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An otherwise healthy 72-year-old Chinese patient diagnosed with exudative age-related macular degeneration and decreased vision in left eye was fully investigated. The retrospective analysis of past multimodal imaging revealed bilateral severe choroidal neovascularization and choroiditis associated with a positive tuberculin skin testing and interferon-gamma release assay (QuantiFERON-TB Gold – Cellestis®, Chadstone, VIC, Australia) suggestive of latent ocular tuberculosis. The variable presentation and tests’ results interpretation represent the greatest limitations in understanding and treating intraocular TB (IOTB). This may present without any other systemic symptoms, the intraocular tissues are of limited access to biopsies and other tests, including imaging and immunological tests, are of relative value. This case highlights how variable may be the presentation of IOTB, which can be easily misdiagnosed leading to a delayed treatment and worse prognosis.

BACKGROUND: A single 2-year National Health and Nutrition Examination Survey (NHANES) cycle is designed to provide accurate and stable estimates of conditions with prevalence of at least 10%. Recent NHANES-based estimates of a tuberculin skin test ≥10 mm in the noninstitutionalized U.S. civilian population are at most 6.3%. METHODS: NHANES included a tuberculin skin test in 1971–1972, 1999–2000, and 2011–2012. We examined the robustness of NHANES-based estimates of the U.S. population prevalence of a skin test ≥10 mm with a bias analysis that considered the influence of non-U.S. birth distributions and within-household skin test results, reclassified borderline-positive results, and adjusted for tuberculin skin test item nonresponse. RESULTS: The weighted non-U.S. birth distribution among NHANES participants was similar to that in the overall U.S. population; further adjustment was unnecessary. We found no evidence of bias due to sampling multiple participants per household. Prevalence estimates changed 0.3% with reclassification of borderline-positive tuberculin skin test results and 0.2%–0.3% with adjustment for item nonresponse. CONCLUSIONS: For estimating the national prevalence of a tuberculin skin test ≥10 mm during these three survey cycles, a conventional NHANES analysis using the standard participant weights and masked design parameters that are provided in the public-use datasets appears robust.

We report on a 15-year-long outbreak of bovine tuberculosis (bTB) in wildlife from a Brazilian safari park. A timeline of diagnostic events and whole-genome sequencing (WGS) of 21 Mycobacterium bovis isolates from deer and llamas were analyzed. Accordingly, from 2003 to 2018, at least 16 animals, from eight species, died due to TB, which is likely an underestimated number. In three occasions since 2013, the deer presented positive tuberculin tests, leading to the park closure and culling of all deer. WGS indicated that multiple M. bovis strains were circulating, with at least three founding introductions since the park inauguration in 1977. Using a previously sequenced dataset of 71 M. bovis genomes from cattle, we found no recent transmission events between nearby farms and the park based on WGS. Lastly, by discussing socio-economic and environmental factors escaping current regulatory gaps that were determinant of this outbreak, we pledge for the development of a plan to report and control bTB in wildlife in Brazil.

Delayed diagnosis of congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) is a serious problem in terms of infection control. Here, we report our preemptive infection control activities implemented after the diagnosis of miliary TB in a mother of preterm twins (index twins, NB1 and NB2) in the NICU. In addition, we reviewed previous case reports of congenital TB exposure in the NICU setting. Immediately after diagnosing miliary TB in the mother, the index twins were isolated before their TB diagnosis and received preemptive anti-TB medication; contact investigations were also conducted. Eventually, NB1 was diagnosed with congenital TB at 29 days of age, and NB2 showed no definite evidence of TB. Through contact investigation, 11 of the 16 exposed infants received isoniazid prophylaxis and no positive tuberculin skin test results were obtained after 3 months. One of the 31 exposed healthcare workers showed new interferon-gamma release assay conversion. Moreover, our case showed a much shorter contagious period compared to that in previous reports (8 versus 17-102 days). This suggests that a high index of suspicion and prompt measures can help prevent congenital TB outbreaks and reduce the burden of infection control activities in the NICU.

In 2018, Brazilian guidelines changed to recommend tuberculosis (TB) preventive therapy for all people with HIV and a CD4 cell count 350 cells/μl or less, but only for those with a positive tuberculin skin test (TST) if CD4 cell count is than 350 cells/μl. We determined the potential effectiveness of CD4-based guidelines for TB testing and preventive therapy.Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT).We analyzed data from 4114 newly registered patients with HIV in 29 clinics followed until TB diagnosis, death, or administrative censoring. We compared incidence rates of TB and TB/death between CD4, TST, IPT, and antiretroviral therapy categories.Initial CD4 cell count was 350 cells/μl or less in 2138 (52%) and more than 350 cells/μl in 1976 (48%) patients. TST was performed for 2922 (71%), of whom 657 (16%) were TST-positive [278 (13%) CD4 ≤ 350 vs. 379 (19%) CD4 350]. A total of 619 (15%) received IPT and 2806 (68%) received antiretroviral therapy. For patients with CD4 cell count 350 cells/μl or less who did not receive IPT, the incidence rate of TB was 1.79/100 person-years (pys) and TB/death was 3.89/100 pys. For patients with CD4 cell count more than 350 who did not receive IPT, the incidence rates of TB and TB/death were 0.57/100 and 1.49/100 pys for TST-negatives, and 1.05/100 and 1.64/100 pys for TST-unknowns.TB incidence was high among all patients who did not receive IPT, including those with CD4 cell count more than 350 cells/μl and negative or unknown TST results. TB preventive therapy should be provided to all people living with HIV in medium burden settings, regardless of CD4 cell count and TST status.

Following large declines in tuberculosis transmission the United States, large-scale screening programs targeting low-risk healthcare workers are increasingly a source of false-positive results. We report a large cluster of presumed false-positive tuberculin skin test results in healthcare workers following a change to 50-dose vials of Tubersol tuberculin.Infect Control Hosp Epidemiol 2018;39:750–752

Mycobacterium bovis is the cause of tuberculosis in most mammalian species, most notably cattle and other members of the family Bovidae; however, many species of the family Cervidae are also susceptible. In North America, tuberculosis has been identified in both captive and free-ranging cervids. Captive cervids are tested for tuberculosis following many of the same guidelines applied to cattle, including intradermal tuberculin testing using M. bovis purified protein derivative (PPD). Both captive and free-ranging deer and elk have been implicated as the source of infection for many cattle herds. Vaccination with the human vaccine M. bovis BCG has been considered as one possible tool to aid in eradication of tuberculosis from cattle and both captive and free-ranging cervids. Studies in cattle have demonstrated that BCG vaccination can induce false positive intradermal tuberculin test reactions in some cattle. Similar findings have been reported for red deer. We orally vaccinated white-tailed deer with BCG and showed that vaccination can induce false positive skin test reactions in some deer and that the rate of false positive reactions is greater with a higher vaccine dose.

Rationale: Noninferiority trials of treatment for latent tuberculosis infection (LTBI) are challenging because of imperfect LTBI diagnostic tests.Objectives: To assess the effect on study outcomes of different enrollment strategies for a noninferiority trial of LTBI treatment.Methods: We mathematically simulated a two-arm randomized clinical trial of LTBI in which the experimental therapy was 50% efficacious and the control was 80% efficacious, with an absolute 0.75% noninferiority margin. Five enrollment strategies were assessed: 1) enroll based on no LTBI diagnostic test; 2) enroll based on a positive tuberculin skin test (TST); 3) enroll based on a positive IFN-γ release assay (IGRA); 4) enroll based on either a positive TST or IGRA; and 5) enroll regardless of test result, assuming 70% had negative TSTs, 20% positive TSTs, and 10% unknown results.Measurements and Main Results: Under most LTBI prevalence assumptions, enrolling based on a positive IGRA was least likely to result in falsely declaring noninferiority of the experimental regimen. Enrolling based on no test or regardless of test result led to falsely declaring noninferiority unless LTBI prevalence in the underlying population was higher than 45%. Enrolling based on a mix of TST and IGRA substantially reduced the likelihood of falsely declaring noninferiority over enrolling based on TST alone, even if as many as 70% of participants were enrolled based on positive TST.Conclusions: Noninferiority trials of LTBI should enroll based on the most specific diagnostic tests available (i.e., IGRAs) to avoid misclassifying inferior treatment regimens as noninferior.

Erythema nodosum is a form of panniculitis that presents as red lumps most commonly on the shins. It commonly presents due to tuberculosis, streptococcal infections, sarcoidosis, or can be drug related. This report describes the case of a young woman who presented with erythema nodosum and reactive arthritis; this was determined to be a sequelae of tuberculosis. Investigations were ordered as there was a high level of clinical suspicion for an underlying systemic cause for the presenting complaints. The systemic condition was determined to be tuberculosis due to the endemic environment and a positive tuberculin skin test.

During 2000 to 2018, 1831 children were screened as part of tuberculosis contact investigation at the Stockholm Northern Clinic. The risk of a child having a positive tuberculin skin test was 33% and positive interferon-gamma release assay 12%. The risk of tuberculosis disease was 6.1% (tuberculin skin test) and 13% (interferon-gamma release assay) in positive-testing children.

AIM Increasing numbers of migrants to Sweden are screened for tuberculosis (TB), and a rational approach to screening is required. We evaluated positive tuberculin skin tests (TSTs) and interferon-gamma release assays (IGRAs) on paediatric migrants in relation to the TB incidence in the corresponding foreign-born populations in Stockholm. METHODS This study examined the characteristics of migrants under the age of 18 who were referred to a paediatric TB clinic at Karolinska University Hospital from 2008 to 2014 by primary care centres in Stockholm County. RESULTS We saw 943 TST-positive children with a median age of 14 years at the TB clinic and performed IGRAs on 557. IGRA positivity ranged from 64% in migrants from Somalia to 20% in those from the former Soviet Union and eastern Europe, with an estimated population level prevalence of 18.8% and 4.2%, respectively. These were significantly correlated to TB incidence in foreign-born Stockholm children. We diagnosed active TB in 20 screened migrants, and advanced, symptomatic TB was diagnosed in 10 recently arrived migrants without screening. CONCLUSION IGRAs showed higher specificity than TST in identifying tuberculosis. TB screening should focus on migrants from high-incidence countries, but this may be inadequate to detect advanced TB cases.

Spanish Pediatric TB Research Network (pTBred) and the European NontuberculouS MycoBacterial Lymphadenitis in childrEn (ENSeMBLE) Study., [Objectives] To assess the performance of interferon-gamma release assays (IGRAs) in the differential diagnosis between Mycobacterium avium complex (MAC) and tuberculosis (TB) in children affected with subacute/chronic submandibular/cervical lymphadenitis., [Study design] Multicenter observational study comparing children with microbiologically confirmed MAC lymphadenitis from the European NontuberculouS MycoBacterial Lymphadenitis in childrEn study with children with TB lymphadenitis from the Spanish Network for the Study of Pediatric TB database., [Results] Overall, 78 patients with MAC and 34 with TB lymphadenitis were included. Among MAC cases, 44 out of 74 (59.5%) had positive tuberculin skin test (TST) results at the 5-mm cut-off, compared with 32 out of 33 (97%) TB cases (P < .001); at the 10-mm cut-off TST results were positive in 23 out of 74 (31.1%) vs 26 out of 31 (83.9%), respectively (P < .001). IGRA results were positive in only 1 out of 32 (3.1%) patients with MAC who had undergone IGRA testing, compared with 21 out of 23 (91.3%) TB cases (P < .001). Agreement between TST and IGRA results was poor in MAC (23.3%; κ = 0.017), but good in TB cases (95.6%; κ = 0.646). IGRAs had a specificity of 96.9% (95% CI 84.3%-99.8%), positive predictive value of 95.4% (95% CI 78.2%-99.8%), and negative predictive value of 93.9% (95% CI 80.4%-98.9%) for TB lymphadenitis., [Conclusions] In contrast to TST, IGRAs have high specificity, negative predictive value, and positive predictive value for TB lymphadenitis in children with subacute/chronic lymphadenopathy, and consequently can help to discriminate between TB and MAC disease. Therefore, IGRAs are useful tools in the diagnostic work-up of children with lymphadenopathy, particularly when culture and polymerase chain reaction results are negative.

The genus Mycobacterium comprises a broad spectrum of obligate microorganisms most notably the M. tuberculosis complex bacteria; potentially-pathogenic or opportunistic species gathered under the common name of M. avium-intracellulare complex, and finally saprophytic mycobacteria. In cattle farming, Mycobacterium bovis (M. bovis) is considered as the principle cause for bovine tuberculosis (bTB). Nevertheless, non-tuberculosis mycobacteria (NTM) are potential pathogens that are increasingly reported to interfere with contemporary intradermal tuberculin tests in veterinary medicine. Therefore, these neglected mycobacteria are capable to make hurdles for bTB diagnosis. In the Iranian environment, the extent and importance of this phenomenon in regard with the public health and economical aspects is just underestimated. This work was therefore intended to isolate and characterize the mycobacterial organisms potentially involved in causing positive reactions in tuberculination of Iranian cattle. Abattoir meat inspection and laboratory microbiological investigation of slaughtered heifers from a 2,000-head Simental cattle farm with 10% of the herd positive tuberculin reactors, failed to provide any evidence of M. bovis infection. No mycobacteria was detected in bacterial culture of specimens from feedstuff, water or even the visiting feral rodents of the farm. When the farm workers were included in assessments, 22 individuals were found tuberculin-positive with 5 of them also smear-positive in their sputa assessment. Molecular identification of the five isolates from workers through sequencing of the 16SrRNA proved their identity as Mycobacterium thermoresistibile (Mth). Removing of the carrier workers from the farm vicinity, successfully ended the issue of the constantly-positive tuberculin test in the herd with no return of the problem until now. We are convinced further investigations are essential in search for interference extent and importance of NTM species in cattle tuberculination scheme in Iran.

Children’s paucibacillary tuberculosis (TB) and their difficulty to expectorate leads to low diagnostic sensitivity. Most TB in children are diagnosed by clinical scoring systems limited by the TB clinical presentation. Pediatric TB diagnosis research should be focused on new biomarkers from non-invasive and non-sputum-based samples. By metabolomics we can obtain a “fingerprint” of the metabolites presents in a biological sample, allowing the study of sets of metabolites affected by host-pathogen interactions and the identification of diagnostic markers. This study aims to identify urine metabolite biomarkers with pediatric TB diagnostic potential. The urine spectra from High-resolution 1H Nuclear Magnetic Resonance (NMR) spectroscopy were obtained in a cross-sectional study of 73 children (0-14 years) screened for suspected TB in a pediatric hospital of Haiti. Enrolled children had a positive Tuberculin Skin Test and were classified as follows: 23 TB, 27 probable TB, 13 unlikely TB, and 10 latent TB infection (LTBI). Among all NMR tested samples, an algorithm was developed with 33 spectra from core groups (23 TB, 10 LTBI). We identified eight metabolites with significant changes between groups and when comparing TB and LTBI, we achieved a specificity and sensitivity of 95.49% and 89.90%, respectively. Moreover, when including probable TB and unlikely TB, we classified 92.65% and 53.85%, respectively as TB. We suggest a combination of metabolites that discriminate TB from LTBI, improving the diagnostic accuracy. This urine-based metabolomic algorithm may improve the pediatric TB diagnosis identifying those children with unconfirmed TB diagnostic and therefore, reducing the undiagnosed pediatric TB.

Rationale: Asymptomatic subjects with positive tuberculin skin testing (TST) and negative interferon-gamma release assay (IGRA) results are often felt to have false(+) TST for latent tuberculosis infection (LTBI). We hypothesized that optimized immune profiling methods in subjects with TST(+)/IGRA(-) can identify LTBI with potential false(-) whole-blood IGRA results. Objective: Optimized IGRA and flow cytometric (FC) antigen-specific immune reactive methods were applied to seek biomarkers that differentiate subjects with TST(+)/IGRA(-) at risk of LTBI from unexposed subjects. Methods: An ELISPOT and FC assay that detects induction of CD25+CD134+ co-expression on TB-antigen-stimulated T-cells from PBMCs after 2-day incubation with co-stimulatory antibodies. Results: Ninety-five subjects with TST(+)/IGRA(-) and TST(-)/IGRA(-) results were studied, including 68 (71.6%) subjects at risk of LTBI. There were statistical differences in ELISPOT (median sfc [IQR]) and FC assay (median %CD8+ T-cells) between subjects with TST(+)/IGRA(-) and TST(-)/IGRA(-) results: ELISPOT (ESAT6/CFP10 or RD1 peptides –nil)= 52.3[8-92] vs. 17.3[2.2-58.8] (P=0.033), ELISPOT (RD1 peptides –nil)/ELISPOT (PPD-nil) ratio= 64.1[27.4-117.9] vs. 25.7[7.6-74.0] (P=0.007), and FC assay for CD8+ T-cells (RD1 peptides –nil)= 0.17[0.04-1.08] vs. 0.07[0.0-0.24] (P=0.021). Subjects with TST(+)/IGRA(-) had higher likelihood of potential TB exposure than TST(-)/IGRA(-) subjects, after adjusting for BCG vaccination (OR=5.1 [95%CI:1.3-34.2]; P=0.017). Conclusion: The strategy of optimizing immunoassay analysis is capable of detecting subset profiles that distinguish subjects with TST(+)/IGRA(-) and potential false(-) IGRA results.

In the second quarter of 2017 there were 7778 (including 1606 dependants and 547 unaccompanied children) applications for asylum in the UK.1 The health needs of asylum-seeking children are wide ranging and can vary depending on their country of origin, broadly dividing into infectious diseases, anaemia, vitamin deficiencies and potential growth retardation, dental and mental health. Asylum-seeking children have probably not been immunised as per UK immunisation schedule. They are also at higher risk of certain infections. TB is common among asylum seekers, its detection and treatment being particularly important in children who are at higher risk of latent TB Infection (LTBI) reactivation and more likely to have extra-pulmonary spread, including TB meningitis.2 Of 1825 screened refugee children in Massachusetts, 25% had a positive tuberculin (purified protein derivative [PPD]) test.3 Chest X-rays screen for active pulmonary TB but do not …

n human beings, infection with the tubercle bacillus usually results in inapparent disease, recognized only by a positive tuberculin reaction. However, about 10% of tuberculin-positive people develop clinically active tuberculosis (TB). The Lurie tubercle count method is probably the most accurate way to measure a vaccine's ability to prevent such clinical disease. Yet, it is rarely used. Briefly, vaccinated and control rabbits are infected by aerosol with a known quantity of virulent human-type tubercle bacilli (strain H37Rv). [Human-type bacilli are not fully virulent for rabbits.] Five weeks later, the rabbits are sacrificed, and counts are made of the number of grossly visible primary tubercles in their lungs. The best vaccines cause the greatest reduction in the number of such visible tubercles. This report describes the method, and the immunologic mechanisms involved. It also suggests how the method can be used to test TB vaccines in both mice and guinea pigs, as well as in rabbits.

Objective: To evaluate the performance of interferon gamma release assays and tuberculin skin test in HIV-infected children and adolescents with immune reconstitution. Methods: A cross-sectional study was conducted in HIV-infected patients aged 5-18 years receiving antiretroviral treatment with CD4 T-lymphocytes >25% or >500 cells/mm3 for at least 6 months. QuantiFERON-TB Gold, T-SPOT.TB, and tuberculin skin test were performed in each patient. Results: A total of 50 patients were enrolled with median age of 13.7 years, CD4 counts of 753 (IQR: 587-989) cells/mm3. Among 27 patients with tuberculosis (16) or tuberculosis exposure (11), 8 (29.6%) were positive to at least one test, 2 (7.4%) were positive QuantiFERON-TB Gold, 3 (11.1%) positive T-SPOT.TB, and 7 (25.9%) had tuberculin skin test ≥5 mm. Among 23 patients without history of tuberculosis or exposure, all had negative interferon gamma release assays, while 2 (8.7%) had positive tuberculin skin test. Conclusions: All tests had low sensitivity despite immune reconstitution.

Objective The current study analyzed the chemoprophylactic effect of isoniazide on close contacts of patients with active tuberculosis and positive tuberculin skin tests (TSTs). Methods A total of 1206 close contacts of patients with active tuberculosis and strongly-positive TSTs were enrolled. The patients had chest X-ray examinations. Patients without tuberculosis and other diseases were divided into the following groups: 90 patients in the prophylaxis group, who were given 300 mg of isoniazid qd (3–5 mg/kg for children) over a 10-month treatment course; and 89 patients in the control group without drug therapy. Both groups were followed for 10 years. Results (1) There were 568 patients with negative results and 638 with positive results, including 445 with ordinarily- and moderately-positive results, and 193 with strongly-positive results (a positive rate of 52.9% [638/1206] and a strongly-positive rate of 16.0% [193/1206]). Fourteen tuberculosis patients were identified (tuberculosis detection rate of 1.1%). (2) During the 3-year period of follow-up, there were 4 patients in the prophylaxis group and 12 patients in the control group who acquired tuberculosis (a morbidity rate of 4.7% [4/84] and 13.4% [12/89], respectively), and the difference was statistically significant (χ2=3.916, P=0.048). Six patients in the prophylaxis group, all of whom were children, discontinued medication use during the course of treatment due to adverse drug reactions, for an adverse drug reaction occurrence rate of 6.6% (6/90), a medication completion rate of 93.3% (84/90), and a 3-year protection ratio of 64.6%. (3) During the 4–6 year period, there were two patients in the prophylaxis group and three patients in the control group who acquired tuberculosis (a morbidity rate of 2.5% [2/78] and 4.1% [3/73], respectively), two in the prophylaxis group and four in the control group who were lost to follow-up (a loss to follow-up rate of 2.5% [2/80] and 5.1% [4/77], respectively), and the difference was not statistically significant (χ2=0.006, P=0.940; χ2=0.215, P=0.643). (4) During the 7–10 year study, there was one patient in the prophylaxis group and two patients in the control group who acquired tuberculosis (a morbidity rate of 1.3% [1/72] and 3.1% [2/64], respectively), and four in the prophylaxis group and six in the control group who were lost to follow-up (a loss to follow-up rate of 5.2% [4/76] and 8.5% [6/70], respectively), and the difference was not statistically different (χ2=0.011, P=0.918; χ2=0.176, P=0.675). (5) Within 10 years, there were 7 patients in the prophylaxis group and 17 patients in the control group who acquired tuberculosis (a morbidity rate of 8.3% [7/84] and 21.5% [17/79], respectively; χ2=4.770, P=0.029), and 6 in the prophylaxis group and 10 in the control group were lost to follow-up (the loss to follow-up rate was 7.1% [6/84] and 11.2% [10/89], respectively; χ2=0.863, P=0.353). Conclusion Close contacts of patients with active tuberculosis are at high-risk for acquiring tuberculosis. It is safe and effective for patients with strongly-positive TST results to undergo isoniazid chemoprophylaxis for 10 months.

Purpose: To describe a case of bilateral presumed tuberculous choroiditis which resolved promptly with a short course of antituberculous therapy. Case Report: A 44-year-old lady presented with bilateral visual loss of 8 months'duration. Considering the presence of pan-uveitis, severe macular edema, multifocal leakage on fluorescein angiography, positive tuberculin skin test, and after excluding other diseases, she underwent anti-tuberculous therapy (ATT) for disseminated choroiditis due to presumed ocular tuberculosis. She improved promptly and completely. There were no signs of relapse 18 months after completion of the treatment course. In a young patient with disseminated choroiditis and relatively short duration of symptoms, a course of ATT for 6 months may effectively treat the disease preventing relapse for a considerable period of time. Conclusion: In Presumed Tuberculous chroiditis early diagnosis is crucial for prompt and complete improvement.

Objective To assess readability of 24-h tuberculin response in adolescent school children. Design Prospective observational study in school. Subjects 601 healthy adolescent children. Interventions Tuberculin (1TU PPD RT23 Tween80) was administered and indurations at 24 and 72 h were compared. Main outcome measure Tuberculin reaction at 24 h. Results One hundred twelve children (18.6%) had a positive tuberculin reaction. Prevalence of tuberculin positivity was least (14.2%) in the 10-year age-group and maximum in the 13-year age-group (21.2%). When individual values of tuberculin reaction at 24 and 72 h were compared, a significant difference was noted irrespective of the tuberculin status (t = 8.46, p = 0.001). However, when tuberculin reaction was considered as positive or negative, this difference was not significant (t = 1.89, p > 0.05). Conclusions Tuberculin status in adolescents can be read as positive or negative at 24 h, irrespective of their bacillus Calmette-Guerin scar status.

Introduction: Tuberculosis is an endemic infectious disease in Sudan and other developing countries. Healthcare workers, including students, are at a great risk of exposure and possible infection. This study is conducted to determine the pattern and prevalence of positive tuberculin skin test (TST) among students of the University of Medical Sciences and Technology during distinct periods of their training, and to study the influencing factors for positive results. Design and Setting: A cross-sectional study conducted among 100 students in the period between October 2010 to March 2011 using questionnaires, and administration of the Tuberculin Skin Test (TST) by a licensed professional. Students were divided into two groups, high risk group (medical students), and low risk group (non-medical students) according to their level of exposure. Demographics, BCG vaccination, potential exposure to TB patients and symptomatology were obtained and analyzed. Results: The overall prevalence of positive TST was 19%, 2% were strongly positive, 17% being moderately positive. The high risk group exhibited a significantly higher rate of positive TST (26%). Positive TST was found to correlate significantly with contact with TB patients (P 0.08). No significant correlation was found between positive TST and gender (P 0.834), country of residence (P 0.242), vaccination (P 0.094), presence of BCG scar (P 0.793), drinking unpasteurized milk (p 0.647), immunosuppressive therapy (P 0.674) and crowding (P 0.872). Conclusion: The TST positivity rate was high among our students; it correlates with in-hospital training stage. More attention should be paid to prevention strategies in medical students prior to and during their clinical training.

Background The association between Mycobacterium tuberculosis infection and atopy remains controversial. Reaction to tuberculosis infection is mediated by Th-1 immune responses whereas allergic reactions are mediated by Th- 2 immune response. In patients with atopic syndrome who also suffer from tuberculosis infection, the Th-2 response will be suppressed and allergy manifestations will decrease. Therefore, it is important to determine the appropriate allergy test and to predict outcome after completing tuberculosis treatment. Objective To evaluate the influence of a positive tuberculin test on skin test results in diagnosing atopic disease. Methods A cross sectional study was conducted in the pediatric allergy outpatient clinic, Soetomo Hospital, Surabaya, Indonesia between 2004 and 2007. Eighty-five patients were enrolled in this study. The tuberculin test was performed on all patients with allergy. The allergy test was carried out by performing a skin scratch test. Results There was a weak inverse correlation between positive tuberculin tests and positive allergy skin tests in children (house dust mite, food and pet allergies). The correlation between a positive tuberculin test and house dust mite allergy test was r: -0.364 (P=O.OOl; a=O.Ol). The correlation between the tuberculin test and food allergies was r: -0.420 (P=O.OOl; a=O.Ol). The correlation between the tuberculin test and pet allergies was r: -0.344 (P= 0.001; a=O.Ol). Conclusions A positive tuberculin test is weakly correlated with positive allergy skin test results, suggesting that it is appropriate to do allergy skin testing even in children with a positive tuberculin test.

Background: Errors involving the mix-up of tuberculin purified protein derivative (PPD) and vaccines leading to adverse reactions and unnecessary medical management have been reported previously. Objectives: To determine the frequency of PPD-vaccine mix-ups reported to the US Vaccine Adverse Event Reporting System (VAERS) and the Adverse Event Reporting System (AERS), characterize adverse events and clusters involving mix-ups and describe reported contributory factors. Methods: We reviewed AERS reports from 1969 to 2005 and VAERS reports from 1990 to 2005. We defined a mix-up error event as an incident in which a single patient or a cluster of patients inadvertently received vaccine instead of a PPD product or received a PPD product instead of vaccine. We defined a cluster as inadvertent administration of PPD or vaccine products to more than one patient in the same facility within 1 month. Results: Of 115 mix-up events identified, 101 involved inadvertent administration of vaccines instead of PPD. Product confusion involved PPD and multiple vaccines. The annual number of reported mix-ups increased from an average of one event per year in the early 1990s to an average of ten events per year in the early part of this decade. More than 240 adults and children were affected and the majority reported local injection site reactions. Four individuals were hospitalized (all recovered) after receiving the wrong products. Several patients were inappropriately started on tuberculosis prophylaxis as a result of a vaccine local reaction being interpreted as a positive tuberculin skin test. Reported potential contributory factors involved both system factors (e.g. similar packaging) and human errors (e.g. failure to read label before product administration). Conclusions: To prevent PPD-vaccine mix-ups, proper storage, handling and administration of vaccine and PPD products is necessary.

Background : Tuberculosis infection among medical students is thought to be higher than that among comparable groups. Objectives : To determine the prevalence of positive Tuberculin Skin Test (TST) and associated factors among medical students at Makerere University. Methods : A-cross-sectional study among randomly selected medical students. Using intra-dermal technique, TST was performed by administering 0.1ml of purified protein derivative. Readings performed after 72 hours and positive TST based on an induration of ≥10mm. Results : Of 302 students selected to participate, 292 received TST and 288 were analyzed. Of 288 students, 173(60%) were pre-clinical (years 1-3) and 115(40%) clinical (years 4&5). Overall 130 students [45.1%(C.I.39.3–51.1)] had positive TST, not different from one derived from mixture analysis [46.3%(95% Bayesian credibility interval 36.5%-55.8%)]. Positive TST prevalence among pre-clinical was 39.9%(67/173) compared to 53.0%(61/115) among clinical students, OR=1.70,C.I.(1.06-2.74) and increases in a linear pattern with increasing years of study (p=0.002,OR=5.04). Conclusion : The prevalence of TB infection among medical students was twice higher than that of adults living in the suburbs and higher among those in clinical relative to pre-clinical years suggesting that exposure and infection might be related to clinical work. We recommend urgent institution of infection control measures. Key words : Tuberculin skin testing, tuberculosis, medical students, Uganda

Objective The purpose of this study was to explore the association between tuberculin reaction size in contacts with positive tuberculin skin test results and a variety of contact and index patient variables. Patients and Methods We reviewed the contact investigation records for tuberculosis patients identified by the Tuberculosis Prevention and Control Center of Lleida, Spain, over a period of 7 years. Patients with pulmonary and/or extrapulmonary disease were included. Tuberculosis infection had been diagnosed using the Mantoux skin test with 2 tuberculin units of purified protein derivative RT-23, and tuberculosis disease had been detected on the basis of clinical data, chest radiographs, and cultures. We examined the association between tuberculin reaction size and contact age, close contact with index patients with positive sputum smears, and diagnosis of tuberculosis disease in contacts. Associations were analyzed using the χ2 test for linear trend. Results Tuberculin reaction size was 10 mm or greater in 85.9% of the 768 contacts analyzed and 15 mm or greater in 63.8%. The percentage of contacts under 15 years of age (P=.006) who had close contact with an index patient with a positive sputum smear (P=.013) and who were diagnosed with tuberculosis disease (P=.029) increased with tuberculin reaction size. Conclusions We found that larger tuberculin reaction size in contacts with positive tuberculin skin test results was most frequently associated with recent infections in the contact, close contact with an index patient with a positive sputum smear, and diagnosis of tuberculosis disease in contact.

Background: Prospective cohort study of close contacts of smear positive tuberculosis (TB) cases. Treatment of latent TB infection (LTBI) is recommended to the contacts with positive tuberculin skin testing (TST) and interferon gamma releasing assay (IGRA) Objectives: To find out the rate of progression to active TB among IGRA positive close contacts according to the induration size of TST. Methods: Family and school contacts were followed up for about 2 years after exposure to infectious TB cases. TST until positive reaction, QuantiFERON Gold In-Tube Assay (QFT-GIT), and chest X-ray were examined at initial and 3 to 6 months after exposure. Tracing of TB cases among contacts were carried out by regular follow-up examinations and monitoring by the TB surveillance system. Results: A total of 3,088 contacts with a mean age of 15.3 ± 2.4 years old were recruited among the contacts of 117 index cases. QFT-GIT at the initial or follow up examination was positive in 530 cases (17.2%). Totally 24 close contacts (0.87%) developed active TB including 21 clinical TB. Treatment of LTBI was provided to 218 cases. Active TB among the QFT-GIT positive reactors was developed in 4 cases (2.8%) in 141 contacts with 10-14 mm induration size of TST, 14 cases (7.8%) in 180 contacts with 15-19 mm reactors, and 6 cases (10.5%) in 57 contacts with 20 mm or more reactors. No active TB case was identified among 152 contacts with 9 mm or less reactors (P=0.001). Conclusion: Treatment of LTBI may not be necessary to the contacts with positive QFT-GIT but negative TST.

Matching Mycobacterium tuberculosis isolates were noted among 11 young tuberculosis patients socially linked through illicit drug-related activities. A large proportion of their friends, 14 (64%) of 22, had positive tuberculin skin-test results. The behavior of "hotboxing" (smoking marijuana inside a closed car with friends to repeatedly inhale exhaled smoke) fueled transmission.

background The prevention of active tuberculosis through the treatment of latent tuberculosis infection is a major element of the national strategy for eliminating tuberculosis in the United States. Targeted treatment for persons who are at the highest risk for reactivation tuberculosis will be needed to achieve this goal. A more precise assessment of the lifetime risk of reactivation tuberculosis, usually estimated at 5 to 10 percent, could help to identify patients who are at the highest risk and motivate them to complete treatment. Currently, the rate of completion of treatment is low. methods Published reports were reviewed to obtain estimates of the risk of tuberculosis among persons with a positive tuberculin skin test. Using these data, I constructed a model to estimate the lifetime risk of tuberculosis among persons with specific medical conditions. results The lifetime risk of reactivation tuberculosis is 20 percent or more among most persons with induration of 10 mm or more on a tuberculin skin test and either human immunodeficiency virus infection or evidence of old, healed tuberculosis. The lifetime risk is 10 to 20 percent among persons with recent conversion of a tuberculin skin test and among most persons younger than 35 years of age who are receiving infliximab therapy and have induration of 15 mm or more on a tuberculin skin test. The risk is also 10 to 20 percent among children five years of age or younger who have induration of 10 mm or more on a tuberculin skin test. conclusions Persons with these characteristics should be targeted for intensive efforts to ensure full treatment of latent tuberculosis. Improved rates of completion of treatment among such persons could help to eliminate tuberculosis in the United States.

Study objectives In the United States, chest radiographs are performed on patients with positive tuberculin skin test (TST) results. It is not known whether, in addition to a single posteroanterior radiograph, a lateral chest radiograph is clinically indicated or cost-effective. We sought to determine the utility of the lateral chest radiograph in evaluating TST-positive adults. Design Cross-sectional study. Setting Tertiary-care hospital. Patients Adults with positive TST results. Mreasurements Findings on posteroanterior radiographs alone were compared to posteroanterior and lateral chest radiographs. Results In 2 of 535 cases (0.4%), lateral chest radiographs revealed a calcified granuloma not visible on posteroanterior radiographs. This finding did not alter patient management. In all other cases, lateral radiographs only confirmed findings seen on posteroanterior chest radiographs. Conclusion Treatment altering findings were always visible on posteroanterior radiographs alone. These results suggest that lateral chest radiographs are not useful in evaluating adults with positive TST results.

Tuberculosis is both a nosocomial and an occupational infection. The prevalence of positive tuberculin skin reactions at King Abdulaziz University Hospital, Saudi Arabia, was investigated by testing 298 health care workers. Conventional tuberculin skin testing was performed using 0.1 mL of purified protein derivative injected intracutaneously. After 48-72 hours, induration size was recorded. The prevalence of positive tests [induration > / = 10 mm] was 78.9% overall, 60.0% for Saudi Arabians compared with 81.8% for non-Saudi Arabians [P < 0.01]. The mean response size [8.9 +/- 7 mm] for Saudis was also significantly lower than for non-Saudis [13.9 +/- 7 mm, P < 0.001]. To enhance the protection of both health care workers and hospitalized patients, effective preventive measures and annual tuberculin testing of health care workers should be considered

Patients with prior positive tuberculin skin test (TST) results may benefit from prophylaxis after repeat exposure to infectious tuberculosis (TB).To evaluate factors associated with active TB disease among persons with prior positive TST results named as contacts of persons with infectious TB.Population-based retrospective cohort study.A total of 2,933 contacts with prior positive TST results recently exposed to infectious TB identified in New York City's TB registry during the period from January 1, 1997 through December 31, 2003.Contacts developing active TB disease ≤ 4 years after exposure were identified and compared with those who did not, using Poisson regression analysis. Genotyping was performed on selected Mycobacterium tuberculosis-positive isolates.Among contacts with prior positive TST results, 39 (1.3 %) developed active TB disease ≤ 4 years after exposure (≤ 2 years: 34). Risk factors for contacts that were independently associated with TB were age5 years (adjusted prevalence ratio [aPR] = 19.48; 95 % confidence interval [CI] = 7.15-53.09), household exposure (aPR = 2.60;CI = 1.30-5.21), exposure to infectious patients (i.e., cavities on chest radiograph, acid-fast bacilli on sputum smear; aPR = 1.9 3; CI = 1.01-3.71), and exposure to a U.S.-born index patient (aPR = 4.04; CI = 1.95-8.38). Receipt of more than 1 month of treatment for latent TB infection following the current contact investigation was found to be protective (aPR = 0.27; CI = .08-0.93). Genotype results were concordant with the index patients among 14 of 15 contacts who developed active TB disease and had genotyping results available.Concordant genotype results and a high proportion of contacts developing active TB disease within 2 years of exposure indicate that those with prior positive TST results likely developed active TB disease from recent rather than remote infection. Healthcare providers should consider prophylaxis for contacts with prior TB infection, especially young children and close contacts of TB patients (e.g., those with household exposure).

Sweet's syndrome (acute febrile neutrophilic dermatosis, SS) may be considered a reactional dermatosis with numerous associated diseases. We describe a rare association between SS and acute sarcoidosis in a 55-year-old woman. The atypical feature of positive tuberculin reaction is discussed. In this association, diagnosis may be challenging with coexistent skin lesions of both diseases. Acute sarcoidosis should be considered when SS is accompanied with mediastinal lymphadenopathy, uveitis or erythema nodosum. Deep-seated nodular lesions in the context of SS are not always 'deep' SS lesions.

Latent tuberculosis was studied in a research laboratory. A prevalence of positive tuberculin skin test results (> 15mm) of 20% was found and the main predictors were place of birth in a foreign country with high prevalence of tuberculosis and a history of contact with patients with untreated active tuberculosis. A tuberculose latente foi estudada em um laboratório de investigação. Foi encontrada uma prevalência de 20% de resultados positivos para o teste cutâneo de tuberculina (> 15mm) e os principais fatores preditores foram ser natural de um país estrangeiro com alta prevalência de tuberculose e ter uma história de contato com doentes com tuberculose ativa não tratada.

OBJECTIVE: To determine the extent to which a history of Bacille Calmette-Guerin (BCG) vaccination influences the likelihood of positive tuberculin skin test (TST) results.DESIGN: Cross-sectional survey using a hospital-based tuberculosis surveillance program.SETTING: Health Sciences Centre, a tertiary care hospital in Winnipeg, Manitoba.METHODS: The 476 health care workers (HCWs) who had TST as part of the surveillance program between 1993 and 1997 constituted the study population. The two-step test was done in 91% of the participants who did not have a positive initial test, defined as 10 mm or greater of induration. Data were gathered through chart review supplemented by a short questionnaire administered to the HCWs.MAIN RESULTS: One hundred and thirty-eight HCWs (29%) had a positive TST. In a stepwise, multiple logistic model controlling for age, sex, job title, work area, age of receiving BCG, time since BCG and duration of employment, only a history of BCG vaccination (odds ratio [OR] 22; 95% CI 12 to 41) and birth outside of Canada (OR 2.6; 95% CI 1.4 to 5.8) were significantly associated with a positive TST. When the definition of a positive TST was modified by increments of 1 mm, from 10 mm up to 20 mm of induration in BCG recipients, BCG was associated with positive reactions with indurations up to 19 mm but not 20 mm or greater. The OR declined with each increment. Of the 84 HCWs who were documented to have at least 20 years between BCG vaccination and testing, 41 (49%) had positive reactions.CONCLUSIONS: BCG vaccination can produce lasting tuberculin reactivity, and indurations of 19 mm or less may be due to the effects of the vaccine.

Interferon-gamma release assays (IGRAs) are newly approved for diagnosing latent tuberculosis infection (LTBI). An internal audit was conducted to review the use of a newly implemented IGRA at the Hôpital du Sacré-Coeur de Montréal (Montréal, Québec) to evaluate its concordance with Canadian recommendations and its implication on diagnosis.From April 2007 to January 2009, all Quantiferon TB Gold In-Tube (QFT, Cellestis inc, USA) tests performed in at the Hôpital du Sacré-Coeur de Montréal were retrieved. Strategies used to investigate LTBI and clinical interpretation of test results were compared with the local algorithm, which is derived from the current national guidelines.A total of 200 patients tested with QFT were included in the analysis. LTBI investigation and QFT testing were considered to be appropriate in 87.5% and 66.5% of patients, respectively. Overall, 67 QFT tests were performed inappropriately; 25 were performed when a LTBI investigation was not indicated and 42 were performed whe LTBI interpretation was possible with the result of the tuberculin skin test alone. Among the 175 patients investigated appropriately for LTBI, 49 QFT tests (28%) were interpreted incorrectly; 32 patients (at high risk of developing active tuberculosis) had a positive tuberculin skin test and a negative QFT result wrongly interpreted as being negative for LTBI and 13 patients should have undergone further LTBI investigations.Globally, the present study revealed that there are discrepancies on how the IGRA was employed and interpreted in a Montreal hospital and that strict compliance to the guidelines could significantly reduce errors in interpretation.Les tests de libération d’interféron gamma (TLIG) ont récemment été approuvés pour diagnostiquer une infection tuberculeuse latente (ITBL). Une vérification interne a été organisée pour examiner l’utilisation d’un nouveau TLIG à l’Hôpital du Sacré-Cœur de Montréal (Montréal, Québec) ainsi que pour en évaluer la concordance avec les recommandations canadiennes et les conséquences sur le diagnostic.D’avril 2007 à janvier 2009, les chercheurs ont extrait tous les tests Quantiferon TB Gold In-Tube (QFT) effectués à leur centre. Ils ont comparé les stratégies utilisées pour évaluer l’ITBL et l’interprétation clinique des résultats des tests avec leur algorithme local, dérivé des lignes directrices nationales à jour.Au total, 200 patients ayant subi le test QFT ont participé à l’analyse. L’examen de l’ITBL et le test QFT ont été considérés comme convenables chez 87,5 % et 66,5 % des patients, respectivement. Dans l’ensemble, 67 tests QFT avaient été mal exécutés, soit 25 lorsque l’examen de l’ITBL n’était pas indiqué et 42 lorsqu’il était possible d’interpréter l’ITBL grâce aux seuls résultats du test cutané à la tuberculine. Chez les 175 patients ayant subi des examens convenables de l’ITBL, 49 tests QFT (28 %) avaient été mal interprétés. En effet, 32 patients (très vulnérables à une tuberculose active) présentaient un test cutané à la tuberculine positif et un résultat négatif du test QFT interprété à tort comme négatif à l’ITBL, tandis que 13 patients auraient dû subir des examens plus approfondis de l’ITBL.Globalement, la présente étude a révélé des divergences dans l’utilisation du TLIG au centre et établi qu’un respect rigoureux des lignes directrices pourrait réduire considérablement les erreurs d’interprétation.

Objectives. We evaluated a strategy for preventing tuberculosis (TB) in communities most affected by it. Methods. In 1996, we mapped reported TB cases (1985–1995) and positive tuberculin skin test (TST) reactors (1993–1995) in Smith County, Texas. We delineated the 2 largest, densest clusters, identifying 2 highest-incidence neighborhoods (180 square blocks, 3153 residents). After extensive community preparation, trained health care workers went door-to-door offering TST to all residents unless contraindicated. TST-positive individuals were escorted to a mobile clinic for radiography, clinical evaluation, and isoniazid preventive treatment (IPT) as indicated. To assess long-term impact, we mapped all TB cases in Smith County during the equivalent time period after the project. Results. Of 2258 eligible individuals, 1291 (57.1%) were tested, 229 (17.7%) were TST positive, and 147 were treated. From 1996 to 2006, there were no TB cases in either project neighborhood, in contrast with the preintervention decade and the continued occurrence of TB in the rest of Smith County. Conclusions. Targeting high-incidence neighborhoods for active, community-based screening and IPT may hasten TB elimination in the United States.

A cross sectional abattoir based study was conducted from February 2014 to October, 2015 on camels slaughtered at Akaki municipality abattoir to determine the prevalence of Tuberculosis in camels and assess the association of risk factors with the prevalence of Tuberculosis in camels using single intra-dermal comparative cervical tuberculin (SICCT). Of the total of 387 camels investigated, overall camel tuberculosis prevalence of 9.82% (95% CI: 6.84%-12.8%) at a cut off value ≥ 4mm and prevalence of 17.05% (95% CI: 13.3%-20.82%) at a cut off value ≥ 2mm, were recorded. Pearson chi-square test reveals, there was statistically significant association of prevalence with the origin of camels at a cut off value ≥ 2mm (χ2 = 13.461, P=0.000). However, there was no statistically significant association (P>0.05) of risk factors of age, sex, body condition and origin of camels with the prevalence at a cut off value ≥ 4mm.The multivariate logistic regression analysis shows at a cut off value ≥ 4mm, being old aged (adjusted OR= 0.999, 95% CI: 0.450-2.22), female (adjusted OR= 2.226, 95% CI: 0.5099-9.719) were identified as risk factors for positive tuberculin reactivity. Similarly, the multivariate analysis at a cut off value ≥ 2mm, showed being moderate body conditioned (adjusted OR= 1.583, 95% CI: 0.7399-3.385) was identified as risk factor for higher tuberculin reactivity. The present study aimed to determine tuberculin reactivity of camels and assess associated risk factors with the prevalence. It was concluded that Tuberculosis is an existing phenomenon in camels. It is therefore, recommended that detailed epidemiological investigations should be conducted for the better understanding of the epidemiology of the disease in camels of pastoral communities with particular emphasis to zoonotic significance in camel rearing areas of Ethiopia. Keywords : Akaki abattoir, Camel Tuberculosis, Ethiopia, Prevalence, Risk factors, Comparative Tuberculin testing.

Objectives: To better identify inmates with tuberculosis infection at admission and to have more accurate estimates of conversion rates with annual retesting. I evaluated two-step tuberculin skin testing of newly admitted inmates at the Addiction Center of the Massachusetts Department of Corrections. Method: In a population of inmates admitted to the Addiction Center between January and May 1994, a second tuberculin skin test was performed 1 week after the first for those who initially had a negative response. Results: There were 628 admissions during the study period; 51 of these inmates (8%) had a history of positive skin test results. Of the 570 initial tuberculin skin tests that were read, 12 (2.1%) had positive results. Five of 510 second tuberculin skin tests (1%) had positive results. Conclusion: I evaluated the feasibility and utility of two-step tuberculin skin testing among newly admitted inmates at a Massachusetts correctional facility. We identified 40% more inmates with positive tuberculin skin test results after conducting 510 additional skin tests. Unlike the Addiction Center inmates, newly admitted inmates at other reception facilities are subject to interfacility transfer, and the rate of reading initial tuberculin skin tests is significantly lower than the 99% obtained at the Addiction Center. 1 expect serial testing to increase the identification of tuberculosis infected inmates at all facilities; however, its implementation should be deferred until a higher reading rate is obtained for the initial skin test.

Tuberculin skin test (TST)is often used in the diagnostic process. Wereport on a seldom considered cause offalse-positive results to TST, possibly lead-ing to a wrong diagnosis.A 15-year-old, Indian-born girl wasadmitted to our hospital because of a6-month history of diarrhea and abdominalpain. She also presented recurrent painfuloral ulcers, and ocular redness and pain inthe left eye. One year earlier, she had re-ceived a diagnosis of tuberculosis-relatederythema nodosum. A TST performed onthat occasion resulted in extensive indura-tion followed by blistering and ulceration ofa 3-cm-wide skin area. Chest radiographwas negative for tuberculosis lesions, andshe had been treated with a 6-month courseof isoniazid. On admission to our hospital,laboratory tests showed elevated erythro-cyte sedimentation rate, 78 mm/h, and fecalcalprotectin (74 mg/kg of stools; normalvalues, 15), a marker of intestinal inflam-mation. Colonoscopy and video capsule en-doscopy were performed to rule out ITBand inflammatory bowel disease. Sparseaphthous lesions were seen in the distalileum. Polymerase chain reaction assay for

A 52-year-old woman with end-stage renal disease secondary to diabetes requires hemodialysis. Her physician reviewed her history of tuberculosis (TB) exposure, noting that she immigrated to Canada from the Philippines two years prior and had never been tested for TB. She reported no known exposure

Este artigo tem o objetivo de contribuir para o debate sobre a transmissão nosocomial da TB em profissionais de saúde em um país onde esta é endêmica. Verificamos que até 1900 não se aceitava que os profissionais envolvidos no cuidado de pacientes portadores de TB pudessem ser mais susceptíveis à infecção pelo bacilo que a população geral. Vários estudos entre 1920 e 1930 apresentaram achados significativos nas taxas de conversão do teste tuberculínico dos estudantes da área de saúde, mas a maioria dos clínicos continuava se recusando a reconhecer a suscetibilidade dos profissionais de saúde em relação à TB. Nos diferentes locais onde o cuidado ao paciente com TB foi implantado, os profissionais de saúde são descritos como uma população especialmente exposta ao risco de contrair a infecção e adoecer. É urgente que a comunidade científica e os trabalhadores de saúde se organizem, que se reconheçam como uma população sujeita ao risco de adoecimento, e que ações se efetivem no sentido de minimizar os riscos potenciais nos locais onde acontece o cuidado a pacientes com TB. The objective of this review was to contribute to the debate on the nosocomial transmission of TB among health professionals in a country where TB is endemic. Prior to 1900, there was no reason to believe that health professionals interacting with TB patients were more susceptible to becoming infected with the bacillus than was the general population. Between 1920 and 1930, various studies showed significant findings regarding the rates of positive tuberculin skin tests among students in the area of health care. However, most clinicians remained skeptical about the susceptibility of health professionals to becoming infected with TB. In the various locales where the treatment of patients with TB has been implemented, health professionals have been described as an especially predisposed population to becoming infected with and developing active TB. It is urgent that the scientific community and health professionals become mobilized, recognizing themselves as a population at risk of developing TB, and that actions be taken in order to minimize the potential risks of acquiring the disease at locales where patients with TB are treated.

The granulomatous inflammation of tuberculosis usually involves the lungs and the hilar lymph nodes. Musculoskeletal tuberculosis (TB) occurs in 1–3% of patients with TB, while TB of the chest wall constitutes 1% to 5% of all cases of musculoskeletal TB. Furthermore, nowadays it is rarer to find extrapulmonary TB in immunocompetent rather that non-immunocompetent patients. The present case reports a fifty-six-year-old immunocompetent man with an anterior chest wall tuberculous abscess. The rarity of the present case relates both to the localization of the tuberculous abscess, and to the fact that the patient was immunocompetent. The diagnosis of musculoskeletal tuberculous infection remains a challenge for clinicians and requires a high index of suspicion. The combination of indolent onset of symptoms, positive tuberculin skin test, and compatible radiographic findings, strongly suggests the diagnosis. TB, however, must be confirmed by positive culture or histologic proof. Prompt diagnosis and treatment are important to prevent serious bone and joint destruction.

Summary Objectives To investigate the use of new gamma-interferon (IFN-γ)-based blood tests to determine whether or not a higher-than-expected proportion of positive tuberculin skin tests (TSTs) were due to tuberculosis infection. Study design When an unexpectedly high proportion of children in a high school in Leeds were found to have positive TSTs, a cohort study was undertaken based on blood tests and long-term follow-up of the affected children. IFN-γ-based blood tests are reported to be more specific for tuberculosis infection than TSTs. Methods One hundred and ninety children, aged 13–14 years, were screened and 28 (15%) had a positive TST. None had any known risk factor for tuberculosis infection. Parental consent was requested for testing with QuantiFERON-TB Gold (Cellestis, Carnegie, Victoria, Australia). Active cases of tuberculosis with any possible connection to the school or the children were sought through the routine diagnosis and reporting service over the next 36 months. Results Consent was given for 26 children with Heaf Grade 2 results to be tested using QuantiFERON-TB Gold, and blood was obtained from 24 of these children. All tested negative. None of these children developed active tuberculosis, and no cases of active tuberculosis were identified with any connection to the children or the school. Conclusion QuantiFERON-TB Gold testing appeared to identify false-positive TSTs correctly in this group. This supports the recent recommendation to use IFN-γ-based blood tests in people with positive TSTs to confirm or refute the diagnosis of tuberculosis infection.

We report a case of atypical necrotizing lymphadenitis. Necrotizing lymphadenitis has a characteristic clinical pattern of lymphadenopathy of the neck, tenderness of the lymph nodes, fever, and leukopenia. The patient was a 25-year-old man, complaining of only multiple lymphadenopathy in the submental and submandibular regions. The clinical diagnosis was a strong suspicion of tuberculous lymphadenitis or toxoplasmic lymphadenitis because of a positive tuberculin reaction and an elevated antibody titer to Toxoplasma. These lymph nodes were excised and necrotizing lymphadenitis was diagnosed histopathologically and immunohistochemically.

Lichen scrofulosorum (LS) and papulonecrotic tuberculids are unique reaction patterns – tuberculids – of the skin caused by hematogenous dissemination of the mycobacterium in those individuals possessing a high/moderately high immunity. Consequently, the bacilli are speedily destroyed in the skin, and are hard to demonstrate by smear. Accordingly, the presence of a perceptible active or concealed, systemic and/or cutaneous focus of tuberculosis is the vital prerequisite for a tuberculid. More often than not a strongly positive tuberculin reaction is indicative of tuberculids. Its histogenesis is enigmatic. However, type IV hypersensitivity reaction incited by chronic tuberculous focus may be plausible. 1,2

Resume en francais Cadre : Policlinique pediatrique a Lausanne en Suisse, pays rencontrant une proportion importante de tuberculose au sein de la population de migrants. But : Determiner les facteurs de risque associes a un test tuberculinique positif (ou test de Mantoux), notamment l'influence du BCG (Bacille Calmette Guerin) et d'un contact avec un personne ayant une tuberculose active. Les patients concernes etaient des enfants examines dans le cadre d'un controle de sante ou dans le cadre d'une etude d'entourage d'un cas declare de tuberculose. Methode : Etude descriptive comprenant des enfants ayant eu un test tuberculinique (2 unites RT23) entre novembre 2002 et avril 2004. L'âge, le sexe, l'anamnese de contact avec une personne ayant une tuberculose active, la vaccination par le BCG, le pays d'origine et le lieu de naissance (en Suisse ou hors de la Suisse) etaient repertories. Resultats : Parmi les 234 enfants de l'etude, 176 (75%) avaient une reaction tuberculinique egal a zero et 31 (13%) avaient une reaction positive (> 10mm). Dans le modele de regression lineaire, la taille de la reaction tuberculinique variait significativement selon l'anamnese de contact avec une personne ayant une tuberculose active, l'âge, l'incidence de la tuberculose dans le pays d'origine et la vaccination par le BCG. Le sexe ou le lieu de naissance n'influencait pas la taille de la reaction. Dans le modele de regression logistique incluant toutes les valeurs repertoriees, les parametres significativement associes avec un Mantoux positif etaient l'âge (Odds Ratio = 1.21, 95% CI 1.08 ; 1.35), l'anamnese de contact avec une personne ayant une tuberculose active (OR = 7.31, 95% CI 2.23 ; 24) et l'incidence de la tuberculose dans le pays d'origine (OR = 1.01, 95% CI 1.00 ; 1.02). Le sexe (OR = 1.18, 95% CI 0.50 ; 2.78) et la vaccination par le BCG (OR = 2.97, 95% CI 0.91 ; 9.72) n'etaient pas associes avec une reaction tuberculinique positive. Conclusions : L'incidence de la tuberculose dans le pays d'origine, la vaccination par le BCG et l'âge influencent le test de Mantoux (taille ou proportion de reaction > 10mm). Toutefois, le facteur de risque le plus important d'avoir une reaction tuberculinique positive est l'anamnese de contact avec. une personne ayant une tuberculose active.