A five-year analysis of latent tuberculosis infection in Queensland, 2016-2020.

Background Australia is aiming to reach tuberculosis pre-elimination targets by 2035. As a low-incidence setting, control efforts will increasingly rely on the management of latent tuberculosis infection (LTBI). We undertook this descriptive analysis to assess the recent trends of LTBI testing in Queensland. Methods Our objective was to describe the features of LTBI testing in Queensland, and to estimate the range of possible annual notifications were it to be made a notifiable condition. We collated both state-wide and region-specific data on tuberculin skin testing (TST) and interferon gamma release assays (IGRA) conducted in Queensland during the five-year period 1 January 2016 - 31 December 2020. We used reports on Medicare-funded TST and IGRA testing in Queensland, as well as tuberculosis notification data, to understand the representativeness of our data and to derive state-wide estimates. Results We analysed 3,899 public TST, 5,463 private TST, 37,802 public pathology IGRA, and 31,656 private pathology IGRA results. The median age of people tested was 31 years; 57% of those tested were female. From our data sources, an annual average of 1,067 positive IGRA and 354 positive TST results occurred in Queensland. Building on this minimum value, we estimate possible latent tuberculosis notifications in Queensland could range from 2,901 to 6,995 per annum. Private laboratory TSTs are estimated to contribute the lowest number of potential notifications (range: 170-340), followed by private laboratory IGRA testing (range: 354-922), public laboratory IGRA testing (range: 706-1,138), and public setting TSTs (range: 1,671-4,595). Conclusion If LTBI were to be made notifiable, these estimates would place it among the ten most notified conditions in Queensland. This has implications for potential surveillance methods and goals, and their associated system and resource requirements.

Implementation of a Routine Screening Program for Latent Tuberculosis Infection among Patients with Acute Leukemia at a Canadian Cancer Center.

BACKGROUND: Screening for latent tuberculosis infection (LTBI) in patients with hematological malignancy is recommended because of their increased risk of tuberculosis (TB). We assessed the utility of tuberculin skin test (TST) screening in patients with acute leukemia and subsequent outcomes of LTBI treatment. METHODS: We retrospectively evaluated patients ≥16 years of age with acute leukemia from 2013-2014 with a TST planted and read prior to the initiation of antineoplastic chemotherapy treatment. Demographics, clinical information and treatment outcomes of LTBI therapy were compared between patients with positive TST (≥10 mm induration) and negative TST. RESULTS: A total of 389 patients with acute leukemia were included in the cohort. Of them, 37/389 (9.5%) had a positive TST. Only 3.4% (8/235) of individuals originating from North and South America as well as the Caribbean were TST positive, while 21% (20/95) of individuals from Asia were TST positive. Diagnostic imaging findings consistent with prior tuberculosis infection were higher in TST positive patients compared to TST negative ones (29.7% versus 9.4%, p < 0.0001). Furthermore, 31/38 patients (81.6%) who were TST positive received LTBI therapy, which was well tolerated. There was no significant difference in overall survival among those who received LTBI therapy compared to those who did not. No patients developed active TB. CONCLUSIONS: Universal screening with TST may be of low yield in individuals with acute leukemia unless patients originate from a TB endemic country. When therapy for LTBI is prescribed, patients with acute leukemia do not experience drug-induced liver toxicity and are likely to complete the intended duration of therapy, thus preventing the development of active tuberculosis.

GeneXpert or chest-X-ray or tuberculin skin testing for household contact assessment (GXT): protocol for a cluster-randomized trial.

BACKGROUND: The World Health Organization recommends tuberculosis (TB) preventive treatment (TPT) for all people living with HIV (PLH) and household contacts (HHC) of index TB patients. Tests for TB infection (TBI) or to rule out TB disease (TBD) are preferred, but if not available, this should not be a barrier if access to these tests is limited for high-risk people, such as PLH and HHC under 5 years old. There is equipoise on the need for these tests in different risk populations, especially HHC aged over 5. METHODS: This superiority cluster-randomized multicenter trial with three arms of equal size compares, in Benin and Brazil, three strategies for HHC investigation aged 0-50: (i) tuberculin skin testing (TST) or interferon gamma release assay (IGRA) for TBI and if positive, chest X-Ray (CXR) to rule out TBD in persons with positive TST or IGRA; (ii) same as (i) but GeneXpert (GX) replaces CXR; and (iii) no TBI testing. CXR for all; if CXR is normal, TPT is recommended. All strategies start with symptom screening. Clusters are defined as HHC members of the same index patients with newly diagnosed pulmonary TBD. The main outcome is the proportion of HHC that are TPT eligible who start TPT within 3 months of the index TB patient starting TBD treatment. Societal costs, incidence of severe adverse events, and prevalence of TBD are among secondary outcomes. Stratified analyses by age (under versus over 5) and by index patient microbiological status will be conducted. All participants provide signed informed consent. The study was approved by the Research Ethic Board of the Research Institute of the McGill University Health Centre, the Brazilian National Ethical Board CONEP, and the "Comité Local d'Éthique Pour la Recherche Biomédicale (CLERB) de l'Université de Parakou," Benin. Findings will be submitted for publication in major medical journals and presented in conferences, to WHO and National and municipal TB programs of the involved countries. DISCUSSION: This randomized trial is meant to provide high-quality evidence to inform WHO recommendations on investigation of household contacts, as currently these are based on very low-quality evidence. TRIAL REGISTRATION: ClinicalTrials.gov NCT04528823.

Scaling up investigation and treatment of household contacts of tuberculosis patients in Brazil: a cost-effectiveness and budget impact analysis.

Background: In Brazil, investigation and treatment of tuberculosis infection (TBI) in households contacts (HHC) of TB patients is not a priority. We estimated the cost-effectiveness and budget-impact of scaling-up an enhanced HHC management in Brazil. Methods: We conceptualized a cascade-of-care that captures how HHC of tuberculosis patients are investigated in Brazil (status quo) and two enhanced strategies for management of HHC focusing on: (1) only tuberculosis disease (TBD) detection and, (2) TBD and TBI detection and treatment. Effectiveness was the number of HHC diagnosed with TBD and completing TBI treatment. Proportions in the cascades-of-care were derived from a meta-analysis. Health-system costs (2019 US$) were based on literature and official data from Brazil. The impact of enhanced strategies was extrapolated using reported data from 2019. Findings: With the status quo, 0 (95% uncertainty interval: 0-1) HHC are diagnosed with TBD and 2 (0-16) complete TBI treatment. With strategy(1), an additional 15 (3-45) HHC would be diagnosed with TBD at a cost of US$346 each. With strategy(2), 81 (19-226) additional HHC would complete TBI treatment at a cost of US$84 each. A combined strategy, implemented nationally to enhance TBD detection and TBI treatment would result in an additional 9,711 (845-28,693) TBD being detected, and 51,277 (12,028-143,495) more HHC completing TBI treatment each year, utilizing 10.9% and 11.6% of the annual national tuberculosis program budget, respectively. Interpretation: Enhanced detection and treatment of TBD and TBI among HHC in Brazil can be achieved at a national level using current tools at reasonable cost. Funding: None.

High rate of transmission in a pulmonary tuberculosis outbreak in a junior high school in China, 2020.

Background: School tuberculosis outbreaks are common in China. This study aimed to introduce a new screening process to help control outbreaks. Methods: An epidemiological investigation into a school-based tuberculosis outbreak was conducted in order to identify the origin of the infection, and how it was transmitted. Results: In total, 10 confirmed active tuberculosis cases were diagnosed among student contacts in the index case's class, giving an incidence rate of 19.2% (10/52). Three were found through a proactive visit and seven through screening. Of the nine secondary cases, two had purified protein derivation of tuberculin (PPD) ≥ 15 mm or blister (confirmed by computed tomography (CT) scan before preventive therapy), five had TST ≥ 10 mm and < 15 mm (two with abnormal chest radiography scan and three with positive T-SPOT tests, confirmed by CT) and two with PPD ≥ 5 mm and < 10 mm (confirmed by CT scan through proactive visit). Conclusion: Further to our results based on this school outbreak, a new screening process is recommended that involves conducting interferon gamma release assays on those students with PPD ≥ 5 mm and < 15 mm if there are three or more active tuberculosis patients in the class with an epidemiological link. Furthermore, a CT scan is recommended for students who have had a recent tuberculosis infection before they have preventive therapy.

Aetiology of pyrexia of unknown origin in north India.

The aetiology of pyrexia of unknown origin (PUO) varies dramatically according to epidemiology. We studied the cause and spectrum of PUO in Indian adults. A total of 152 patients (112 prospectively and 40 retrospectively) met Petersdorf and Beeson's criteria. The diagnostic evaluation was guided by potentially diagnostic clues, based on a 'step-wise' approach. The five main categories, i.e. infectious, neoplastic, non-infectious inflammatory, miscellaneous and undiagnosed comprised 43.4%, 21.5%, 19.7%, 2.0% and 12.5%, respectively. The top three causes were tuberculosis (n = 43, 28.3%), lymphoma (n = 19, 12.5%) and adult-onset Still's disease (n = 12, 7.9%). Tuberculosis predominated in all age groups, and about 70% of cases had the extrapulmonary form, the most common being gastrointestinal. Hodgkin and non-Hodgkin lymphomas were equally distributed, but solid malignancies were uncommon. Adult-onset Still's disease was the second commonest cause in adults aged ≤ 40 years. Fever resolved spontaneously in 12/19 cases of undiagnosed cause. Extrapulmonary tuberculosis remains the most prevalent PUO in India.

Intravesical Bacillus Calmette-Guérin (BCG) treatment's severe complications: A single institution review of incidence, presentation and treatment outcome.

OBJECTIVES: Intravesical Bacillus Calmette-Guérin (BCG) treatment for superficial bladder cancer is interrupted in approximatively 8% of cases as a result of complications. The objective is to report the severe related complications of Bacillus Calmette-Guérin (BCG) following an intravesical instillation for bladder tumor encountered at our institution for the past 5 years. METHODS: Medical records of a tertiary teaching hospital, located in Beirut, Lebanon, were retrospectively analyzed from June 2014 to June 2019 searching for severe related complications of BCG. A comprehensive review of articles on this subject was conducted. RESULTS: The incidence of severe systemic adverse events related to BCG instillation was 1.5% (5 out of 332 patients). A total of five patients were found to have a severe BCG related complication, with fever, chills, and irritative urinary signs being the most frequent symptoms. All patients received antituberculosis therapy (Isoniazid, Rifampin and Ethambutol). Two were put on add-on corticosteroids. Three patients had a computed tomography scan image in favor of an infection. Two patients had a favorable outcome, three patients died. CONCLUSION: BCG severe adverse events were mostly seen in patients with a traumatic instillation. Treatment used at our institution was similar to most cases reported in the literature. A standardized diagnostic and treatment approach should be implemented to help physicians tackle these life-threatening complications.

Enduring Challenge of Latent Tuberculosis in Older Nursing Home Residents: A Brief Review.

Tuberculosis (TB) kills almost 4,000 people a day and is competing with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) as the most deadly infectious disease in the world. The gold standards of detection and management of latent tuberculosis infection (LTBI) have not been successful in complete eradication of the disease. Current screening modalities of TB include tuberculin skin testing (TST) and/or interferon-γ release assay (IGRA). However, these screening tests have been heavily studied in healthy populations but not in the elderly who are more likely to have multiple risk factors for progression to active TB from LTBI. The largest population that is harboring LTBI is the elderly, specifically those residing in nursing homes. Yet, unfortunately, guidelines for standards of detection and treatment for this specific group are lacking. In this review, we look at TST versus IGRA screening for LTBI in the elderly living in nursing homes. We review a cross-sectional study done at Staten Island University Hospital, and several other assessments of the sensitivity and accuracy of both screening tools. Furthermore, this review looks at the appropriateness of current LTBI treatment and prophylaxis in elderly patients residing in close quarters. The reviews point to the superiority of IGRA testing in the elderly for screening LTBI. The IGRA has been shown to be more sensitive to the detection of LTBI than TST. Additionally, medical complexities that the elderly population possesses may present challenges and resistance to standard treatments of LTBI. It is recommended via the literature that the addition of vitamin D, or alternative therapies (e.g. rifampin) could produce better outcomes for elderly patients with LTBI than the current 9 months of isoniazid (INH). As the older adults represent the fastest growing segment of our population and the largest LTBI reservoir in the USA, revisiting screening and treatment of LTBI in the elderly living in nursing homes may prove to lead to a path of TB eradication once and for all.

Interferon-γ release assay as a sensitive diagnostic tool of latent tuberculosis infection in patients with HIV: a cross-sectional study.

BACKGROUND: In developing countries, tuberculosis (TB) is a major public health problem and the leading cause of death among patients with HIV (Human Immunodeficiency Virus). Until 2001, the tuberculin skin test (TST) was the only available tool for the diagnosis of latent tuberculosis infection (LTBI), but false-negative TST results are frequently reported. Recently, the interferon-γ (IFN-γ) release assay (IGRA) has gained ground because it can detect the IFN-γ secreted by circulating lymphocytes T cells when stimulated by specific TB antigens. However, the role of IGRA in the diagnosis of LTBI in HIV-infected patients has not been well established. METHODS: This cross-sectional study compared the accuracy of TST (performed by the Mantoux method) and IGRA (QuantiFERON-TB Gold In-Tube, Cellestis, Carnegie, Australia) on the diagnosis of LTBI among patients with HIV. LTBI is defined by LTBI risk and at least one positive test (TST or IGRA), without clinical evidence of active TB. We also assessed the accuracy of TST and IGRA among HIV patients with high and low risk for LTBI. RESULTS: Among 90 HIV patients, 80 met the study criteria for LTBI, fifty-nine (73.7%) patients were TST positive, 21 (26.2%) were negative, whereas 75 patients (93.7%) were IGRA positive, and five (6.2%) were negative. TST showed poor agreement with the diagnosis of LTBI (Kappa: 0.384), while IGRA demonstrated good agreement (Kappa: 0.769). Among 69 patients with high risk and 21 with low risk for LTBI, TST was positive in 48 (69.5%) and 11 (52.4%), while IGRA was positive in 68 (98.5%) and 7 (33.3%) patients, respectively. There were no association between TST and the level of risk (P = 0,191). Conversely, we observed a strong association between the IGRA and risk for LTBI (p < 0.001). CONCLUSIONS: Compared to TST, IGRA positivity is consistent with the risk of TB infection and seems to be a better diagnostic tool for LTBI in HIV-infected patients.

Prevalence and associated risk factors of latent tuberculosis infection among undergraduate and postgraduate dental students: A retrospective study.

To estimate the prevalence of latent tuberculosis (TB) infection (LTBI) in Italian dental students exposed to the same occupational risks as dental health care personnel and to evaluate potential risk factors, a cross-sectional study was conducted on undergraduate and postgraduate students. After clinical evaluation, students were given a tuberculin skin test; in those found positive, an interferon-γ release assay (IGRA) was conducted. Of the 281 students enrolled, 10 were only TST positive; 8 were TST or/and IGRA positive. We found that participants testing positive at TST and/or IGRA, a group in which the risk of false LTBI positives is minimal, were older and had been studying longer. Although the prevalence of LTBI among dental students in our study was low, a risk of acquiring a work-related infection exists even in a country with a low incidence of TB. Thus, dental students should be screened to catch LTBI early on.

Mycobacterium tuberculosis infections in cynomolgus monkey transplant recipients and institution of a screening program for the prevention and control of tuberculosis.

BACKGROUND: Tuberculosis is a major health concern in not only humans, but also in non-human primates. In this paper, we report recent cases of Mycobacterium tuberculosis in cynomolgus monkeys from Cambodia used in transplantation research in a Korean facility and describe a program instituted to prevent and control subsequent infections. CASE PRESENTATION: All monkeys were antibody negative for tuberculosis during quarantine; however, suspected tuberculosis gross lesions were observed in two cynomolgus monkeys who underwent allograft kidney transplantation. Lung tissue from one monkey was found to be weakly positive by PCR for detection of M. tuberculosis. After PCR confirmation of tuberculosis, we decided to sacrifice the remaining animals and instituted a program for preventing subsequent infections. During necropsy of the remaining monkeys, two additional suspected tuberculosis cases were observed. A total of four monkeys with nodular lesions in the respiratory tract, suspected to be tuberculosis, demonstrated no clinical signs. Acid-fast bacilli were identified on slides from the lung or liver in all four monkeys. Two of four monkeys tested PCR positive. We decided that new monkeys entering from Cambodia should undergo a single gastric aspiration PCR and tuberculin skin testing (TST) every 2 weeks until four consecutive negatives to detect latent tuberculosis are obtained before starting experiments. Monkeys should then undergo a chest X-ray monthly and TST every 6 months. CONCLUSIONS: Detection of latent tuberculosis by an effective preventive screening program before starting experiments is an essential process to reduce the risk of reactivation of tuberculosis, especially in studies using immunosuppressive drugs. It also serves to protect the health of captive non-human primates, their caretakers and researchers.

Prevalence of latent tuberculosis infection and associated risk factors among 1557 nursing students in a context of low endemicity.

INTRODUCTION: The risk of tuberculosis (TBC) in nurses is related to its incidence in the general population. Nursing students involved in clinical training could be exposed to occupational risks similar to those of healthcare workers (HCWs). To better understand the epidemiology of nosocomial TBC among nurses in a context of low endemicity, we recruited a cohort of young nursing trainees at the Second University of Naples. METHODS: A screening programme for LTBI in nursing students was conducted between January 2012 and December 2013, at the Second University of Naples, with clinical evaluations, tuberculin skin test (TST) and, in positive TST student, the interferon-g release assays (IGRA). Putative risk factors for LTBI were assessed by a standardized questionnaire. RESULTS: 1577 nursing students attending the Second University of Naples have been submitted to screening programme for TBC. 1575 have performed TST as first level test and 2 Quantiferon test (QFT). 19 students were TST positive and continued the diagnostic workup practicing QFT, that was positive in 1 student. Of the 2 subjects that have practiced QFT as first level test only 1 was positive. In 2 students positive to QFT test we formulated the diagnosis of LTBI by clinical and radiographic results. CONCLUSION: The prevalence of LTBI among nursing students in our study resulted very low. In countries with a low incidence of TBC, the screening programs of healthcare students can be useful for the early identification and treatment of the sporadic cases of LTBI.

Prevalence and risk factors of latent Tuberculosis among adolescents in rural Eastern Uganda.

BACKGROUND: Latent Tuberculosis treatment is a key tuberculosis control intervention. Adolescents are a high risk group that is not routinely treated in low income countries. Knowledge of latent Tuberculosis (TB) burden among adolescents may influence policy. OBJECTIVES: We determined the prevalence and risk factors of latent TB infection among adolescents in rural Uganda. METHODS: We analyzed baseline data from a study that assessed the prevalence and incidence of Tuberculosis disease among adolescents. We extracted socio-demographics, medical assessment information, and tuberculin skin test results and estimated prevalence ratios (PR) of latent TB infection risk factors by binomial regression. RESULTS: The prevalence of latent TB was 16.1%, 95% CI (15.1 - 17.2). Significant risk factors were: a BCG scar, APR 1.29 (95% CI 1.12 - 1.48); male gender, APR 1.37 (95% CI 1.21 - 1.56); age 17 -18 years, APR 1.46 (95% CI 1.24 - 1.71) and 15-16 years, APR 1.25 (95% CI 1.07 - 1.46) compared to 12-14 years; being out of school, APR 1.31 (95% CI 1.05 - 1.62); and a known history of household TB contact in last 2 years, APR 1.91 (95% CI 1.55 - 2.35). CONCLUSION: Targeted routine latent TB treatment among adolescents out of school may be crucial for TB disease control in low income countries.

Prevalence of positive tuberculin skin test and associated factors among Makerere medical students, Kampala, Uganda.

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.

Prevalence of latent tuberculosis infection and associated risk factors among 3,374 healthcare students in Italy.

INTRODUCTION: The risk of tuberculosis (TB) in healthcare personnel (HCP) is related to its incidence in the general population. Healthcare students involved in clinical training could be exposed to occupational risks similar to those that HCP face. The prevalence of latent tuberculosis infection (LTBI) among undergraduate healthcare students with different working seniority in Italy was analysed. METHODS: A cross-sectional study under a screening programme for LTBI among undergraduate and postgraduate students attending Medical School at the Second University of Naples was conducted between January 2012 and December 2013 with clinical evaluations, tuberculin skin testing (TST) and, in positive TST students, Interferon-γ release assays (IGRA). Putative risk factors for LTBI were assessed by means of a standardised questionnaire. RESULTS: 3,374 students attending the Medical School of the Second University of Naples were submitted to a screening programme for TBC. 3,331 performed TST as a first-level test and 43 performed a Quantiferon test (QFT). 128 students were TST-positive and continued the diagnostic work with QFT, which was positive in 34 students. Of the 43 subjects who took the QFT as a first-level test only 1 was positive. In 35 students positive to the QFT test we formulated the diagnosis of LTBI by clinical and radiographic results. A correlation was found between age, non-Italian born persons, studying age, post-medical school status and LTBI. CONCLUSIONS: The prevalence of LTBI among healthcare students in our study was very low. In countries with a low incidence of TB, the screening programmes of healthcare students can be useful for early identification and treatment of sporadic cases of LTBI.

Effects of repeated tuberculin skin testings on immune responses in experimental monkeys.

Though many alternative methods to tuberculin skin testing (TST) have been established and evaluated in recent years, sensitivities and specificities of most methods could not meet the requirements of golden standards. In this study, we sought to identify whether repeated TSTs could affect the immune responses in experimental monkeys. Nine natural tuberculosis (TB) monkeys receiving repeated TSTs biweekly were used to demonstrate the effect on TST responsiveness. Two healthy monkeys were administrated with repeated TSTs to analyze the immune response profiling. Intrapalpebral reactions in TB infections gradually weakened or presented intermittent positive reactions. The leukocyte counts, cytokine responses, and antibody responses to all antigens except Old tuberculin (OT) and MPT64L showed no specific changes for TB in healthy monkeys. Positive antibody responses to OT and MPT64L emerged during the first half experimental period, which may cause by their cross-reactivity with mycobacterial species. Results showed that repeated TSTs had no significant effects on immune responses in healthy monkeys but a progressive reduction in TST responsiveness in TB infections.

Interferon-gamma release assays are a better tuberculosis screening test for hemodialysis patients: A study and review of the literature.

Diagnosing latent tuberculosis (TB) infection (LTBI) in dialysis patients is complicated by poor response to tuberculin skin testing (TST), but the role of interferon-gamma release assays (IGRAs) in the dialysis population remains uncertain. Seventy-nine patients were recruited to compare conventional diagnosis (CD) with the results of two IGRA tests in a dialysis unit. Combining TST, chest x-ray and screening questionnaire results (ie, CD) identified 24 patients as possible LTBI. IGRA testing identified 22 (QuantiFERON Gold IT, Cellestis, USA) and 23 (T-spot.TB, Oxford Immunotec, United Kingdom) LTBI patients. IGRA and CD correlated moderately (κ=0.59). IGRA results correlated with history of TB, TB contact and birth in an endemic country. TST was not helpful in identifying LTBI patients in this population. The tendency for IGRAs to correlate with risk factors for TB, active TB infection and history of TB argues for their superiority over TST in dialysis patients. There was no superiority of one IGRA test over another.

Le diagnostic d'infection tuberculeuse latente (ITBL) chez les patients sous dialyse est compliqué par le peu de réponse au test cutané à la tuberculine (TCT), mais le rôle du test de libération d'interféron gamma (TLIG) au sein de la population sous dialyse demeure incertain. Les auteurs ont recruté 79 patients pour comparer le diagnostic classique (DC) aux résultats de deux TLIG au sein d'une unité de dialyse. L'association du TCT, de la radiographie pulmonaire et des résultats d'un questionnaire de dépistage (c.-à-d. le DC) a permis de dépister 24 patients comme pouvant être atteints d'une ITBL. Le TLIG a permis de dépister 22 (QuantiFERON Gold IT, Cellestis, États-Unis) et 23 (T-spot.TB, Oxford Immunotec, Royaume-Uni) patients atteints d'une ITBL. Le TLIG et le DC avaient une corrélation modérée (κ=0,59). Les résultats du TLIG étaient corrélés avec les antécédents de tuberculose (TB), les contacts atteints de TB et la naissance dans un pays endémique. Le TCT ne contribuait pas à dépister les patients atteints d'une ITBL au sein de cette population. La tendance des TLIG à être corrélés avec les facteurs de risque de TB, une infection active par la TB et les antécédents de TB laisse supposer leur supériorité par rapport au TCT chez les patients sous dialyse. Aucun type de TLIG n'était supérieur aux autres.

Latent Mycobacterium tuberculosis Infection in Liver Transplant Recipients-Controversies in Current Diagnosis and Management.

Liver transplantation for end-stage liver disease is increasingly being undertaken in India.(1) Routine tuberculin skin testing (TST) for latent Mycobacterium tuberculosis infection (LTBI) and isoniazid prophylaxis in TST-positive liver-transplant recipients (LTRs) is recommended(2,3) but seldom implemented worldwide.(4-7) The role of TST-testing and isoniazid prophylaxis in LTRs remains further undefined in high prevalence areas, including India. We describe the burden of LTBI in LTRs; the epidemiological aspects of M. tuberculosis infection in high prevalence areas; identifiable risk factors for M. tuberculosis infection; the limitations of current diagnostic techniques for LTBI in LTRs and the efficacy and toxicity of isoniazid prophylaxis in TST-positive LTRs and suggest directions for future investigations in this area.

Avaliação da positividade ao teste tuberculínico entre os trabalhadores da rede básica de saúde / Evaluation of reactivity to tuberculin skin testing among workers of the public health system

Introdução: Os trabalhadores da área da saúde apresentam um risco elevado de infectarem-se com o Mycobacterium tuberculosis, principalmente aqueles envolvidos no contato direto com o paciente portador de tuberculose. Objetivos: Avaliar a prevalência de infecção por M. tuberculosis e investigar as características epidemiológicas dos trabalhadores da rede básica de saúde da cidade de Santa Cruz do Sul (RS). Métodos: No mês de outubro de 2009, foram entrevistados 60 trabalhadores da saúde que, posteriormente, foram submetidos ao teste tuberculínico (TT). Foram coletados dados epidemiológicos para a avaliação de características associadas à infecção latente. Resultados: Entre os 60 participantes do estudo, 16 (26,7%) apresentaram TT positivo. A positividade ao TT foi significativamente maior entre os trabalhadores com menor tempo de exposição. Conclusões: A infecção latente por M. tuberculosis entre os trabalhadores foi de 26,7%. Os dados encontrados reforçam a necessidade de implementar medidas para diminuir a exposição ocupacional, isto é, a realização de busca ativa por sintomáticos respiratórios na comunidade e a realização de diagnóstico precoce.

Background: Health care workers are at high risk of being infected with Mycobacterium tuberculosis, especially those who are in direct contact with patients with tuberculosis (TB). Aim: To evaluate the prevalence of infection with M. tuberculosis and to investigate the epidemiological characteristics of workers in the primary health care system in the city of Santa Cruz do Sul, Rio Grande do Sul, Brazil. Methods: In October 2009, we interviewed 60 health care workers who later underwent tuberculin skin testing (TST). We collected epidemiological data to assess the characteristics associated with latent infection. Results: Among the 60 participants of the study, 16 (26.7%) had positive TST. A positive TST was significantly higher among workers with shorter exposure time. Conclusions: Latent infection by M. tuberculosis among the health care workers was 26.7%. These findings underscore the need to implement measures to reduce occupational exposure, i.e., conducting an active search for respiratory symptoms in the community and establishing early diagnosis.

Viragem da prova tuberculínica entre profissionais da área de saúde em um hospital universitário, referência para AIDS, no Rio de Janeiro, Brasil / Tuberculin skin test conversion among health care workers in an universitary hospital, reference for AIDS, in Rio de Janeiro, Brazil

Introdução: existem escassos dados sobre o risco de infecção pelo mycobacterium tuberculosis entre profissionais de saúde (PS) em países em desenvolvimento. Estudo conduzido com o objetivo de para avaliar o risco ocupacional de infecção tuberculosa num hospital geral, no Rio de Janeiro, Brasil. Material e métodos: no período entre fevereiro de 1994 a setembro de 1994 foi realizado um inquérito da prova tuberculínica (PT) em um estudo transversal seguido de outro longitudial. Os PS responderam a um questionário padronizado e foram submetidos a duas etapas da PT. Resultados: entre 1250 PS que participaram da primeira fase do estudo, 649 (52%) apresentaram PT positiva (i.e. ³ 10mm), o fenômeno "booster" ocorreu em 7,8% (35/449) deles e esteve significativamente associados apenas ao relato de tuberculose prévia na família (OR: 3,29; 1,39-7,68, p= 0,004). Durante o período de estudo, 32 (8.7%) apresentaram conversão à prova tuberculínica entre os 368 PS seguidos pelo menos por 12 meses. Na regressão logística do estudo transversal apenas a idade superior a 30 anos (OR: 1,88; 1,35-3,47, p= 0,0001), a escolaridade inferior a 8 anos (OR: 1,44; 1,09 - 672, p= 0,02) e pertencer a categoria de enfermagem (OR: 1,55; 1,21 -4,78, p=0,01) permaneceram significativamente associados ao resultado positivo da PT. No estudo longitudinal, os PS com idade superior a 30 anos apresentaram menor risco de conversão à PT (RR: 0,37, 0,23-0,89, p=0,01) enquanto pertencer a categoria profissional de médico e enfermagem este risco foi significantemente maior (RR:4,21, 1,17-8,94, p= 0,03). Conclusões: estes resultados sugerem um elevado risco ocupacional de TB e sinaliza para uma urgente implementação de medidas de biossegurança em hospitais gerais que atendem pacientes com tuberculose.