Rate Of Latent Tuberculosis Infection Research Articles

One-month daily and three-month weekly rifapentine plus isoniazid are comparable in completion rate and safety for latent tuberculosis infection in non-HIV Population: A randomized controlled trial

ObjectivesThe 3HP regimen, consisting of 12 doses of weekly rifapentine plus isoniazid, improves completion rate of latent tuberculosis infection (LTBI) treatment, but flu-like symptoms are common. The novel 1HP regimen, involving daily rifapentine plus isoniazid for 28 days, has demonstrated low toxicity in Human Immunodeficiency Virus (HIV)-infected populations. We aimed to investigate whether 1HP has a lower incidence rate of systemic drug reaction (SDR) compared with 3HP during treatment in non-HIV populations. MethodsThis randomised, multicentre trial compared the completion rate and risks of SDRs of 1HP and 3HP in aged ≥13-years non-HIV subjects with LTBI between September 2019 and September 2023 (ClinicalTrials.gov: NCT04094012). We also investigated associations between SDRs and plasma levels of drugs and their metabolites. ResultsA total of 251 and 239 individuals were randomised to 1HP and 3HP groups, respectively, with completion rates of 82.9% (208/251) and 84.5% (202/239), respectively. Among them, 12.7% (32/251) and 10.9% (26/239) of 1HP and 3HP groups experienced SDRs, respectively (p=0.522), predominantly urticaria in 1HP group (59.4% [19/32]) and flu-like syndrome in 3HP group (80.8% [21/26]). Among participants experiencing SDRs, 43.8% (14/32) and 34.6% (9/26) in 1HP and 3HP groups, respectively, completed treatment (p=0.470). Cutaneous reactions were more common in 1HP than 3HP group (32.7% [82/251] vs. 13.0% [31/239], p<0.001). In 1HP group, urticaria was associated with a higher plasma desacetyl-rifapentine level (ug/mL) at both 2 (median [interquartile range]: 36.06 [17.46–50.79] vs. 22.94 [14.67–31.65], p=0.018) and 6 hours (26.13 [15.80–53.06] vs. 29.83 [18.13–34.01], p=0.047) after dosing. ConclusionsIn non-HIV population, the incidence rate of SDR under 1HP is not lower than 3HP. Notably, urticaria, rather than flu-like syndrome, was the predominant SDR associated 1HP. The findings of this study underscore the feasibility of 1HP regimen in non-HIV populations with a high completion rate exceeding 80%.

Latent tuberculosis infection and infection-associated risk factors for miner workers with silicosis in eastern China.

Silicosis people are at high risk of developing pulmonary tuberculosis. Whether silica exposure increases the likelihood of latent tuberculosis infection (LTBI) was not well understood, and potential factors involved in LTBI risk among silicosis people were not evaluated before. Thus, LTBI among silicosis people and potential risk factors for LTBI among silicosis people were evaluated in this study. A cross-sectional study was undertaken for 130 miner workers with silicosis. The QFT-GIT was performed for LTBI detection. The LTBI was high to 31.6% (36/114) for silicosis participants, and 13.1% (13/99) had a history of tuberculosis. Drinking was associated with LTBI risk (OR = 6.92, 95%CI, 1.47-32.66, P = 0.015). Meanwhile, tunneling work was associated with an increased risk of LTBI compared with other mining occupations (OR = 3.91,95%CI,1.20-12.70, P = 0.024). The LTBI rate of silicosis participants was high and more than 10% had a history of tuberculosis. Drinking alcohol and tunneling were independent risk factors for LTBI in silicosis participants.

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.

Smoking Exposure and the Risk of Latent Tuberculosis Infection: Results from NHANES 2011-2012.

The association between smoking exposure and latent tuberculosis infection (LTBI) has been investigated in a few studies; however, further investigation is needed. In this study, the 2011-2012 NHANES population was used to evaluate smoking exposure and LTBI risk. A total of 7042 participants with available LTBI results and without active tuberculosis were included for analysis. Smoking was defined as participants who smoked at least 100 cigarettes in their life. Both univariable and multivariable analysis were adopted to evaluate smoking exposure, as well as related factors on the risk of LTBI. LTBI rates among current smokers (12.1%) and former smokers (9.9%) were higher than non-smokers (5.9%). However, current smokers and former smokers were not significantly associated with LTBI risk when compared to non-smokers after adjusting by age and sex in the multivariable analysis. Meanwhile, we found that passive smoking was not associated with LTBI (adjusted odds ratio (AOR), 0.85; 95%CI, 0.66-1.09). In multivariable analysis, current smoking was associated with LTBI (OR, 1.67; 95%CI, 1.28-2.19), while former smokers had an increased OR of LTBI, but the OR did not reach statistical significance (OR, 1.15; 95%CI, 0.90-1.48). Household tuberculosis (TB) contact was also related to LTBI (OR, 1.93; 95%CI, 1.25-2.99). However, BMI and diabetes were not found to be associated with LTBI. Smoking, especially current smoking, was significantly associated with LTBI. LTBI screening should be recommended for active smokers. Former smoking and passive smoking exposure were not found to have a significant relationship with LTBI risk. However, the high LTBI rate among quitters indicated we should pay more attention to former smokers with LTBI.

Diagnostic performance of a novel ESAT6-CFP10 skin test for tuberculosis infection in school tuberculosis outbreak in China.

The ESAT6-CFP10 (EC) skin test is recommended by the World Health Organization for latent tuberculosis infection (LTBI). However, it is still unknown how the EC skin test performs in students during a school tuberculosis outbreak. We conducted an epidemiological investigation to assess the performance of the EC skin test in this high-risk population. A total of 9 active student patients were confirmed in the same class as the index case, with an incidence rate of 18.0% (9/50). Among the 50 close contacts, 14 (28%) were over 15 years old and had a chest X-ray (CXR), and none of them had abnormal CXR findings. The rates of positive tuberculin skin test (TST) ≥ 5 mm and < 10 mm, ≥ 10 mm and < 15 mm, and ≥ 15 mm were 12.0% (6/50), 16.0% (8/50), and 10.0% (5/50), respectively. On the second screening, 44 students with the same class as the index case had the EC skin test, of which 31 (70.5%) had positive EC tests. All patients had negative sputum smear results, of whom 4 (44.4%) had positive Xpert results; three had a TST induration diameter between 5 mm and 10 mm, but all of them had an EC diameter > 15 mm; 5 (55.6%) had abnormal CXR results, but all the confirmed patients had abnormal CT results; Except for four cases that were diagnosed by Xpert, the remaining five were confirmed by CT scan. The novel EC skin test performed well in students during the school tuberculosis outbreak. In some special conditions, such as when the index case is bacteriologically positive for tuberculosis and the rate of LTBI is higher than the average for the local same-age group, secondary screening is recommended 2-3 months after the first screening. Furthermore, we cannot ignore the role of CT in the diagnosis of early student tuberculosis.

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.

LTBI-negative close contacts of tuberculosis are more likely to develop the disease: enlightenment and lessons from a cluster outbreak.

Tuberculosis (TB) prevention and control among groups living together, such as students, workers, older adults in nursing homes, and prisoners, present many challenges due to their particular age and environmental factors, which can make them more susceptible to TB clusters with significant societal impact. This study aimed to evaluate a TB cluster outbreak epidemic in a university and provide suggestions for improving TB control strategies for groups living together. Pulmonary TB screening and close-contact investigation were conducted using acid-fast staining, sputum culture, GeneXpert testing, tuberculin skin testing (TST), interferon-gamma release assay (IGRA), and chest computed tomography (CT). GraphPad Prism 9.5.1 was utilized for data analysis. Collected epidemic data were comprehensively analyzed by rate comparison. The TB cluster outbreak epidemic was identified with an index case confirmed positive. The initial screening was conducted on potential close contacts of the index case, and the TST's positive rate (diameter ≥ 5 mm) and strong positive rate (diameter ≥ 15 mm) among these close contacts were 65.60% (21/32) and 34.40% (11/32), respectively. Moreover, the latent TB infection (LTBI) rate (diameter ≥ 10 mm) was 43.75% (14/32), and the IGRA's positive rate was 9.30% (3/32). Chest CT scans did not reveal any abnormalities. Surprisingly, 5 of the close contacts developed active TB in the second screening, accompanied by changes from negative to positive TST and/or IGRA results, after 3 months of follow-up. Accordingly, we expanded the screening scope to include another 28 general contacts. We found that the positive rate (78.00%, 25/32), strong positive rate (50.00%, 16/32), and LTBI rate (62.50%, 20/32) of the 32 close contacts were significantly higher than those of the additional general contacts (28.00%, 8/28; 14.3%, 4/28; 25.00%, 7/28), as indicated by p < 0.05. In the event of an epidemic TB outbreak, it is essential to rapidly identify the source of infection and initiate timely screening of close contacts. The initial screening should be focused on individuals without LTBI, who are at higher risk of developing TB. In purified protein derivative-negative individuals living in groups, additional vaccination or revaccination with Bacille Calmette-Guérin may help prevent cluster outbreaks of TB.

Positive rate and risk factors of latent tuberculosis infection among persons living with HIV in Jiangsu Province, China.

To analyze the latent tuberculosis infection (LTBI) among persons living with HIV(PLWH) in Jiangsu Province, to explore the factors affecting the positive rate of LTBI, and to take appropriate measures to control tuberculosis (TB) infection. A cross-sectional study was conducted among PLWH in Jiangsu Province from June to July 2021. All PLWH in Jiangsu Province were used as the study population. Currently, the diagnosis of LTBI lacks a "gold standard" and can only be assisted by the immunological method. In this study, Tuberculin skin test (TST), ESAT6-CFP10 test (EC), and QuantiFERON-TB gold in-tube (QFT) were used to detect the positive rate of LTBI among PLWH and to analyze their risk factors. A total of 340 prisoners were included, 89.7% were male, the median age was 38 years [Interquartile Range (IQR):32-46 years], these patients were on Antiviral Therapy (ART), and median CD4 counts was 376 (IQR: 261-496), 103 (30.3%) were positive in at least one test, LTBI by TST was 16.5%, LTBI by EC was 15.9%, LTBI by QFT was 26.2%. Univariate analysis showed the results for TST, EC, and QFT were not affected by CD4 counts (p>0.05), and multivariate analysis showed that a history of incarceration was associated with an increased risk of positive TST (adjusted odds ratio [aOR]=1.98;95% CI,1.03-3.82), EC (aOR=2.65;95% CI,1.37-5.12) and QFT (aOR=2.01;95%CI,1.12-3.57), in addition, female gender was associated with increased risk of positive TST (aOR=3.66;95%CI,1.60-8.37) and EC (aOR=3.43;95%CI,1.46-8.07), and contact history of TB patients was associated with increased risk of TST (aOR= 2.54;95%CI,1.23-5.22) and QFT (aOR=2.03;95%CI,1.03-3.99), and ethnic minorities (aOR=0.26;95%CI,0.12-0.57), longer duration of incarceration was associated with an increased risk of positive QFT (aOR=1.12;95%CI,1.02-1.24). Conclusions Female gender, and ethnic minorities, history of incarceration, longer duration of incarceration, and contact history of TB patients are risk factors for LTBI among PLWH in Jiangsu Province, and attention should be paid to TB control in this population.

1437. Investigation of Increased Latent Tuberculosis Infection Rates During the COVID-19 Pandemic Among International Students at a U.S. University Campus

Abstract Background The COVID-19 pandemic has caused dramatic changes in the epidemiology of many diseases globally due to various changes in exposure to different pathogens, social restrictions, and demographic shifts. A university student health center located in the U.S. Midwest detected an increase in latent tuberculosis infection (LTBI) rate among its incoming international students (INTS) from 5.7% to 8.1% in the fall semesters of 2019 and 2021, respectively. We describe our approach to investigating the increase in LTBI rate at a university campus in a low-endemicity area. Methods Factors that may affect LTBI rates were evaluated. LTBI testing policy and methods were reviewed. Medical and lab staff were interviewed regarding the consistency of specimen collection, transport, and processing. LTBI risks in the general population such as older age, male gender, and country of origin (COO) were also considered. Factors that were expected to be uncommon in the INTS (homelessness, incarceration, and illicit drug abuse) were not evaluated. Results No changes in the INTS screening policy were noted. All incoming INTS were screened for LTBI during initial health screening, regardless of COO. The same manufacturer's QuantiFERON®-TB Plus test was utilized. Compared to previous years, no inconsistencies in the testing logistics were reported. A total of 1,016 INTS were screened in 2019 and 1,179 in 2021. There were no significant differences in average age in years (23.1 vs. 23.3) or male gender (59.6% vs. 56.8%) between 2019 and 2021, respectively. Most INTS came from two countries (A and B). Country A was COO of 21.6% of INTS in 2019, which dropped to 8.4% in 2021. Country B was COO of 44.8% of INTS in 2019, which increased to 57.6% in 2021 (p&amp;lt; 0.001; Figure 1). Although LTBI rates within each country (A and B) remained similar before and during the COVID-19 pandemic (Figure 2), country B had consistently higher rates than country A (p&amp;lt; 0.001), which contributed to the overall increased rate of LTBI in 2021. Figure 1.Numbers and percentages of international students from countries A and B.Figure 2.LTBI positivity rates for countries A and B before and during COVID-19 pandemic. Conclusion Evaluating changes in COO of INTS is essential in investigating trends in LTBI rates at otherwise low-endemicity universities. In our investigation, demographic changes in university admissions over two years relative to COVID-19 pandemic restrictions contributed to an increase in the overall LTBI rate. Disclosures Moises A. Huaman, MD, MSc, Gilead: Grant/Research Support|Insmed: Grant/Research Support.

Analysis of Factors Affecting the Rate of Latent Tuberculosis Infection and Management in Pediatrics.

The incidence of tuberculosis remains high in South Korea; the management of latent tuberculosis infection (LTBI) has become the prime target for reducing the infection rate. The management of pediatric LTBI is especially crucial because children can serve as a long-term source of infection upon developing active tuberculosis. Therefore, it is important to assess pediatric LTBI using contact investigation and follow-up. We conducted a retrospective study on children aged between 0 and 18 years who visited our hospital for tuberculosis contact screening from February 2012 to February 2021. Tuberculosis index cases and their clinical characteristics were also reviewed retrospectively. A total of 350 children were investigated, and 68 of 247 (27.5%) were diagnosed with LTBI. The rate of LTBI (r = 7.98, p < 0.001) and the risk of loss to follow-up (r = 27.038, p < 0.001) were higher in cases with close household contact. Sputum (r = 10.992, p < 0.001) and positive acid-fast bacillus (AFB) stain (r = 4.458, p = 0.001) in tuberculosis index cases were related to the diagnosis of LTBI in pediatric contacts. Active management is needed for tuberculosis screening in pediatric contacts, especially when the contacts are older and the index case is within the family, and when the index case has sputum and has tested positive for AFB smear.

Unique Reciprocal Association Seen Between Latent Tuberculosis Infection and Diabetes Is Due to Immunoendocrine Modulation (DM-LTB-1).

AimThe prevalence of latent tuberculosis infection (LTBI) among diabetes patients is poorly studied. In the present study, the prevalence of LTBI among pre-diabetes and diabetes patients was studied, along with immunoendocrine biomarkers (n = 804).MethodsLTBI was screened by Quantiferon TB gold in Normal glucose tolerance [(NGT); n = 170, [Pre-diabetes (PDM; n = 209), Newly diagnosed diabetes (NDM; n = 165) and Known diabetes (KDM; n = 260) subjects. CRP, TNF-α, IL-6, IL-1β, IFN-β, IL-12, IFN-γ, IL-2, insulin, leptin, and adiponectin levels in serum and IFN-γ levels in quantiferon supernatants were quantified by ELISA. The expression of T-bet was quantified using qRT-PCR. Serum TBARS and nitrite levels were quantified by colorimetry.ResultsThe LTBI prevalence was 32% in NGT, 23% in PDM, 24% in NDM, and 32% in KDM groups, with an adjusted OR of 0.61 (p < 0.05). Downregulation of CRP, TNF-α, and nitrites and upregulation of adiponectin could be responsible for LTBI mediated protection against insulin resistance (IR), while the high levels of IL-1β, IL-12, and leptin could be responsible for IR mediated anti-TB immunity. The defective antigen-specific IFN-γ response, as seen in the KDM group, could be responsible for the low detection rate of LTBI and high probability of endogenous reactivation.ConclusionThere appears to be a biphasic relationship between diabetes-latent tuberculosis: At the early stages of diabetes it is reciprocal, while at a late stage it is synergistic, this important phenomenon obviously needs further research.

Prevalence trends of latent tuberculosis infection at the global, regional, and country levels from 1990–2019

ObjectivesTo track the prevalence trends of latent tuberculosis infection (LTBI) at the global, regional, and national levels. MethodsData on the prevalence of LTBI were extracted from the Global Burden of Disease database. The average annual percent change (AAPC) was estimated by joinpoint regression and was used to evaluate the epidemic of the disease. ResultsGlobally, the prevalence rate of LTBI decreased from 30.66% in 1990 to 23.67% in 2019, with an AAPC of -0.9%. The prevalence rate of LTBI varied from 5.02% (Jordan) to 48.35% (Uganda) in 1990 and from 2.51% (Jordan) to 43.75% (Vietnam) in 2019 at the country level. The prevalence decreased in all the six World Health Organization (WHO) regions and in most countries, with the AAPC ranging from -0.5% in the Western Pacific Region to -2.1% in the European Region and from -4.3% (Bhutan) to -0.1% (Malaysia, Myanmar, South Africa, Tokelau, and Vietnam), respectively. Disparities were also observed among different sex and age groups. ConclusionThe prevalence of LTBI decreased slightly worldwide in the last three decades, but the decrease is slow and not sufficient to meet the targets of WHO tuberculosis elimination. Much more effort and progress should be made in order to decrease the prevalence of LTBI.

A change in the timing of the Bacillus Calmette–Guérin vaccination in 2013 was associated with an increase in the incidence rate of infants with latent tuberculosis infection

BackgroundA change in the timing of the Bacillus Calmette–Guérin (BCG) vaccination among infants in Japan appears to be associated with an increase in the incidence rate of latent tuberculosis infection (LTBI). MethodsData on both active and latent tuberculosis (TB) infections from 2007 to 2019, which were reported by the Japan Anti-Tuberculosis Association, were statistically analyzed by comparing TB incidence rates in 2007–2012 and 2013–2019. ResultsAlthough the incidence rate for active TB disease did not statistically increase nor decrease in the infant age group for either sex (and in fact decreased for some of the other age groups), the incidence rates of LTBI for both sexes were increased in the infant age group, while the incidence rates decreased in the other age groups. Between 2007 and 2012, the incidence rate of LTBI in females was statistically greater than those of males in the 1–4-year-old age group. From 2013 to 2019, the incidence rates of females were greater than those of males in both the infant and 1–4-year-old age groups, suggesting a growing preponderance of infections among female children in the youngest age groups. ConclusionIt may be that the change of BCG vaccination timing in Japan which took place in 2013 affected the infant incidence rate of LTBI, with a more prominent effect on females than males. In order to control TB infection, the ramifications of a change in vaccination timing therefore need careful exploration, as one such change appears associated with increased numbers of infants with LTBI, with disproportionate effects on females.

Impact of Immunosuppressive Therapy on the Performance of Latent Tuberculosis Screening Tests in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Screening for latent tuberculosis infection (LTBI) is mandatory before commencing tumor necrosis factor (TNF)-α inhibitor use. However, the impact of immunosuppressive therapy (IST), including corticosteroids and immunomodulators, on the performance of LTBI screening in patients with inflammatory bowel disease (IBD) has not been fully elucidated. We searched all relevant studies published before November 2021 that examined the performance of interferon γ release assays (IGRAs) and tuberculin skin tests (TSTs) in patients with IBD who received IST, using the Medline, EMBASE, and Cochrane Library databases. We performed meta-analyses of positive or indeterminate rates of IGRA or TST according to IST and calculated the concordance rates between IGRA and TST results. A total of 20 studies with 4045 patients were included in the meta-analysis. The IGRA-positive rate was lower in patients on IST than in those not on IST (odds ratio (OR) (95% confidence interval (CI)) = 0.55 (0.39–0.78)), whereas the IGRA-indeterminate rate was higher in patients on IST than in those not on IST (OR (95% CI) = 2.91 (1.36–6.24)). The TST-positive rate did not differ between the on-IST and not-on-IST groups (OR (95% CI) = 0.87 (0.51–1.50)). The concordance rate between IGRA and TST was 83.3% (95% CI, 78.5–88.1%). The IGRA-negative/TST-positive rate tended to be higher than that the IGRA-positive/TST-negative rate (9.5% vs. 5.8%, respectively), although the difference was not statistically significant. In conclusion, IGRA results were negatively affected by IST in patients with IBD, supporting requirements that IGRA should be performed before initiating IST. The use of both an IGRA and TST in patients with IBD on IST may improve the diagnosis rate of LTBI.

Household contact investigation for the detection of active tuberculosis and latent tuberculosis: A comprehensive evaluation in two high-burden provinces in Iran

BackgroundSystematic evaluation of household contacts of persons with pulmonary tuberculosis (TB) in low- and middle-income countries is recommended by the World Health Organization (WHO). This study recruited adult household contacts of diagnosed TB patients in two high burden provinces of Iran to estimate the prevalence and incidence of active disease and latent TB infection (LTBI) among individuals exposed to TB cases. MethodsWe conducted a cohort study among adults in household contact with a pulmonary TB index case. All subjects were assessed for active disease through evaluation of symptoms. Tuberculin skin test (TST) and QuantiFERON®-TB Gold Plus (QFT-Plus) were used to define LTBI. These tests were performed at the time of the index TB case diagnosis and repeated if the previous result was negative, at three-, 12-, and 18-months post recruitment. In addition, interferon-γ-induced protein-10 (IP-10) concentrations were measured in QFT-Plus supernatants for all participants three months after diagnosing the index case. ResultsA total of 451 individuals who had close contact with 95 active TB patients were enrolled in this study. Five (1.1%) contacts were diagnosed with active TB and 285 (63.2%) were identified with LTBI during our study. The incidence rate of LTBI among adult household contacts of TB index cases was 0.44 per person per year. ConclusionThe overall rate of LTBI was high. Systematic screening of all household contacts of pulmonary TB should be expanded in Iran to make the timely achievement of the global end TB strategy feasible.

Targeting screening and treatment for latent tuberculosis infection towards asylum seekers from high-incidence countries \u2013 a model-based cost-effectiveness analysis

BackgroundEnhancing tuberculosis (TB) prevention and care in a post-COVID-19-pandemic phase will be essential to ensure progress towards global TB elimination. In low-burden countries, asylum seekers constitute an important high-risk group. TB frequently arises post-immigration due to the reactivation of latent TB infection (LTBI). Upon-entry screening for LTBI and TB preventive treatment (TPT) are considered worthwhile if targeted to asylum seekers from high-incidence countries who usually present with higher rates of LTBI. However, there is insufficient knowledge about optimal incidence thresholds above which introduction could be cost-effective. We aimed to estimate, among asylum seekers in Germany, the health impact and costs of upon-entry LTBI screening/TPT introduced at different thresholds of country-of-origin TB incidence.MethodsWe sampled hypothetical cohorts of 30–45 thousand asylum seekers aged 15 to 34 years expected to arrive in Germany in 2022 from cohorts of first-time applicants observed in 2017–2019. We modelled LTBI prevalence as a function of country-of-origin TB incidence fitted to data from observational studies. We then used a probabilistic decision-analytic model to estimate health-system costs and quality-adjusted life years (QALYs) under interferon gamma release assay (IGRA)-based screening for LTBI and rifampicin-based TPT (daily, 4 months). Incremental cost-effectiveness ratios (ICERs) were calculated for scenarios of introducing LTBI screening/TPT at different incidence thresholds.ResultsWe estimated that among 15- to 34-year-old asylum seekers arriving in Germany in 2022, 17.5% (95% uncertainty interval: 14.2–21.6%) will be latently infected. Introducing LTBI screening/TPT above 250 per 100,000 country-of-origin TB incidence would gain 7.3 (2.7–14.8) QALYs at a cost of €51,000 (€18,000–€114,100) per QALY. Lowering the threshold to ≥200 would cost an incremental €53,300 (€19,100–€122,500) per additional QALY gained relative to the ≥250 threshold scenario; ICERs for the ≥150 and ≥ 100 thresholds were €55,900 (€20,200–€128,200) and €62,000 (€23,200–€142,000), respectively, using the next higher threshold as a reference, and considerably higher at thresholds below 100.ConclusionsLTBI screening and TPT among 15- to 34-year-old asylum seekers arriving in Germany could produce health benefits at reasonable additional cost (with respect to international benchmarks) if introduced at incidence thresholds ≥100. Empirical trials are needed to investigate the feasibility and effectiveness of this approach.

Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for inflammatory bowel disease: a hospital-based cohort study from Korea

BackgroundAnti-tumor necrosis factor (TNF) treatment for inflammatory bowel disease (IBD) increases the risk of tuberculosis (TB) infection. In the present study, we analyzed the clinical characteristics and risks of TB in Korean patients with IBD who received anti-TNF treatment.MethodsThe study included patients with IBD who were treated using anti-TNF agents between January 2001 and June 2018 at the Asan Medical Center. Overall, 1434 patients with ulcerative colitis or Crohn’s disease were enrolled. We calculated the incidence of active TB infection after anti-TNF treatment and compared the clinical characteristics of the TB group with those of the non-TB group.ResultsTwenty-one patients (1.46%) developed active TB infection, and the incidence rate of active TB was 366.73 per 100,000 person-years. In total, 198 patients (14.9%) were positive for latent tuberculosis infection (LTBI), of whom only eight (4%) did not complete LTBI treatment. The age at which the anti-TNF therapy was started was significantly higher in the TB group than in the non-TB group (HR 1.041, 95% CI 1.014–1.069, p = 0.002), and as age increased, so did the incidence rate of active TB infection (linearity p < 0.001). There was no significant difference in the incidence rate of LTBI between the TB and non-TB groups (HR 0.896, 95% CI 0.262–3.066, p = 0.862).ConclusionsIn patients with IBD, the incidence rate of TB increased with age at anti-TNF therapy initiation. Active treatment of LTBI may lower the incidence of TB in patients with IBD who are to undergo anti-TNF therapy.

Friend or Foe? Evaluation of BCG Vaccine and Latent Tuberculosis Infection Effect in Patients Diagnosed with COVID-19 Infection

While severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to spread rapidly worldwide, some issues such as the uncertainty of the disease progress, whether intensive care will be needed, and risk classification are still important for clinicians. It is notable that in countries where latent tuberculosis infection (LTBI) is common and participating in the national Bacillus Calmette-Guerin (BCG) vaccination program, the case-fatality rates are relatively low throughout the world. In this study, it was aimed to evaluate the effects of the BCG vaccine and LTBI status on the course of the disease in patients diagnosed with coronavirus-19 (COVID-19) infection and to compare the LTBI rate with people with and without COVID-19 infection. The patients diagnosed with COVID-19 infection who were hospitalized during a period of seven months between May 1st to December 1st, 2020 were investigated by the QuantiFERON-TB Gold Plus (QFT-Plus) test in the blood samples for the presence of LTBI. For the comparison of the patients diagnosed with COVID-19 and people without COVID-19 infections in terms of LTBI rate retrospectively; all consecutive patients who were sent blood samples to the mycobacteriology laboratory for the QFT-Plus test between January 2016 and December 2019 were included in the study. Demographic, clinical, radiological, laboratory, and follow-up data of the patients were obtained from the electronic patient file. A total of 170 patients (n= 9 8 male [57.6%], n= 72 female [42.3%], mean age= 53.5 ± 15.8 years) were enrolled. Twenty-five patients' (25/170 [14.7%]) QFT-plus tests were positive. When the cases with positive QFT-Plus test (n= 25) and the cases with negative QFT-Plus test (n = 145) were compared in terms of disease severity respectively; it was determined that mild/moderate patients were 18/25 (72%) and 108/145 (74.5%), severe patients were 7/25 (28%) and 37/145 (25.5%) (p= 0.988). When these two groups were compared in terms of the clinical course respectively; the need for intensive care was 6/25 (24%) and 34/145 (23.4%) (p= 1.00), oxygen therapy requirement was 13/25 (52%) and 49/145 (33.8%) (p= 0.128), and death was 5/25 (20%) and 18/145 (12.4%) (p= 0.341). QFT-Plus positivity was 25/170 (14.7%) in patients diagnosed with COVID-19, while in control group it was 198/496 (39.9%) (OR= 0.259, 95% CI [0.164-0.411], p<0.001). When the values were evaluated quantitatively, in the COVID-19 patient group, QFT-Plus T1/T2 (IU/ml) interferon (IFN)-ɣ was 0.87 ± 1.52/0.62 ± 1.53, while in the control group it was 1.52 ± 3.69/1.50 ± 3.33 (p= 0.032, p= 0.04). There was no significant difference in the parameters investigated between 82 (48.2%) patients with BCG vaccine and those 88 (51.8%) without BCG vaccine. Although it was not statistically significant in our study, increased oxygen therapy requirement and higher mortality rates in the QFT-Plus positive group were remarkable. The detection of statistically significantly lower LTBI rates and T1-T2/IFN-ɣ values in the COVID-19 group supported that SARS-CoV-2 infection may suppress lymphocyte functions in patients and IFN-ɣ response. We believe that the results of our study are remarkably valuable, but more clinical studies are needed to elucidate the relationship between BCG vaccine, LTBI, and COVID-19 infection.

Latent tuberculosis infection in medical students in the Northeast of Mexico

BackgroundMedical students are considered to be personnel with a high level of risk for developing latent tuberculosis infection (LTBI). One possible reason is lack of knowledge about the transmission, prevention, and biosafety standards for tuberculosis disease. ObjectiveThis research aimed to determine the rate of LTBI among medical students studying in a private School of Medicine in Monterrey, Mexico. MethodsIn this cross-sectional study, we obtained blood samples from 174 medical students. LTBI was diagnosed using the QuantiFERON®-TB Gold Plus test. The prevalence of LTBI was compared with the socio-demographic data of the students and their level of knowledge and use of personal protective equipment (PPE). ResultsThe proportion of LTBI in the students was 20.6%. Medical students in their first few years of medical school had a lower prevalence of LTBI than students in their final years of medical school. Additionally, students with a low level of knowledge on LTBI and low use of proper PPE had a higher prevalence of LTBI. ConclusionsIn a School of Medicine in Monterrey, Mexico, the proportion of medical students with LTBI was low but the proportion increased in advanced students. Students who demonstrated adequate knowledge and use of respiratory protective masks had lower prevalence rates for LTBI.

Upregulation of PD-1 expression on circulating CD8+ but not CD4+ T cells is associated with tuberculosis infection in health care workers

BackgroundHealth care workers (HCWs) are at risk for occupationally acquired Mycobacterium tuberculosis infection and tuberculosis (TB) disease due to repeated exposure to workplace tubercle bacilli. To determine whether continual mycobacterial stimulation correlates with increased expression of inhibitory T cell receptors, here we compared PD-1 receptor expression on surfaces of circulating T cells between naïve (uninfected) HCWs and HCWs with latent TB infection (LTBI).ResultData collected from 133 medical workers who met study selection criteria were included in the final analysis. QuantiFERON-TB Gold In-​Tube (QFT-GIT) testing yielded positive results for 32 HCWs, for an overall LTBI rate of 24.1%. Multivariate analysis identified HCW length of service > 15 years as an independent risk factor for a positive QFT-GIT result. In addition, comparisons of blood T cell subgroup profiles between QFT- and QFT+ groups indicated QFT+ subjects possessed greater proportions of mature (TM), transitional memory (TTM) and effector memory (TEM) CD4+ T cell subgroups and lower proportions of naïve T cells (TN). Moreover, the QFT+ group percentage of CD8+ T cells with detectable surface PD-1 was significantly higher than the corresponding percentage for the QFT- group. Meanwhile, no statistical intergroup difference was observed in percentages of CD4+ T cells with detectible surface PD-1.ConclusionsOur data demonstrated that upregulated PD-1 expression on circulating CD8+, but not CD4+ T cells, was associated with latent TB infection of HCWs. As compared to other hospitals, occupational TB infection risk in our hospital was substantially mitigated by implementation of multitiered infection control measures.