Intradermal Tuberculin Skin Test Research Articles

Tuberculin skin test and Interferon-gamma release assay agreement, and associated factors with latent tuberculosis infection, in medical and nursing students in Bandung, Indonesia.

No gold standard diagnostic test exists for latent tuberculosis infection (LTBI). The intra-dermal tuberculin skin test (TST) has known limitations and Interferon-gamma release assays (IGRA) have been developed as an alternative. We aimed to assess agreement between IGRA and TST, and risk factors for test positivity, in Indonesian healthcare students. Medical and nursing students starting their clinical training were screened using IGRA and TST. Agreement between the two tests was measured using Cohen's Kappa coefficient. Logistic regression was used to identify factors associated with test positivity. Of 266 students, 43 (16.2%) were IGRA positive and 85 (31.9%) TST positive. Agreement between the two tests was 74.7% (kappa 0.33, 95% CI 0.21-0.45, P<0.0001). Students who had direct contact with family or friends with TB were less likely to be test positive using IGRA (AOR 0.18, 95% CI 0.05-0.64) and using TST (AOR 0.51, 95% CI 0.26-0.99). Test positivity for LTBI was lower when measured by IGRA than by TST, with poor agreement between the two tests. Known close TB contact was unexpectedly negatively associated with positivity by either test. Longitudinal studies may be required to help determine the best test for LTBI in healthcare students in Indonesia.

Tuberculosis detection in nonhuman primates is enhanced by use of testing algorithms that include an interferon-γ release assay.

To develop a testing algorithm that incorporates multiple assays to evaluate host cellular and humoral immunity and antigen detection concerning Mycobacterium tuberculosis complex (MTBC) infection in captive nonhuman primates. Cohorts of captive-bred and wild-caught macaques from 5 different geographic regions. Macaques were tested for MTBC infection by use of a γ interferon tuberculosis (GIFT) assay, an interferon-γ release assay, and other assays. In the first 2 cohorts (n = 15 and 181), initial validation of the GIFT assay was performed by use of experimentally infected and unexposed control macaques. In the next 3 cohorts (n = 59, 42, and 11), results were obtained for opportunistically collected samples from macaques exposed during spontaneous outbreaks. Sensitivity and specificity of the GIFT assay in the control cohorts were 100% and 97%, respectively, and were variable but enhanced by incorporating results from multiple assays in spontaneous outbreaks. The detection and management of MTBC infection in captive nonhuman primate populations is an ongoing challenge, especially with animal imports and transfers. Despite standardized practices of initial quarantine with regular intradermal tuberculin skin testing, spontaneous outbreaks continue to be reported. Since infection encompasses a range of disease manifestations over time, a testing algorithm that incorporates multiple assays, such as the GIFT assay, to evaluate host cellular and humoral immunity in addition to agent detection is needed. Testing a combination of samples from controlled studies and spontaneous outbreaks of MTBC infection in nonhuman primates would advance the development and validation of a functional algorithm that incorporates promising tools such as the GIFT assay.

Tuberculosis in goats in Benoue area of North Cameroon: Prevalence, diagnostic performance of intradermal tuberculin skin test and zoonotic risk factors

Tuberculosis (TB) due to Mycobacterium bovis is a wasting disease of animals with severe public health significance. Though widely diagnosed in cattle and the performance of Tuberculin Skin Test (TST) at different cut-off points compared in various environmental conditions, there is dearth of information with respect to TB in goats in Cameroon. This study estimated the prevalence of bovine TB in goats in Benuoe area of Cameroon, based on the performance of TST against detection of tuberculous-like lesions and acid-fast bacilli as gold tests. The study detected goat TB based on tuberculous-like lesions (27.87%), acid-fast bacilli (3.29%); and bovine TB positive reactions (12.28%, 95%CI: 9.19–15.95), (8.95%, 95%CI: 6.31–12.23) and (5.37%, 95%CI: 3.36–8.09) at Single intradermal cervical tuberculin (SICT) ≥2.5mm, ≥3mm, and ≥4mm and (2.30%, 95%CI: 1.06–4.32), (1.79%, 95%CI: 0.72–3.65) and (1.02%, 95%CI: 0.28– 2.60) at Single intradermal comparative cervical tuberculin (SICCT) ≥2mm, ≥3mm, and ≥4mm cut-off points, respectively. SICT and SICCT sensitivity (11.76%) against detection of tuberculous-like lesions was significantly lower [p&lt;0.05] with slight agreements [Kappa=0.161] compared to sensitivity (100%) and perfect agreements [Kappa=1.00] against detection of acid-fast bacilli at these cut-offs. The Bayesian model revealed a goat TB prevalence of 18.41% (95%CI: 11.73–27.00) using SICT and 4.28 (95%CI: 1.26–8.60) using SICCT with the performance characteristic being higher for SICT than SICCT at ≥2mm cut-off. However, two-graph ROC (TG-ROC) analysis revealed that the optimal goat TB diagnosis with SICCT was at ≥2mm cut-off point. Many goat handlers were aware of health hazards of zoonotic TB but ignorant about goat TB and its possible zoonotic transmission to humans. The study reports the first comparative tuberculin skin test of goats in Benoue area of North-Cameroon and confirmed that zoonotic TB is a neglected health and production problem of goats in Cameroon that needs further investigated.

Detection of tuberculosis in cynomolgus macaques (Macaca fascicularis) using a supplementary Monkey Interferon Gamma Releasing Assay (mIGRA)

Cynomolgus monkeys (Macaca fascicularis; MF) are commonly used as nonhuman primate models for pharmaceutical product testing. In their habitat range, monkeys have close contact with humans, allowing the possibility of bidirectional transmission of tuberculosis (TB) between the two species. Although the intradermal tuberculin skin test (TST) is used for TB detection in MF, it has limitations. Herein, we established the mIGRA, combining human QuantiFERON-TB Gold-Plus and monkey IFN-γ ELISApro systems, and used it to investigate 39 captive MF who were cage-mates or lived in cages located near a monkey who died from the naturally TB infection. During a 12-month period of study, 14 (36%), 10 (26%), and 8 (21%) monkeys showed TB-positive results using the mIGRA, the TST, and TB culture, respectively. Among the 14 mIGRA-positive monkeys, 8 (57.1%) were TST-positive and 7 (50%) were culture-positive, indicating early TB detection in the latent and active TB stages with the mIGRA. Interestingly, 3 (37.5%) of the TST-negative monkeys were culture-positive. Our study showed that the mIGRA offers many advantages, including high sensitivity and high throughput, and it requires only one on-site visit to the animals. The assay may be used as a supplementary tool for TB screening in MF.

Study on the prevalence and risk factors of bovine tuberculosis in dairy cattle in Adama city, central Ethiopia

Bovine tuberculosis (bTB) is a serious infectious disease of cattle with significant economic impact and public health risk. It is particularly important in Ethiopia where effective control measures are lacking. This cross-sectional study was carried out between April and July 2016 on 1038 cattle selected from 206 dairy farms in Adama city located in central Ethiopia to estimate the prevalence of bTB and identify the potential risk factors using comparative intradermal tuberculin skin test. Accordingly, the individual animal level prevalence was found to be 2.1% (95% CI: 1.35 – 3.22). Of the 206 dairy farms included in the study, 7.3% (95% CI: 4.29 – 11.98) had one or more 15 cattle positive for the tuberculin test. Furthermore, 5.5% of the examined cattle were found reactive for atypical Mycobacterium. Among the risk factors considered, age and lactation status of the animals were significantly associated (p&lt; 0.05) with the prevalence of bTB. It was noted that the apparent prevalence of bTB positive reactivity was greater in young and non-lactating cattle than their counterparts. In conclusion, the present study revealed 2.1% prevalence of bTB in the dairy farms investigated and culling of positive reactors is recommended as a feasible control intervention.&#x0D; Keywords: Adama; Bovine tuberculosis; CIDT; dairy cattle; Ethiopia

Prevalence Of Bovine Tuberculosis In Different Cattle Breeds In Dairy Farm In Egypt

Due to direct economic repercussions on livestock and indirect consequences for human health, knowing the prevalence rates of bovine tuberculosis is essential to define an effective control strategy. Our study was performed in 32 dairy cattle farms as we subjected 10800 dairy cattle to the Single Intradermal Comparative Tuberculin skin Test (SICTT). The skin test was interpreted according to guidelines of the World Organization for animal health (OIE). Twenty five farms (78%) have reactors to the SICTT. We also studied the relation between physiological variables with breeds, pregnancy, lactation, size of farms and the other risk factors explained in the study. Out of the 10800 tested animals, 228 (2.1%) were reactors to the skin test. The factors identified as possibly enhancing the risk of bovine tuberculosis (bTB) were herd size, age of animal, farming (housing) conditions. Other factors including breed and physiological status of the animal did not contribute to tuberculin sensitivity. The finding that large size and intensively (often poorly) managed herds were at greater risk of bovine tuberculosis and suggests that significance of bTB is increasing in Egypt parallel to an increase in the dairy operation. This surely indicates that if measures are not taken promptly, the impact of the economy and public health could be enormous. It was concluded that bTB continues to infect animals in Egypt but the prevalence was moderate, nevertheless the continued threat of economic loss in animal industry due to the persistence of bTB that should not be ignored.

Prevalence of bovine tuberculosis in the Aksu Region of Xinjiang, China, between 1985 and 2016

ABSTRACT Prevalence of bovine tuberculosis infection in cattle in Aksu Prefecture determined by intradermal tuberculin skin test (TST), between 1985 and 2016. Cattle were analyzed according to region, feeding pattern, herds and age. A total of 890,009 cattle were tested, with overall bovine tuberculosis prevalence of 0.13% (1172/890009). Statistically significant difference was found in feeding pattern and herds. Prevalence in cows (0.19%, 615/327022) was higher than that in beeves (P&lt; 0.01, OR= 1.903, 95% CI = 1.696 to 2.134). Significant difference (P&lt; 0.01; OR= 2.238, 95%; CI= 1.937 to 2.585) was evident for rates for bovine tuberculosis in the peasant household (0.12%, 942/802343) and farm groups (0.26%, 230/87666). The overall prevalence of bTB was decreased in the Aksu Prefecture, especially the positive rate was under 0.1% in 2010s. We concluded that the control measures forbovine tuberculosis in the Aksu region cattle herds are effective.

Bovine tuberculosis in Eastern Ethiopia: prevalence, risk factors and its public health importance

Bovine tuberculosis is among the primary zoonotic disease caused by Mycobacterium bovis. A cross-sectional study was conductedon 315 cattle in selected areas of eastern Ethiopia, aiming to estimate the occurrence of bovine tuberculosis using comparative intradermal tuberculin skin test and assess cattle owners’ awareness on its public health implication. Random sampling method was applied in order to select animals from farm/household. Forty three farm/household owners of tuberculin tested animals were interviewed using pre-tested structured questionnaires. The overall prevalence of bovine tuberculosis was 20.3 % (n=64) in dairy cattle at recommended cut off >4 mm. From a total of 43 farms/households tested, 22 were positive; each farm exhibited at least one tuberculin positive reactor animal with a total herd level prevalence of 51.2 %. The prevalence of bovine tuberculosis in individual animal level was significantly different (χ2=45.2; P-value <0.001) in different sites. Farming system, herd size and other risk factors were significantly (P<0.05) associated with bovine tuberculosis occurrence. Of the total interviewed farm owners, only 33 % had the knowledge of or had heard about bovine tuberculosis and 23 % respondents were aware of the zoonotic importance of the disease. More than 50 % of the interviewees had shown their preference of raw milk consumption. The study showed bovine tuberculosis is highly prevalent. The majority of cattle owners lack awareness about the disease and its public health significance. Awareness rising about the disease, its transmission and zoonotic implication is of great importance for reduction and control measures.

Bovine tuberculosis in eastern Ethiopia: prevalence, risk factors and its public health importance

BackgroundBovine tuberculosis is among the primary zoonotic disease caused by Mycobacterium bovis which has significant impact on the health of livestock and human. It has been significantly a cause for great economic loss in animal production.MethodologyA cross-sectional study was conducted from December 2014 to June 2016 on 315 cattle in selected areas of eastern Ethiopia, aiming to estimate the occurrence of bovine tuberculosis using comparative intradermal tuberculin skin test and assess cattle owners’ awareness on its public health implication. Random sampling method was applied in order to select animals from farm/household and associated risk factors were recorded before purified protein derivative (PPD) injection. Forty three farm/household owners of tuberculin tested animals were interviewed using pre-tested structured questionnaires.ResultsThe overall prevalence of bovine tuberculosis was 20.3% (n = 64) in dairy cattle at recommended cut off > 4 mm. From a total of 43 farms/households tested, 22 were positive; each farm exhibited at least one tuberculin positive reactor animal with a total herd level prevalence of 51.2%. The prevalence of bovine tuberculosis in individual animal level was significantly different (χ2 = 45.2; P-value = 0.000) in different sites with a higher prevalence (50%) in Dire Dawa. Farming system, herd size and other risk factors were significantly (p < 0.05) associated with bovine tuberculosis occurrence. Of the total interviewed farm owners, only 33% had the knowledge of or had heard about bovine tuberculosis and 23% respondents were aware of the zoonotic importance of the disease. More than 50% of the interviewees had shown their preference of raw milk consumption. Out of the total interviewed households, 3 (7%) farm workers had TB cases that had direct contact with the animals.ConclusionThe study showed bovine tuberculosis is highly prevalent. Associated risk factors contributed to the prevalence of the disease in cattle and its transmission. Moreover, the majority of cattle owners lack awareness about the disease and its public health significance. Awareness rising about the disease, its transmission and zoonotic implication is of great importance for reduction and control measures. Evidence of tuberculosis patient farm attendants calls also for further detail investigation.

Prevalence and risk factors analysis of bovine tuberculosis in cattle raised in mixed crop-livestock farming system in Tigray region, Ethiopia.

Bovine tuberculosis (BTB) is a disease of animal and public health importance in developing countries. In rural Ethiopia, there is potential for a shift in the epidemiologic of this disease driven by transformation of dairy industry. This includes gradual change from the traditional mixed crop-livestock husbandry practice to a semi-intensification system. It is therefore, essential to document the prevalence and risk factors of BTB to continuously update the designing and implementation of control and prevention strategies. Here, we present findings of a cross-sectional study on the prevalence and associated risk factors of BTB among cattle reared under mixed crop-livestock farming system in Tigray region, Ethiopia. A multistage purposive sampling approach was used to select districts, villages, herds and individual cattle. A total of 1,357 cattle from 310 herds were examined for BTB infection using a comparative intradermal tuberculin skin test (CIDT). Questionnaires were used to gather data on herd structure and herd management practices. A multilevel logistic mixed effect model was used to determine risk factors after accounting for clustering effect at three levels (village, herd and individual animal). Overall prevalence of BTB was 4.3% (95% CI=3.4-5.6), with the highest prevalence recorded in Alamata district (5.6%) and lowest in Korem (1.6%). Multilevel logistic mixed effect model analysis identified exotic breed (OR=3, p=0.014), closed barn (OR=2.6, p=0.018), large herd size (OR=2.6, p=0.05) and purchase of cattle (OR=2.1, p=0.027) as important risk factors for BTB. Taken together, these findings suggest that the current dairy development program centred on the introduction of exotic and or crossed animals could have contributed to changing epidemiological situations of BTB in the study area.

Prevalence of bovine and avian tuberculosis in camel herds and associated public health risk factors in Isiolo County, Kenya.

A cross-sectional study was conducted among 308 lactating camels selected from 15 herds from three different camel milk clusters in Isiolo County, Kenya, to determine prevalence of bovine and avian tuberculosis using Single Comparative Intradermal Tuberculin Skin test. Seventy-five (75) questionnaires were administered to pastoralists/herders, and focus group discussions were conducted among 3-5 pastoralists/herders selected from each camel herd to collect information on camel husbandry and health management practices and knowledge on tuberculosis in livestock and wildlife. An overall prevalence of bovine and avian reactors was 3.57 and 18.18%, respectively, with bovine and avian reactors for different clusters being 2.38, 3.82, and 4.48% and 25, 17.2, and 11.94%, respectively. There was significant difference (p < 0.05) in prevalence of bovine and avian reactors between different clusters. There was a negative correction (r = -0.1399) between herd size and bovine reactors, while there was a positive correlation (r = 0.0445) between herd size and avian reactors. The respondents indicated that camel herds are exposed to several risk factors like close contact with other herds or livestock or wildlife during grazing and at watering points. Pastoralists have poor knowledge on mode of infection and transmission of bovine or avian tuberculosis. The high prevalence of bovine and avian reactors and pastoralists' poor knowledge on mode of transmission signify potential risk to public health.

Development and evaluation of an interferon gamma assay for the diagnosis of tuberculosis in red deer experimentally infected with Mycobacterium bovis

BackgroundRed deer (Cervus elaphus) is regarded as an epidemiologically relevant host for Mycobacterium bovis (M. bovis) and closely related members of the Mycobacterium tuberculosis complex that cause animal tuberculosis (TB). The standard antemortem screening test for the detection of TB in deer is the intradermal tuberculin skin test, but the detection of interferon-gamma (IFNγ) produced by white blood cells exposed to M. bovis antigens can be used as an alternative or supplemental assay in most TB eradication/control programs. This study aims to develop an in-house sandwich ELISA for deer IFNγ, based on the cross-reactivity of the antibodies to both cervid and bovine IFNγ, and to evaluate the potential of this assay to detect M. bovis-infected red deer in response to the in vitro stimulation of whole-blood cells with bovine purified protein derivative (bPPD), p22 protein complex derived from bPPD or using the specific tuberculous mycobacterial proteins ESAT-6/CFP-10, Rv3615c and Rv3020c. The positive control stimulant used in this study was pokeweed mitogen, which resulted in a consistent induction of IFNγ in samples from red deer, thus allowing the interpretation of the assay.ResultsThe percentage of animals correctly classified by this technique as M. bovis non-infected was 100%. The detection of infected animals as positive was high and ranged widely depending upon the antigen and the cut-off value applied, as well as the time after infection. Our findings indicate that this protocol may serve as a reliable assay for the antemortem diagnosis of TB from the initial stage of M. bovis-infection, and may also be adequately sensitive.ConclusionsThe suggested optimal antigens and cut-off are bPPD, p22 and the combination of ESAT-6/CFP-10 and Rv3020c with a 0.05 Δ optical density, which yielded a up to 100% correct classification of TB positive and negatve red deer under our experimental conditions. This technique will aid in TB testing of farmed and translocated deer. Future studies should evaluate the ability of this IFNγ assay to detect specific responses under field conditions.

Tuberculin Skin Testing Boosts Interferon Gamma Responses to DIVA Reagents in Mycobacterium bovis-Infected Cattle.

Mycobacterium bovis BCG vaccination sensitizes cattle to bovine tuberculin, which compromises the use of the current bovine tuberculosis (TB) surveillance tests. Although the performance of a blood test (that utilizes antigens expressed by Mycobacterium bovis but not by BCG) capable of discriminating infected from vaccinated animals (DIVA interferon gamma test [DIT]) has been evaluated in naturally infected TB field reactors, there is a need to perform similar analysis in a BCG-vaccinated M. bovis-infected population. Furthermore, we explored different scenarios under which a DIT may be implemented alongside BCG vaccination: (i) serial testing to resolve potential false-positive skin test results or (ii) a standalone test to replace the single intradermal comparative cervical tuberculin (SICCT) skin test. Our results demonstrated significantly better relative test sensitivity when the DIT was evaluated in a serial test scenario. Direct comparison of pre- and post-skin test blood samples revealed that the SICCT test induced significant boosting of the gamma interferon response in M. bovis-infected animals to both the ESAT-6-CFP-10 and Rv3615c peptide cocktails that comprise the DIT, which persisted for the ESAT-6-CFP-10 reagent for at least 14 days. Importantly, no similar boosting effects were observed in noninfected BCG vaccinates, suggesting that DIVA blood testing after a recent skin test would have minimal impact on test specificity.

Meta-analyses of the sensitivity and specificity of ante-mortem and post-mortem diagnostic tests for bovine tuberculosis in the UK and Ireland

Bovine Tuberculosis (bTB) in cattle is a global health problem and eradication of the disease requires accurate estimates of diagnostic test performance to optimize their efficiency. The objective of this study was, through statistical meta-analyses, to obtain estimates of sensitivity (Se) and specificity (Sp), for 14 different ante-mortem and post-mortem diagnostic tests for bTB in cattle. Using data from a systematic review of the scientific literature (published 1934–2009) diagnostic Se and Sp were estimated using Bayesian logistic regression models adjusting for confounding factors. Random effect terms were used to account for unexplained heterogeneity. Parameters in the models were implemented using Markov Chain Monte Carlo (MCMC), and posterior distributions for the diagnostic parameters with adjustment for covariates (confounding factors) were obtained using the inverse logit function. Estimates for Se and/or Sp of the tuberculin skin tests and the IFN-γ blood test were compared with estimates published 2010–2015. Median Se for the single intradermal comparative cervical tuberculin skin (SICCT) test (standard interpretation) was 0.50 and Bayesian credible intervals (CrI) were wide (95% CrI 0.26, 0.78). Median Sp for the SICCT test was 1.00 (95% CrI 0.99, 1.00). Estimates for the IFN-γ blood test Bovine Purified Protein Derivative (PPD)-Avian PPD and Early Secreted Antigen target 6 and Culture Filtrate Protein 10 (ESAT-6/CFP10) ESAT6/CFP10 were 0.67 (95% CrI 0.49, 0.82) and 0.78 (95% CrI 0.60, 0.90) respectively for Se, and 0.98 (95% CrI 0.96, 0.99) and 0.99 (95% CrI 0.99, 1.00) for Sp. The study provides an overview of the accuracy of a range of contemporary diagnostic tests for bTB in cattle. Better understanding of diagnostic test performance is essential for the design of effective control strategies and their evaluation.

Transmission dynamics and elimination potential of zoonotic tuberculosis in morocco.

Bovine tuberculosis (BTB) is an endemic zoonosis in Morocco caused by Mycobacterium bovis, which infects many domestic animals and is transmitted to humans through consumption of raw milk or from contact with infected animals. The prevalence of BTB in Moroccan cattle is estimated at 18%, and 33% at the individual and the herd level respectively, but the human M. bovis burden needs further clarification. The current control strategy based on test and slaughter should be improved through local context adaptation taking into account a suitable compensation in order to reduce BTB prevalence in Morocco and decrease the disease burden in humans and animals. We established a simple compartmental deterministic mathematical model for BTB transmission in cattle and humans to provide a general understanding of BTB, in particular regarding transmission to humans. Differential equations were used to model the different pathways between the compartments for cattle and humans. Scenarios of test and slaughter were simulated to determine the effects of varying the proportion of tested animals (p) on the time to elimination of BTB (individual animal prevalence of less than one in a thousand) in cattle and humans. The time to freedom from disease ranged from 75 years for p = 20% to 12 years for p = 100%. For p > 60% the time to elimination was less than 20 years. The cumulated cost was largely stable: for p values higher than 40%, cost ranged from 1.47 to 1.60 billion euros with a time frame of 12 to 32 years to reach freedom from disease. The model simulations also suggest that using a 2mm cut off instead of a 4mm cut off in the Single Intradermal Comparative Cervical Tuberculin skin test (SICCT) would result in cheaper and quicker elimination programs. This analysis informs Moroccan bovine tuberculosis control policy regarding time frame, range of cost and levels of intervention. However, further research is needed to clarify the national human-bovine tuberculosis ratio in Morocco.

Tuberculosis Infection in Cattle and Cattle Owners in North Eastern Parts of Ethiopia

Introduction: Ethiopia is one of the highest TB burden countries in the world. Transmission of M. tuberculosis between humans is well known, however, little is known about the transmission of M. tuberculosis complex species between human and animals, in particular cattle. The purpose of this study was, therefore, to investigate the status of bovine tuberculosis infection in cattle owned by tuberculosis suspected households and isolate M. tuberculosis complex species from sputum of chronic coughers in North Wollo Zone of the Amhara National Regional State, Ethiopia. Method: A cross-sectional study was conducted in selected Kebeles of North Wollo Zone. An intradermal tuberculin skin test was carried out on 381 cattle and sputum samples collected from 124 chronic coughers. Sputum samples were cultured and positive ones were identified by polymerase chain reaction using RD4 and RD9 as a marker. Result: Of the 124 sputum samples cultured, 4/ 124 (3.2%) were positive. Polymerase Chain Reaction using has confirmed that 2/4 (50%) were found to be M. tuberculosis while the rest was atypical Mycobacterial species. Of the 381 tested cattle 5/381 (1.31%) and 10/38 (2.63%) were found positive according to manufacturer recommendation (with a cutoff value > 4 mms) and a cutoff value > 2 mms, respectively. About 67% (6/9) of the individuals who owned positive cattle were having the habit of drinking raw milk. Among the ten positives, five of them resided in lowland (Kolla) areas (1300-1500 mabs). However, none of the owners of tuberculin positive cattle were found to be TB positive. Conclusion: This study has shown 3.2% of culture positivity and of these two were found to be M. tuberculosis. The sputum sample culturing from suspected chronically coughing individuals would help detection of the TB causative agents. According to the current findings BTB is considerable in Ethiopia and cattle should be seen as a potential source of zoonotic TB to humans

Evaluation of different diagnostics tests for detection of tuberculosis in cattle

Single intradermal cervical tuberculin skin testing (TST) is only available diagnostic test for detection of tuberculosis in bovines in India. TST may miss some positive tuberculosis cases due to its limited sensitivity. Present study was aimed to evaluate different diagnostic tests (ELISA and PCR) for detection of tuberculosis in cattle. A total of 123 randomly selected cattle were examined for tuberculosis with TST, ELISA and PCR. Detection rate of tuberculosis by TST, ELISA and PCR were 8.94%, 13.82% and 5.69% respectively. This detection rate could be increased up to 18.69% by using multiple diagnostic tests serially. ELISA and PCR could detect the disease condition in advance stage, failing to detect by TST. Use of multiple diagnostic tests may minimize chance of missing the positive cases.

AB0433 Quantiferon-Tb More Useful than Tuberculin Skin Test for Latent Tuberculosis Screening: A Hospital Experience

BackgroundThe use of interferon gamma-release assays (IGRA) has become a very useful tool in the detection of latent tuberculosis (LTB) among patients on biological disease modifying anti-rheumatic drugs (bDMARDs). The...

Comparison between intradermal tuberculin skin testing and interferon gamma ELISA for diagnosis of bovine tuberculosis in Jabalpur region

Interferon gamma ELISA was compared with the conventional tuberculin testing for the antemortem diagnosis of bovine tuberculosis. A single intradermal tuberculin skin test (SID) was carried out as per the standard protocol on animals from which 10 ml blood was collected earlier and Mycobacterium bovis gamma interferon ELISA for cattle was performed. Out of the 100 animals tested, 36 animals (36%) were found positive by tuberculin testing and 24% (22% bovine and 2% avian tuberculin) were found positive for interferon gamma. From 36 tuberculin positive cases only 16 (44.44%) were positive for interferon gamma. Interestingly, from 64 tuberculin negative cases, 8 (12.50%) were determined to be positive for interferon gamma. It can be concluded that SID has a high rate of false-positive as well as false-negative results and the specificity of interferon gamma assay was more than SID.

Bovine tuberculosis and its associated risk factors in pastoral and agro-pastoral cattle herds of Afar Region, Northeast Ethiopia

Bovine tuberculosis (BTB) has a potential public health risk and economic impact in pastoralist community whose livelihood depends on their livestock. A cross-sectional study was carried out from September, 2008 to June, 2011 on 1087 cattle under pastoral and agro-pastoral production system in four districts of Afar Pastoral Region of Ethiopia using comparative intradermal tuberculin skin test to estimate the prevalence of BTB and assess the associated risk factors for infection. The individual animal prevalence of BTB in cattle of Afar pastoralists was 11% (95% confidence interval (CI): 9 to 13%) with ≥ 4 mm cut-off and 18% (95% CI: 16% to 21%) with ≥2 mm cut-off. The herd prevalence was 44% (95% CI: 36 to 51%) and 56% (95% CI: 48 to 63%) at ≥4 and ≥2 mm cut-off points, respectively. In bivariate analysis, the prevalence was significantly associated with study districts, herd size, sex and age, and in multivariable logistic regression analysis, the statistical significance was maintained with study district, age and herd size of the cattle. In conclusion, the present study revealed a moderately high prevalence of BTB in Afar Pastoral Region of Ethiopia and further investigation is recommended to assess the zoonotic significance of the disease to the pastoralist communities of the region. Key words: Bovine tuberculosis, prevalence, risk factors, comparative intradermal tuberculin test, Afar pastoral region, Ethiopia.