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1.
Rev Sci Tech ; 40(1): 105-118, 2021 Jun.
Artigo em Inglês, Francês, Espanhol | MEDLINE | ID: mdl-34140737

RESUMO

The availability of rapid, highly sensitive and specific molecular and serologic diagnostic assays, such as competitive enzyme-linked immunosorbent assay (cELISA), has expedited the diagnosis of emerging transboundary animal diseases, including bluetongue (BT) and African horse sickness (AHS), and facilitated more thorough characterisation of their epidemiology. The development of assays based on real-time, reverse-transcription polymerase chain reaction (RT-PCR) to detect and identify the numerous serotypes of BT virus (BTV) and AHS virus (AHSV) has aided in-depth studies of the epidemiology of BTV infection in California and AHSV infection in South Africa. The subsequent evaluation of pan-serotype, real-time, RT-PCR-positive samples through the use of serotype-specific RT-PCR assays allows the rapid identification of virus serotypes, reducing the need for expensive and time-consuming conventional methods, such as virus isolation and serotype-specific virus neutralisation assays. These molecular assays and cELISA platforms provide tools that have enhanced epidemiologic surveillance strategies and improved our understanding of potentially altered Culicoides midge behaviour when infected with BTV. They have also supported the detection of subclinical AHSV infection of vaccinated horses in South Africa. Moreover, in conjunction with whole genome sequence analysis, these tests have clarified that the mechanism behind recent outbreaks of AHS in the AHS-controlled area of South Africa was the result of the reversion to virulence and/or genome reassortment of live attenuated vaccine viruses. This review focuses on the use of contemporary molecular diagnostic assays in the context of recent epidemiologic studies and explores their advantages over historic virus isolation and serologic techniques.


Assuntos
Vírus da Doença Equina Africana , Doença Equina Africana , Vírus Bluetongue , Doenças dos Cavalos , Doença Equina Africana/diagnóstico , Doença Equina Africana/epidemiologia , Animais , Animais Selvagens , Cavalos , África do Sul
2.
Aust Vet J ; 99(3): 66-71, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33184848

RESUMO

This initial retrospective study presents information on bacterial and fungal causes of abortion in domestic ruminants in South Africa over 10 years (2006-2016). A complete set of data was collected at the Faculty of Veterinary Science through a keyword search of pathology and bacteriology laboratory registers. Additional electronic data were received from an external laboratory. A total of 288 cases were recorded from six provinces. Overall diagnostic rate was 35.1%. In 14.6% of cases, histological evidence of an infectious process was found, but no aetiological agent was detected. Several cases did not include aetiological diagnoses because applicable diagnostic techniques were not available or not applied when necessary. Increased submission of placenta, as well as additional conventional and molecular diagnostic methods, can contribute to an improved diagnostic rate. In addition, the study highlights the superior significance of Brucella abortus as a major bovine pathogen in South Africa.


Assuntos
Aborto Animal , Doenças dos Bovinos , Aborto Animal/epidemiologia , Animais , Bactérias , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Gravidez , Estudos Retrospectivos , Ruminantes , África do Sul/epidemiologia
3.
BMC Vet Res ; 14(1): 73, 2018 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-29514650

RESUMO

BACKGROUND: The aim of the current study was to assess the prevalence of bovine tuberculosis (BTB) in cattle, goats, and camels, and its zoonotic potential within the traditional livestock raising communities in four regions of Eritrea. The Single Intradermal Comparative Tuberculin Test (SICTT) as indicator of M. bovis infection was conducted on 1077 cattle, 876 goats, and 195 camels. To elucidate possible risk factors for BTB transmission between animals and its potential zoonotic implication, questionnaire based face-to-face interviews were conducted in households of which 232 raised cattle, 128 goats, and 29 camels. RESULTS: The results of the SCITT were interpreted using the OIE standard (> 4 mm cut-off) for positive responses. In cattle, individual animal (n = 1077) and herd (n = 413) prevalences were 1.2% (n = 13) [Confidence Interval (CI) 95% CI, 1.0-1.3%] and 3.2% (n = 13) (95% CI, 3.0-3.4%), respectively. In goats (n = 876), none of the animals was positive. In camels, individual animal (n = 195) and herd (n = 70), BTB prevalences were 1.5% (n = 3) (95% CI,1.4-1.6%) and 2.9(n = 2) (95% CI, 0.9-4.6%), respectively. Overall, male animals were more at risk (OR = 2.6; 95% CI:1.0-8.7) when compared to females. Sharing of water points, introduction of new animals into herds and migration of animals over large distances were common events that may contribute to intra and inter-species transmission of BTB. Consumption of raw milk, lack of BTB transmission awareness, and low levels of education were common in the farming communities. CONCLUSION: The current study highlighted a low prevalence of M. bovis in cattle, goats and camels in extensive traditional livestock in Eritrea. Despite this, the spatial distribution of affected animals across most of the sampled regions and consumption of unpasteurized milk warrants surveillance, cautious and timely control measures for the disease.


Assuntos
Camelus/microbiologia , Doenças das Cabras/epidemiologia , Tuberculose Bovina/epidemiologia , Criação de Animais Domésticos , Animais , Bovinos , Eritreia/epidemiologia , Feminino , Doenças das Cabras/microbiologia , Cabras , Gado/microbiologia , Masculino , Prevalência , Inquéritos e Questionários , Teste Tuberculínico/veterinária
4.
Prev Vet Med ; 152: 16-22, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29559101

RESUMO

Accurate diagnosis of tuberculosis in cattle may be compromised in areas where there are high rates of exposure to environmental/non-tuberculous mycobacteria (NTM). This cross reaction of immune responses to Mycobacterium bovis antigens shared with NTMs can result in reduced specificity of commonly used diagnostic tests including tuberculin skin tests and the interferon gamma assay (IFN-É£). In this study we assessed the cross-reactive immune responses of M. bovis (infected) and NTM exposed animals to M. bovis and M. avium tuberculin, the ESAT6/CFP10 cocktail antigen, tuberculin derived from cultures of selected NTMs, and a panel of recombinant mycobacterium tuberculosis complex (MTBC) antigens sharing homology with orthologues in NTM. Gamma interferon (IFN-É£) responses were measured in whole blood cultures using the IFN-É£ assay and the IFN-É£ elispot assay on purified peripheral blood mononuclear cells (PBMC). We observed the expected strong IFN-É£ response to PPD-B in the M. bovis infected animals that distinguished this group from non-infected NTM exposed cattle. The IFN-É£ responses to PPD-N (M. nonchromogenicum), were relatively high in both infected and non-infected NTM exposed cattle, but were not significantly different to classify the true infection status of each group. The results indicated that the cross-reactive responses to PPD-B and/or PPD-A with PPD-N, likely arose from prior exposure to environmental non-tuberculous mycobacteria. The IFN-É£ immune responses to the 10 R-Mag measured by the IFN-É£ elispot assay revealed that three of the selected antigens, Rv3615 (ESpC), Rv0287 (esxG) and the ESAT6/CFP10, were immunogenic in the infected cattle, and distinguished the infected cattle from the non-infected NTM exposed animals. The combined data of PPDs and R-Mags derived from NTM mycobacteria may prove useful in future development of novel bTB diagnostic tests.


Assuntos
Antígenos de Bactérias/imunologia , Mycobacterium bovis/imunologia , Micobactérias não Tuberculosas/imunologia , Animais , Bovinos , Reações Cruzadas/imunologia , Irlanda , Tuberculina/imunologia
5.
Transbound Emerg Dis ; 65(2): e344-e354, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29143466

RESUMO

Transfrontier conservation areas represent an international effort to encourage conservation and sustainable development. Their success faces a number of challenges, including disease management in wildlife, livestock and humans. Tuberculosis (TB) affects humans and a multitude of non-human animal species and is of particular concern in sub-Saharan Africa. The Kavango-Zambezi Transfrontier Conservation Area encompasses five countries, including Zimbabwe, and is home to the largest contiguous population of free-ranging elephants in Africa. Elephants are known to be susceptible to TB; thus, understanding TB status, exposure and transmission risks to and from elephants in this area is of interest for both conservation and human health. To assess risk factors for TB seroprevalence, a questionnaire was used to collect data regarding elephant management at four ecotourism facilities offering elephant-back tourist rides in the Victoria Falls area of Zimbabwe. Thirty-five working African elephants were screened for Mycobacterium tuberculosis complex antibodies using the ElephantTB Stat-Pak and the DPP VetTB Assay for elephants. Six of 35 elephants (17.1%) were seropositive. The risk factor most important for seropositive status was time in captivity. This is the first study to assess TB seroprevalence and risk factors in working African elephants in their home range. Our findings will provide a foundation to develop guidelines to protect the health of captive and free-ranging elephants in the southern African context, as well as elephant handlers through simple interventions. Minimizing exposure through shared feed with other wildlife, routine TB testing of elephant handlers and regular serological screening of elephants are recommended as preventive measures.


Assuntos
Elefantes/microbiologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/veterinária , África , Animais , Animais Selvagens , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/sangue , Conservação dos Recursos Naturais , Feminino , Masculino , Mycobacterium tuberculosis/imunologia , Fatores de Risco , Estudos Soroepidemiológicos , Tuberculose/epidemiologia
6.
Transbound Emerg Dis ; 65(1): 105-113, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28332294

RESUMO

The aim of our study was to determine the association of selected potential risk factors with the presence of bovine tuberculosis (BTB) in dairy herds in Eritrea. A case-control study was conducted in the three major milk-producing regions of the country by stratified random sampling of 61 case and 65 control herds combined with completion of a standardized pretested questionnaire pertaining 36 relevant risk factors (variables). The variables were divided into two clusters, based on potential association with either "introduction" or "establishment" of BTB on the farms to elucidate association with incident or prevalent cases separately. Subsequent to univariable analysis of the 36 risk factors at herd level, 14 of these were offered to multivariable logistic regression models. Farms with higher numbers of cows, and those with concrete floors, were 3.6, and 7.5 times more at risk for presence of BTB, respectively, compared with their references. These findings will be useful as entry points for future informed decision-making towards BTB control and eradication programme in the country.


Assuntos
Fazendas , Tuberculose Bovina/epidemiologia , Animais , Estudos de Casos e Controles , Bovinos , Indústria de Laticínios , Eritreia/epidemiologia , Feminino , Modelos Logísticos , Fatores de Risco , Tuberculose Bovina/virologia
7.
PLoS One ; 12(11): e0188448, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29155877

RESUMO

Conventional control and eradication strategies for bovine tuberculosis (BTB) face tremendous difficulties in developing countries; countries with wildlife reservoirs, a complex wildlife-livestock-human interface or a lack of veterinary and veterinary public health surveillance. Vaccination of cattle and other species might in some cases provide the only suitable control strategy for BTB, while in others it may supplement existing test-and-slaughter schemes. However, the use of live BCG has several limitations and the global rise of HIV/AIDS infections has furthermore warranted the exploration of inactivated vaccine preparations. The aim of this study was to compare the immune response profiles in response to parenteral vaccination with live BCG and two inactivated vaccine candidates in cattle. Twenty-four mixed breed calves (Bos taurus) aged 4-6 months, were allocated to one of four groups and vaccinated sub-cutaneously with live M. bovis BCG (Danish 1331), formalin-inactivated M. bovis BCG, heat-killed M. bovis or PBS/Montanide™ (control). Interferon-γ responsiveness and antibody production were measured prior to vaccination and at weekly intervals thereafter for twelve weeks. At nine weeks post-priming, animals were skin tested using tuberculins and MTBC specific protein cocktails and subsequently challenged through intranodular injection of live M. bovis BCG. The animals in the heat-killed M. bovis group demonstrated strong and sustained cell-mediated and humoral immune responses, significantly higher than the control group in response to vaccination, which may indicate a protective immune profile. Animals in this group showed reactivity to the skin test reagents, confirming good vaccine take. Lastly, although not statistically significant, recovery of BCG after challenge was lowest in the heat-killed M. bovis group. In conclusion, the parenteral heat-killed M. bovis vaccine proved to be clearly immunogenic in cattle in the present study, urging further evaluation of the vaccine in challenge studies using virulent M. bovis and assessment of vaccine efficacy in field conditions.


Assuntos
Anticorpos Antibacterianos/biossíntese , Vacina BCG/administração & dosagem , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Interferon gama/biossíntese , Mycobacterium bovis/efeitos dos fármacos , Tuberculose Bovina/prevenção & controle , Animais , Bovinos , Formaldeído , Temperatura Alta , Esquemas de Imunização , Imunogenicidade da Vacina , Injeções Subcutâneas , Interferon gama/metabolismo , Masculino , Mycobacterium bovis/imunologia , Tuberculose Bovina/imunologia , Tuberculose Bovina/microbiologia , Vacinas Atenuadas , Vacinas Vivas não Atenuadas
8.
Transbound Emerg Dis ; 64(3): 815-825, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26563417

RESUMO

Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is a multihost pathogen of public health and veterinary importance. We characterized the M. bovis isolated at the human-livestock-wildlife interface of the Serengeti ecosystem to determine the epidemiology and risk of cross-species transmission between interacting hosts species. DNA was extracted from mycobacterial cultures obtained from sputum samples of 472 tuberculosis (TB) suspected patients and tissue samples from 606 livestock and wild animal species. M. bovis isolates were characterized using spoligotyping and Mycobacterial Interspersed Repetitive Units-Variable Tandem Repeats (MIRU-VNTR) on 24 loci. Only 5 M. bovis were isolated from the cultured samples. Spoligotyping results revealed that three M. bovis isolates from two buffaloes (Syncerus caffer) and 1 African civet (Civettictis civetta) belonged to SB0133 spoligotype. The two novel strains (AR1 and AR2) assigned as spoligotype SB2290 and SB2289, respectively, were identified from indigenous cattle (Bos indicus). No M. bovis was detected from patients with clinical signs consistent with TB. Of the 606 animal tissue specimens and sputa of 472 TB-suspected patients 43 (7.09%) and 12 (2.9%), respectively, yielded non-tuberculous mycobacteria (NTM), of which 20 isolates were M. intracellulare. No M. avium was identified. M. bovis isolates from wildlife had 45.2% and 96.8% spoligotype pattern agreement with AR1 and AR2 strains, respectively. This finding indicates that bTB infections in wild animals and cattle were epidemiologically related. Of the 24 MIRU-VNTR loci, QUB 11b showed the highest discrimination among the M. bovis strains. The novel strains obtained in this study have not been previously reported in the area, but no clear evidence for recent cross-species transmission of M. bovis was found between human, livestock and wild animals.


Assuntos
Animais Selvagens/microbiologia , Ecossistema , Gado , Tuberculose/veterinária , Animais , Búfalos/microbiologia , Bovinos , Humanos , Repetições Minissatélites , Mycobacterium bovis/isolamento & purificação , Tanzânia/epidemiologia , Tuberculose/epidemiologia , Tuberculose/microbiologia , Tuberculose/transmissão , Zoonoses
9.
BMC Vet Res ; 12: 80, 2016 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-27225267

RESUMO

BACKGROUND: The prevalence of bovine tuberculosis (BTB) in dairy cattle in the three major milk producing regions of Eritrea was assessed by subjecting 15,354 dairy cattle, 50 % of Eritrea's dairy cattle population, to the single intradermal comparative tuberculin test (SICTT). Skin test results were interpreted according to guidelines of the World Organization for Animal Health (OIE) with >4 mm as cutoff in skin thickness increase. In addition, we studied the relation between 'physiological' variables related to pregnancy and lactation, and the variable 'region' on the probability to be skin test positive. RESULTS: The BTB prevalences at animal and herd levels were: 21.5% and 40.9% in Maekel, 7.3% and 10% in Debub, and 0.2% and 1.6% in the Anseba region, respectively. Overall, in the regions included, prevalence was 11.3% (confidence interval (CI) 95% CI, 11.29 - 11.31%) and 17.3% (95% CI, 17.27-17.33%), at animal and herd level, respectively. Considering positive herds only, the animal BTB prevalence was 36.8%, 30.1%, and 1.8%, in Maekel, Debub and Anseba, respectively, and the overall animal prevalence within these herds was 32%. In adult dairy cattle the probability of positive reactivity in the SICTT test was highest in pregnant animals as compared to the other categories. CONCLUSION: This study reports persistent prevalence of BTB as defined by positive SICTT in the dairy sector of Eritrea, especially in the regions of Maekel and Debub that are located in the central highlands of the country. To our understanding this is the first report that has encompassed all the major dairy farms in Eritrea and it will be instrumental in advocating future BTB control programs in the dairy sector.


Assuntos
Tuberculose Bovina/epidemiologia , Animais , Bovinos , Estudos Transversais , Indústria de Laticínios , Eritreia/epidemiologia , Feminino , Masculino , Fatores de Risco
10.
Vet Immunol Immunopathol ; 169: 68-73, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26827841

RESUMO

The African buffalo (Syncerus caffer) is considered the most important maintenance host of bovine tuberculosis (BTB) in wildlife in Southern Africa. The diagnosis of Mycobacterium bovis infection in this species mostly relies on the single intradermal comparative tuberculin test (SICTT). As an alternative, the BOVIGAM® 1G, an interferon-gamma (IFN-γ) release assay, is frequently used. The test performance of cell-mediated immunity (CMI-) and humoral immunity (HI-) based assays for the detection of M. bovis infections in buffaloes was compared to identify the test or test combination that provided the highest sensitivity in the study. Buffaloes were sampled during the annual BTB SICTT testing in the Hluhluwe-iMfolozi-Park (KwaZulu-Natal, South Africa) during June 2013. A total of 35 animals were subjected to the SICTT, 13 of these tested positive and one showed an inconclusive reaction. CMI-based assays (BOVIGAM® 1G (B1G) and BOVIGAM® 2G (B2G)) as well as a serological assay (IDEXX TB ELISA) were used to further investigate and compare immune responsiveness. Thirteen SICTT positive buffaloes and one inconclusive reactor were slaughtered and a post-mortem (PM) examination was conducted to confirm BTB. Lesions characteristic of BTB were found in 8/14 animals (57.1%). Test results of individual assays were compared with serial and parallel test interpretation and the sensitivity was calculated as a percentage of test positives out of the number of SICTT positive animals with granulomatous lesions (relative sensitivity). The B1G assay showed the highest individual sensitivity (100%; 8/8) followed by the B2G assay (75%; 6/8) and the IDEXX TB ELISA (37.5%; 3/8). Therefore, using in parallel interpretation, any combination with the B1G showed a sensitivity of 100% (8/8), whereas combinations with the B2G showed a 75% sensitivity (6/8). Out of the 21 SICTT negative animals, 7 animals showed responsiveness in the B2G or IDEXX TB ELISA. In conclusion, this study has shown that the BOVIGAM® IFN-γ assay had the highest test performance.


Assuntos
Búfalos , Imunoensaio/veterinária , Tuberculose/veterinária , Animais , Animais Selvagens , Búfalos/imunologia , Testes Imunológicos/veterinária , Interferon gama/metabolismo , Sensibilidade e Especificidade , África do Sul , Teste Tuberculínico/veterinária , Tuberculose/diagnóstico
11.
Prev Vet Med ; 115(1-2): 10-7, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24703246

RESUMO

Tuberculosis caused by Mycobacterium bovis is recognized worldwide as a significant health risk in domestic cattle, farmed and wild animal species as well as in humans. We carried out spoligotyping and variable number of tandem repeat (VNTR) typing methods to characterize 490 M. bovis isolates from livestock (cattle, n=230; pig n=1) and wildlife species (n=259) originating from different farms and regions in South Africa, with the aim to further establish the genetic diversity of the isolates, study the population structure of M. bovis and elucidate the extent of interspecies transmission of bovine tuberculosis. A total of ten spoligotype patterns were identified, two of which were novel (SB2199 and SB2200) and reported for the first time in the literature, while VNTR typing revealed a total of 97 VNTR profiles. Our results showed evidence of clonal expansion for some ancestral strains as well as co-infections with two or three M. bovis strains on some of the cattle and game farms, which suggested independent introductions of infected animals from epidemiologically unrelated sources. Five spoligotypes and nine VNTR profiles were shared between cattle and wildlife. Our findings showed that besides cattle, at least 16 different animal species in South Africa are infected with bovine tuberculosis, and highlight a strong evidence of inter and intra-species transmission of M. bovis. Infection of the blue wildebeest (Connochaetes taurinus) with M. bovis is described for the first time in this report. This update in epidemiological information raises concerns that bovine tuberculosis has increased its spatial distribution in South Africa and is also affecting an increasing number of wildlife species compared to ten years ago.


Assuntos
Tuberculose Bovina/transmissão , Tuberculose/veterinária , Animais , Técnicas de Tipagem Bacteriana/veterinária , Bovinos , Variação Genética , Repetições Minissatélites , Dados de Sequência Molecular , Mycobacterium bovis/genética , Mycobacterium bovis/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase/veterinária , Prevalência , Análise de Sequência de DNA/veterinária , África do Sul/epidemiologia , Tuberculose/epidemiologia , Tuberculose/microbiologia , Tuberculose/transmissão , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/microbiologia
12.
Transbound Emerg Dis ; 61 Suppl 1: 31-42, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24382104

RESUMO

A population of approximately 70,000 rusa deer (Cervus timorensis russa) represents the most important mammal species reared for food on the island of Mauritius, being the main source of red meat for the local population. However, very limited information is available on the circulation of pathogens affecting the productivity and health of this species. To produce baseline data on the circulation of infectious pathogens in rusa deer under production, a serological survey and/or direct pathogen detection for six selected infectious diseases was undertaken in 2007 in a sample of 53% of the herds reared in semi-free-ranging conditions in hunting estates. Seropositive results were recorded for Johne's disease with an indirect ELISA test (1.7%, n = 351), heartwater with an immunofluorescence antibody test (IFAT) (95.5%, n = 178) and leptospirosis with a Microscopic Agglutination Test (MAT) (25.9%, n = 363). Significant associations were found between seroprevalence to some of the leptospiral serogroups detected (Tarassovi, Pomona, Sejroe and Mini) and age of the animals, animal density or location of the estates (being more prevalent in hotter and more humid areas). In addition, Mycobacterium bovis and M. avium subspecies paratuberculosis were confirmed in two deer carcasses by culture and PCR, respectively. No antibodies against Brucella spp. nor Rift Valley Fever virus were detected with the use of respective indirect ELISA's. The results obtained suggest that the population of rusa deer from Mauritius is exposed to a wide range of pathogens which may affect their productivity. In addition, the results highlight the potential public health risks incurred by deer industry workers and consumers. This survey fills an important gap in knowledge regarding the health of tropical deer meat in Mauritius and justifies the need to implement more regular surveys of selected pathogens in the deer population.


Assuntos
Cervos/microbiologia , Hidropericárdio/epidemiologia , Leptospirose/veterinária , Paratuberculose/epidemiologia , Testes de Aglutinação/veterinária , Animais , Anticorpos Antibacterianos/sangue , Coleta de Dados , Ensaio de Imunoadsorção Enzimática/veterinária , Técnica Direta de Fluorescência para Anticorpo/veterinária , Leptospirose/epidemiologia , Maurício/epidemiologia , Mycobacterium avium/genética , Mycobacterium bovis/genética , Mycobacterium bovis/imunologia , Reação em Cadeia da Polimerase/veterinária , Estudos Soroepidemiológicos
13.
Rev Sci Tech ; 33(2): 583-92, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25707185

RESUMO

Early discoveries in the field of tuberculosis more than a century ago indicated that the success of disease control in human populations would depend on the success of control measures in animals, and vice versa. Recognising the zoonotic importance of a cattle-derived pathogen was the beginning of the eradication of bovine tuberculosis from most of the cattle population in Europe. It was a costly and resource-intensive process, but a successful one. The resulting near disappearance of zoonotic tuberculosis from the human population exemplifies probably one of the largest One Health successes in medical history. Since that time many advances in tuberculosis diagnosis, vaccinology, molecular epidemiology and immunopathogenetic studies have been made within the disciplinary divides of human and animal health research. More recently, the discovery of similarities in the interactions between the natural hosts and the causative agents of tuberculosis, as well as similarities in the resulting disease consequences, have led to a renewed appraisal of the benefits of collaborative approaches. It is to be hoped that, in the future, the combined body of scientific knowledge will also provide the basis for practical One Health initiatives at community level.


Assuntos
Saúde Global , Internacionalidade , Tuberculose/veterinária , Zoonoses/prevenção & controle , Animais , Humanos , Incidência , Epidemiologia Molecular , Mycobacterium tuberculosis/genética , Tuberculose/epidemiologia , Tuberculose/microbiologia
14.
Transbound Emerg Dis ; 60 Suppl 1: 46-52, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24171848

RESUMO

This study reports on an investigation of Mycobacterium tuberculosis cases in mostly captive wild animals using molecular typing tools [Variable Number of Tandem Repeat (VNTR) typing and Restriction Fragment Length Polymorphism typing]. The investigation included cases from (i) the National Zoological Gardens of South Africa (NZG) recorded between 2002 and 2011; (ii) Johannesburg Zoo, where tuberculosis was first diagnosed in 2007 and has since been detected in three antelope species; (iii) a rehabilitation centre for vervet monkeys (Chlorocebus pygerythrus) in which M. tuberculosis was diagnosed in 2008; and (iv) incidental cases in other facilities including a sable antelope (Hippotragus niger), two unrelated cases in chacma baboons (Papio ursinus) (one of which was from a free-ranging troop) and a colony of capuchin monkeys (Cebus capucinus). Identical genetic profiles of the latter three isolates indicate the persistence of a single M. tuberculosis strain in this population since at least 2006. Results of the outbreak investigation in the captive vervet monkey colony indicate that it was caused by two unrelated strains, while all 13 M. tuberculosis isolates from 11 animal species in the NZG showed different VNTR patterns. A substantial increase in tuberculosis cases of 60% was recorded in the NZG, compared with the previous reporting period 1991-2001, and may indicate a countrywide trend of increasing spillover of human tuberculosis to wild animals. South Africa ranks among the countries with the highest-tuberculosis burden worldwide, complicated by an increasing rate of multidrug-resistant strains. Exposure and infection of captive wildlife in this high prevalence setting is therefore a growing concern for wildlife conservation but also for human health through potential spillback.


Assuntos
Animais Selvagens/microbiologia , Mycobacterium tuberculosis/classificação , Tuberculose/veterinária , Animais , Efeitos Psicossociais da Doença , Surtos de Doenças/veterinária , Humanos , Repetições Minissatélites , Tipagem Molecular , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Polimorfismo de Fragmento de Restrição , África do Sul , Tuberculose/diagnóstico , Tuberculose/epidemiologia
15.
Transbound Emerg Dis ; 60 Suppl 1: 60-6, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24171850

RESUMO

Mycobacterium bovis is the causal agent of bovine tuberculosis (BTB), with a diverse host range, extending from livestock to domestic and captive wild animals as well as free-ranging wildlife species. In South Africa, BTB is endemic in the Kruger National Park (KNP) and the Hluluwe iMfolozi National Park (HiP), where the high prevalence of M. bovis infections in buffalo herds has led to infection of a number of wildlife species. This has raised concerns about the spillover into the rhinoceros population, a species known to be susceptible to both M. bovis and Mycobacterium tuberculosis, jeopardizing breeding and relocation projects that serve to conserve and protect this species. In view of the advantages of the interferon-gamma (IFN-γ) assay in the diagnosis of BTB in a variety of species worldwide, such an assay has been developed for rhinoceroses by Morar and co-workers in 2007. In this study, this assay was optimized using recombinant eukaryotic rhinoceros IFN-γ and the lower detection limit was calculated to be 0.5 ng/ml. Subsequently, assessing the detection of native rhinoceros IFN-γ protein in whole-blood samples revealed stimulation with each of the mitogens: pokeweed (PWM), phytohaemagglutinin (PHA) & phorbol 12-myristate 13-acetate and calcium ionophore (PMA/CaI), though most prominently with the latter two. In addition, samples collected from 52 clinically healthy rhinoceroses, of presumed negative BTB status, from two different areas in South Africa were used to determine the cut-off value for a negative test result. This was calculated to be 0.10 (OD490 nm ) and as determined in this study is a preliminary recommendation based on IFN-γ responses observed in samples from BTB-free rhinoceroses only.


Assuntos
Interferon gama/sangue , Mycobacterium bovis/isolamento & purificação , Perissodáctilos/microbiologia , Tuberculose/diagnóstico , Tuberculose/veterinária , Animais , Bovinos , Proteínas Recombinantes/imunologia , África do Sul/epidemiologia , Tuberculose/epidemiologia
17.
Comp Immunol Microbiol Infect Dis ; 36(3): 269-85, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23218541

RESUMO

Mycobacterium bovis, causing bovine tuberculosis (BTB), has been recognized as a global threat at the wildlife-livestock-human interface, a clear "One Health" issue. Several wildlife species have been identified as maintenance hosts. Spillover of infection from these species to livestock or other wildlife species may have economic and conservation implications and infection of humans causes public health concerns, especially in developing countries. Most BTB management strategies rely on BTB testing, which can be performed for a range of purposes, from disease surveillance to diagnosing individual infected animals. New diagnostic assays are being developed for selected wildlife species. This review investigates the most frequent objectives and associated requirements for testing wildlife for tuberculosis at the level of individual animals as well as small and large populations. By aligning those with the available (immunological) ante mortem diagnostic assays, the practical challenges and limitations wildlife managers and researchers are currently faced with are highlighted.


Assuntos
Animais Selvagens/microbiologia , Monitoramento Epidemiológico , Tuberculose Bovina , Animais , Bovinos , Países em Desenvolvimento , Reservatórios de Doenças/microbiologia , Humanos , Mycobacterium bovis/imunologia , Tuberculose Bovina/diagnóstico , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/transmissão , Zoonoses/diagnóstico , Zoonoses/epidemiologia , Zoonoses/transmissão
18.
Vet Immunol Immunopathol ; 149(3-4): 292-7, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22921684

RESUMO

The ongoing spread of bovine tuberculosis (BTB) in African free-ranging lion populations, for example in the Kruger National Park, raises the need for diagnostic assays for BTB in lions. These, in addition, would be highly relevant for zoological gardens worldwide that want to determine the BTB status of their lions, e.g. for translocations. The present study concerns the development of a lion-specific IFN-γ assay, following the production and characterization of monoclonal antibodies specific for lion interferon-gamma (IFN-γ). Recombinant lion IFN-γ (rLIFN-γ) was produced in mammalian cells and used to immunize mice to establish hybridoma cell lines producing monoclonal antibodies. These were used to develop a sensitive, lion IFN-γ-specific capture ELISA, able to detect rLIFN-γ to the level of 160 pg/ml. Recognition of native lion IFN-γ was shown in an initial assessment of supernatants of mitogen stimulated whole blood cultures of 11 known BTB-negative lions. In conclusion, the capture ELISA shows potential as a diagnostic assay for bovine tuberculosis in lions. Preliminary results also indicate the possible use of the test for other (feline) species.


Assuntos
Ensaio de Imunoadsorção Enzimática/veterinária , Interferon gama/análise , Interferon gama/imunologia , Leões/imunologia , Mycobacterium bovis/imunologia , Tuberculose/veterinária , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Bovinos , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Interferon gama/sangue , Interferon gama/genética , Leões/sangue , Leões/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium bovis/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Tuberculose/sangue , Tuberculose/imunologia , Tuberculose/microbiologia
19.
Eur J Gastroenterol Hepatol ; 9 Suppl 1: S23-6, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22498903

RESUMO

The annual incidence of peptic ulcer disease in developed countries is around one to three per thousand inhabitants. Since the introduction of acid-secretion inhibitors, the indirect costs of this disease, which has a high rate of relapse, have steadily decreased, although direct costs have been increasing. The possibility of healing the patient through Helicobacter pylori eradication has the potential for a huge economic impact considering the long-term cost: benefit ratio. A recent study has shown that H. pylori eradication therapy can save between US$750,000 and US$1,000,000 per year per million inhabitants in western Europe compared to maintenance or episodic therapy. This paper reviews the cost implications of various management strategies for peptic ulcer disease, comparing the cost: benefit ratios of five different treatment regimens.

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