Latent Tuberculosis Infection Risk Research Articles

Significant association between methyl mercury level and latent tuberculosis infection risk: a cross-sectional study

ObjectivesThis cross-sectional study aimed to explore the association between methyl mercury (MeHg) level and latent tuberculosis infection (LTBI) risk based on the data from National Health and Nutrition Examination Survey (NHANES 2011–2012).MethodsA total of 5243 participants with 20 variables were enrolled. The importance of these variables on TB infection was first ranked by XGBoost and Random Forest methods. Then the association between MeHg level and infection risk was evaluated by restricted cubic spline, threshold effect, and generalized linear regression analyses. We also explored the factors correlated with the difference in MeHg level and finally conducted a mediation analysis to assess the mediating effect of MeHg in LTBI.Results521 participants were experiencing the LTBI, and 12 variables showed the differences between infection and non-infection groups (all P < 0.05). Of them, MeHg presented the highest importance on the LTBI. Restricted cubic spline (RCS) next revealed a significant non-linear correlation of MeHg with LTBI (all P < 0.05). Adjusted regression models further indicated their independent association (all P < 0.05), and infection risk increased with the increase of MeHg (P for trend < 0.05). We also found a significant turning point, and their association was significantly observed when MeHg > 5.75 µg/L (P < 0.05). In addition, asthma history was related to the difference in MeHg levels between LTBI and non-LTBI groups. Mediation analysis found that MeHg level partially mediated the association of asthma and LTBI risk (all P < 0.05).ConclusionsOur study identified MeHg as an independent risk factor for LTBI risk. Their causal relationship needs more investigation to verify.

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.

Higher blood manganese level associated with increased risk of adult latent tuberculosis infection in the US population.

The associations between blood heavy metal levels and latent tuberculosis infection (LTBI) have not been fully elucidated. The aim of this study was to investigate the potential association between blood heavy metal levels and LTBI in adults using National Health and Nutrition Examination Survey data from 2011 to 2012. We enrolled 1710 participants in this study, and compared the baseline characteristics of participants involved. Multivariate logistic regression analysis, restricted cubic splines (RCS) analysis, along with subgroup analysis and interaction tests were utilized to explore the association between blood manganese (Mn) level and LTBI risk. Participants with LTBI had higher blood Mn level compared to non-LTBI individuals (p < 0.05), while the levels of lead, cadmium, total mercury, selenium, copper, and zinc did not differ significantly between the two groups (p > 0.05). In the fully adjusted model, a slight increase in LTBI risk was observed with each 1-unit increase in blood Mn level (OR = 1.00, 95% CI: 1.00-1.01, p = 0.02). Participants in the highest quartile of blood Mn level had a threefold increase in LTBI risk compared to those in the lowest quartile (OR = 4.01, 95% CI: 1.22-11.33, p = 0.02). RCS analysis did not show a non-linear relationship between blood Mn level and LTBI (non-linear p-value = 0.0826). Subgroup analyses and interaction tests indicated that age, alcohol consumption, and income-to-poverty ratio significantly influenced LTBI risk (interaction p-values<0.05). Individuals with LTBI had higher blood Mn level compared to non-LTBI individuals, and higher blood Mn level associated with increased LTBI risk.

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.

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.

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 and COVID-19: Analysis of a Cohort of Patients from Careggi University Hospital (Florence, Italy).

Data regarding the relationship between coronavirus disease (COVID-19) and active or latent tuberculosis (TB) are discordant. We conducted a retrospective study examining the impact of latent tuberculosis infection (LTBI) on the clinical progression of COVID-19 patients. We selected 213 patients admitted with COVID-19 in a tertiary-level Italian hospital (February-December 2020), who underwent a QuantiFERON-TB test (QFT) and/or chest radiological exam. The population was divided into three groups: (i) QFT negative and without radiological TB sequelae (Neg); (ii) QFT positive and without radiological TB sequelae (Pos); (iii) radiological TB sequelae regardless of QFT result (Seq). In-hospital mortality and oro-tracheal intubation (OTI) showed significantly higher results in the Seq group (Seq 50% vs. Pos 13.3% vs. Neg 9.3%, p < 0.001; Seq 16.7% vs. Pos 6.7% vs. Neg 4.9%, p = 0.045). Considering the Pos and Seq groups' patients as the population with defined LTBI, in-hospital mortality (20/51, 39.2%) and OTI risk (7/51, 13.7%) were statistically higher with respect to patients without LTBI (in-hospital mortality: 15/162, 9.3%, p < 0.001; OTI risk: 8/162, 4.9%, p = 0.023), respectively. Multivariate analysis showed that radiological sequelae and the Charlson Comorbidity Index (CCI) were significantly associated with higher mortality rate; despite the higher CCI of Seq population, we cannot exclude the correlation between COVID-19 in-hospital mortality and the presence of radiological TB sequelae.

Changes in the rate of bacillus tuberculosis infection in health workers in the first year of the COVID-19 epidemic in Kashan- Iran

ObjectiveThis cohort study aimed to determine the prevalence and risk factors of latent tuberculosis infection among healthcare workers during the COVID-19 pandemic. MethodsA one-year cohort study was conducted in a referral hospital in Kashan, involving 176 medical, educational, and cleaning personnel. Initial evaluations and tuberculin skin tests were performed, followed by a one-year follow-up period. Data were analyzed using SPSS version 26 software. ResultsAmong the participants, 26.1% (46 individuals) tested positive for latent tuberculosis infection. Age was a significant risk factor, with a 3.6% increase in latent tuberculosis infection risk with each advancing year. Men had 2.19 times (1.10–4.35) the chance of having a latent infection compared to women. Hospital staff were 3.7 times more at risk of tuberculosis infection than students. Among the hospital job categories, nursing assistants had the highest chance of tuberculosis infection, 6.77 times higher than medical students, followed by cleaning staff and nurses. The ICU, General, and Obstetrics and Gynecology departments had an infection chance of 2.46 (1.11–5.46) compared to other departments. No new positive cases were detected during the follow-up period. ConclusionThis study contributes to the understanding of latent tuberculosis infection prevalence and its risk factors among healthcare workers during the COVID-19 pandemic. The findings highlight the importance of infection control measures and targeted interventions to protect healthcare workers from occupational tuberculosis exposure.

Latent Tuberculosis Infection and Associated Risk Factors among People Living with HIV and HIV-Uninfected Individuals in Lithuania.

People living with HIV (PLHIV) with latent tuberculosis infection (LTBI) are at increased risk of tuberculosis (TB) reactivation compared to the HIV-negative population. Lithuania belongs to the 18 high-priority TB countries in the European region. The aim of this study was to compare the prevalence of LTBI and LTBI-related risk factors between PLHIV and HIV-uninfected populations. A cross-sectional study was conducted in three Lithuanian Infectious Diseases centres from August 2018 to May 2022 using the interferon gamma release assay (IGRA) and tuberculin skin test (TST) in Vilnius, and IGRA only in Siauliai and Klaipeda. Cohen's kappa was used to assess IGRA and TST agreement. A structured questionnaire was completed by the study participants. LTBI-related risk factors were identified using a multivariable logistic regression model. In total, 391 PLHIV and 443 HIV-uninfected individuals enrolled, with a median age of 41 (IQR 36-48) and 43 (IQR 36-50), consisting of 69.8% and 65.5% male, respectively. The prevalence of LTBI defined by positive IGRA and/or TST among PLHIV was higher compared to that in the HIV-uninfected population (20.5% vs. 15.3%; OR 1.42; 95% CI 1.02-2.03; p = 0.04). The concordance between IGRA and TST was fair: kappa = 0.23 (95% CI 0.09-0.34). In multivariable analyses, association with injecting drug use (IDU) (ORa 2.25, 95% CI 1.27-3.99, p = 0.01) and imprisonment (ORa 1.99, 95% CI 1.13-3.52, p = 0.02) in all participants, IDU (ORa 2.37, 95% CI 1.09-5.15; p = 0.029) in PLHIV and a history of contact with an active TB patient (ORa 3.33, 95% CI 1.53-7.24; p = 0.002) in HIV-uninfected individuals were significant associations evidenced by LTBI. The prevalence of LTBI among PLHIV in Lithuania is higher compared to that in the HIV-uninfected population and the European average. The association with IDU in PLHIV emphasizes the need for integrated HIV, TB and substance abuse treatment to provide patient-centred care.

The Risk of Latent Tuberculosis Infection Among Healthcare Workers at a General Hospital in Bisha, the Kingdom of Saudi Arabia.

Background and objective Tuberculosis (TB) is a global health issue, often preceded by a latent tuberculosis infection (LTBI) in individuals. Significant global and local efforts have recently beendirected toward this infection, focusing on TB control and eradication. This study aimedto assessthe magnitude of LTBI among healthcare workers (HCWs) in the Kingdom of Saudi Arabia, by evaluating its prevalence and associated risk factors. Methods An analytical cross-sectional study was conducted among HCWs at the King Abdullah Hospital (KAH), from January to August 2018, by using two surveys: the first one involved data related to HCW demographics and the tuberculin skin test (TST) readings, and the second involved a questionnaire that assessed LTBI risk factors. Results Out of the total 561 HCWs who participated in the study, 66 had an induration reading of more than 10 mm in TST.Many factors were associated with LTBI cases,but multivariate analysis showed that age, gender, and nationality were statistically significant risk factors. Conclusion Given the nature of their work, HCWs are at a greater risk of TB and LTBI. At the same time, HCWs are uniquely positioned to play a crucial role in halting the spread of TB. Gaps in preventive measures may result in the increased spread of TB. Our study assessedrisk factors associated with the increased risk of LTBI and proposed possible ways of addressing them.

Possible sex difference in latent tuberculosis infection risk among close tuberculosis contacts

ObjectivesMore men than women develop and die of tuberculosis (TB). Fewer data exist on sex differences in latent TB infection (LTBI). We assessed for potential sex differences in LTBI acquisition among close TB contacts. MethodsRegional Prospective Observational Research for TB-Brazil is an observational multi-center cohort of individuals with culture-confirmed pulmonary TB and their close contacts. Participants were enrolled from five sites in Brazil from June 2015 - June 2019. Close contacts were followed for 24 months after enrollment, with LTBI defined as a positive interferon-γ release assay (IGRA; QuantiFERON 3rd or 4th generation) at baseline or 6 months. We performed univariate, bivariate, and multivariable logistic regression and propensity-score weighted models to assess odds ratios (OR) and 95% confidence intervals (CI) for LTBI acquisition by birth sex among close contacts. ResultsOf 1093, 504 (46%) female close contacts were IGRA positive compared to 295 of 745 (40%) men. The unadjusted OR for IGRA positivity among women vs men was 1.31 (95% CI: 1.08-1.58). Bivariate adjustments yielded ORs in women vs men ranging from 1.19 to 1.33 (P-value range: <0.01-0.07). Multivariable regression and weighted models yielded similar ORs in women vs men, of 1.14 (95% CI: 0.92-1.41) and 1.15 (95% CI: 0.94-1.40), respectively. ConclusionThe point estimate for LTBI among close TB contacts in Brazil was higher in women, though less pronounced in multivariable models. If the sex difference in LTBI is confirmed in additional settings, studies of possible underlying differences in socio-behavioral factors or TB pathogenesis are warranted.

Latent tuberculosis infection: Misperceptions among non-U.S.–born-populations from countries where tuberculosis is common

ABSTRACT The Centers for Disease Control and Prevention works to eliminate tuberculosis (TB) disease by finding and treating cases of TB disease and expanding latent tuberculosis infection (LTBI) testing and treatment to prevent TB disease. Approximately 70% of reported TB cases in the United States occur among non-U.S.–born persons. We conducted 15 focus groups with U.S. residents born in the six most common countries of birth among non-U.S.–born TB patients: Mexico, the Philippines, India, Vietnam, China and Guatemala. Participants reacted to 39 messages on LTBI and TB disease risk factors, the Bacille Calmette-Guérin (BCG) vaccine, and LTBI testing and treatment. There was low awareness of LTBI, the TB blood test, and how the TB blood test is not affected by prior BCG vaccination. Several participants thought TB disease is contracted by sharing kitchenware. Some felt negatively targeted when presented with information about countries where TB disease is more common than the U.S. Findings highlight the need for communication aimed at increasing LTBI testing and treatment to include messages framed in ways that will be resonant and actionable to populations at risk. Focus groups revealed LTBI misconceptions which highlight areas for targeted education to decrease TB stigma and increase LTBI testing and treatment.

Cross-sectional study of prevalence and risk factors, and a cost-effectiveness evaluation of screening and preventive treatment strategies for latent tuberculosis among migrants in Singapore

ObjectivesWHO recommends that low burden countries consider systematic screening and treatment of latent tuberculosis infection (LTBI) in migrants from high incidence countries. We aimed to determine LTBI prevalence and risk...

Association of TAP1 1177A>G and 2090A>G gene polymorphisms with latent tuberculosis infections in sheltered populations, in the metropolitan area of Guadalajara, Mexico: a pilot study.

ABSTRACTLatent tuberculosis infection (LTBI) is a condition that has no clinical signs and symptoms. LTBI patients are characterized by persistent immune responses to Mycobacterium tuberculosis, and approximately 5-10% of these infected individuals will develop active TB at some point in their lives. The antigen transporter associated with antigen processing (TAP1) is a protein involved in the transport of the antigen from the cytoplasm to the endoplasmic reticulum by means of the association with MHC class I molecules. It plays a fundamental role in the immune response, promoting the clearance of intracellular pathogens. Our pilot study aimed to determine the association between TAP1 gene 1177A>G (rs1057141) and 2090A>G (rs1135216) genetic polymorphisms with susceptibility to LTBI. In this case-control study, 153 individuals from shelters were analyzed (46 were LTBI-positive and 92 were controls). Genotyping of the rs11352216 (2090A>G) and rs1057141 (1177A>G) gene IDs was performed using the Applied Biosystems Step One Thermal Cycler Real-Time PCR allelic discrimination technology. The haplotypic analyses were performed with the Arlequin 3.5 program. Social assistance centers and shelters that serve vulnerable populations represent high-risk sites due to overcrowding and the impaired nutritional status of their residents. The G allele (OR=1.99, CI=1.109-3.587, p=0.021) and the GG genotype of rs11352216 (A>G) were associated with susceptibility to LTBI, according to the codominant genetic model (OR=8.32, CI=1.722-61.98, p=0.007). The rs1057141 (A>G) polymorphism was not associated with LTBI risk. The results suggest that carriers of the G allele of rs1135216 (A>G) are susceptible to LTBI.

RISK FACTORS OF LATENT TUBERCULOSIS INFECTION IN HEALTHCARE WORKERS AT HOSPITALS IN JEMBER CITY INDONESIA.

Background:Healthcare workers in Tuberculosis (TB) and non-TB units in hospitals have a high risk of experiencing Latent Tuberculosis Infection (LTBI), because of exposure to droplets containing Mycobacterium tuberculosis. This study aims to prove LTBI incidence and risk factors to healthcare workers at the hospital in Jember City.Material and Methods:a cross-sectional study, from January to March 2020 in two hospitals in Jember City. Healthcare workers in the TB care and non-TB care unit were examined using Tuberculin skin test (TST) with a cut off ≥ 10 mm for positive LTBI. Chest x-ray and clinical examination to rule out active TB and a standardized questionnaire were also used.Results:128 healthcare workers completed the questionnaires, clinical, tuberculin skin test (TST), and chest x-ray data. LTBI incidence of positive results 61.7% (n = 79). Contacts TB in the workplace (p value = 0.219; OR = 1.643; CI = 0.742-3.641) and a unit of work (p value = 0.102; OR = 0.760; CI = 0.559-1.031) has no relationship with LTBI. The profession (p value = 0.020; OR = 1.112; CI = 0.896-1.403), the duration of the work (p value = 0.039; OR = 2.984; CI = 1.067-8.342), and BCG immunization (p value =0.000; OR = 0.151; CI = 0.052-0.438) have important relationships with LTBI.Conclusion:TB infection with a high incidence, a risk of transmission to healthcare workers, and a relationship between occupational risk factors and LTBI among healthcare workers in Jember City, Indonesia have been established in this study.

Comparison of Latent Tuberculosis Infections among General versus Tuberculosis Health Care Workers in Myanmar

Health care workers (HCWs) in high tuberculosis (TB) prevalence countries have to care for many cases, thus increasing their risk of infection. The objective of the study was to compare the prevalence of latent TB infection (LTBI) between general HCWs and TB HCWs, and also to explore the associated factors. A cross-sectional study was conducted in Nay Pyi Taw, Myanmar from September 2019 to January 2020. Staff working at two general hospitals were recruited. Those allocated for TB care were classified as TB HCWs, while the remaining were classified as general HCWs. Participants were interviewed using a structured questionnaire, and screened for LTBI using a tuberculin skin test (TST). Individuals who had an induration of 10 mm or more with normal chest radiograph were regarded as having LTBI. The prevalence of LTBI among general HCWs was 2.04 times higher than that of TB HCWs (31.2% vs. 15.3%, p < 0.001). The associated factors for LTBI included low education level, duration of work experience ≥ 10 years, a low knowledge of regular TB screening, and teaching cough etiquette to TB patients. The higher prevalence of LTBI in the general HCWs in this study was due to confounding by education and experience. After adjustment for these, we have no evidence to support that either group of HCWs had higher LTBI risk.

Prevalence of latent tuberculosis among refugee children in Malaysia.

IntroductionTuberculosis remains one of the top 10 major causes of global mortality, imposing social–economic and medical challenges in Malaysia. Refugees sheltered in Malaysia are a high-risk population but basic health checks upon their arrival, including tuberculosis screening, are not practised. This study aimed to identify the prevalence and risk factors of tuberculosis and latent tuberculosis infection (LTBI) among refugee children in Malaysia.MethodsA cross-sectional study was performed in three refugee schools in the Klang Valley, Malaysia, using tuberculin skin tests or interferon-γ release assays. Participants who tested positive were sent for further examination with chest radiography to confirm the tuberculosis diagnosis.ResultsFrom April 2018 to April 2019, we screened 430 refugee children with a median age of 13.0 years. Most of the children were born in Myanmar (n=274, 63.7%) and Pakistan (n=60, 14.0%). No children were diagnosed with active tuberculosis but 55 of the children (12.8%) were diagnosed with LTBI. Children with LTBI were generally older (OR 3.01, 95% CI 1.71–5.29; p<0.001) than those without LTBI infection. Sex, history of bacille Calmette–Guérin vaccination and country of birth were not associated with increased risk of LTBI.ConclusionThe relatively high LTBI burden among refugee children in this study poses an indication of possible LTBI risk among this population nationwide, and thus would be an important group to target for preventive therapy. This provides a unique opportunity for researchers to further examine and implement well-structured preventive strategies in combating the endemic infectious disease in Malaysia.

High risk for latent tuberculosis infection among medical residents and nursing students in India.

Defining occupational latent tuberculosis infection (LTBI) risk among healthcare workers is needed to support implementation of prevention guidelines. Prospective cohort study of 200 medical residents and nursing students in India was conducted May 2016—December 2017. Tuberculin skin test (TST) and QuantiFERON TB Gold Test-in-tube (QFT-GIT) were performed at study entry and 12 months. Primary outcome was incident LTBI (≥10mm TST induration and/or ≥0.35IU/mL QFT-GIT) at 12 months; secondary outcomes included baseline LTBI prevalence and risk factors for incident and prevalent LTBI using Poisson regression. Among 200, [90 nursing students and 110 medical residents], LTBI prevalence was 30% (95% CI, 24–37); LTBI incidence was 26.8 (95% CI, 18.6–37.2) cases per 100 person-years and differed by testing method (28.7 [95% CI, 20.6–38.9] vs 17.4 [95% CI, 11.5–25.4] cases per 100 person-years using TST and QFT-GIT, respectively). Medical residents had two-fold greater risk of incident LTBI than nursing students (Relative Risk, 2.16; 95% CI, 1.05–4.42). During study period 6 (3%) HCWs were diagnosed with active TB disease. Overall, median number of self-reported TB exposures was 5 (Interquartile Range, 1–15). Of 60 participants with prevalent and incident LTBI who were offered free isoniazid preventive therapy (IPT), only 2 participants initiated and completed IPT. High risk for LTBI was noted among medical residents compared to nursing students. Self-reported TB exposure is underreported, and uptake of LTBI prevention therapy remains low. New approaches are needed to identify HCWs at highest risk for LTBI.

Tuberculosis among migrant workers in Taiwan

BackgroundAlthough the worldwide incidence of tuberculosis (TB) has been slowly decreasing, the migrant workers remains an important gap for regional TB control. In Taiwan, the numbers of the migrant workers from countries with high TB incidence increase significantly in past decades and the impact on public health remains unknown. This study aimed to explore the difference of TB incidence between Taiwanese and the migrant workers.MethodsThe migrant workers are obligated to receive pre-arrival, post-arrival and regular chest X-ray screening during their stay in Taiwan. We retrospectively collected these data extracted from the Alien Workers Health Database in Centers for Disease Control, Taiwan from Jan. 1, 2004 to Dec. 31, 2013. Poisson regression models were used to compare the hazard ratios of TB between Taiwanese and the migrant workers after adjusting gender and age groups.ResultsThe total migrant workers in Taiwan reached 314,034 persons in 2004 and 489,134 persons in 2013, accounting for 2% of Taiwan population. The TB incidence of migrant workers was similar to Taiwanese (53–73.7 per 105 vs 45.5–76.8 per 105). Comparing with Taiwanese, the TB risk was significantly lower in male migrant workers (HR: 0.76; 95% CI: 0.70–0.83, P < 0.001), but higher in female migrant workers (HR: 1.40; 95% CI: 1.35–1.46, P < 0.001). Besides, we found that the TB risk in migrant workers was 5.30-fold (95% CI: 4.83–5.83, P < 0.001) in youngest group (≤24 year-old) comparing with Taiwanese.ConclusionsMigrant workers in Taiwan have higher TB incidence than Taiwanese in young groups, especially in females. The mainstay young laborers with latent tuberculosis infection risk is an important vulnerability for public health. Further investigation and health screening are warranted.

Precision immunoprofiling to reveal diagnostic signatures for latent tuberculosis infection and reactivation risk stratification.

Latent tuberculosis infection (LTBI) is estimated in nearly one quarter of the world's population, and of those immunocompetent and infected ~10% will proceed to active tuberculosis (TB). Current diagnostics cannot definitively identify LTBI and provide no insight into reactivation risk, thereby defining an unmet diagnostic challenge of incredible global significance. We introduce a new machine-learning-driven approach to LTBI diagnostics that leverages a high throughput, multiplexed cytokine detection technology and powerful bioinformatics to reveal multi-marker signatures for LTBI diagnosis and risk stratification. This approach is enabled through an individualized normalization procedure that allows disease-relevant biomarker signatures to be revealed despite heterogeneity in basal immune response. Specifically, cytokines secreted from antigen-challenged peripheral blood mononuclear cells were detected using silicon photonic sensor arrays and multidimensional data correlation of individually-normalized immune responses revealed signatures important for LTBI status. These results demonstrate a powerful combination of multiplexed biomarker detection technologies, precision immune normalization, and feature selection algorithms that revealed positively correlated multi-biomarker signatures for LTBI status and reactivation risk stratification from a relatively simple blood-based assay.