Ukraine in the period 1994–2020

Bovine tuberculosis (bTB) – is a chronic infectious disease, the causative agent of which affects many species of mammals. It is a zoonosis caused by various types of mycobacteria in the complex Mycobacterium tuberculosis family Mycobacteriaceae. The most important etiological agent of bTB in cattle is M. bovis, which has been isolated from tuberculosis infected cattle for centuries. Livestock and species of the Bovidae family are the most susceptible to this pathogen and are the main reservoir species for animals and humans. In Ukraine, the main methods of diagnosing tuberculosis in animal husbandry are lifetime (clinical examination, allergic intradermal test with tuberculin), and postmortem techniques (pathological changes, bacteriological investigation). The authors performed a retrospective analysis of the epizootic situation of tuberculosis among cattle in Ukraine for the period 1994–2020 and conducted a critical assessment of the work done to prevent and control this disease. In total, over the last 27 years, 219 088 head of cattle with tuberculosis and 933 affected locations have been identified in Ukraine. The results of this work showed that in our country the epizootic situation of bovine tuberculosis on farms of various forms of ownership is fully controlled. The most active fight against tuberculosis was carried out during 1995–2015. In 1994–1997, the largest number of affected locations was registered, from 90 to 144, respectively, and the largest number of animals with tuberculosis – 21 395–33 474. In 1994–1995, the largest number of sick animals per one affected point was registered (371.9 and 471.7 head, respectively). Currently, official statistics show that many farms, especially in Vinnytska, Cherkaska and Kyivska regions, continue to show positive allergic reactions to tuberculin (46 898 reactions for the last 12 years). Applying diagnostic methods of research in complex (bacteriological, bioassay, molecular), excludes affection of cattle by pathogenic mycobacteria. This study showed that for the last 5 years no farms with confirmed pathological diagnosis by bacteriological methods have been registered and no culture of the pathogen from animals has been detected. Besides the scurpulous work of the veterinary service, in our opinion, the catastrophic decline in the number of cattle in Ukraine also had a significant impact on improving the epizootic situation regarding tuberculosis.

A survey of shared pathogens at the domestic-wild ruminants' interface in Doñana National Park (Spain)

A cross-sectional study was carried out to evaluate shared pathogens that can be transmitted by close or non-close contact at the domestic-wild ruminants' interface. During summer-autumn 2015, a total of 138 cattle and 203 wild ruminants (red deer, Cervus elaphus, and fallow deer, Dama dama) were sampled in Doñana National Park (DNP, south-western Spain), a Mediterranean ecosystem well known for the interaction network occurring in the ungulate host community. Pestiviruses, bovine respiratory syncytial virus (BRSV; Bovine orthopneumovirus), bovine herpesvirus 1 (BoHV-1; Bovine alphaherpesvirus 1) and Mycobacterium tuberculosis complex (MTC) were assessed using serological, microbiological and molecular techniques. The overall seroprevalence against viruses in cattle was 2.2% for pestiviruses, 11.6% for BRSV and 27.5% for BoHV-1. No virus-specific antibodies were found in wildlife. MTC incidence in cattle was 15.9%, and MTC seroprevalence in wild ruminants was 14.3%. The same Mycobacterium bovis spoligotypes (SB1232, SB1230 and SB1610) were identified in cattle, red deer and fallow deer. The serological results for the selected respiratory viruses suggest epidemiological cycles only in cattle. Surveillance efforts in multi-host epidemiological scenarios are needed to better drive and prioritize control strategies for shared pathogens.

Development of a Multiplex Bead Assay for Simultaneous Serodiagnosis of Antibodies against Mycobacterium bovis, Brucella suis, and Trichinella spiralis in Wild Boar

The aim of this study was to evaluate the diagnostic performance of a multiplex bead assay for the simultaneous detection of antibodies against Mycobacterium bovis, Brucella suis, and Trichinella spiralis. Sera from Eurasian wild boar of known serological status for TB (64 seropositive, 106 seronegative), Brucella (30 seropositive, 39 seronegative), and Trichinella (21 seropositive, 97 seronegative) were used for the development and evaluation of the assay. Magnetic beads coated with recombinant MPB83 antigen (TB), a whole-cell B. suis 1330 antigen, and an E/S T. spiralis antigen were used for the detection of specific antibodies using Bio-Rad Bio-Plex technology. The sensitivities (Se) and specificities (Sp) of the multiplex assay were, for M. bovis, 0.98 and 0.86; for B. suis, 1.00 and 0.97; and for T. spiralis, 0.90 and 0.99 (Se and Sp, respectively). The results show the diagnostic potential of this assay for the simultaneous detection of antibodies against M. bovis, B. suis, and T. spiralis in wild boar.

Mycobacterium tuberculosis complex in wildlife: Review of current applications of antemortem and postmortem diagnosis

Tuberculosis (TB) is a chronic inflammatory and zoonotic disease caused by Mycobacterium tuberculosis complex (MTBC) members, which affects various domestic animals, wildlife, and humans. Some wild animals serve as reservoir hosts in the transmission and epidemiology of the disease. Therefore, the monitoring and surveillance of both wild and domestic hosts are critical for prevention and control strategies. For TB diagnosis, the single intradermal tuberculin test or the single comparative intradermal tuberculin test, and the gamma-interferon test, which is regarded as an ancillary test, are used. Postmortem examination can identify granulomatous lesions compatible with a diagnosis of TB. In contrast, smears of the lesions can be stained for acid-fast bacilli, and samples of the affected organs can be subjected to histopathological analyses. Culture is the gold standard test for isolating mycobacterial bacilli because it has high sensitivity and specificity compared with other methods. Serology for antibody detection allows the testing of many samples simply, rapidly, and inexpensively, and the protocol can be standardized in different laboratories. Molecular biological analyses are also applicable to trace the epidemiology of the disease. In conclusion, reviewing the various techniques used in MTBC diagnosis can help establish guidelines for researchers when choosing a particular diagnostic method depending on the situation at hand, be it disease outbreaks in wildlife or for epidemiological studies. This is because a good understanding of various diagnostic techniques will aid in monitoring and managing emerging pandemic threats of infectious diseases from wildlife and also preventing the potential spread of zoonotic TB to livestock and humans. This review aimed to provide up-to-date information on different techniques used for diagnosing TB at the interfaces between wildlife, livestock, and humans.

Molecular characterization of Mycobacterium bovis infection in cattle and buffalo in Amazon Region, Brazil

The aim of this study was to characterize Mycobacterium bovis from cattle and buffalo tissue samples, from two Brazilian states, and to analyse their genetic diversity by spoligotyping. Tissue samples from tuberculosis suspect animals, 57 in Amazonas State (12 cattle and 45 buffaloes) and six from Pará State (5 cattle and one buffalo) from slaughterhouses under State Veterinary Inspection, were isolated in culture medium Stonebrink. The positive cultures were confirmed by PCR and analysed by the spoligotyping technique and the patterns (spoligotypes) were identified and compared at the Mycobacterium bovis Spoligotype Database (http://www.mbovis.org/). There was bacterial growth in 44 (69.8%) of the tissues of the 63 animals, of which PCR for region of differentiation 4 identified 35/44 (79.5%) as Mycobacterium bovis. Six different spoligotypes were identified among the 35 Mycobacterium bovis isolates, of which SB0295, SB1869, SB0121 and SB1800 had already been described in Brazil, and SB0822 and SB1608 had not been described. The most frequent spoligotype in this study (SB0822) had already been described in buffaloes in Colombia, a neighbouring country of Amazonas state. The other identified spoligotypes were also described in other South American countries, such as Argentina and Venezuela, and described in the Brazilian states of Rio Grande do Sul, Santa Catarina, São Paulo, Minas Gerais, Mato Grosso do Sul, Mato Grosso and Goiás, indicating an active movement of Mycobacterium bovis strains within Brazil.

Tuberculosis in the wild boar: Frequentist and Bayesian estimations of diagnostic test parameters when Mycobacterium bovis is present in wild boars but at low prevalence

The Eurasian wild boar (Sus scrofa) is increasingly considered as a relevant actor in the epidemiology of animal tuberculosis (TB). Therefore, monitoring TB in this species is key when establishing comprehensive control schemes for this disease still present in Europe. No data are available on direct and indirect TB diagnostic methods in wild boars in epidemiological contexts where TB is endemic in cattle and detected in wild boars at low prevalence. We aimed to estimate and compare sensitivity and specificity values for bacterial culture, PCR and three commercial ELISAs, i.e. the TB ELISA-VK (using the bPPD antigen), INgezim TB Porcine and IDEXX M. bovis Ab Test (both using the MPB83 and MPB70 antigens), under field conditions in France. We used frequentist methods, with bacteriology as the gold standard, and a Bayesian formulation of the latent class analysis (LCA), without using a gold standard. Submandibular lymph nodes and sera from 495 wild boars hunter-harvested in three endemic areas (Aquitaine region, Côte d’Or region, and Corsica region) were collected between 2014 and 2016. Only eight individuals were positive for M. bovis by bacteriology (1.61%; CI_95% 0.70–3.51%). The LCA method provided high specificities (99.2%; CI_95% 98.2–99.8% for INgezim TB Porcine and 99.7%; CI_95% 98.8–100% for IDEXX M. bovis Ab Test) and sensitivities (78.5%; CI_95% 65.1–88.8% for INgezim TB Porcine and 83.9%; CI_95% 58.9–97.2% for IDEXX M. bovis Ab Test) for both ELISAs using the MPB83 and MPB70 antigens. Bacterial culture showed limited sensitivity (42.8%; CI_95% 19.0–70.6%), estimated as the probability of a positive result in an animal exposed to M. bovis. PCR and ELISA using the bPPD antigens demonstrated high specificities, and sensitivities intermediates between culture and the ELISAs using the MPB83 and MPB70 antigens. These results suggest that ELISA tests using the MPB83 and MPB70 antigens are useful to detect and monitor TB exposure of wild boar populations in field conditions in France.

A new test to detect antibodies against Mycobacterium tuberculosis complex in red deer serum

Red deer (Cervus elaphus) farming is a growing economic activity worldwide. However, the capacity of this species to act as reservoir of animal tuberculosis (TB) poses a threat to other wildlife and to livestock. Diagnostic assay accuracy in this species is therefore highly relevant for prevention and control measures. Our aim was to evaluate the diagnostic performance of the protein complex P22, obtained from Mycobacterium bovis derived purified protein derivative (bPPD), as a candidate antigen for the detection of antibodies against Mycobacterium tuberculosis complex (MTC). We assessed the performance of this new antigen in indirect enzyme-linked immunosorbent assays (ELISA) in TB-positive and TB-negative red deer, in comparison with a bPPD-based ELISA. The P22 ELISA achieved a higher specificity (Sp) and similar sensitivity (Se) in comparison with the bPPD ELISA at all the cut-off points considered. The P22 ELISA yielded optimal Sp (99.02%; 95% confidence intervals [CI_95%]: 96.5-99.8) and appropriate Se (70.1%; CI_95%: 63.6-76) at the selected cut-off point of 100%. These results suggest that P22 can be used as an alternative antigen in the immunodiagnosis of animal TB through the use of an ELISA-type detection of antibodies against MTC in red deer, thus contributing to the diagnosis of animal TB in this species as a measure for further disease prevention and control programs.

Validation of a new serological assay for the identification of Mycobacterium tuberculosis complex-specific antibodies in pigs and wild boar

BACKGROUND AND OBJECTIVES

Animal tuberculosis (TB) is a multi-host disease involving a wide variety of domestic and wild mammals and causing a significant economic burden and sanitary problems. Wild boar and domestic pigs (Sus scrofa) are indicators of the circulation of the Mycobacterium tuberculosis complex (MTC) and can play a role in its maintenance. The proper diagnosis of MTC contact in these species is, therefore, a key factor as regards controlling TB. The objective of the current study is to evaluate the diagnostic performance of the protein complex P22 as a candidate for use in an in-house ELISA to identify M. tuberculosis complex-specific antibodies for the diagnosis of TB in comparison to the commonly used bPPD-based ELISA (bPPD ELISA) in suids.

METHODS

We conducted a retrospective study. Sera were collected from wild boar during hunting season and from domestic pigs during routine handling, and all the animals underwent reference standard tests (detailed necropsy followed by bacteriological culture and isolation). Animal TB was confirmed to be positive in 277 animals and negative in 366 animals based on both reference standard tests. Sera from those animals were tested by P22 ELISA as well as bPPD ELISA.

RESULTS

Both ELISAs yielded a good diagnostic value, however, a higher sensitivity (Se) and specificity (Sp) was achieved with the P22 ELISA (Se: 84.1%; CI_95%: 79.3-88.2% / Sp: 98.4%; CI_95%:96.5-99.4%) when compared to the bPPD ELISA (Se: 77.3%; CI_95%: 71.9-82.2% / Sp: 97.3%; CI_95%: 95-98.3%). An optimum Sp of 100% (CI_95%: 98.54-100%) was attained with white pigs for both the bPPD and the P22 ELISA.

DISCUSSION

The results suggest that serological tests for MTC-antibody detection, and particularly the P22 ELISA, are valuable tools in the diagnosis of TB in wild boar and domestic pigs when attempting to detect contact with MTC and thereby facilitate TB control and management.

The most common spoligotype of Mycobacterium bovis isolated in the world and the recommended loci for VNTR typing; A systematic review

Mycobacterium bovis is a neglected zoonotic organism that epidemiological studies are of crucial importance in identifying its source, control it and prevent it from spreading. The aim of this study was to investigate the most common spoligotypes of Mycobacterium bovis circulating around the world and introduce the most and least strong determine powers of loci for VNTR. We have used different databases such as ISC, science direct, Embase (Elsevier), Web of Science, Scopus and Medline via PubMed. Searches were performed by key words including: Mycobacterium bovis, MIRU -VNTR, spoligotyping and discrimination power. Finally, thirty-one articles were selected after filtering out some titles, abstracts and full texts. Spoligotype SB0120 was the most common circulating type on several continents while SB0121 existed in Europe, Africa and America. SB0140 was also detected in Asia, Europe and America. QUB3232 and QUB11b were more appropriate loci among the loci with high discriminatory power. MIRU 10 and MIRU4 were among the loci with poor discriminatory power. Taking the published data into consideration, SB0120 and SB0121 are predominant spoligotypes of M. bovis circulating among animals around the world. Determining the most common spoligotype of M. bovis is the key to find source of infection, control and prevent the disease.

Management of hunting waste as control measure for tuberculosis in wild ungulates in south-central Spain

In recent decades, habitat change and the intensive management of wild ungulates for hunting have led to an increase in their populations in south-central Spain. This implies a higher generation of hunting waste, which can favour the transmission of infectious diseases, including tuberculosis (TB). The aim of this study was to assess the usefulness of the proper disposal of hunting waste as TB control measure in wild boar (Sus scrofa) and red deer (Cervus elaphus) during the 2008/2009 to 2016/2017 hunting seasons. Blood samples from 664 wild boar and 934 red deer were obtained in 14 game estates in two provinces in Andalusia (Area 1), where the disposal of hunting waste was implemented since the 2012/2013 hunting season. Besides, six game estates in the province of Ciudad Real, in Castilla-La Mancha (Area 2), an adjacent region where this management measure was not implemented during the studied period, were used as controls, sampling 277 wild boar and 427 red deer sera. The Mycobacterium tuberculosis complex (MTC), seroprevalence detected in wild boar from Area 1, was significantly higher before the disposal of big game hunting by-products (82.8%; 2008/2009-2012/2013) compared to the second period (61.8%; 2013/2014-2016/2017) (p < .001), after this control measure became established. By contrast, no significant differences between periods were found in wild boar (41.3% versus 44.8%; p = .33) and red deer (14.9% versus 11.6%; p = .19) from Area 2 as well as in red deer (10.8% versus 10.5%; p = .48) from Area 1. The proper disposal of hunting waste contributed to achieve a 25% reduction in MTC seroprevalence in wild boar. These results are of particular relevance regarding wild boar in the current context of re-emerging and emerging diseases such as TB and African Swine Fever in Europe. Further studies are needed to assess the effect of this measure on the health status of livestock and other wildlife species.

Evaluation of five serologic assays for bovine tuberculosis surveillance in domestic free-range pigs from southern Spain

In countries where bovine tuberculosis (bTB) is still prevalent the contact among different animal species in extensive systems contributes to the circulation of Mycobacterium bovis (M. bovis) and other members of the Mycobacterium tuberculosis complex (MTC). Thus, free-range pigs can develop subclinical infections and may contribute to disease spread to bovine and wildlife. Serodiagnosis has been proposed as a screening tool for detecting infected pig herds; however, the value of this method to obtain an accurate diagnosis in this species is still not clear. In this study, sensitivity (Se) and specificity (Sp) estimates of four ELISAs and a lateral flow immunochromatographic antibody assay based on different M. bovis antigens, including MPB70 and MPB83 proteins, were evaluated in naturally infected domestic free-range pigs. For this purpose, submandibular lymph nodes and blood samples from 217 pigs from both TB-infected and historically negative farms were sampled at slaughterhouse and analysed by gross examination, histopathology, bacteriological culture and qPCR. Se and Sp estimates of the 5 evaluated assays ranged from 66.1% to 78% (CI₉₅ from 52.6 to 87.7%) and from 98.9% to 100% (CI₉₅ from 93.8 to 100%), respectively. Results of our study suggest that all the evaluated assays could be used as a first screening tool to conduct bTB surveillance in domestic pigs at population level; however, animals from seropositive herds should later be surveyed by other methods in order to reduce false negative results.

Effects of repeated comparative intradermal tuberculin testing on test results: a longitudinal study in TB-free red deer

BACKGROUND

Diagnosing tuberculosis (TB) in farmed red deer (Cervus elaphus) is challenging and might require combining cellular and humoral diagnostic tests. Repeated skin-testing with mycobacterial purified protein derivatives (PPDs) might sensitize or desensitize the subjects to both kinds of diagnostic tools. We evaluated the effect of repeated (every 6 months) comparative tuberculin skin testing on skin test and ELISA responsiveness in farmed red deer hinds from a TB-free herd. Eighteen 8-month old hinds were inoculated with bovine and avian PPDs and the mitogen phytohaemagglutinin (PHA), as positive control and concurrently tested by ELISA for antibodies against avian (avian PPD, aPPD and protoplasmatic antigen 3, PPA3) and bovine antigens (bPPD and MPB70). Blood serum was also sampled three weeks after each skin testing round and tested for antibodies against aPPD and bPPD, in order to detect eventual antibody level boosts. Testing took place every six months from winter 2012 until winter 2015.

RESULTS

The skin test response to both PPDs peaked during the second and third test round, returning to standard values thereafter. Individual variability was particularly high at the first year and early second year testing rounds (first intradermal test and blood sampling; first winter). The antibody response to avian antigens increased through time, while no such increase was recorded for bovine antigens. The antibody boost three weeks after skin testing was more marked for avian PPD. However, there was no consistent trend in the boosting response through time.

CONCLUSION

Repeated comparative skin testing at six month intervals did not cause progressive increments in skin test responsiveness or antibody production. Specifically, we observed no loss of the skin test response to bPPD and also no progressive loss of the boosting effect in the ELISA responses. However, we recorded increases through time in the antibody levels against avian mycobacterial antigens, possibly due to the progressive exposure to MAP or to other cross-reacting environmental mycobacteria. These findings should be taken into account in designing and interpreting TB testing schemes in farmed deer.

Association between vitamin D supplementation and severity of tuberculosis in wild boar and red deer

Tuberculosis (TB) is a chronic disease affecting humans and other mammal species. Severity of TB caused by Mycobacterium tuberculosis in humans seems to be influenced by nutritional factors like vitamin D3 intake. However, this relationship has been scarcely studied in cattle and other mammals infected with Mycobacterium bovis. The aim of this work was to assess if wildlife reservoirs of M. bovis show different levels of TB severity depending on the level of vitamin D found in serum after supplementation with vitamin D3. Forty hunted wildlife mammals were included in this study: 20 wild boar and 20 red deer. Ten wild boar and ten red deer had been supplemented with a vitamin D3-enriched food, whereas the remaining animals had received no supplementation. TB diagnosis was carried out in each animal based on microbiological isolation of M. bovis. Animals infected with M. bovis were then classified as animals with localized or generalized TB depending on the location and dissemination of the lesions. Furthermore, serum levels of vitamin D2 and D3 were determined in each animal to evaluate differences not only between supplemented and non-supplemented animals but also between those with localized and generalized TB. Levels of vitamin D3 found in both, supplemented wild boar and red deer, were significantly higher than those found in the non-supplemented animals. Interestingly, higher levels of vitamin D3 were observed in animals suffering localized TB when compared to animals with generalized TB suggesting that vitamin D3 concentration correlates negatively with TB severity in these wildlife reservoirs.

Six-Year Follow-up of Slaughterhouse Surveillance (2008-2013): The Catalan Slaughterhouse Support Network (SESC)

Meat inspection has the ultimate objective of declaring the meat and offal obtained from carcasses of slaughtered animals fit or unfit for human consumption. This safeguards the health of consumers by ensuring that the food coming from these establishments poses no risk to public health. Concomitantly, it contributes to animal disease surveillance. The Catalan Public Health Protection Agency (Generalitat de Catalunya) identified the need to provide its meat inspectors with a support structure to improve diagnostic capacity: the Slaughterhouse Support Network (SESC). The main goal of the SESC was to offer continuing education to meat inspectors to improve the diagnostic capacity for lesions observed in slaughterhouses. With this aim, a web-based application was designed that allowed meat inspectors to submit their inquiries, images of the lesions, and samples for laboratory analysis. This commentary reviews the cases from the first 6 years of SESC operation (2008-2013). The program not only provides continuing education to inspectors but also contributes to the collection of useful information on animal health and welfare. Therefore, SESC complements animal disease surveillance programs, such as those for tuberculosis, bovine cysticercosis, and porcine trichinellosis, and is a powerful tool for early detection of emerging animal diseases and zoonoses.

Serological Follow-up of Tuberculosis in a Wild Boar Population in Contact with Infected Cattle

There is an increasing concern in several European countries over the role that tuberculosis (TB)-infected wild boar may play in the progress of bovine TB eradication campaigns. In 2004, as a consequence of the detection of a TB focus in wild boar from a National Game Reserve (NGR) located in southern Catalonia, a surveillance programme based on post-mortem inspection for detection of macroscopic TB-like lesions (TBLL) was initiated in the affected area. The source of infection for wild boar was linked to a tuberculous cattle herd located in the same area. Besides, the results of the surveillance programme in wild boar were used for the validation of an indirect enzyme-linked immunosorbent assay (ELISA) specific for Mycobacterium tuberculosis complex (MTBC) IgG antibodies. Using this ELISA, a seven-year serological study of MTBC in wild boar from the NGR was conducted in 173 animals (93 adults, 44 juveniles-yearlings and 36 piglets) culled between 2004 and 2010. ELISA results and presence of TBLL showed excellent agreement for adult and juvenile wild boar (Kappa index = 0.85; 95% CI: 0.76-0.95). Of the thirty-eight adults, yearlings and juveniles classified as positives by the ELISA, 34 (89%) showed TBLL at necropsy. In contrast, none of the ELISA-positive wild boar piglets (n = 20) showed TBLL, suggesting the detection of early antibody responses to the infection. Overall, this study contributes to the knowledge of wild boar humoral responses to MTBC. The results also highlight the usefulness of this serological test for wild boar TB surveillance.

Epidemiological investigation of bovine tuberculosis herd breakdowns in Spain 2009/2011

We analyzed the most likely cause of 687 bovine tuberculosis (bTB) breakdowns detected in Spain between 2009 and 2011 (i.e., 22% of the total number of breakdowns detected during this period). Seven possible causes were considered: i) residual infection; ii) introduction of infected cattle from other herds; iii) sharing of pastures with infected herds; iv) contiguous spread from infected neighbor herds; v) presence of infected goats in the farm; vi) interaction with wildlife reservoirs and vii) contact with an infected human. For each possible cause a decision tree was developed and key questions were included in each of them. Answers to these key questions lead to different events within each decision tree. In order to assess the likelihood of occurrence of the different events a qualitative risk assessment approach was used. For this purpose, an expert opinion workshop was organized and ordinal values, ranging from 0 to 9 (i.e., null to very high likelihood of occurrence) were assigned. The analysis identified residual infection as the most frequent cause of bTB breakdowns (22.3%; 95%CI: 19.4–25.6), followed by interaction with wildlife reservoirs (13.1%; 95%CI: 10.8–15.8). The introduction of infected cattle, sharing of pastures and contiguous spread from infected neighbour herds were also identified as relevant causes. In 41.6% (95%CI: 38.0–45.4) of the breakdowns the origin of infection remained unknown.

Veterinary officers conducting bTB breakdown investigations have to state their opinion about the possible cause of each breakdown. Comparison between the results of our analysis and the opinion from veterinary officers revealed a slight concordance. This slight agreement might reflect a lack of harmonized criteria to assess the most likely cause of bTB breakdowns as well as different perceptions about the importance of the possible causes. This is especially relevant in the case of the role of wildlife reservoirs.

Preliminary assessment of bovine tuberculosis at the livestock/wildlife interface in two protected areas of northern Botswana

Protected areas of northern Botswana such as the Okavango Delta (OD) or Chobe National Park (CNP) are well-known hot spots for the conservation of African wildlife. However, their infection status regarding bovine tuberculosis (BTB) at the domestic/wildlife interface has never been investigated. To provide preliminary baseline data on the circulation of Mycobacterium bovis in those sites, we performed a cross-sectional survey on 130 buffalo in both protected areas (60 individuals from CNP and 70 from OD) and 818 cattle in their surrounding communal lands (369 in CNP and 449 in the OD). Whole-blood samples were tested using a commercial interferon-gamma assay (IFN-γ) with modifications. The apparent BTB prevalence in buffalo was nil in CNP and 0.7% 95% CI [0.2-1.9] in the OD, while the apparent BTB prevalence in cattle was 0.7% 95% CI [0.2-2.1] in the OD and 2.4% 95% CI [1.2-4.7] in CNP. True prevalence values calculated on the basis of the locally applicable IFN-γ test performance suggested that BTB prevalence was nil in both buffalo populations and in cattle from the OD interface, but reached 2.3% 95% CI [0.2-4.5] in cattle populations around CNP. The results of a questionnaire survey conducted among a sample of farmers living in the communities adjacent to each conservation area (97 and 38 persons in the OD and CNP, respectively) suggested a higher risk of the circulation of M. bovis at the wildlife/livestock interface of the CNP than at that of the OD. However, further comprehensive studies are needed to confirm the circulation of M. bovis and to monitor the inter-species and transboundary transmission of BTB in northern Botswana.

Spatio-temporal variability of bovine tuberculosis eradication in Spain (2006-2011)

In this study we analyzed the space-time variation of the risk of bovine tuberculosis (bTB) in cattle between 2006 and 2011. The results indicated that at country level, there were no significant temporal changes between years, but, at county level bTB evolution was more heterogeneous. In some counties, between some years, the prevalence and the incidence of the disease was higher as compared to the global rate in the rest of the counties of Spain. The analysis of potential risk factors indicated that both, a large number of movements from counties with high incidence (>1%), and presence of bullfighting cattle herds increased bTB risk. Red deer abundance, number of goats and number of mixed cattle-goat farms were not significantly associated with the prevalence/incidence of bTB.

Evaluation of single and comparative intradermal tuberculin tests for tuberculosis eradication in caprine flocks in Castilla y León (Spain)

Goats can act as reservoirs for tuberculosis (TB) infection. The main etiological agents of TB in goats are Mycobacterium caprae and Mycobacterium bovis and they infect also a wide range of domestic and wild animals and humans. Control programmes based mainly on the application of single and comparative intradermal tuberculin (SIT and SCIT respectively) tests are being implemented in certain regions of Spain with a high density of caprine flocks as Castilla y León, including goats with epidemiological relationship with cattle. The aim of this study was to evaluate the performance of the intradermal tests in naturally TB-infected caprine flocks from this region. The study was performed using data from 17,450 goats in 54 different flocks that were classified as TB-infected in the control programmes executed in 2010 and 2011. Data from 1237 goats from 7 dairy flocks depopulated after the first intradermal testing were used to estimate the sensitivity (Se) using bacteriology as the gold-standard. Overall Se of the SIT test using the severe interpretation was 43.9% (CI 95%, 40.4-47.4) and decreased to 38.8% (CI 95%, 35.5-42.3) using the standard interpretation. Overall Se of the SCIT test ranged between 21.3% (CI 95%, 17.6-25.4) and 7% (CI 95%, 4.9-9.8) depending of the interpretation criteria. A significant weak positive correlation was found between age and skin fold thickness (Spearman's test p<0.05). Results from this study yielded, in general, low Se values probably due the systematic detection and slaughter of reactors as a consequence of the eradication programme in previous years or the presence of factors that may interfere in the diagnosis. Therefore, these results suggest the necessity of including ancillary diagnostic tools and/or strict interpretation criteria to maximize detection of positive animals in infected settings.