Evaluation of cytokine profiles related to Mycobacterium tuberculosis latent antigens using a whole-blood assay in the Philippines.

Introduction: There is no useful method to discriminate between latent tuberculosis infection (LTBI) and active pulmonary tuberculosis (PTB). This study aimed to investigate the potential of cytokine profiles to discriminate between LTBI and active PTB using whole-blood stimulation with Mycobacterium tuberculosis (MTB) antigens, including latency-associated antigens. Materials and methods: Patients with active PTB, household contacts of active PTB patients and community exposure subjects were recruited in Manila, the Philippines. Peripheral blood was collected from the participants and used for whole-blood stimulation (WBS) with either the early secretory antigenic target and the 10-kDa culture filtrate protein (ESAT-6/CFP-10), Rv3879c or latency-associated MTB antigens, including mycobacterial DNA-binding protein 1 (MDP-1), α-crystallin (Acr) and heparin-binding hemagglutinin (HBHA). Multiple cytokine concentrations were analyzed using the Bio-Plex™ multiplex cytokine assay. Results: A total of 78 participants consisting of 15 active PTB patients, 48 household contacts and 15 community exposure subjects were eligible. The MDP-1-specific IFN-γ level in the active PTB group was significantly lower than that in the household contact group (p < 0.001) and the community exposure group (p < 0.001). The Acr-specific TNF-α and IL-10 levels in the active PTB group were significantly higher than those in the household contact (TNF-α; p = 0.001, IL-10; p = 0.001) and community exposure (TNF-α; p < 0.001, IL-10; p = 0.01) groups. However, there was no significant difference in the ESAT-6/CFP-10-specific IFN-γ levels among the groups. Conclusion: The patterns of cytokine profiles induced by latency-associated MTB antigens using WBS have the potential to discriminate between LTBI and active PTB. In particular, combinations of IFN-γ and MDP-1, TNF-α and Acr, and IL-10 and Acr are promising. This study provides the first demonstration of the utility of MDP-1-specific cytokine responses in WBS.

Impact of annual TB screening on stone quarry workers in high-incidence Portuguese municipalities.

The Portuguese municipalities of Penafiel and Marco de Canaveses are high TB incidence areas, where stone quarry workers represent a vulnerable population.To assess the annual rate of TB infection (ARI) in stone quarry workers and to compare it with the TB notification rate in the general community.An annual TB infection screening strategy using interferon-gamma release assay (IGRA) was implemented in 2018 for workers from high-risk stone quarries. A prospective cohort was enrolled and workers screened in periods of 2 years were included. IGRA-positive workers were referred for preventive treatment. ARI was calculated as the proportion of workers with IGRA conversion.Of the 232 IGRA-negative workers in 2018, 20 tested positive in 2019 (8.6% ARI). Of 171 IGRA-negative workers in 2019, eight tested positive in 2021 (4.7% in 2 years). Two of the 150 IGRA-negative workers in 2021 tested positive in 2022 (1.3% ARI). ARI decreased by 84.9% between 2019 and 2022. In the two municipalities, the TB notification rate declined 23.9% between 2018 and 2021.A more pronounced reduction in ARI was observed among stone quarry workers regularly screened for TB infection compared to the notification rate among the general population in high-incidence municipalities. A screening strategy for high-risk populations, together with enforced community measures, could foster risk reduction in the community..

Screening for latent tuberculosis in migrants-status quo and future challenges.

OBJECTIVES: To review the evidence that migrants from tuberculosis (TB) high-incidence countries migrating to TB low-incidence countries significantly contribute to active TB cases in the counties of destination, primarily through reactivation of latent TB. METHODS: This is a narrative review. The different screening programs in the countries of destination are reviewed either based on screening and preventive treatment of latent TB pre or more commonly - post arrival. RESULTS: Screening can be performed using interferon-gamma release assays (IGRA) or tuberculin skin tests (TST). Preventive treatment of latent TB is using either monotherapy with isoniazid, or in combination with rifampicin or rifapentine. We discuss the ethical issues of preventive treatment in asymptomatic individuals and how these are addressed in different screening programs. CONCLUSION: Screening migrants from TB high endemic countries to TB low endemic countries is beneficial. There is a lack of standardization and agreement on screening protocols, follow up and treatment.

RATE OF INFECTION (TUBERCULOSIS) IN BRAZILIANS IBD PRIVATE PATIENTS: FOLLOW-UP 15 YEARS.

BACKGROUND: Latent tuberculosis (LTB) is a condition where the patient is infected with Mycobacterium tuberculosis but does not develop active TB. There's a possibility of tuberculosis (TB) activation following the introduction of anti-TNFs. OBJECTIVE: To assess the risk of biological therapy inducing LTB during inflammatory bowel diseases (IBD) treatment over 15 years in a high-risk area in Brazil. METHODS: A retrospective study of an IBD patients' database was carried out in a private reference clinic in Brazil. All patients underwent TST testing and chest X-ray prior to treatment, and once a year after starting it. Patients were classified according to the Montreal stratification and risk factors were considered for developing TB. RESULTS: Among the analyzed factors, age and gender were risk factors for LTB. DC (B2 and P) and UC (E2) patients showed a higher number of LTB cases with statistical significance, what was also observed for adalimumab and infliximab users, compared to other medications, and time of exposure to them favored it significantly. Other factors such as enclosed working environment have been reported as risk. CONCLUSION: The risk of biological therapy causing LTB is real, so patients with IBD should be continually monitored. This study reveals that the longer the exposure to anti-TNFs, the greater the risk. BACKGROUND: •Rate of infection (tuberculosis) in Brazilians IBD private patients: follow-up 15 years. BACKGROUND: •Patients treated with immunosuppressants and/or anti-TNFs have a higher risk of developing opportunistic infections, among them the most common is latent tuberculosis or even active tuberculosis. BACKGROUND: •Similar risks may be noted in patients with inflammatory bowel diseases (IBDs). BACKGROUND: •This study reveals that the longer the exposure to anti-TNFs, the greater the risk for de IBD patients. BACKGROUND: •The study demonstrated the importance of monitoring these patients permanently and continuously.

Relationship between biologic modifying agents and development of latent tuberculosis in pediatrics.

INTRODUCTION: Biologic modifying agents are associated with an increased risk for infection with mycobacteria. The aim of this study is to document patients who received different biologic modifying therapies in our pediatric rheumatology department and the possibility of development of tuberculosis (TB). METHODOLOGY: This retrospective study was conducted in Ankara City Hospital. Pediatric patients who were treated with biologic modifying agents between 2010-2020 were documented. Development of TB and the risk factors were assessed in this patient group. RESULTS: There were 72 patients who were treated with different biologic modifying agents. Tuberculin skin test (TST) was positive in 7 (9.7%) patients during follow up. Three patients whose TST was positive had received canakinumab, 2 received etanercept, 1 received adalimumab and 1 received anakinra. Median duration of therapy was 43.5 (16.5-168) months for these patients and the duration was longer than patients who did not develop latent tuberculosis (p = 0.04). Patients who developed latent TB under treatment were significantly older than the patients who did not (p = 0.01). CONCLUSIONS: According to our findings, 9.7% of pediatric patients who received biologic modifying agent therapy developed latent TB. Patients who developed latent TB were older, and the duration of treatment was longer than patients who did not develop latent TB. Although not statistically significant, canakinumab, which is known as an agent less likely to cause TST conversion, was in fact the most common agent that caused TST conversion.

Identification of differentially recognized T cell epitopes in the spectrum of tuberculosis infection.

There is still incomplete knowledge of which Mycobacterium tuberculosis (Mtb) antigens can trigger distinct T cell responses at different stages of infection. Here, a proteome-wide screen of 20,610 Mtb-derived peptides in 21 patients mid-treatment for active tuberculosis (ATB) reveals IFNγ-specific T cell responses against 137 unique epitopes. Of these, 16% are recognized by two or more participants and predominantly derived from cell wall and cell processes antigens. There is differential recognition of antigens, including TB vaccine candidate antigens, between ATB participants and interferon-gamma release assay (IGRA + /-) individuals. We developed an ATB-specific peptide pool (ATB116) consisting of epitopes exclusively recognized by ATB participants. This pool can distinguish patients with pulmonary ATB from IGRA + /- individuals from various geographical locations, with a sensitivity of over 60% and a specificity exceeding 80%. This proteome-wide screen of T cell reactivity identified infection stage-specific epitopes and antigens for potential use in diagnostics and measuring Mtb-specific immune responses.

Cost-effectiveness of interferon-γ release assay for screening of latent tuberculosis infection in individuals with schizophrenia.

Schizophrenia is recognized as a significant risk factor for tuberculosis (TB). This study aimed to evaluate the effectiveness and cost-effectiveness of interferon-γ release assay (IGRA) with preventive treatment for screening of latent tuberculosis infection (LTBI) in individuals with schizophrenia. A state transition model was developed from a healthcare payer perspective on a lifetime horizon. Ten strategies were compared by combining two different tests for LTBI, i.e. IGRA and tuberculin skin test (TST), and five different preventive treatments, i.e. 9-month isoniazid (9H), 3-month isoniazid and rifapentine (3HP) by directly observed therapy, 3HP by self-administered therapy, 3-month isoniazid and rifampin (3RH), and 4-month rifampin (4R). The main outcomes were costs, quality-adjusted life-years (QALYs), life expectancy life-years (LYs), incremental cost-effectiveness ratios, drug-sensitive tuberculosis (DS-TB) cases, and TB-related deaths. For both bacillus Calmette-Guérin (BCG)-vaccinated and non-BCG-vaccinated individuals, IGRA with 4R was the most cost-effective and TST with 3RH was the least effective. Among schizophrenic individuals in Japan, IGRA with 4R saved US$17.8 million, increased 58,981 QALYs and 935 LYs, and prevented 222 DS-TB cases and 75 TB-related deaths compared with TST with 3RH. In individuals with schizophrenia, IGRA with 4R is recommended for LTBI screening with preventive treatment to reduce costs, morbidity, and mortality from TB.

Latent tuberculosis infection in Korean patients with multiple sclerosis and neuromyelitis optica spectrum disorder.

BACKGROUND: Latent tuberculosis infection (LTBI) is defined as an immune response to Mycobacterium tuberculosis infection that does not manifest clinically as active tuberculosis (TB). Since some immunotherapies can alter cellular immunity, LTBI screening has been recommended for patients with multiple sclerosis (pwMS) before initiation of long-term immunotherapies. In this study, we investigated the frequency of LTBI in Korean pwMS and patients with neuromyelitis optica spectrum disorder (pwNMOSD) and reported the long-term observation of untreated LTBI under various immunotherapies. METHODS: We enrolled pwMS or pwNMOSD who visited the Neurology department of the National Cancer Center between 2017 and 2021. LTBI was determined based on positive results of interferon-gamma release assay (IGRA) using QuantiFERON Gold Plus test and no evidence of active TB. Annual chest X-ray and careful monitoring for TB symptoms were performed until April 2023 or the time of follow-up loss. RESULTS: Among 531 patients who underwent the IGRA test, 25 pwMS (10.5%) and 42 pwNMOSD (14.3%) were diagnosed with LTBI. Of the 67 patients with LTBI, 59 patients (24 pwMS and 35 pwNMOSD) declined to receive preventive anti-TB drugs. None of the 59 with untreated LTBI demonstrated TB reactivation during 74.8 person-years in pwMS and 166.1 person-years in pwNMOSD. In addition, eight patients who completed the treatment for LTBI experienced no TB reactivation for a median of 5.5 years. CONCLUSION: The LTBI prevalence in Korean pw MS and pwNMOSD was 10.5% and 14.3%, respectively, which was much higher than that in pwMS from Western countries. Notably, none of the 59 patients with untreated LTBI showed TB reactivation over 240 person-years even under long-term immunotherapies, indicating the need for additional research to stratify the risk of LTBI-reactivation.

Risk factors and prognosis for latent tuberculosis infection in dialysis patients: A retrospective cohort study at a single tertiary care center.

INTRODUCTION: Recent studies report that latent tuberculosis infection (LTBI) may lead to an increased risk of cardiovascular disease (CVD) that led us to hypothesize that LTBI may play an important role in major adverse cardiovascular events (MACE) in dialysis patients. METHODS: A single-center retrospective cohort study was conducted. A total of 270 patients undergoing hemodialysis or peritoneal dialysis more than 3 months were included. The interferon enzyme-linked immunospot (IFN-γ ELISPOT) assay was used for the diagnosis of LTBI. Primary endpoints were MACE, including all-cause death and acute coronary syndrome (ACS). The association between LTBI and MACE was examined using multivariate Cox proportional hazards regression after adjusting for covariates and Kaplan-Meier survival analysis. RESULTS: In our study, the patients were classified into LTBI (n = 47) or non-LTBI (n = 223) groups. Independent risk factors for LTBI in dialysis population were prior tuberculosis (TB) history (odds ratio [OR] 4.817 [1.064-22.306]), tobacco use (OR 2.903 [1.155-7.299]), and older age (OR 1.027 [1.002-1.053]). After a median follow-up of 39 months, the incidence of active TB was 6.4% versus 0% in dialysis patients with and without LTBI, respectively (p = 0.005). Multivariate Cox analysis showed that LTBI was significantly associated with MACE (hazard ratio [HR] 2.540 [1.490-4.350]) after adjustment for potential confounders. CONCLUSIONS: Prior TB history, tobacco use, and the elderly can be used to select cost-effective LTBI screening target groups in dialysis patients. LTBI is not only closely related to active TB but also an independent risk factor for higher incidence of MACE in dialysis population.

Screening for tuberculosis infection and effectiveness of preventive treatment among people with HIV in low-incidence settings.

OBJECTIVE: To determine the yield of screening for latent tuberculosis infection (LTBI) among people with HIV (PWH) in low tuberculosis (TB) incidence countries (<10 TB cases per 100 000 persons). DESIGN: A systematic review and meta-analysis were performed to assess prevalence and predictive factors of LTBI, rate of TB progression, effect of TB preventive treatment (TPT), and numbers needed to screen (NNS). METHODS: PubMed and Cochrane Library were searched for studies reporting primary data, excluding studies on active or paediatric TB. We extracted LTBI cases, odds ratios, and TB incidences; pooled estimates using a random-effects model; and used the Newcastle-Ottawa scale for bias. RESULTS: In 51 studies with 65 930 PWH, 12% [95% confidence interval (CI) 10-14] had a positive LTBI test, which was strongly associated with origin from a TB-endemic country [odds ratio (OR) 4.7] and exposure to TB (OR 2.9). Without TPT (10 629 PWH), TB incidence was 28/1000 person-years (PY; 95% CI 12-45) for LTBI-test positive versus 4/1000 PY (95% CI 0-7) for LTBI-test-negative individuals. Among 625 PWH (1644 PY) receiving TPT, 15 developed TB (6/1000 PY). An estimated 20 LTBI-positive individuals would need TPT to prevent one case of TB, and numbers NNS to detect LTBI or prevent active TB varied according to a-priori risk of LTBI. CONCLUSION: The relatively high prevalence of LTBI among PWH and the strong correlation with origin from a TB-endemic country support risk-stratified LTBI screening strategies for PWH in low-incidence countries and treating those who test positive.

Tuberculosis and childhood cancer - A review of literature.

Tuberculosis and malignancy are major public health problems in developing countries like India and causes significant morbidity and mortality. Mycobacterium tuberculosis is an aerobic acid-fast bacilli which is an important pathogen especially complicating clinical status of paediatric oncology patients and treatment of infection with this bacilli is challenging in this subpopulation of patients because of ongoing immunosuppression and relative lack of published guidelines. Atypical presentations of tuberculosis in children also complicate the diagnosis and management. All the more, in tuberculosis endemic area lung cancer may be mistakenly diagnosed as tuberculosis or vice versa and this wrong diagnosis increases the burden on country's health status. It is noted that tuberculosis prevalence is high in children with haematological malignancy and head and neck tumours compared to other solid organ tumours. Moreover, it is found that morbidity and mortality from tuberculosis is more in children from WHO listed high TB burden countries who undergo hematopoietic stem cell and solid organ transplantation. Use of immune checkpoint inhibitors as novel therapy in treatment of childhood malignancies has led to modification of the body's immunological response and has resulted in increased latent tuberculosis infection reactivation as one immune-related infectious consequence. Latent TB infection screening is important concept in management of paediatric oncology patients. Currently, the tests employed as screening diagnostics for LTBI are interferon-gamma release assay (IGRA) blood test and the tuberculin skin test (TST). Various regimens have been suggested for the treatment of LTBI. But, after a positive IGRA or TST and prior to latent TB treatment, active tuberculosis should be ruled out by detailed history taking, examination and appropriate investigations so as to minimize the risk of drug resistance with anti-tuberculosis monotherapy used in LTBI treatment. To add on to literature, Non tuberculous mycobacteria are universally present environmental organisms. However, in immunocompromised children especially in subpopulation of malignancy, NTM is known to cause infections which needs protocol based management. Also importance has to given to implementation of adequate preventive and corrective measures to prevent such opportunistic infection in paediatric oncology subpopulation. In this review, we provide an overview of tuberculosis in paediatric oncology patients and summarize the expansive body of literature on the tuberculosis mimicking carcinoma, tuberculosis burden in transplantation patients and those receiving immune check point inhibitors, latent TB infection screening and management, and NTM infection in children with malignancy.

[Tuberculosis infection in patients with inflammatory bowel diseases. Clinacal cases].

In most cases Tuberculosis (TB) affects the lungs, but 10-15% of patients have extrapulmonary TB localisations, that is difficult to diagnose. TB is more spread among patients having the human immunodeficiency virus and among those who receive immunosuppressive therapy, specifically in patients with inflammatory bowel disease requiring long-term treatment with immunosuppressants and/or biologics. The symptoms of intestinal TB are nonspecific and may include chronic diarrhea, weight loss, fever and ascites. Differential diagnosis includes Crohn's disease, malignant neoplasms, periappendiceal abscesses, yersiniosis, etc. The article presents cases showing similarity of the intestinal form of TB with Crohn's disease, complexity dealing, diagnosing and treating patients with inflammatory bowel disease also having latent tuberculosis infection.

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.

[Massive pulmonary thromboembolism in a patient with Crohn's disease and latent tuberculosis treated with ustekinumab]. / Tromboembolia pulmonar masiva en un paciente con enfermedad de Crohn y tuberculosis latente tratada con ustekinumab.

Inflammatory bowel disease (IBD) is a spectrum of chronic immune-mediated diseases that affect the gastrointestinal tract and other extraintestinal systems, behaving as a systemic disease. Thromboembolic phenomena are a frequent complication in IBD, because of hypercoagulability states associated with disease activity, and their presence has a negative impact on prognosis and patient survival. Due to this, the control of the inflammatory activity of IBD is one of the pillars in the control of thromboembolic events. Biological drugs are associated with rapid control of the inflammatory process, however, the security profile for the reactivation of latent infections, particularly tuberculosis, is always discussed. We present the case of a 37-year-old patient who presented with deep vein thrombosis in the left lower limb and later with massive pulmonary thromboembolism. During his evaluation, he was diagnosed with Crohn's disease (CD). When carrying out the studies prior to the use of biologics, PPD and quantiferon tests were positive. After discussing the case, we decided to start treatment with ustekinumab.

Impact of Human Immunodeficiency Virus and Peripartum Period on Mycobacterium tuberculosis Infection Detection.

BACKGROUND: Pregnancy and human immunodeficiency virus (HIV) may influence tuberculosis infection detection using interferon (IFN)-γ release assay (QFT-Plus; Qiagen) and tuberculin skin test (TST). METHODS: Participants in Western Kenya underwent QFT-Plus and TST in pregnancy, 6 weeks postpartum (6wkPP) and 12 months postpartum (12moPP). RESULTS: 400 participants (200 with HIV [WHIV], 200 HIV-negative) enrolled during pregnancy (median 28 weeks' gestation [interquartile range, 24-30]). QFT-Plus positivity prevalence was higher than TST in pregnancy (32.5% vs 11.6%) and through 12moPP (6wkPP, 30.9% for QFT-Plus vs 18.0% for TST; 12moPP, 29.5% vs 17.1%; all P < .001), driven primarily by QFT-Plus-positive/TST-negative discordance among HIV-negative women. Tuberculosis infection test conversion incidence was 28.4/100 person-years (PY) and higher in WHIV than HIV-negative women (35.5 vs 20.9/100 PY; hazard ratio, 1.73 [95% confidence interval, 1.04-2.88]), mostly owing to early postpartum TST conversion among WHIV. Among QFT-Plus-positive participants in pregnancy, Mycobacterium tuberculosis  (Mtb)-specific IFN-γ responses were dynamic through 12moPP and lower among WHIV than HIV-negative women with tuberculosis infection at all time points. CONCLUSIONS: QFT-Plus had higher diagnostic yield than TST in peripartum women. Peripartum QFT-Plus positivity was stable and less influenced by HIV than TST. Mtb-specific IFN-γ responses were dynamic and lower among WHIV. Tuberculosis infection test conversion incidence was high between pregnancy and early postpartum, potentially owing to postpartum immune recovery.

Prevalencia de infección tuberculosa latente e incidencia de viraje tuberculínico en contactos escolares mayores de 5 años en la Ciudad Autónoma de Buenos Aires / Prevalence of latent tuberculosis infection and incidence of tuberculin conversion among school contacts older than 5 years in the City of Buenos Aires

Introducción. La tuberculosis continúa siendo un problema frecuente en contextos de vulnerabilidad socioeconómica. El objetivo principal fue establecer la prevalencia de infección latente y viraje tuberculínico en contactos escolares de casos de tuberculosis. Población y métodos. En un área programática del sur de la ciudad, se evaluó la prevalencia de infección y viraje tuberculínico de 691 niñas, niños y adolescentes utilizando la prueba cutánea de tuberculina. Se investigó la asociación entre pérdida de seguimiento por parte del equipo de salud y características demográficas, escolares y asistencia inicial, y se describió el grado de adherencia cuando la quimioprofilaxis con isoniacida fue indicada. Resultados. Según las definiciones consideradas, la prevalencia de infección latente fue entre el 3,4 % (IC95 %: 2,3-5,2) y el 11,6 % (IC95 %: 9,3-14,4) de los 610 contactos con al menos una prueba cutánea aplicada. La incidencia de viraje tuberculínico se encontró entre el 0,3 % y el 6,8 % de los 294 evaluados. La edad mayor de 18 años, la mayor prevalencia de necesidades básicas insatisfechas en la comuna escolar, la pertenencia al turno escolar vespertino, la negatividad en la baciloscopia del caso índice y la ausencia de aplicación de la prueba cutánea inicial se asociaron con pérdida de seguimiento del contacto. Conclusiones. La incidencia de viraje tuberculínico en contactos escolares fue baja. La adherencia a isoniacida continúa siendo limitada. Se identificaron factores asociados con la pérdida de seguimiento de contactos que podrían orientar estrategias necesarias para mejorar este proceso.

Introduction. Tuberculosis continues to be a common problem in settings of socioeconomic vulnerability. Our primary objective was to establish the prevalence of latent infection and tuberculin conversion among school contacts of tuberculosis cases. Population and methods. In a programmatic area in the south of the City of Buenos Aires, the prevalence of latent infection and tuberculin conversion was assessed in 691 children and adolescents using the tuberculin skin test. The association between loss to follow-up by the health care team and the demographic, school, and baseline care characteristics was studied, and the level of adherence when isoniazid chemoprophylaxis was indicated was described. Results. According to established definitions, the prevalence of latent infection was between 3.4% (95% confidence interval [CI]: 2.3­5.2) and 11.6% (95% CI: 9.3­14.4) in the 610 contacts with at least one skin test. The incidence of tuberculin conversion was between 0.3% and 6.8% in the 294 assessed participants. Age older than 18 years, a higher prevalence of unmet basic needs in the school district, attending the afternoon school shift, negative sputum smear results in the index case, and absence of baseline skin test were associated with contact lost to follow-up. Conclusions. The incidence of tuberculin conversion among school contacts was low. Adherence to isoniazid treatment remains limited. Factors associated with loss of contact tracing were identified, which may guide strategies necessary to improve this process.

The safety of vedolizumab in a patient with Crohn's disease who developed anti-TNF-alpha agent associated latent tuberculosis infection reactivation: A case report.

RATIONALE: Latent tuberculosis (TB) infection screening before inducing anti-tumor necrosis factor (anti-TNF) alpha agents is important to prevent TB reactivation. However, latent TB infection reactivation may still occur, and the ideal therapeutic strategy for patients with inflammatory bowel disease (IBD) who develop active TB infection has not been established. Vedolizumab (VDZ) has a good safety profile, with low incidence rates of serious infections. However, its safety in patients with latent TB infection reactivation associated with anti-TNF-alpha agents remains unknown. PATIENT CONCERNS: A 21-year-old Vietnamese male patient presented to our hospital with hemorrhagic stool. He had no personal or family history of IBD or TB. DIAGNOSES: Colonoscopy revealed multiple longitudinal ulcers and a cobblestone appearance in the terminal ileum, as well as multiple small erosions and aphtha throughout the colon. Computed tomography revealed a right lung nodular lesion. Serological interferon-gamma release assay and several culture tests were all negative. Thus, he was diagnosed with ileocolonic Crohn's disease (CD) without TB. INTERVENTIONS: The intravenous anti-TNF-alpha agent administration with an immunomodulator was initiated. OUTCOMES: Computed tomography revealed nodular lesion expansion at the right lung, and serological interferon-gamma release assay was positive. He was diagnosed with latent TB infection reactivation. Anti-TNF-alpha agent with an immunomodulator was immediately discontinued, and anti-TB therapy was initiated. His endoscopic findings were still active, and VDZ was selected for maintenance therapy because VDZ has a favorable safety profile with low incidence rates of serious infections. Consequently, mucosal healing was achieved without active TB relapse. LESSONS: This case report presented a patient in whom VDZ was continued as maintenance therapy without inducing TB relapse in a patient with CD who developed latent TB infection reactivation associated with anti-TNF-alpha agents and summarized the safety profile of VDZ for patients with IBD with active or latent TB infection. VDZ may be a safe option for induction and maintenance therapy in patients with CD, even in cases with latent TB infection reactivation.