Prevalence Of Latent Tuberculosis Infection Research Articles

Prevalence of latent TB infection among childhood contacts of adults with sputum positive pulmonary TB

BackgroundTuberculosis is a global public health challenge. More stringent activities are needed for evaluation of ongoing TB transmission. The study was aimed at estimating the prevalence of LTBI in children below 15 years who are household contacts of adults with sputum positive pulmonary TB and identify the determinants involved in TB transmission. The compliance and incidence of adverse events were also studied. MethodologyAn observational study was conducted among 194 children below 15 years who were in contact with 145 adults with smear positive pulmonary TB. All children below 5 years underwent TST and were offered LTBI chemoprophylaxis as per NTEP program while IGRA was used to diagnose LTBI in children above 5 years. A structured questionnaire was used to collect data on determinants of TB transmission. Children were followed up during the LTBI treatment period for assessing compliance and the adverse effects. ResultsThe prevalence of LTBI among the study participants was 15.4 %. Children who received LTBI treatment showed good acceptance with a drug compliance of 98.5 % and only 21 % showed adverse events, all of which were minor. Malnutrition (p value-0.03), overcrowding (P value = 0.014) and exposure to tobacco smoke (p value = 0.000) were identified as the socio-demographic determinants affecting TB transmission. ConclusionChildren below 15 years are at high risk of contracting TB from household adult contacts. Overcrowding, malnutrition and exposure to tobacco smoke being the determinants of TB transmission, screening programmes should prioritise children exposed to such situations, especially in resource limited settings like India.

Latent tuberculosis prevalence, diagnosis and treatment in Multiple Sclerosis as a strategy for reducing infection reactivation during immunosuppressant therapy

BackgroundTuberculosis is an infectious disease with a risk of reactivation in Multiple Sclerosis patients on immunosuppressant therapy. Diagnosis and treatment of Latent Tuberculosis Infection (LTBI) prevents the infection. ObjectiveTo diagnose and treat LTBI in Multiple Sclerosis (MS). MethodsCross-sectional study of the prevalence and treatment of LTBI in MS, between February 2021 and June 2023. LTBI was defined as an absence of symptoms, positive PPD or IGRA and normal chest X-ray. ResultsOf the 58 patients with MS, 17 (29.3 %) were diagnosed with LTBI, 15 with PPD > 5 mm and 2 with positive IGRA, 10 (58.8 %) female and 7 (41.1 %) male, mean age of 41.3 (SD ±13.4) years. All patients with LTBI were treated with immunomodulators or immunosuppressants: Fingolimod 5 (29.4 %), Natalizumab 5 (29.4 %), Cladribine 2 (11.8 %), Glatiramer 2 (11.8 %), Ocrelizumab 2 (11.8 %), and Interferon beta 1 (5.9 %). Steroids therapy for relapses, were used in 5/17 (93.8 %) with LTBI and 30/37 (81.1 %) without LTBI. To treat LTBI, 11 (64.7 %) received Isoniazid and 6 (35.3 %) Isoniazid plus Rifapentine. Hepatotoxicity occurred in 3 (17.6 %) with INH. There were no interruptions of ILTB treatment during the study. ConclusionThe prevalence of LTBI was found to be high and treatment proved safe.

Analysis of Tuberculosis Incidence among Employees of Forensic Medicine Bureau in Tyumen Region in 2003-2022

The objective: to analyze tuberculosis incidence and assess prevalence of latent tuberculosis infection (LTBI) among employees of Forensic Medicine Bureau (FMB) in Tyumen Region.Subjects and Methods. Tuberculosis incidence was retrospectively studied, and employees of Forensic Medicine Bureau in Tyumen Region were examined in order to detect latent tuberculosis infection.Results. In 2003-2022, the long-time average annual incidence made 105.4±23.6 per 10,000 workers. The number of employees who had suffered tuberculosis with up to 5 years of experience in the bureau was greater versus employees with 6-10 years of experience and 11-15 years of experience. The level of LTBI based on the TRA test results was 32.7±4.5%. Tuberculosis incidence and the rate of LTBI among employees performing autopsies were higher versus employees of other departments of Forensic Medicine Bureau.

Cost-effectiveness of latent tuberculosis infection testing and treatment with 6-week regimen among key population in rural communities in China: a decision analysis study.

Several model studies suggested the implementation of latent tuberculosis infection (LTBI) testing and treatment could greatly reduce the incidence of tuberculosis (TB) and achieve the 2035 target of the "End TB" Strategy in China. The present study aimed to evaluate the cost-effectiveness of LTBI testing and TB preventive treatment among key population (≥ 50 years old) susceptible to TB at community level in China. A Markov model was developed to investigate the cost-effectiveness of LTBI testing using interferon gamma release assay (IGRA) and subsequent treatment with 6-month daily isoniazid regimen (6H) (as a standard regimen for comparison) or 6-week twice-weekly rifapentine and isoniazid regimen (6-week H2P2) in a cohort of 10,000 adults with an average initial age of 50 years. In the base-case analysis, LTBI testing and treatment with 6H was dominated (i.e., more expensive with a lower quality-adjusted life year (QALY)) by LTBI testing and treatment with 6-week H2P2. LTBI testing and treatment with 6-week H2P2 was more effective than no intervention at a cost of $20,943.81 per QALY gained, which was below the willingness-to-pay (WTP) threshold of $24,211.84 per QALY gained in China. The one-way sensitivity analysis showed the change of LTBI prevalence was the parameter that most influenced the results of the incremental cost-effectiveness ratios (ICERs). As estimated by a Markov model, LTBI testing and treatment with 6-week H2P2 was cost-saving compared with LTBI testing and treatment with 6H, and it was considered to be a cost-effective option for TB control in rural China.

Prevalence of Latent Tuberculosis Infection Among Nurses Working in Critical Areas at a Tertiary Care Hospital in Riyadh, Saudi Arabia.

Introduction Tuberculosis is a critical health issue worldwide.Most infected persons are asymptomatic and categorized as having a latent tuberculosis infection (LTBI). Healthcare workers (HCWs) are more prone to being infected with tuberculosis and should be enrolled in a screening program for early detection. Objectives The study aims to estimate the prevalence of LTBI among nurses working in critical areas which include adult intensive care units, pediatric intensive care units, emergency departments, oncology departments, dialysis departments, tuberculosis labs, isolation rooms, and cardiac center intensive care units. Methods A record-based cross-sectional survey measured the prevalence of LTBI among nurses working in critical areas at Prince Sultan Military Medical City (PSMMC), Riyadh, Saudi Arabia. We reviewed the occupational health records of all nurses working in critical areas from June 1, 2021, to June 1, 2022. We recorded the data reviewed throughout the year in the Occupational Health Department at PSMMC. We excluded all participants with previously documented positive tuberculin skin test (TST) from the study. We analyzed the sociodemographic data, working years, working location, job title, and TST results. Results We included a total of 771 out of 2025 nurses in this study. Participants were mostly women (88%) and in the 26-35-year age group (67.7%). Most of the participants were originally from the Philippines (66.3%). The overall LTBI prevalence among nurses was 34.5%. The highest prevalence of LTBI was among nurses working in the cardiac intensive care unit (53.5%), and the lowest prevalence was among nurses working in the isolation department (8.9%; p-value <0.0001). Those who worked more in the hospital were significantly more infected with LTBI (p-value <0.04). Conclusion LTBI remains a significant health risk worldwide andin the Middle East as well as among HCWs. This underscores the necessity of comprehensive pre-hiring screening, annual screening, infection control protocols, and active management of HCWs with LTBI.

Prevalence of Latent Tuberculosis Infection [LTBI] in Prison Officers: A Systematic Review and Meta-Analysis

Prevalence of Latent Tuberculosis Infection [LTBI] in Prison Officers: A Systematic Review and Meta-Analysis

ЛАТЕНТНАЯ ТУБЕРКУЛЕЗНАЯ ИНФЕКЦИЯ У ЛИЦ С НАЛИЧИЕМ ОСТАТОЧНЫХ ПОСТТУБЕРКУЛЕЗНЫХ ИЗМЕНЕНИЙ В ОРГАНАХ ДЫХАНИЯ ПО ДАННЫМ КОЖНОЙ ПРОБЫ С ПРЕПАРАТОМ ДИАСКИНТЕСТ®

Aim: to study the prevalence of latent tuberculosis infection (LTI) among individuals with residual post-tuberculosis changes in the lungs and assess the effectiveness of the Diaskintest® for LTI detection. Materials and methods. We carried out a retrospective analysis of results of the skin test with recombinant tuberculosis allergen (RTA), i.e. Diaskintest®, in 181 patients (109 men and 72 women) with residual post-tuberculosis changes in the lungs in 2011–2022. The study did not include household or occupational contacts of active TB patients or HIV-infected individuals. Results. We established LTI in 52.5% of individuals with residual post-tuberculosis changes in the lungs. LTI was common among young men (56%) with history of active TB and TB treatment (69%), and those with large residual changes (57.3%). The frequency of LTI detection in individuals with inactive residual post-tuberculosis changes in the lungs allowed classifying them as high riskgroup for TB recurrence. This group requires dynamic observation including yearly fluorography screening and sputum examination for M. tuberculosis detection. Conclusion. Frequent detection of LTI among individuals with residual post tuberculosis changes in the lungs justifies the use of the Diaskintest® during dynamic follow-up of this group, which is predisposed to TB recurrence.

Prevalence of tuberculosis infection among patients with Takayasu arteritis: a meta-analysis of observational studies

To clarify the risk of tuberculosis (TB) infection in patients with Takayasu arteritis (TAK). In this study, we conducted a comprehensive search across multiple databases, including PubMed, Web of Science, Embase, Cochrane, and Medline, from the inception of the Literature Library to May 16, 2023. Using a specific set of keywords, including “Takayasu Arteritis”, “Tuberculosis”, and “Mycobacterium tuberculosis”, the main objective of this search was to identify all relevant observational studies, including case-control studies, cohort studies, and cross-sectional studies, that report the prevalence of TB in individuals diagnosed with TAK. Two independent evaluators rigorously screened the studies, extracted data, and assessed the study quality using the Joanna Briggs Institute (JBI) critical appraisal tools. Statistical analyses were conducted using R software version 4.3.0, which allowed for the synthesis of prevalence and subgroup analyses. Subgroup analyses were stratified based on quality scores, World Health Organization regional categorizations, and TB categories. Assessment of publication bias was performed using a funnel plot. The study included a total of 30 studies with 5548 participants. The findings showed that individuals with TAK exhibited an average prevalence of TB infection at 31.27% (95% CI 20.48–43.11%). Significantly, the prevalence of TB infection demonstrated notable regional disparities, ranging from 16.93% (95% CI 7.71–28.76%) in the Western Pacific Region to 63.58% (95% CI 35.70–87.66%) in the African Region. Moreover, the study revealed that patients with TAK displayed a high prevalence of latent TB infection (LTBI) at 50.01% (95% CI 31.25–68.77%) and active TB at 14.40% (95% CI 9.03–20.68%). The high heterogeneity observed in the data highlights significant variability in TB infection rates among the populations studied, with the African Region exhibiting the highest rates. The study concludes that there is a high prevalence of TB infection in the TAK population, with regional variations. Consideration should be given to implementing rigorous TB screening measures and preventive interventions specifically tailored for the TAK population.

Prevalence of Latent Tuberculosis Infection Among Rheumatology Patients and Management Practices in the United Arab Emirates: A Single-Center Retrospective Cohort Study.

Introduction Prior to immunosuppression, rheumatology patients are routinely screened for latent tuberculosis (TB) infection using interferon-gamma release assays (IGRAs). Variability in the management of latent and indeterminate IGRA results across institutionslimited long-term outcome data. A retrospective study was conducted at Tawam Hospital, United Arab Emirates, to investigate the incidence and management protocols associated with positive and indeterminate IGRAresults, as well as TBinfection, among patients with rheumatic conditions. Methods A single-center retrospective observational study was performed at Tawam Hospital, Abu Dhabi, UAE. Ethical approval for this study was obtained from the Tawam Human Research Ethics Committee. Laboratory records and the hospital's electronic medical system were used to obtain information about IGRA results over a 12-year period (April 2010-April 2022). The hospital's electronic medical system was used to obtain patient information and subsequent management approaches of positive and indeterminate IGRAs.Moreover, long-term follow-up data were collected to determine the risk of TB reactivation in the cohort. Results We found a total of 1,012 positive and 223 indeterminate IGRA test results within the 12-year period. Within the rheumatology department, 123 positive and 39 indeterminate IGRA results were identified. In the indeterminate IGRA group, the majority were women (n = 24, 61.5%) and UAE nationals (n = 22, 56.4%), and their mean age was 38.6 years. Systemic lupus erythematosus was the most prevalent rheumatologic condition (n = 21, 53.8%). Thirteen (33.3%) were on disease-modifying anti-rheumatic drugs (DMARDs) and 26 (66.7%) were on corticosteroids during IGRA testing. A total of eight patients (20.5%) received anti-TB medications. In the positive IGRA group, the mean age was 55.7 years and the female-to-male ratio was 3:1. The most common rheumatologic condition was rheumatoid arthritis (n = 69, 56%). Sixty-five (52.8%) patients were on conventional DMARDs, 43 (34.9%) were on corticosteroids during IGRA testing, and 74 (60%) received anti-TB medications. Two cases (1.6%) of active TB infections were detected among patients with positive IGRA tests, both of whom were receiving anti-tumor necrosis factor alpha inhibitor treatment in combination with methotrexate. No cases of active TB infection were observed in the indeterminate IGRA group. Conclusion Long-term data on the risk of TB activation in positive and indeterminate IGRA results for rheumatological conditions are low. It is recommended to reassess the choice of using anti-TNF-α, with a positive IGRA result if no other feasible alternatives can be offered. Our findings stress the importance of age, underlying diseases, and immunosuppressive treatments in interpreting IGRA results and guiding patient management. A large multicenter study is needed to understand the differences and outcomes of such patients in TB endemic and nonendemic geographical areas.

Tuberculosis screening characteristics amongst freshmen in Changping District, Beijing, China

BackgroundScreening for Tuberculosis (TB) is a critical tactic for minimizing the prevalence of illness within schools. Tuberculosis Preventive Therapy (TPT), in turn, effectively staves off the development of TB from latent tuberculosis infection (LTBI). Unfortunately, there is limited research on LTBI and TPT among students. This study aimed to assess LTBI among freshmen in Changping District and advocate for the implementation of TPT.MethodsThe prospective study collected data from 12 educational institutions within the Changping District of Beijing. The Kolmogorov − Smirnov test and other statistical methods were used for statistical analysis, x2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${x}^{2}$$\\end{document} was obtained using the formula x2=\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${x}^{2}=$$\\end{document} nΣA2/nRnC-1, df = (C-1) (R-1). We analyzed potential factors impacting the LTBI rate, and scrutinized the possible causes behind the low application of TPT and its efficacy for LTBI treatment, China.ResultsAmong 19,872 freshmen included in this study, 18 active TB cases (91 per 10,0000) and 2236 LTBI cases (11.6% of 19,223) were identified, respectively. Furthermore, of those with LTBI, 1045 (5.4% of 19,223) showed a strong positive for purified protein derivative (PPD), but only 312 opted for TB preventive treatment. There appeared to be no significant difference in the prevalence of LTBI and TPT rate between male and female students. Concurrently, 11 (71 per 100,000) and 7 (158 per 100,000) cases of active tuberculosis were identified in 6 universities and 6 higher vocational colleges, respectively. Interestingly, almost all freshmen who underwent TPT came from universities, suggesting a statistically significant disparity in TPT rate (χ2 = 139.829, P < 0.001) between these two types of educational institutions. Meanwhile, as for the age-wise distribution of latent infection among 17–20 years old freshmen, the LTBI rate exhibited 10.5%, 11.6%, 12.1% and 13.5%, respectively. Correlation between LTBI rate, the strong positive rate was statistically significant among different ages (χ2 = 34.559, P < 0.001). Over a follow-up period of 2 years, three students were diagnosed with active tuberculosis, one of which was resistant to rifampicin. All three students manifested a strong positive for PPD and declined preventive treatment during TB screening.ConclusionsThe data indicates a high rate of LTBI amongst students in areas with a heavy TB burden, potentially leading to cross-regional TB transmission due to the migration of students. Education level might contribute to the limited uptake of TPT. Therefore, improving the implementation of TB preventive treatments is crucial in controlling and preventing TB across schools.

PREVALENCE OF LATENT TUBERCULOSIS IN DIABETIC AND NON-DIABETIC INDIVIDUALS IN A TERTIARY CARE CENTER: A COMPARATIVE STUDY

Aims and Objectives: The aims of this study were as follows: (1) To study the prevalence of latent tuberculosis (TB) in diabetic and non-diabetic population attending the tertiary care hospital. (2) To investigate the association between diabetes mellitus (DM) and latent TB, evaluating the prevalence of positive tuberculin tests and assessing glycemic parameters in diabetic patients with latent TB. Methods: This was a single-center, hospital-based, observational, and comparative study conducted in the department of general medicine of a tertiary care medical college. One hundred and thirty-six diabetic patients of either gender or 137 healthy individuals acting as control group were included in this study on the basis of a predefined inclusion and exclusion criteria. Patients were evaluated by detailed history and clinical examination. The diagnosis of latent TB was based on a positive tuberculin test without any clinical features of active TB. The prevalence of latent TB infection was compared in both the groups. p&lt;0.05 was taken as statistically significant. Results: Patients in both the groups were found to be comparable in terms of gender distribution and mean age. Predominant patients were found to have type 2 DM. The mean duration of DM was noted to be 91.58±60.68 months. The most common diagnoses of patients in non-diabetes group were COVID-19 (9.49%), neurological diseases (8.76%), infections (7.3%), acute myocardial infarction (6.57%), and iron deficiency anemia (5.84%). About 21.32% of cases in DM group were noted to have latent TB, while the proportion of latent TB was noted to be 7.30% in the non-diabetes group. The mean fasting blood sugar, mean post-prandial blood sugar, as well as mean HbA1c were significantly higher (p&lt;0.05) in the subgroup with latent TB versus the subgroup without latent TB. Conclusion: Individuals with diabetes mellitus were found to have increased risk of latent TB infection. In addition, male gender and elevated glycemic parameters were found to be key factors associated with latent tuberculous infection in diabetes.

Tuberculin test using Indian indigenous purified-protein derivative (PPD) shows only moderate agreement with international standard PPD

BackgroundIn India, the prevalence of Latent TB infection (LTBI) is estimated to be around 40%. Various formulations of PPD(Purified protein derivative) are available, for diagnosis of LTBI, which may give variable responses. The commercially available PPD in India is by Arkray Healthcare (TST-Arkray). It is unclear if this product may have a similar sensitivity compared to other internationally accepted tuberculins (TST-Tubersol). ObjectivesTo assess the performance of the two TSTs compared to Quantiferon-Gold Plus (QFT-Plus). MethodologyA blood sample was collected for the QFT-Plus test. Both the TSTs were placed in the right and the left volar aspect of the forearms and 48 hrs later, the subjects came back to the study site for reading. ResultsAmong the 512 participants who were recruited, 326 subjects were healthcare professionals and 186 subjects were household contacts of patients with tuberculosis. They were tested with both TST-Tubersol and TST-Arkray, 139(27 %) participants tested positive for TST-Tubersol (≥10 mm), whereas 203 participants (40.1 %)tested positive for TST-Arkray. There was moderate agreement between the two tests with k = 0.58. Also, there was only poor agreement between both the TSTs with QFT Plus(kappa = 0.19 for Tubersol and 0.17 for Arkray). With QFT-Plus as gold standard, the sensitivity, specificity, PPV and NPV of TST-Tubersol, ast an induration cut-off of 10 mm was 46.8 %,76.3 %,31.8 % and 85.8 %. respectively and TST- Arkray; 60.6 %, 64 %, 28.5 % and 87.2 % respectively. ConclusionThe Indian TST (Arkray Diagnostics) has shown moderate agreement with the internationally accepted Tubersol. Additionally, there was poor agreement between the TSTs and QFT plus test.

Prevalence of Tuberculosis Infection and Disease Among Homeless Persons Staying in NGO Shelters in Chennai

Latent tuberculosis infection (LTBI) is a inactive stage after being infected with Mycobacterium tuberculosis and it reactivates into pulmonary tuberculosis (PTB). This study was to estimate the prevalence of LTBI in homeless persons staying in 13 shelters run by NGOs in Chennai metro city, India. A cross-sectional survey was conducted from January to April 2018. All inmates aged 15 years and above were screened for PTB infection using tuberculin skin test (TST) and disease smear and culture examinations. Out of a total of 1,068 registered, 1,016 persons were screened for PTB disease and 818 persons for LTBI. Among them, PTB was detected in two persons and TST was positive in 275 persons. Univariate and multivariate analyses were performed to find out the factors associated with LTBI. It was found that LTBI is significantly associated with male gender, aged more than 40 years and with chest X-ray TB lesions. This study finding highlights that low prevalence of TB disease and one third of homeless persons infected with tuberculosis. Our finding suggests that there is a need for prevention interventions to eliminate TB in this key population.

Factors Associated with Treatment Prescription to Pulmonary Tuberculosis Contacts in Catalonia (2019-2021): A Population-Based Epidemiological Study.

In countries with low tuberculosis (TB) incidence, the systematic testing and treatment of latent TB infection (LTBI) in contacts of pulmonary TB index cases is the standard of care. The objective of this study, conducted in Catalonia over 2019-2021, was to assess the factors associated with LTBI treatment prescription to close contacts of pulmonary TB index cases. In this population-based epidemiological study of LTBI prevalence among pulmonary TB contacts between 2019 and 2021, multiple logistic backward stepwise regression was used to identify the factors associated with treatment prescription, for which the adjusted odds ratio (aOR) and 95% confidence intervals (CI) were calculated. A total of 1487 LTBI contacts of 542 pulmonary TB index cases were studied, 80.6% of whom received a prescription. The factors associated with LTBI treatment prescription were exposure ≥6 h/day (aOR 14.20; 95% CI 5.22-38.66) and exposure <6 h/day (aOR 7.32, 95% CI 2.48-21.64), whereas the factors associated with no LTBI treatment prescription were age ≥55 years (aOR 0.22, 95% CI 0.08-0.64) and bacillus Calmette-Guerin vaccination (aOR 0.38, 95% CI 0.16-0.90). Crucial to LTBI treatment prescription is information on the contact's duration of exposure to pulmonary TB, not only for contacts exposed for ≥6 h/day, but also for contacts with lower daily exposure levels.

Latent tuberculosis infection (LTBI) in health-care workers: a cross-sectional study at a northern Peruvian hospital

BackgroundHealthcare workers (HCWs) have a higher risk of latent tuberculosis infection (LTBI) and active tuberculosis than the general population. In HCWs, the risk of tuberculosis infection depends on the local tuberculosis prevalence, HCWs’ characteristics, the healthcare facility, and prevention and control measures. We aimed to estimate the prevalence and risk factors for LTBI in HCWs at a northern Peruvian hospital.MethodsThis study had two phases: (1) a cross-sectional phase involving recruitment, history taking, and sampling for the Interferon-Gamma Release Assays (IGRA test), and (2) a prospective follow-up of IGRA-positive participants. We enrolled direct and non-direct patient caregivers among HCWs. We defined an LTBI case if the IGRA test was positive and clinical, laboratory, and radiological evaluations for active tuberculosis were negative.ResultsWe recruited 308 participants between November 2022 and May 2023. The mean age was 38.6 ± 8.3 years. Over 75% of the participants were female. The most common job category was technicians (30.5%), physicians (22.7%), nurses (20.5%), and other HCWs groups (17.5%). Most participants worked in hospital wards (28.2%), diagnostics departments (16.9%), and critical care departments (15.6%). The LTBI prevalence among HCWs was 17.86% (95% CI 13.84–22.70). In multivariate analysis, after adjusting for age, time working in our hospital, and family history of tuberculosis, males had a higher risk of LTBI (aPR 1.69, 95% CI 1.01–2.77) than females. Working for more than 10 years increased the risk of LBTI (aPR 2.4, 95% CI 1.44–3.97) compared to working for ≤10 years. Even further, participants who had worked for more than 20 years had an aPR of 4.31 (95% CI 1.09–13.65) compared to those with ≤10 years. Similarly, occupational exposure increased the risk of LTBI (aPR 2.21, 95% CI 1.27–4.08) compared to those HCWs not occupationally exposed.ConclusionThe LTBI prevalence in HCWs at a northern Peruvian hospital was lower compared to other Peruvian cities. Males, more experienced, and occupational exposed HCWs are at higher risk of LTBI. LTBI prevalence in Peruvian HCWs is still high. More studies are needed to address some aspects this study has not examined.

Losses in the Care Cascade for Latent Tuberculosis Infection in the Tracing Contact Studies

Background: The control of latent tuberculosis infection (LTBI) encompasses multiple stages. The objective was to calculate the losses in the LTBI care cascade for pulmonary TB contacts in Catalonia (Spain). Methods: The LTBI care cascade was studied for pulmonary TB contacts reported from 1 January 2019 to 30 June 2021, considering three dependent variables: non-performance of testing; non-receipt of a treatment prescription; and non-adherence to treatment. Variables associated with the cascade were analysed using adjusted OR (aOR) and 95% confidence intervals (CI). Results: Identified from 847 cases of pulmonary TB were 7087 contacts, of whom 6537 (92.2%) could be screened for LTBI. LTBI prevalence was 25.5% (1670/6537); 69.4% of persons with LTBI (1159/1670) received a treatment prescription and 71.3% (827/1159) completed it. Treatment prescription was associated with age ≥65 years (aOR = 0.3; 95%CI: 0.2–0.6) and a daily exposure of ≥6 h to the TB index case (aOR = 3.6; 95%CI: 2.6–5.0). Treatment adherence was lower in men (aOR = 0.7; 95%CI: 0.5–1.0) and immigrants (aOR = 0.7; 95%CI: 0.5–0.9). Conclusions: Under 50% of contacts make it to the end of the LTBI cascade. Losses need to be reduced through education of both healthcare providers and patients and through treatment monitoring. The greater involvement of primary care physicians could help in monitoring and controling LTBI.

1886. Prevalence Of Latent TB Infection Among Critically Ill COVID-19 Population In a Tertiary Teaching Hospital In Mexico

Abstract Background Tuberculosis (TB) is the leading cause of death from a single infectious agent. Latent tuberculosis infection (LTBI) is defined as TB infection without clinical symptoms or microbiological evidence. LTBI is a risk factor to later development of active TB. COVID-19 pandemic represents an emerging infectious disease. Immunosuppressants as corticoids and tocilizumab are the standard of care of critically ill COVID-19 patients. Those drugs have previously been shown to increase the risk of developing active TB, especially in patients with latent TB. Methods We conduct a cross-sectional study to determine the prevalence of latent tuberculosis infection, through QuantiFERON, in patients who have been hospitalized with severe or critical COVID-19 at the ABC Medical Center in Mexico City-Mexico, from March 2020 to March 2021. Results From 1174 records reviewed, a total of 503 patients who have a QuantiFERON® test were included. The prevalence of LTBI in hospitalized patients with severe or critical COVID-19 in our hospital was 10.1% (n=51). Of the total of patients with a diagnosis of LTBI, 82.3% had severe disease and 17.6% had critical illness requiring invasive mechanical ventilation (IMV) and 42 (82%) received corticosteroids and 29 (57%) received tocilizumab. Conclusion To the best of our knowledge this is the first report that depict the LTBI prevalence in a cohort of severe and critical COVID-19 patients in a Lower-Middle Income Country. Our prevalence was lower than previously reported global prevalence of LTBI. Disclosures All Authors: No reported disclosures

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

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). 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). 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. 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. 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.

Latent tuberculosis infection in myasthenia gravis patients on immunosuppressive therapy: high incidence yet moderate reactivation rate

Background Immunosuppressive therapies (ISTs) are mainstays for management of myasthenia gravis (MG). Meanwhile, latent tuberculosis infection (LTBI) is common in the setting of high-burden countries. However, the prevalence of LTBI among MG patients and whether receiving ISTs for MG would aggravate LTBI reactivation remain unknown. Methods We retrospectively analyzed the frequency of LTBI via interferon-gamma release assay (IGRA) positivity among hospitalized MG patients from both rural and urban areas in a tertiary hospital, and those receiving ISTs were followed up to investigate the reactivation risk of LTBI. Results A total of 300 MG patients with determinate IGRA results were enrolled, where the frequency of LTBI was 35.0%. Male (OR = 1.910, 95% CI: 1.181–3.089, p = .008) and elderly (OR = 1.044, 95% CI: 1.027–1.061, p < .001) patients were prone to LTBI. Of those with LTBI, 78 individuals on ISTs were successfully followed up for a median duration of 18.3 (8.5–24.0) months, of which 25 (32.1%) received anti-tuberculosis (TB) treatments. The rate of various degrees of adverse events was 82.1% over the course of the follow-up, but was not different between individuals with and without therapies against TB (χ 2 < 0.001, p > .999). Only 1 patient eventually reported lymph node and intestinal TB, with the incidence rate of LTBI reactivation preliminarily estimated to be 0.81 per 100 person years. Conclusion The frequency of LTBI is high in our MG cohort, especially among those with advanced age and males. However, receiving immunosuppressives seems not to increase the risk of LTBI reactivation. LTBI screening is strongly recommended for all MG patients ready to receive ISTs, while preventive anti-TB chemotherapy should be prescribed after weighing potential benefits against the risk of side effects in those with LTBI. In-depth investigation is still entailed to further verify these findings due to the limitation of the retrospective single-center design of our study.

Possibilities of Detecting an Epidemic Focus of Tuberculosis Infection in an Indicator Patient with a Positive Immunological Test for Tuberculosis

Relevance. In connection with the advent of new diagnostic immunological tests, it became possible to determine a potential focus of infection not only through the identification of patients with tuberculosis, but also through the identification of patients infected with M. tuberculosis, who still do not have manifestations of a local form of the disease. This made it possible to search for persons who were infected with an unknown source of tuberculosis infection in order to conduct an in-depth epidemiological investigation and detect hitherto unknown foci of tuberculosis. Aims. To study the effectiveness of identifying the source of infection in the environment of a patient with a positive immunological test for tuberculosis («indicator» patient). Materials and methods. 1) A retrospective study of the data of all 30 patients with tuberculosis in the period from 2014 to 2019 in Moscow, identified by indicator patients with a positive immunological test, was carried out. 2) A cohort of patients with latent tuberculosis infection with and without HIV infection (Moscow) was studied in the period 2020–2021. to determine the prevalence of latent infection in the close circle of communication of indicator patients. Results. Patients with tuberculosis, forming hidden foci and identified by the indicator patients infected by them with a latent infection, in 56.7% of cases were not examined for tuberculosis for 2–10 years, in 50.0% they suffer from tuberculosis with registered bacterial excretion, in 46.7% of cases are internal or external migrants. The prevalence of latent tuberculosis infection among indicator patients is 10%, which is many times higher than the prevalence of latent tuberculosis infection among the permanent population of Moscow (less than 1%), in HIV-infected risk groups (up to 5%), in known foci of tuberculosis on average in Moscow (5%). The TB notification rate in the environment of indicator patients with latent tuberculosis infection is 38.8 per 100,000 of the corresponding group and exceeds that among the permanent population of Moscow by 5.4 times. Conclusion. A modified epidemiological investigation aimed at examining the environment of persons with latent TB infection among adults makes it possible to identify TB patients who have infected indicator patients and to identify other infected patients.