Risk Of Latent Tuberculosis Infection Research Articles

Latent tuberculosis infection and diagnostic performance of the tuberculin skin test among type 2 diabetics in Sana’a city, Yemen

BackgroundTuberculosis (TB) is one of the most widespread infectious diseases worldwide, typically persisting in the body as a latent TB infection (LTBI). Patients with type 2 diabetes have an increased risk of LTBI progressing to active TB. Therefore, this study determined the prevalence and predictors of LTBI and assessed the agreement between tuberculin skin test (TST) and interferon-gamma release assay (IGRA) in diagnosing LTBI among type 2 diabetics in Sana’a city, Yemen.MethodsA cross-sectional study was conducted among 150 type 2 diabetics in private health facilities in Sana’a in 2023. Data about demographics, diabetes-related characteristics, and potential risk factors for LTBI were collected using a structured questionnaire. Patients were then screened for LTBI using TST and IGRA. Univariate analysis was used to identify LTBI-associated risk factors, and multivariable binary logistic regression was used to identify independent predictors of LTBI. The agreement between TST and IGRA for diagnosing LTBI was assessed using Cohen’s kappa coefficient (κ).ResultsLTBI was prevalent among 29.3% of type 2 diabetics using both types of tests (25.3% with IGRA and 21.3% with TST). Male gender was an independent predictor of LTBI (AOR = 4.4, 95% confidence interval: 1.30–15.08; P = 0.018). However, being employed (AOR = 0.3, 95% CI: 0.09–0.75; P = 0.013) and longer duration since diabetes diagnosis (AOR = 0.3, 95% CI: 0.12–0.98; P = 0.046) were identified as predictors of lower LTBI risk. The agreement between TST and IGRA for the diagnosis of LTBI was 88%, with a good and statistically significant agreement between the two test types (κ = 0.670; P < 0.001).ConclusionsLTBI is common among type 2 diabetics seeking medical care in Sana’a city, with about one-third of them possibly being latently infected. A higher LTBI risk can be predicted among males, while a lower risk can be predicted among those employed or being diagnosed with diabetes for at least five years. The TST shows good agreement with IGRA in diagnosing LTBI among type 2 diabetics, supporting its continued use as a cost-effective and easily accessible test for diagnosing LTBI in the country.

Prevalence of latent tuberculosis infection (LTBI) in healthcare workers in Latin America and the Caribbean: systematic review and meta-analysis.

Tuberculosis remains a significant global health concern, and healthcare workers (HCWs) face a high risk of acquiring latent tuberculosis infection (LTBI) through occupational exposure. In the Latin American and Caribbean (LAC) region, where the burden of tuberculosis is substantial, understanding the prevalence of LTBI among HCWs is crucial for effective infection control measures. Therefore, we conducted a systematic review and meta-analysis to estimate the prevalence of LTBI among HCWs in LAC countries. Our search included MEDLINE, Scopus, EMBASE, Web of Science, and Google Scholar databases, focusing on relevant English-language records. We looked for observational studies from inception until December 2023. Our analysis included 38 studies representing 15,236 HCWs and 6,728 LTBI cases. These studies spanned the period from 1994 to 2023 and were conducted in Brazil, Peru, Cuba, Colombia, Trinidad and Tobago, Mexico, and Chile. The mean prevalence of LTBI among HCWs was 35.32% (range 17.86-56.00%) for interferon-gamma release assay (IGRA) and 43.67% (range 6.68-70.29%) for tuberculin skin test (TST). The pooled prevalence of LTBI among HCWs was 34.5% (95% CI 25.4-44.1%) for IGRA and 43.0% (95% CI 35.5-50.7%) for TST. When considering both IGRA and TST tests, the overall prevalence of LTBI among HCWs was 40.98% (95% CI 34.77-47.33%). LTBI was associated with longer lengths of employment and exposure to patients, family members, or any person with TB. Additionally, older HCWs faced a higher risk of LTBI. Specific professional roles (such as nurses, nurse technicians, or physicians), smoking, and deficient TB infection control measures increased the likelihood of LTBI. However, information regarding gender and BCG vaccination status showed discordance among studies. Our findings underscore a substantial burden of LTBI among HCWs in LAC countries. Implementing adequate infection control measures is essential to prevent and control transmission within healthcare settings.

Toll-Like Receptor Genes and Risk of Latent Tuberculosis Infection in People Infected with HIV-1.

The purpose of this study was to determine the contribution of genetic factors, i.e., the level of expression and polymorphisms of Toll-like receptors (TLR), to the susceptibility of latent tuberculosis infection in a Russian cohort of individuals infected with HIV. The patients (n = 317) with confirmed HIV infection were divided into two groups according to the results of the STANDARD E TB-Feron test: 63 cases with a latent TB infection and 274 controls without LTBI. Total DNA and RNA were isolated from whole-blood samples. SNP genotyping and expression levels of five TLR genes (TLR1, TLR2, TLR4, TLR6, and TLR8) were determined by means of real-time PCR. There were no significant differences in the expression levels of the TLRs between the case and control groups. In addition, we did not observe any significant association between the analyzed SNPs and the susceptibility of Latent tuberculosis infection (LTBI) in patients with HIV. However, patients from an entire cohort with the rs4986790-GG (TLR4) and rs5743708-GG (TLR2) genotypes were characterized by lower CD4 T-cell counts compared to carriers of alternative alleles. Moreover, we found a significant risk of a hazardous drop in the CD4 T-cell count below 350 cells/mm3 associated with the rs4986790-G (TLR4) allele. Latent tuberculosis infection in individuals infected with HIV does not significantly modify the level of TLR gene expression.

Exposure to bovine livestock and latent tuberculosis infection in children: Investigating the zoonotic tuberculosis potential in a large urban and peri-urban area of Cameroon.

Bovine tuberculosis (bTB), a neglected zoonotic disease, is endemic in cattle in many Sub-saharan African countries, yet its contribution to tuberculosis (TB) burden is understudied. Rapid urbanisation and increase in demand for animal proteins, including dairy products, increases the risk of spill over. This study compared the latent tuberculosis infection (LTBI) risk in children, a proxy-measure for recent TB infection, in children living in high cattle density areas to children from the general population in Cameroon. Cross-sectional study in the Centre Region of Cameroon in 2021, recruiting 160 children aged 2-15 years, stratified by exposure to livestock, people treated for pulmonary TB (PTB) and the general community. Veinous blood was tested for LTBI using QuantiFERON-TB Gold-Plus. Prevalence were calculated and the association to exposure and other risk factors investigated using logistic regression models. The crude LTBI prevalence were 8.2% in the general population, 7.3% in those exposed to cattle and 61% in pulmonary TB household contacts. After adjusting for confounding and sampling design, exposure to cattle and exposure to pulmonary TB were associated with higher risk of LTBI than the general population (respectively odds ratio (OR): 3.56, 95%CI: 0.34 to 37.03; and OR: 10.36, 95%CI: 3.13 to 34.21). Children frequently consuming cow milk had higher risk of LTBI (OR: 3.35; 95%CI 0.18 to 60.94). Despite limited statistical power, this study suggests that children exposed to cattle in a setting endemic for bTB had higher risk of LTBI, providing indirect evidence that Mycobacterium bovis may contribute to TB burden.

Prevalence and Risk Factors of LTBI at Madura Boarding School as a High-Risk Congregate Setting

Highlights: Boarding school is a high-risk location for TB transmission. Therefore, stricter early prevention measures are required. Gender and knowledge level were significantly related to LTBI, but there was no significant relationship between age and nutritional status. Low level of knowledge was the highest risk factor compared to other factors, with a five times greater risk of contracting LTBI. Abstract Introduction: Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is a highly contagious airborne disease. High-risk environments with frequent close interactions contribute to the spread of TB. This study examined latent TB infection (LTBI) epidemiology in such settings to inform public health interventions and strategies to curb TB transmission in similar environments. Methods: This cross-sectional observational study, conducted from January to August 2022 at two boarding schools in Bangkalan, involved 100 adolescents aged 10-18 years old tested for LTBI using interferon-gamma (IFN-γ) release assay (IGRA). Data were collected via questionnaires. Bivariate analysis was used to determine the correlation between LTBI prevalence and each research variable using Pearson correlation and odds ratio (OR). A p-value &lt;0.05 was considered statistically significant. Results: This study found that 30% of 100 adolescents in boarding schools had LTBI. Risk analysis showed a significant association between gender and LTBI, with males having a 1.02 times higher risk (p-value 0.000). Additionally, lower education levels were significantly associated with a 5.2 times higher risk of LTBI (p-value 0.021). Conclusion: Boarding schools pose a TB transmission risk. Early LTBI screening is essential for TB eradication in Indonesia, and these findings emphasize the need to improve LTBI detection and prophylaxis therapy as a preventive measure against TB outbreaks.

Effects of the Beijing genotype on latent tuberculosis infection, TB disease risk, and clustering of TB cases

BackgroundThe Beijing genotype of Mycobacterium tuberculosis (Mtb) has sparked debate regarding its virulence and transmissibility. This study contributes to this discussion by assessing its effect on the risk of latent tuberculosis infection (LTBI), active tuberculosis (TB) disease among contacts, and clustering of known TB cases. MethodsWe conducted a retrospective cohort study using the records of 4457 culture-confirmed TB patients and their contacts (20,448) reported to the Florida Department of Health between 2009 and 2023. Univariate and multivariate analyses were used to evaluate the effect of the Beijing strain on LTBI, active TB risk among contacts, and case clustering. ResultsOur study revealed no significant difference in transmissibility between the Beijing and non-Beijing genotypes among contacts. LTBI prevalence was 19.9%, slightly higher in non-Beijing than Beijing genotypes (20.2% vs. 15.5%, p < 0.001). The prevalence of active TB was 1.8%, with no significant difference between the Beijing and non-Beijing genotypes (1.4% vs. 1.8%, p = 0.296). Increased LTBI risk was associated with older age, male sex, Hispanic ethnicity, multidrug-resistant TB exposure, household exposure, and a longer exposure duration. Active TB risk was higher for males, HIV-positive individuals, and contacts with more prolonged exposure to index cases. The Beijing genotype was associated with increased TB case clustering (aOR = 1.98, 95%CI: 1.53, 2.55, p < 0.001) as compared to the non-Beijing genotypes. US birthplace (aOR = 2.75, 95%CI: 2.37, 3.19, p < 0.001), pulmonary disease (aOR = 1.27, 95%CI: 1.04, 1.56, p < 0.020), cavitary TB (aOR = 1.25, 95% CI: 1.08, 1.44, p < 0.003), previous year alcohol use (aOR = 1.68, 95%CI: 1.38, 2.04, p < 0.001), and recreational drug use (aOR = 1.32, 95%CI: 1.04, 1.67, p < 0.024) were also associated with an increased risk of TB case clustering. ConclusionWhile the Beijing genotype did not increase the risk of LTBI or active TB among contacts, it showed a higher tendency for case clustering. Hence, interventions should prioritize populations where this genotype is prevalent.

Acute Leukemia and Latent Tuberculosis Infection in Italy: Quantiferon-Tb Test Screening in a Low Tuberculosis Incidence Country.

Identification of latent tuberculosis infection (LTBI) is a critical step of tuberculosis surveillance, especially in low-incidence countries. However, it is limited to situations with a higher probability of developing active disease, e.g., patients with hematological malignancies. According to guidelines, in TB non-endemic countries, no clear screening program is established at diagnosis for patients with acute leukemia (AL). The primary endpoint of this study was to establish the prevalence of LTBI in patients with a diagnosis of AL using QuantiFERON (QFT)-TB. Secondarily, radiological and clinical features driving the increased risk of LTBI were evaluated. QFT-TB screening was performed before induction or consolidation in all patients with AL (myeloid and lymphoid) treated at our Institution between October 2019 and August 2023. We accrued 62 patients, of whom 7 (11,3%) tested positive, without any symptoms or signs of active TB, and 2 (3,2%) resulted as indeterminate. All positive patients started prophylaxis with isoniazid 300 mg daily, while patients whose test was indeterminate did not receive any prophylaxis. Active TB was excluded by imaging, as well as microscopic, cultural, and molecular examination on bronchoalveolar lavage if signs of any infection were detected. During the 46 months of observation, no patients developed TB reactivation. Despite the low sample size, 1/10 of our patients had prior TB exposure, hinting that LTBI could be more common than expected in Italy. This finding suggests implementing TB screening in the pre-treatment setting, particularly at a time when more active treatments are becoming available also for patients ineligible for intensive chemotherapy.

Prevalence, Risk Factors, and Result Features in the Detection of Latent Tuberculosis Infection in Thai Healthcare Workers Using QuantiFERON-TB Gold Plus.

Introduction Latent tuberculosis infection (LTBI) is an enormous reservoir for tuberculosis (TB), and healthcare workers (HCWs) are at high risk for TB infection. QuantiFERON-TB Gold Plus (QFT-Plus) is an alternative to the tuberculin skin test for LTBI detection, but data on its application and LTBI detected by QFT-Plus in high TB burden countries are limited. This study aimed to determine the prevalence of LTBI and its risk factors, and to investigate the QFT-Plus results in Thai HCWs. Methods A cross-sectional analytical study was conducted among HCWs at a secondary care hospital in Health Region 5, Thailand. Eligible HCWs were enrolled and underwent QFT-Plus testing. Interferon-gamma (IFN-γ) values in tubes were analysed. The prevalence and associated risk factors for LTBI were assessed based on laboratory and sociodemographic data. Logistic regression analyses were applied to calculate odds ratios (OR, aOR) reported with 95% confidence intervals (CI). Results Of the 269 participants enrolled, their median age was 42 years and 93.31% (n = 251/269) were female. The majority (n = 178/269, 66.17%) were nurses or nurse assistants and 42.75% (n = 115/269) worked in the inpatient medical wards. Overall, the QFT-Plus results showed 110 (40.89%) positive with good agreement (93.68%; κ 0.87) and high correlation (Spearman's ρ 0.91) of IFN-γ concentrations in the two antigen tubes. A true difference inIFN-γ values for predicting a recent infection was found about 7.81% (n = 21/269). By univariate and multivariate analyses, the participants' age > 40 years (OR = 3.21, 95% CI: 1.84-5.64%; aOR = 2.05, 95% CI: 1.07-3.96%), and employment duration > 10 years (OR = 3.19, 95% CI: 1.66-6.37%; aOR = 2.34, 95% CI: 1.05-5.21%) were significantly associated with the increased risk of LTBI (p-value < 0.05). Conclusions The prevalence of LTBI among these HCWs was high, and the increased risk factors for LTBI according to QFT-Plus positivity were age over 40 years and working time in the hospital for more than 10 years. It is important to screen HCWs in this setting for LTBI, particularly those with long employment durations and older ages. The high prevalence of LTBI suggests that LTBI management, such as regular screening and treatment, should be considered together with strengthening preventive measures, especially in high-risk groups.

Interpreter usage and associations with latent tuberculosis infection treatment acceptance and completion in the USA among non-U.S.-born persons, 2012-2017.

Latent tuberculosis infection (LTBI) screening and treatment interventions that are tailored to optimize acceptance among the non-U.S.-born population are essential for U.S. tuberculosis elimination. We investigated the impact of medical interpreter use on LTBI treatment acceptance and completion among non-U.S.-born persons in a multisite study. The Tuberculosis Epidemiologic Studies Consortium was a prospective cohort study that enrolled participants at high risk for LTBI at ten U.S. sites with 18 affiliated clinics from 2012 to 2017. Non-U.S.-born participants with at least one positive tuberculosis infection test result were included in analyses. Characteristics associated with LTBI treatment offer, acceptance, and completion were evaluated using multivariable logistic regression with random intercepts to account for clustering by enrollment site. Our primary outcomes were whether use of an interpreter was associated with LTBI treatment acceptance and completion. We also evaluated whether interpreter usage was associated treatment offer and whether interpreter type was associated with treatment offer, acceptance, or completion. Among 8,761 non-U.S.-born participants, those who used an interpreter during the initial interview had a significantly greater odds of accepting LTBI treatment than those who did not use an interpreter. There was no association between use of an interpreter and a clinician's decision to offer treatment or treatment completion once accepted. Characteristics associated with lower odds of treatment being offered included experiencing homelessness and identifying as Pacific Islander persons. Lower treatment acceptance was observed in Black and Latino persons and lower treatment completion by participants experiencing homelessness. Successful treatment completion was associated with use of shorter rifamycin-based regimens. Interpreter type was not associated with LTBI treatment offer, acceptance, or completion. We found greater LTBI treatment acceptance was associated with interpreter use among non-U.S.-born individuals.

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.

Tuberculosis among children visiting friends & relatives.

Most paediatric tuberculosis (TB) cases in low-TB-incidence countries involve children born to migrant families. This may be partially explained by trips to their countries of origin for visiting friends and relatives (VFR). We aimed to estimate the risk of latent TB infection (LTBI) and TB in children VFR. We conducted a prospective multicentric observational study in Catalonia (Spain) from June 2017 to December 2019. We enrolled children aged < 15years with a negative tuberculin skin test (TST) at baseline and at least one parent from a high-TB-incidence country, and who had travelled to their parent's birth country for ≥21days. TST and QuantiFERON-TB Gold Plus (QFT-Plus) were performed within 8-12weeks post-return. LTBI was defined as a TST ≥5mm and/or a positive QFT-Plus. Five hundred children completed the study, equivalent to 78.2 person-years of follow-up (PYFU). Thirteen children (2.6%) were diagnosed with LTBI (16.6/per100 PYFU, 95%CI = 8.8-28.5), including two cases (0.4%) of TB (2.5/per100 PYFU, 95%CI = 0.3-9.3). LTBI incidence rates remained high after excluding BCG-vaccinated children (9.7/per100 PYFU, 95%CI = 3.9-20.0). Household tobacco smoke exposure was associated with LTBI (aOR = 3.9, 95%CI = 1.1-13.3). The risk of LTBI in children VFR in high-TB-incidence countries may equal, or perhaps even exceed, the infection risk of the native population. The primary associated risk factor was the presence of smokers in the household. Furthermore, the incidence rate of active TB largely surpassed that of the countries visited. Children VFR in high-TB-incidence countries should be targeted for diagnostic and preventive interventions.

The association of dietary patterns with latent tuberculosis infection among young adults: A case-control study in Shanghai.

In developing and underdeveloped countries, undernutrition plays a major role in subverting the immune system, leading to an increase in TB infections; this study investigated the associations between dietary patterns and latent tuberculosis infection risk among young adults in Shanghai. In a case-control study, 96 cases of latent tuberculosis infection and 192 healthy controls were studied among contacts of students in clusters of tuberculosis epidemics in colleges from January 2021 to March 2023. A standardized questionnaire assessing sociodemographic, lifestyle, and dietary characteristics was applied. Food intake was estimated using a 95-item semiquantitative Food Frequency Questionnaire. Using the principal component analysis to extract dietary patterns from food groups intake. Logistic regression models were applied. Four dietary patterns were identified: "traditional balanced" pattern, "unsaturated fatty acid" pattern, "snack" pattern, and "protein and fruit" pattern. Four components explaining 64.52% of the total variation in consumption were derived. In a conditional logistic regression analysis, three models were created. After adjusting for various confounders, compared to "snack" pattern, the risk of latent TB infection was 91% lower in the "traditional balanced" pattern (OR 0.05, 95% CI 0.01, 0.38, p = 0.004). To prevent TB infection among young adults living in high TB burden areas, a balanced dietary pattern rather than a "snack" pattern should be promoted in school settings. Future research should explore the risk of developing active tuberculosis in Mtb-infected people with different dietary patterns and the prevention of this risk by healthy dietary patterns.

P604 Exploring the role of chest X-ray in latent tuberculosis screening in Inflammatory Bowel Disease

Abstract Background Patients being treated with biologics or JAK inhibitors have an increased reactivation risk of latent tuberculosis infection (LTBI), and this is associated with a more severe infective course. Current ECCO guidance recommends the screening for LTBI by a combination of patient clinical data and epidemiological factors, chest X-ray (CXR), and tuberculin skin test or interferon-gamma release assay (IGRA) prior to starting immunosuppressive treatment. The evidence supporting CXR is categorized at evidence level 5, and information on its use in screening for LTBI originates from two decades ago. Apart from radiation exposure, a single posterior-anterior view has limited diagnostic capabilities. This study aims to determine the relation between CXR findings and IGRA test results in patients undergoing LTBI screening before commencing immunosuppressive therapy for Inflammatory bowel disease (IBD) patients in a low-risk population. Methods This is a retrospective analysis whereby IBD patients (≥16 years) on biologics or JAK inhibitors were identified from our local database. The clinical data, epidemiological, CXR and IGRA result were then analysed from the electronic case records. The IGRA test used was the QuantiFERON-TB Gold. Results A total of 356 patients were included in the study, with 58.7% (n=209) being male. Among these patients, the majority had Crohn's disease (66.6%, n=236), 30.1% (n=109) had ulcerative colitis, and the remaining 2.8% were classified as having IBD-unclassified. Most patients (97.1%) had been exposed to anti-TNF alpha medications and 13.2% were exposed to multiple biologicals. The mean age of IBD diagnosis was 30.3 years (SD+/-15.7). None of the patients had any clinical suggestion nor any evidence for exposure to TB. None of the CXRs performed revealed any radiological signs of prior TB infection. 93.8% (n=334) of the IGRA results were negative and 4.2% (n=15) were categorized as indeterminate. Among those with indeterminate results, 66.7% (n=10) were undergoing corticosteroid treatment for active disease. The remaining 2.0% (n=7) had a positive IGRA test and were treated for LTBI.None of these patients had TB reactivation when then treated with biologicals. Conclusion This research highlights that performing routinely a CXR in individuals with a negative IGRA offers little to no benefit, and subjects patients to unnecessary radiation. It also demonstrates the importance of conducting the IGRA test early, before initiating any immunosuppressive treatment. Furthermore, in patients with a negative IGRA, if chest imaging is required for screening purposes, opting for an ultra-low dose CT might be more prudent than a CXR, as it visualises the lungs better and the radiation exposure is not substantially different.

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.

Latent Tuberculosis Infection Testing Practices in a Large US Integrated Healthcare System.

Tuberculosis (TB) is a public health threat, with >80% of active TB in the United States occurring due to reactivation of latent TB infection (LTBI). We may be underscreening those with high risk for LTBI and overtesting those at lower risk. A better understanding of gaps in current LTBI testing practices in relation to LTBI test positivity is needed. This study, conducted between 1 January 2008 and 31 December 2019 at Kaiser Permanente Southern California, included individuals aged ≥18 years without a history of active TB. We examined factors associated with LTBI testing and LTBI positivity. Among 3 816 884 adults (52% female, 37% White, 37% Hispanic, mean age 43.5 years [standard deviation, 16.1]), 706 367 (19%) were tested for LTBI, among whom 60 393 (9%) had ≥1 positive result. Among 1 211 971 individuals who met ≥1 screening criteria for LTBI, 210 025 (17%) were tested for LTBI. Factors associated with higher adjusted odds of testing positive included male sex (1.32; 95% confidence interval, 1.30-1.35), Asian/Pacific Islander (2.78, 2.68-2.88), current smoking (1.24, 1.20-1.28), diabetes (1.13, 1.09-1.16), hepatitis B (1.45, 1.34-1.57), hepatitis C (1.54, 1.44-1.66), and birth in a country with an elevated TB rate (3.40, 3.31-3.49). Despite being risk factors for testing positive for LTBI, none of these factors were associated with higher odds of LTBI testing. Current LTBI testing practices may be missing individuals at high risk of LTBI. Additional work is needed to refine and implement screening guidelines that appropriately target testing for those at highest risk for LTBI.

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.

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.

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.

Plasma CXCL8 and MCP-1 as surrogate plasma biomarkers of latent tuberculosis infection among household contacts-A cross-sectional study.

Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy. The study investigates whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. The plasma cytokines were measured using a commercial Bio-Plex Pro Human Cytokine 17-plex assay. Increased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold. Our study suggests that CXCL-8 and MCP-1 could serve as the surrogate biomarkers of LTBI, particularly in resource-limited settings. Further laboratory investigations are warranted before extrapolating CXCL8 and MCP-1 for their usefulness as surrogate biomarkers of LTBI in resource-limited settings.

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.