Latent tuberculosis infection in healthcare workers in low- and middle-income countries: an updated systematic review

TB antigen-based skin tests and QFT-Plus for Mycobacterium tuberculosis infection diagnosis in Brazilian healthcare workers: a cost-effectiveness analysis

This study aimed to analyze the cost-effectiveness of three tuberculosis (TB) antigen-based skin tests (TBST) (Diaskintest, C-TST, and Cy-TB) and QFT-Plus for TB infection diagnosis compared to the current standard of care, PPD Rt-23 tuberculin skin test (TST), among healthcare workers in Brazil. A state-transition Markov model was employed, simulating a cohort of healthcare workers (five annual cycles) for testing and treating TB infection with three months of weekly doses of rifapentine and isoniazid (3HP) under the Brazilian public health system perspective. Effects (TB disease averted) and costs for screening and treating TB infection were discounted at 5%. Incremental cost-effectiveness per TB averted was estimated. One-way and probabilistic sensitivity analysis were performed. Brazil, an upper-middle-income country with a high burden of TB, shows one of the largest universal public health systems and provides free-of-charge diagnosis and treatment for TB and TB infection. TST is the standard of care, whereas QFT-Plus is available for very high-risk populations. The three new TBST are under validation for eventual incorporation. Patients or participants: a hypothetical cohort of 10,000 healthcare workers, working at any level of healthcare service, and negative TST results in the previous year of both sexes with a baseline negative TST result. Diaskintest, C-TST, Cy-TB, and QFT-Plus were found to show a higher specificity. Costs with QFT-Plus were higher due to equipment, human labor, and test price. Diaskintest was the most cost-saving strategy, followed by Cy-TB for TB preventive treatment with 3HP. In the Brazilian scenario, Diaskintest and Cy-TB are the most cost-effective tests for sequential testing of healthcare workers.

Knowledge and Prevalence of Latent Tuberculosis Infection: A Feasibility and Pilot Study in a Primary Healthcare Setting in Rural Eastern Cape, South Africa

Latent tuberculosis infection (LTBI) remains a significant global health concern, particularly in regions with high tuberculosis (TB) prevalence, such as South Africa. This pilot study aimed to evaluate the prevalence of LTBI and assess patient knowledge about the condition in a primary healthcare clinic in rural Eastern Cape, South Africa. A cross-sectional design was used, and convenience sampling recruited outpatients aged 18 years and older with no prior history of TB. Blood samples were analyzed using the QuantiFERON-TB Gold assay to determine LTBI status, and a survey assessed patient knowledge of LTBI. Strong positive correlations were observed between what patients understand by the term LTBI and how LTBI differs from TB (0.70), what patients understand by the term LTBI and the risk factors for developing LTBI (0.70), how LTBI differs from TB and the risk factors for developing LTBI (0.78), and how LTBI differs from TB and the recommended treatments for LTBI (0.79), indicating overlap in understanding. In contrast, there were negative correlations between if patients had ever heard of latent LTBI before and their understanding of the term LTBI (-0.25), the risk factors for developing LTBI (-0.22), LTBI progressing to active TB (-0.27), and the recommended treatments for LTBI (-0.27). This divergence points to different dimensions of patient knowledge and awareness. Age, gender, occupation, comorbidities, and HIV status showed varying LTBI positivity trends. Among younger patients aged 20-29, 15.4% tested positive, while the 30-39 group showed a nearly equal split between positive (48.1%) and negative cases. A higher positivity rate was seen in females (39.1%) compared to males (31.6%). Unemployed individuals had higher positivity rates, suggesting socioeconomic factors' influence. Comorbidities, especially hypertension, diabetes, and asthma, correlated with higher LTBI positivity among females, but this was less evident in males. HIV-positive patients had a higher LTBI-negative rate compared to HIV-negative patients. A logistic regression model (accuracy 70%) identified demographic and health factors predicting LTBI outcomes, with comorbidities, particularly hypertension and diabetes, significantly increasing the likelihood of LTBI positivity. These findings suggest that demographic and health factors, including age, gender, occupation, comorbidities, and HIV status, may predict LTBI positivity.

Cost-Effectiveness Analysis of a Latent Tuberculosis Screening Program Among Healthcare Personnel

Screening high-risk groups for Latent Tuberculosis Infection (LTBI) is crucial for TB elimination, as the large global reservoir of Mycobacterium tuberculosis bacilli poses a significant challenge to TB control globally. Assessing the cost-effectiveness of LTBI screening strategies is also crucial in determining the optimal approach. In 2022, Sri Lanka initiated a new program to manage latent tuberculosis infection among high-risk groups, including healthcare personnel, which recorded an 18% Latent Tuberculosis prevalence. This study aimed to evaluate the cost-effectiveness of implementing a screening program for Healthcare Personnel as part of this initiative in Sri Lanka. A decision tree model was developed to assess the cost-effectiveness of LTBI screening among Healthcare Personnel from the health system perspective, using secondary data from 2021 to 2022. The decision tree model was used to evaluate the cost-effectiveness of initiating LTBI screening for Healthcare Personnel in government hospitals. The findings are presented as the Incremental Cost-Effectiveness Ratio (ICER), compared to locally appropriate cost-effectiveness thresholds. The direct costs incurred for the standard LTBI tests and prophylaxis were assessed at the program level. The ICER represents the incremental cost of LTBI screening per Disability Adjusted Life Year (DALY) gained by preventing future active TB cases through treatment of latent TB infection. The total cost for managing an active TB case was $80.44, markedly higher than the $20.84 cost for a Latent TB case. The total cost difference between managing an active TB case and a Latent TB case was $59.60. The Incremental Cost-Effectiveness Ratio was $2381.29 per Disability Adjusted Life Year averted. The decision analysis model indicated that screening Healthcare Personnel for latent tuberculosis infection is highly cost-effective and can be recommended for implementation in Sri Lanka.

Comparison of the standardized incidence ratio of tuberculosis among workers at medical and educational institutions: a nationwide LTBI observational cohort study

BACKGROUND

The objective of this study was to determine the incidence of tuberculosis (TB) among workers at medical institutions based on interferon-gamma release assay (IGRA) and compare it with that of workers at educational institutions and the general population.

METHODS

From March 2017 to December 2020, we used a cohort of workers from medical and educational institutions in Korea, who underwent IGRA as part of a national screening program for latent tuberculosis infection (LTBI). After connecting to the National Health Insurance Service (NHIS) database to detect for any actual cases of active TB, we estimated standardized incidence ratio (SIR) and the expected number of cases to compare the incidence of TB with that of the general population.

RESULTS

Significant disparities in TB incidence were revealed among workers in medical and educational institutions, based on IGRA results, age, and occupation. Individuals positive for IGRA in medical institutions displayed substantially higher SIR for TB, 7.19 (6.15-8.41), compared to counterparts in educational institutions, 3.69 (3.02-4.51). Comparing by age group, we see that the SIRs are higher in younger age groups compared to older ones, with 37.30 (28.11-49.50) and 11.89 (7.28-19.41) for IGRA-positive medical and education workers under 30 years of age, respectively. In the results by occupation within the medical institutions, nurses had the highest SIR at 14.17 (11.14-18.04).

CONCLUSIONS

Healthcare workers in medical institutions are more likely to develop actual TB after a positive result of LTBI screening in Korea. Intensive management and surveillance programs should be reinforced.

Performance of Current Diagnostic Tools in Detecting Latent Tuberculosis Among Healthcare Workers: A Systematic Review

Testing for latent tuberculosis infection is essential for diagnosing Mycobacterium tuberculosis infections in asymptomatic individuals. Preventing the transition of latent to active tuberculosis is imperative, especially in high-risk populations such as healthcare workers. Interferon-gamma release assays (IGRAs) and the Mantoux/tuberculin skin test (TST) are two examples of diagnostic instruments utilized for detection. Systematic evaluations of the characteristics of widely available tests are very helpful for diagnosticians because these tests might not be easily accessible in situations with limited resources. This systematic review aims to evaluate and compare the diagnostic accuracy of tests for latent tuberculosis infection in healthcare workers. The review, conducted from 2013 to 2024, aimed to identify studies on "Latent Tuberculosis," "Healthcare workers," "Diagnostic modalities," "TST," "Interferon-gamma release assays," and "IGRA." The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines and developed a data extraction toolkit. Three authors independently reviewed the literature, ensuring uniformity. Discrepancies were resolved through discussions and mediation until a consensus was reached. Statistical significance was defined as a p-value of 0.05 or lower. The review provides valuable insights into the diagnostic accuracy of these tests, particularly in high-risk populations. The TST had a sensitivity of 76.5% (confidence interval (CI) = 61.5-91.5%) and specificity of 77.2% (CI = 65-85%). Its positive predictive value (PPV) was 54.8% (CI = 45-65%), and the negative predictive value (NPV) was 88.5% (CI = 85-92%), with an odds ratio of 63.6 and an area under the curve (AUC) of 0.72. QuantiFERON-TB Gold In-Tube (QFT-GIT) showed a sensitivity of 68.35% (CI = 67.15-70.55%) and a specificity of 82.32% (CI = 72.32-97.47%). Its PPV was 56% (CI = 54-92%), and NPV was 92.7% (CI = 89-96%), with an odds ratio of 357.9 and an AUC of 0.767. QuantiFERON-TB Gold Plus (QFT-Plus) had a sensitivity of 85% (CI = 78.9-91.1%) and a specificity of 73.52% (CI = 35.71-93.75%). Its PPV was 59.2% (CI = 39.3-78.2%), and NPV was 95% (CI = 91.2-98%), with an odds ratio of 125.39 and an AUC of 0.89. T-SPOT.TB showed a sensitivity of 92% (CI = 87-97%) and a specificity of 95.7% (CI = 94-98%). Its PPV was 86.8% (CI = 85-95.8%), and NPV was 95.8% (CI = 92.5-96.7%), with an odds ratio of 1.03 and an AUC of 0.7. CLIA-IGRA had a sensitivity of 100% (CI = 99.9-100%) and a specificity of 95.57% (CI = 95.57-100%). Its PPV was 96.8% (CI = 96.8-100%), and NPV was 99.8% (CI = 99.8-100%), with an odds ratio of 1509 and an AUC of 0.97. HBHA-induced IGRA showed a sensitivity of 86.4% (CI = 71.1-97.3%) and a specificity of 82.5% (CI = 66.4-92.6%). Its PPV was 86.8% (CI = 66.7-95.3%), and NPV was 86.4% (CI = 57.8-95.7%), with an odds ratio of 6.18 and an AUC of 0.886. There are specific benefits and drawbacks of each diagnostic test for latent tuberculosis infection. With its exceptional sensitivity and specificity, the CLIA-IGRA test is a top choice for a precise diagnosis of tuberculosis. Practical factors such as availability and cost, however, might prevent its widespread usage. Both the QuantiFERON and TST are still useful tools, especially when used in certain populations or situations when their performance characteristics meet clinical requirements.

Intention to receive Latent Tuberculosis Infection (LTBI) treatment and its associated factors among healthcare workers in a Malaysian teaching university hospital

The acceptability of latent tuberculosis infection (LTBI) therapy remains low among healthcare workers (HCWs). Up to 10% of LTBI cases can reactivate into active tuberculosis, posing risks to HCWs and patients. Understanding HCWs' intention to undergo LTBI treatment is crucial for designing effective management policies, especially where no LTBI policy exists. This cross-sectional study investigated the intention to receive LTBI therapy and its associated factors among HCWs in a Malaysian teaching hospital. The study was conducted from 5th to 30th May 2023, in a hospital without an LTBI screening program. Stratified random sampling was used to select HCWs, excluding those undergoing TB or LTBI therapy. Respondents completed a questionnaire measuring intention to receive LTBI treatment, LTBI knowledge, attitude, perceived norm, and perceived behavioral control. Of the 256 respondents, the majority were female (63.7%), under 35 years old (64.45%), had no comorbidities (82.0%), and worked in clinical settings (70.3%). However, 60.5% of respondents had low LTBI knowledge and 60.5% held unfavorable attitudes toward LTBI treatment. Despite this, 53.5% of respondents intended to undergo LTBI therapy if diagnosed. Factors positively associated with this intention included being female [aOR: 2.033, 95% CI: 1.080-3.823], having high LTBI knowledge [aOR 1.926, 95% CI: 1.093-3.397], had favorable attitude [aOR 3.771, 95% CI: 1.759-8.084], and strongly perceiving social norms supportive of LTBI treatment [aOR 4.593, 95% CI: 2.104-10.023]. These findings emphasize the need for an LTBI management policy in the teaching hospital. To boost HCWs' intention and acceptance of LTBI treatment, a focused program improving knowledge, attitude, and perception of social norms could be introduced.

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 in IFN-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.

Accuracy of digital chest x-ray analysis with artificial intelligence software as a triage and screening tool in hospitalized patients being evaluated for tuberculosis in Lima, Peru

Tuberculosis (TB) transmission in healthcare facilities is common in high-incidence countries. Yet, the optimal approach for identifying inpatients who may have TB is unclear. We evaluated the diagnostic accuracy of qXR (Qure.ai, India) computer-aided detection (CAD) software versions 3.0 and 4.0 (v3 and v4) as a triage and screening tool within the FAST (Find cases Actively, Separate safely, and Treat effectively) transmission control strategy. We prospectively enrolled two cohorts of patients admitted to a tertiary hospital in Lima, Peru: one group had cough or TB risk factors (triage) and the other did not report cough or TB risk factors (screening). We evaluated the sensitivity and specificity of qXR for the diagnosis of pulmonary TB using culture and Xpert as primary and secondary reference standards, including stratified analyses based on risk factors. In the triage cohort (n = 387), qXR v4 sensitivity was 0.91 (59/65, 95% CI 0.81-0.97) and specificity was 0.32 (103/322, 95% CI 0.27-0.37) using culture as reference standard. There was no difference in the area under the receiver-operating-characteristic curve (AUC) between qXR v3 and qXR v4 with either a culture or Xpert reference standard. In the screening cohort (n = 191), only one patient had a positive Xpert result, but specificity in this cohort was high (>90%). A high prevalence of radiographic lung abnormalities, most notably opacities (81%), consolidation (62%), or nodules (58%), was detected by qXR on digital CXR images from the triage cohort. qXR had high sensitivity but low specificity as a triage in hospitalized patients with cough or TB risk factors. Screening patients without cough or risk factors in this setting had a low diagnostic yield. These findings further support the need for population and setting-specific thresholds for CAD programs.

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

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

Global, regional and national trends in tuberculosis incidence and main risk factors: a study using data from 2000 to 2021

BACKGROUND

Despite the significant progress over the years, Tuberculosis remains a major public health concern and a danger to global health. This study aimed to analyze the spatial and temporal characteristics of the incidence of tuberculosis and its risk factors and to predict future trends in the incidence of Tuberculosis.

METHODS

This study used secondary data on tuberculosis incidence and tuberculosis risk factor data from 209 countries and regions worldwide between 2000 and 2021 for analysis. Specifically, this study analyses the spatial autocorrelation of Tuberculosis incidence from 2000 to 2021 by calculating Moran's I and identified risk factors for Tuberculosis incidence by multiple stepwise linear regression analysis. We also used the Autoregressive Integrated Moving Average model to predict the trend of Tuberculosis incidence to 2030. This study used ArcGIS Pro, Geoda and R studio 4.2.2 for analysis.

RESULTS

The study found the global incidence of Tuberculosis and its spatial autocorrelation trends from 2000 to 2021 showed a general downward trend, but its spatial autocorrelation trends remained significant (Moran's I = 0.465, P < 0.001). The risk factors for Tuberculosis incidence are also geographically specific. Low literacy rate was identified as the most pervasive and profound risk factor for Tuberculosis.

CONCLUSIONS

This study shows the global spatial and temporal status of Tuberculosis incidence and risk factors. Although the incidence of Tuberculosis and Moran's Index of Tuberculosis are both declining, there are still differences in Tuberculosis risk factors across countries and regions. Even though literacy rate is the leading risk factor affecting the largest number of countries and regions, there are still many countries and regions where gender (male) is the leading risk factor. In addition, at the current rate of decline in Tuberculosis incidence, the World Health Organization's goal of ending the Tuberculosis pandemic by 2030 will be difficult to achieve. Targeted preventive interventions, such as health education and regular screening of Tuberculosis-prone populations are needed if we are to achieve the goal. The results of this study will help policymakers to identify high-risk groups based on differences in TB risk factors in different areas, rationalize the allocation of healthcare resources, and provide timely health education, so as to formulate more effective Tuberculosis prevention and control policies.

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

Background

Healthcare 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.

Methods

This 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.

Results

We 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.

Conclusion

The 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.

Right to Occupational Safety: Prevalence of Latent Tuberculosis Infection in Healthcare Workers. A 1-Year Retrospective Survey Carried out at Hospital of Lecce (Italy)

BACKGROUND

Prevention of latent tuberculosis infection (LTBI) in healthcare workers (HCWs) to ensure the "Right to Occupational Safety" is a special challenge globally, as HCWs have a higher risk of acquiring the infection in hospital settings because of frequent close exposure to patients suffering from tuberculosis (TB).

METHODS

Aretrospective study was performed with the aim of assessing the prevalence of LTBI related to demographical and occupational risk factors among HCWs employed in a large hospital in Italy. The study involved 1461 HCWs screened for LTBI by Mantoux tuberculin skin test (TST) and then confirmed with Interferon Gamma Release Assay (IGRA) test in case of positivity. Immunosuppressed and BGC-vaccinated workers were tested directly with IGRA.

RESULTS

LTBI was diagnosed in 4.1% of the HCWs and the prevalence resulted lower than other studies conducted in low TB incidence countries. The variables significantly linked with higher frequency of the infection were: age ≥40 years (OR = 3.14; 95% CI: 1.13-8.74; p < 0.05), length of service ≥15 years (OR = 4.11; 95% CI: 1.48-11.43; p < 0.05) and not being trained on TB prevention (OR = 3.46; 95% CI: 1.85-6.46; p < 0.05). Not trained HCWs presented a higher risk of LTBI also after adjustment for age and length of service, compared to trained HCWs.

CONCLUSIONS

screening of HCWs for LTBI should be always considered in routinely occupational surveillance in order to early diagnose the infection and prevent its progression. Safety policies in hospital settings centered on workers' training on TB prevention is crucial to minimize LTBI occurrence in HCWs.

Prevalence and incidence of tuberculosis infection among healthcare workers in chest diseases hospitals, Bangladesh: Putting infection control into context

BACKGROUND

Healthcare workers (HCWs) are at increased risk of tuberculosis infection (TBI). We estimated the prevalence and incidence of TBI and risk factors among HCWs in Bangladeshi hospitals to target TB infection prevention and control (IPC) interventions.

METHODS

During 2013-2016, we conducted a longitudinal study among HCWs in four chest disease hospitals. At baseline, we administered a questionnaire on sociodemographic and occupational factors for TB, tuberculin skin tests (TST) in all hospitals, and QuantiFERON ®-TB Gold in-Tube (QFT-GIT) tests in one hospital. We assessed factors associated with baseline TST positivity (induration ≥10mm), TST conversion (induration increase ≥10mm from baseline), baseline QFT-GIT positivity (interferon-gamma ≥0.35 IU/mL), and QFT-GIT conversion (interferon-gamma <0.35 IU/mL to ≥0.35 IU/mL). We included factors with a biologically plausible relationship with TBI identified in prior studies or having an association (p = <0.20) in the bivariate analyses with TST positivity or QFT-GIT positivity in multivariable generalized linear models. The Kaplan-Meier was used to estimate the cumulative TBI incidence rate per 100 person-years.

RESULTS

Of the 758 HCWs invited, 732 (97%) consented to participate and 731 completed the one-step TST, 40% had a positive TST result, and 48% had a positive QFT-GIT result. In multivariable models, HCWs years of service 11-20 years had 2.1 (95% CI: 1.5-3.0) times higher odds of being TST-positive and 1.6 (95% CI 1.1-2.5) times higher odds of QFT-GIT-positivity at baseline compared with those working ≤10 years. HCWs working 11-20 years in pulmonary TB ward had 2.0 (95% CI: 1.4-2.9) times higher odds of TST positivity, and those >20 years had 2.5 (95% CI: 1.3-4.9) times higher odds of QFT-GIT-positivity at baseline compared with those working <10 years. TBI incidence was 4.8/100 person-years by TST and 4.2/100 person-years by QFT-GIT. Females had 8.5 (95% CI: 1.5-49.5) times higher odds of TST conversion than males.

CONCLUSIONS

Prevalent TST and QFT-GIT positivity was associated with an increased number of years working as a healthcare worker and in pulmonary TB wards. The incidence of TBI among HCWs suggests ongoing TB exposure in these facilities and an urgent need for improved TB IPC in chest disease hospitals in Bangladesh.

Facilitators and barriers to latent tuberculosis infection treatment among primary healthcare workers in Malaysia: a qualitative study

BACKGROUND

Healthcare workers (HCWs) have an increased risk of active and latent tuberculosis infection (LTBI) compared to the general population. Despite existing guidelines on the prevention and management of LTBI, little is known about why HCWs who tested positive for LTBI refuse treatment. This qualitative study sought to explore the facilitators and barriers to LBTI treatment uptake among primary HCWs in Malaysia.

METHODS

This qualitative study used a phenomenological research design and was conducted from July 2019 to January 2021. A semi-structured topic guide was developed based on literature and the Common-Sense Model of Self-Regulation. We conducted one focus group discussion and 15 in-depth interviews with primary care HCWs. Interviewees were 7 physicians and 11 allied HCWs who tested positive for LTBI by Tuberculin Skin Test or Interferon Gamma Release Assay. Audio recordings were transcribed verbatim and thematic analysis was used to analyse the data.

RESULTS

We found four factors that serve as barriers to HCWs' LTBI treatment uptake. Uncertainties about the need for LTBI treatment, alongside several other factors including the attitude of the treating physician towards treatment, time constraints during clinical consultations, and concerns about the treatment itself. On the other hand, facilitators for LTBI treatment uptake can be grouped into two themes: diagnostic modalities and improving knowledge of LTBI treatment.

CONCLUSIONS

Improving HCWs' knowledge and informative clinical consultation on LTBI and its treatment benefit, aided with a definitive diagnostic test can facilitate treatment uptake. Additionally, there is a need to improve infection control measures at the workplace to protect HCWs. Utilizing behavioural insights can help modify risk perception among HCWs and promote treatment uptake.

The prevalence and risk factors for tuberculosis among healthcare workers in Yogyakarta, Indonesia

Healthcare workers (HCWs) are at risk of contracting TB, particularly when in high tuberculosis (TB) burden settings. Routine surveillance data and evidence are limited on the burden of TB amongst HCWs in Indonesia. We aimed to measure the prevalence of TB infection (TBI) and disease among HCWs in four healthcare facilities in Yogyakarta province in Indonesia, and explore risk factors for TBI. A cross-sectional TB screening study targeted all HCWs from four pre-selected facilities (1 hospital, 3 primary care) in Yogyakarta, Indonesia. Voluntary screening included symptom assessment, Chest X-ray (CXR), Xpert MTB/RIF (if indicated) and tuberculin skin test (TST). Analyses were descriptive and included multivariable logistic regression. Of 792 HCWs, 681 consented (86%) to the screening; 59% (n = 401) were female, 62% were medical staff (n = 421), 77% worked in the one participating hospital (n = 524), and the median time working in the health sector was 13 years (IQR: 6-25 years). Nearly half had provided services for people with TB (46%, n = 316) and 9% reported ever having TB (n = 60). Among participants with presumptive TB (15%, n = 99/662), none were diagnosed microbiologically or clinically with active TB disease. TBI was detected in 25% (95% CI: 22-30; n = 112/441) of eligible HCWs with a TST result. A significant association was found between TB infection and being male (adjusted Odds Ratio (aOR) 2.02 (95%CI: 1.29-3.17)), currently working in the participating hospital compared to primary care (aOR 3.15 (95%CI: 1.75-5.66)), and older age (1.05 OR increase per year of life between 19-73 years (95%CI: 1.02-1.06)). This study supports prioritisation of HCWs as a high-risk group for TB infection and disease, and the need for comprehensive prevention and control programs in Indonesia. Further, it identifies characteristics of HCWs in Yogyakarta at higher risk of TBI, who could be prioritised in screening programs if universal coverage of prevention and control measures cannot be achieved.

Cost-effectiveness of tuberculosis infection prevention and control interventions in South African clinics: a model-based economic evaluation informed by complexity science methods

INTRODUCTION

Nosocomial Mycobacterium tuberculosis (Mtb) transmission substantially impacts health workers, patients and communities. Guidelines for tuberculosis infection prevention and control (TB IPC) exist but implementation in many settings remains suboptimal. Evidence is needed on cost-effective investments to prevent Mtb transmission that are feasible in routine clinic environments.

METHODS

A set of TB IPC interventions was codesigned with local stakeholders using system dynamics modelling techniques that addressed both core activities and enabling actions to support implementation. An economic evaluation of these interventions was conducted at two clinics in KwaZulu-Natal, employing agent-based models of Mtb transmission within the clinics and in their catchment populations. Intervention costs included the costs of the enablers (eg, strengthened supervision, community sensitisation) identified by stakeholders to ensure uptake and adherence.

RESULTS

All intervention scenarios modelled, inclusive of the relevant enablers, cost less than US$200 per disability-adjusted life-year (DALY) averted and were very cost-effective in comparison to South Africa's opportunity cost-based threshold (US$3200 per DALY averted). Two interventions, building modifications to improve ventilation and maximising use of the existing Central Chronic Medicines Dispensing and Distribution system to reduce the number of clinic attendees, were found to be cost saving over the 10-year model time horizon. Incremental cost-effectiveness ratios were sensitive to assumptions on baseline clinic ventilation rates, the prevalence of infectious TB in clinic attendees and future HIV incidence but remained highly cost-effective under all uncertainty analysis scenarios.

CONCLUSION

TB IPC interventions in clinics, including the enabling actions to ensure their feasibility, afford very good value for money and should be prioritised for implementation within the South African health system.

Challenges and the Way forward in Diagnosis and Treatment of Tuberculosis Infection

Globally, it is estimated that one-quarter of the world's population is latently infected with Mycobacterium tuberculosis (Mtb), also known as latent tuberculosis infection (LTBI). Recently, this condition has been referred to as tuberculosis infection (TBI), considering the dynamic spectrum of the infection, as 5-10% of the latently infected population will develop active TB (ATB). The chances of TBI development increase due to close contact with index TB patients. The emergence of multidrug-resistant TB (MDR-TB) and the risk of development of latent MDR-TB has further complicated the situation. Detection of TBI is challenging as the infected individual does not present symptoms. Currently, there is no gold standard for TBI diagnosis, and the only screening tests are tuberculin skin test (TST) and interferon gamma release assays (IGRAs). However, these tests have several limitations, including the inability to differentiate between ATB and TBI, false-positive results in BCG-vaccinated individuals (only for TST), false-negative results in children, elderly, and immunocompromised patients, and the inability to predict the progression to ATB, among others. Thus, new host markers and Mtb-specific antigens are being tested to develop new diagnostic methods. Besides screening, TBI therapy is a key intervention for TB control. However, the long-course treatment and associated side effects result in non-adherence to the treatment. Additionally, the latent MDR strains are not susceptible to the current TBI treatments, which add an additional challenge. This review discusses the current situation of TBI, as well as the challenges and efforts involved in its control.

Prevalence and risk factors of latent tuberculosis infection among college students: a systematic review and meta-analysis

OBJECTIVES

College students are at increased risk of tuberculosis (TB), which increases their likelihood of developing latent tuberculosis infections (LTBI). This study aimed to estimate the pooled prevalence of LTBI and identify its risk factors.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

We searched PubMed, Embase, Scopus, Web of Science, CNKI, Wanfang and CBM databases (10 March 2022) for studies published in any language. The pooled prevalence of LTBI was estimated using random effects methods. Factors associated with LTBI were evaluated by determining standardised mean difference (SMD) with 95% confidence interval (CI). All analyses were performed using the Stata 15.1.

RESULTS

A total of 50 studies from 18 countries were included, with 44 tuberculin skin test (n = 623,732) and 19 interferon gamma release assay (n = 38,266) estimates. The prevalence of a positive tuberculin skin test was 20% (95% CI: 17-23%), and the prevalence of a positive interferon gamma release assay was 9% (95% CI: 7%-11%) among college students. Older age (SMD: 1.67, 95% CI: 1.31-2.13), no Bacillus Calmette-Guérin vaccination/scar (SMD: 1.51, 95% CI: 1.06-2.16), contact with TB cases (SMD: 1.34, 95% CI: 1.11-1.62), clinical training (SMD: 1.93, 95% CI: 1.65-2.26) and overweight/obesity (SMD: 1.17, 95% CI: 1.06-1.30) were associated with a higher prevalence of LTBI. Sex was not associated with LTBI prevalence.

CONCLUSION

College students have an increased risk of LTBI, although it varies by geographical area. This meta-analysis provides evidence of risk factors for LTBI in college students. Infection control measures should be conducted for college students with LTBI.

Mycobacterium tuberculosis infection and disease in healthcare workers in a tertiary referral hospital in Bandung, Indonesia

Background

Healthcare workers (HCWs), especially in high tuberculosis (TB) incidence countries, are at risk of Mycobacterium tuberculosis infection and TB disease, likely due to greater exposure to TB cases and variable implementation of infection control measures.

Aim

We aimed to estimate the prevalence of tuberculin skin test (TST) positivity, history of TB and to identify associated risk factors in HCWs employed at a tertiary referral hospital in Bandung, Indonesia.

Methods

A cross-sectional study was conducted from April to August 2018. A stratified sample of the HCWs were recruited, screened by TST, assessed for TB symptoms, history of TB disease and possible risk factors. Prevalence of positive TST included diagnosis with TB after starting work. HCWs with TB disease diagnosed earlier were excluded. Survey weights were used for all analyses. Possible risk factors were examined using logistic regression; adjusted odds ratios and 95% confidence intervals (CI) are presented.

Results

Of 455 HCWs recruited, 42 reported a history of TB disease (25 after starting work) and 395 had a TST result. The prevalence of positive TST was 76.9% (95% CI 72.6-80.8%). The odds increased by 7% per year at work (95% CI 3-11%) on average, with a rapid rise in TST positivity up to 10 years of work and then a plateau with around 80% positive.

Discussion

A high proportion of HCWs had a history of TB or were TST positive, increasing with longer duration of work. A package of TB infection control measures is needed to protect HCWs from Mycobacterium tuberculosis infection.

Latent Tuberculosis Cascade of Care Among Healthcare Workers: A Nationwide Cohort Analysis in Korea Between 2017 and 2018

BACKGROUND

In 2017, Korea implemented nationwide latent tuberculosis infection (LTBI) project targeting healthcare workers (HCWs). We aimed to assess its performance using the cascade of care model.

METHODS

We included 45,503 employees of medical institutions with positive interferon-gamma release assay result who participated between March 2017 and December 2018. We described percentages of LTBI participants completing each step in the cascade of care. Poisson regression model was conducted to assess individual characteristics and factors associated with not-visiting clinics for further care, not-initiating LTBI treatment, and not-completing treatment.

RESULTS

Proportions of visiting clinics and initiating and completing treatment in HCWs were 54.9%, 38.5%, and 32.0%, respectively. Despite of less likelihood of visiting clinics and initiating LTBI treatment, older age ≥ 65 years were more likely to complete treatment (adjusted relative risk [aRR], 0.80; 95% confidence interval [CI], 0.64-0.99), compared to young age < 35 years. Compared to nurses, doctors were less likely to visit clinic; however, were more likely to initiate treatment (aRR, 0.88; 95% CI, 0.81-0.96). Those who visited public health centers were associated with not-initiating treatment (aRR, 1.34; 95% CI, 1.29-1.40). When treated at private hospitals, 9-month isoniazid monotherapy was less likely to complete treatment, compared to 3-month isoniazid and rifampicin combination therapy (aRR, 1.33; 95% CI, 1.16-1.53).

CONCLUSION

Among employees of medical institutions with LTBI, only one third completed treatment. Age, occupation, treatment center, and initial regimen were significantly related to LTBI treatment performance indicators. Rifampicin-based short treatment regimens were effective under standard of care.

The characteristics of occupational tuberculosis risk in healthcare workers

BACKGROUND

Tuberculosis (TB) remains to be one of the most common causes of morbidity worldwide, but the discourse of its prevention has disproportionately singled out the occupational risks that affect healthcare workers. In this research, we aimed to: (1) investigate the underlying factor structure of Risk Characteristics (RC), specifically the risk of nosocomial TB transmission in health care facilities; (2) estimate the effects of work-related determinants and RC on risk perception; and (3) compare occupational risk perception of contracting TB with expert risk assessment.

METHOD

A paper-based questionnaire was administered to 179 health care workers (HCWs) working at 10 public health centres and two hospitals in Surabaya, Indonesia. We analysed our data using exploratory factor analysis (EFA) to unravel the latent structure of RC and structural equation modelling (SEM) to identify determinants of risk perceptions.

RESULTS

EFA revealed a two-factor solution for nine qualitative RC: controllability of damage and knowledge-evoked dread. Our SEM analysis found evidence that the controllability aspect of the TB risk was a more profound determinant in predicting risk perception than knowledge-evoked dread, implying that HCWs might benefit from training aims to increase their beliefs on the controllability of TB risk despite its severity.

CONCLUSION

Although further research is necessary, our study highlights the importance of addressing occupational risk perceptions in health facilities, encouraging HCWs to become more active in advocating for the necessary allocation of resources for their workplaces, and raising communities' awareness of TB transmissions.

Tuberculosis attributed to transmission within healthcare facilities, Botswana—The Kopanyo Study

Objective:

Healthcare facilities are a well-known high-risk environment for transmission of M. tuberculosis, the etiologic agent of tuberculosis (TB) disease. However, the link between M. tuberculosis transmission in healthcare facilities and its role in the general TB epidemic is unknown. We estimated the proportion of overall TB transmission in the general population attributable to healthcare facilities.

Methods:

We combined data from a prospective, population-based molecular epidemiologic study with a universal electronic medical record (EMR) covering all healthcare facilities in Botswana to identify biologically plausible transmission events occurring at the healthcare facility. Patients with M. tuberculosis isolates of the same genotype visiting the same facility concurrently were considered an overlapping event. We then used TB diagnosis and treatment data to categorize overlapping events into biologically plausible definitions. We calculated the proportion of overall TB cases in the cohort that could be attributable to healthcare facilities.

Results:

In total, 1,881 participants had TB genotypic and EMR data suitable for analysis, resulting in 46,853 clinical encounters at 338 healthcare facilities. We identified 326 unique overlapping events involving 370 individual patients; 91 (5%) had biologic plausibility for transmission occurring at a healthcare facility. A sensitivity analysis estimated that 3%–8% of transmission may be attributable to healthcare facilities.

Conclusions:

Although effective interventions are critical in reducing individual risk for healthcare workers and patients at healthcare facilities, our findings suggest that development of targeted interventions aimed at community transmission may have a larger impact in reducing TB.

Tuberculosis infection control measures and knowledge in primary health centres in Bandung, Indonesia

Background

Health care workers (HCWs) in low- and middle-income countries (LMICs) continue to have an unacceptably high prevalence and incidence of Mycobacterium tuberculosis infection due to high exposure to tuberculosis (TB) cases at health care facilities and often inadequate infection control measures. This can contribute to an increased risk of transmission not only to HCWs themselves but also to patients and the general population.

Aim

We assessed implementation of TB infection control measures in primary health centres (PHCs) in Bandung, Indonesia, and TB knowledge among HCWs.

Methods

A cross-sectional study was conducted between May and November 2017 amongst a stratified sample of the PHCs, and their HCWs, that manage TB patients in Bandung. Questionnaires were used to assess TB infection control measures plus HCW knowledge. Summary statistics, linear regression and the Kruskal-Wallis test were used for analysis.

Results

The median number of TB infection control measures implemented in 24 PHCs was 21 of 41 assessed. Only one of five management controls was implemented, 15 of 24 administrative controls, three of nine environmental controls and one of three personal respiratory protection controls. PHCs with TB laboratory facilities and high TB case numbers were more likely to implement TB infection control measures than other PHCs (p=0.003). In 398 HCWs, the median number of correct responses for knowledge was 10 (IQR 9-11) out of 11.

Discussion

HCWs had good TB knowledge. TB infection control measures were generally not implemented and need to be strengthened in PHCs to reduce M. tuberculosis transmission to HCWs, patients and visitors.

The burden and predictors of latent tuberculosis infection among immigrants in South Korea: a retrospective cross-sectional study

BACKGROUND

Approximately one-fourth of the global population is latently infected with Mycobacterium tuberculosis. An understanding of the burden of latent tuberculosis infection (LTBI) among immigrants compared with the general Korean population should be the first step in identifying priority groups for LTBI diagnosis and treatment. The study aimed to compute the age-standardized LTBI prevalence and predictors among immigrants with LTBI in South Korea.

METHODS

In 2018, the Korea Disease Control and Prevention Agency implemented a pilot LTBI screening project for immigrants using a chest radiography and the QuantiFERON Gold In-Tube assay. A standardized prevalence ratio (SPR) was computed to compare the LTBI burden in immigrants and the general Korean population.

RESULTS

During the duration of the project, a total of 8108 immigrants (5134 males and 2974 females) underwent LTBI screening. The SPR of 1.547 (95% confidence interval [CI] 1.468-1.629) in males and 1.261 (95% CI 1.177-1.349) in females were both higher than the Korean reference population. Furthermore, among the immigrants, those aged < 40 years and Korean diaspora visa holders had a higher SPR.

CONCLUSION

This study found a higher LTBI prevalence among immigrant population in South Korea compared to that in the general Korean population, and the SPR was higher among those aged < 40 years and the Korean diaspora. The findings can be used as baseline evidence for including immigrants in South Korea in the at-risk group with a priority need for LTBI screening and treatment.

Occupational Risk of Airborne Mycobacterium tuberculosis Exposure: A Situational Analysis in a Three-Tier Public Healthcare System in South Africa

This study aimed to detect airborne Mycobacterium tuberculosis (MTB) at nine public health facilities in three provinces of South Africa and determine possible risk factors that may contribute to airborne transmission. Personal samples (n = 264) and stationary samples (n = 327) were collected from perceived high-risk areas in district, primary health clinics (PHCs) and TB facilities. Quantitative real-time (RT) polymerase chain reaction (PCR) was used for TB analysis. Walkabout observations and work practices through the infection prevention and control (IPC) questionnaire were documented. Statistical analysis was carried out using Stata version 15.2 software. Airborne MTB was detected in 2.2% of samples (13/572), and 97.8% were negative. District hospitals and Western Cape province had the most TB-positive samples and identified risk areas included medical wards, casualty, and TB wards. MTB-positive samples were not detected in PHCs and during the summer season. All facilities reported training healthcare workers (HCWs) on TB IPC. The risk factors for airborne MTB included province, type of facility, area or section, season, lack of UVGI, and ineffective ventilation. Environmental monitoring, PCR, IPC questionnaire, and walkabout observations can estimate the risk of TB transmission in various settings. These findings can be used to inform management and staff to improve the TB IPC programmes.

"If I've got latent TB, I would like to get rid of it": Derivation of the CARD (Constraints, Actions, Risks, and Desires) Framework informed by South African healthcare worker perspectives on latent tuberculosis treatment

BACKGROUND

Healthcare workers (HWs) have at least twice the risk of tuberculosis (TB) compared to the general population. There is growing emphasis on latent TB infection (LTBI) in high-risk populations. Yet we know little about HWs' perspectives of LTBI testing and treatment to inform implementation in high-incidence settings. We developed a qualitative networked approach to analyze HWs' perspectives on LTBI testing and treatment.

METHODS

We conducted 22 in-depth interviews with nurse and physician stakeholders, who had been recruited as part of a larger study evaluating TB transmission risk in HWs at Tygerberg Hospital, Cape Town, South Africa. We performed open coding to identify emergent themes and selective coding to identify relevant text citations. We used thematic analysis to inductively derive the CARD (Constraints, Actions, Risks, Desires) framework.

RESULTS

All HWs desired to avoid developing TB but few felt this was actionable. Despite LTBI knowledge gaps, safety and cost concerns, most HWs reported hypothetical willingness to take LTBI treatment. The CARD framework showed that desire and action related to LTBI testing and treatment was clearly framed by the interactions between constraints, administrative action, and risk. The surprise HWs described on receiving a negative LTBI (Quantiferon-Plus) result suggests LTBI testing may recalibrate HWs' perceptions regarding the futility of actions to reduce their TB risk.

CONCLUSIONS

LTBI testing and treatment are acceptable to HWs and could counteract the perceived inevitability of occupational TB infection that currently may limit risk reduction action. This should be coupled with administrative leadership and infrastructural support. The CARD analytic framework is a helpful tool for implementation scientists to understand current practices within complex health systems. Application of CARD could facilitate the development of contextually-relevant interventions to address important public health problems such as occupational TB.

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

Background

Health 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).

Result

Data 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.

Conclusions

Our 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00433-9.

Classification and regression trees for predicting the risk of a negative test result for tuberculosis infection in Brazilian healthcare workers: a cross-sectional study

OBJECTIVES

Healthcare workers (HCWs) have a high risk of acquiring tuberculosis infection (TBI). However, annual testing is resource-consuming. We aimed to develop a predictive model to identify HCWs best targeted for TBI screening.

METHODOLOGY

We conducted a secondary analysis of previously published results of 708 HCWs working in primary care services in five Brazilian State capitals who underwent two TBI tests: tuberculin skin test and Quantiferon®-TB Gold in-tube. We used a classification and regression tree (CART) model to predict HCWs with negative results for both tests. The performance of the model was evaluated using the receiver operating characteristics (ROC) curve and the area under the curve (AUC), cross-validated using the same dataset.

RESULTS

Among the 708 HCWs, 247 (34.9%) had negative results for both tests. CART identified that physician or a community health agent were twice more likely to be uninfected (probability = 0.60) than registered or aid nurse (probability = 0.28) when working less than 5.5 years in the primary care setting. In cross validation, the predictive accuracy was 68% [95% confidence interval (95%CI): 65 - 71], AUC was 62% (95%CI 58 - 66), specificity was 78% (95%CI 74 - 81), and sensitivity was 44% (95%CI 38 - 50).

CONCLUSION

Despite the low predictive power of this model, CART allowed to identify subgroups with higher probability of having both tests negative. The inclusion of new information related to TBI risk may contribute to the construction of a model with greater predictive power using the same CART technique.

Tuberculosis Screening, Testing, and Treatment of US Health Care Personnel: ACOEM and NTCA Joint Task Force on Implementation of the 2019 MMWR Recommendations

: On May 17, 2019, the US Centers for Disease Control and Prevention and National Tuberculosis Controllers Association issued new Recommendations for Tuberculosis Screening, Testing, and Treatment of Health Care Personnel, United States, 2019, updating the health care personnel-related sections of the Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, 2005. This companion document offers the collective effort and experience of occupational health, infectious disease, and public health experts from major academic and public health institutions across the United States and expands on each section of the 2019 recommendations to provide clarifications, explanations, and considerations that go beyond the 2019 recommendations to answer questions that may arise and to offer strategies for implementation.

A 2019 Update on Occupational Lung Diseases: A Narrative Review

Occupational lung diseases (OLDs) are caused, aggravated or exacerbated by exposures at the workplace. OLDs encompass a wide range of respiratory diseases similar to that found outside the work environment. Occupational asthma is the most commonly diagnosed OLD. Other OLDs may include acute and chronic conditions, ranging from hypersensitivity pneumonitis to chronic obstructive pulmonary disease (COPD) to pulmonary fibrosis. Historically, research into OLDs has centered on diseases resulting from exposures relevant to high-income countries and more obvious hazardous occupations, such as silicosis in coal miners. Peer-reviewed publications in 2019 have broadened the focus to include low- and middle-income countries and once-overlooked occupations such as dry cleaning and animal husbandry. Technological advances and greater understanding of disease etiology have allowed researchers and clinicians to implement improved risk analysis, screening and mitigation strategies to not only treat disease once it occurs, but to identify at-risk populations and institute protections to prevent or limit the negative impacts of workplace hazards. As recognition of OLDs as a worldwide threat in a variety of occupations increases, research is allowing for the development of better treatments and preventive measures that advance workers' rights and ensure their continued good health.

Utility of the Interferon-Gamma Release Assay for Latent Tuberculosis Infection Screening among Indian Health-Care Workers

Background

The utility of interferon-gamma release assays (IGRAs) for latent tuberculosis infection (LTBI) screening among health-care workers (HCWs) in low- and middle-income countries (LMICs) remains unclear.

Methods

This was a prospective cohort study among HCW trainees undergoing annual LTBI screening via tuberculin skin test (TST) and QuantiFERON^® TB Gold Test-in-tube (QFT-GIT) in Pune, India. TST induration ≥ 10 mm and QFT-GIT ≥ 0.35 IU/ml were considered positive. Test concordance was evaluated at entry among the entire cohort and at 1 year among baseline TST-negative participants with follow-up testing. Overall test agreement was evaluated at both timepoints using the kappa statistic: fair (k < 0.40), good (0.41 ≥ k ≤0.60), or strong (k > 0.60).

Results

Of 200 participants, prevalent LTBI was detected in 42 (21%) via TST and 45 (23%) via QFT-GIT; QFT-GIT was positive in 27/42 (64%) TST-positive and 18/158 (11%) TST-negative trainees. Annual TST conversion was 28% (40/142) and included 11 trainees with baseline TST-/IGRA+; QFT-GIT was positive in 17/40 (43%) TST-positive and 5/102 (5%) TST-negative trainees. Overall test concordance was 84% (k = 0.52; 95% confidence interval [CI]: 0.38-0.66) and 80% (k = 0.44; 95% CI: 0.29-0.59) at baseline and 12 months, respectively.

Conclusions

We observed good overall agreement between TST and QFT-GIT, and QFT-GIT detected additional LTBI cases among TST-negative trainees with possible early detection of LTBI conversion. Overall, our results support the use of IGRA for annual LTBI screening among HCWs in a high burden LMIC setting.

Validity and Reliability of Self-Assessment Tool for Risk Prioritization Following Exposure to Tuberculosis in a Hospital Setting

The Modified Self-Assessment (MSA) and Present Self-Assessment (PSA) forms are questionnaires used to prioritize the risk of infection of health workers exposed to tuberculosis (TB) in Srinagarind Hospital in Thailand. As MSA was developed from PSA, the validity and reliability of MSA need to be assessed. The research aim is to examine the content validity of MSA and to assess the respective reliability of MSA and PSA vis-à-vis expert opinion. Seven experts determined the content validity index (CVI) of MSA. MSA and PSA were used to prioritize the TB contact of 108 subjects, and we compared the result with the risk assessed by the experts. The respective Kappa agreements between MSA and PSA and the experts were used to assess reliability. The result of the content validity index revealed that MSA had I-CVI > 0.83 for all questions and an S-CVI/Ave above 0.90 for all factors. The Kappa agreement of contact priority between MSA and the experts was 0.80; it was 0.58 between PSA and the experts. MSA can, thus, be used to prioritize contact with tuberculosis in Srinagarind Hospital. MSA is a valid risk communication tool for aerosol-generating procedures. Further study should be conducted in other hospitals, and the number of participants should be increased in order to come to a concrete result.

High risk of Mycobacterium tuberculosis infection among medical and nursing students in Indonesia: a 1-year prospective study

BACKGROUND

Medical and nursing students entering their clinical programmes are at increased risk for tuberculosis (TB) in TB-endemic settings. Relatively little is known about Mycobacterium tuberculosis infection among such students in high-endemic countries.

METHODS

We examined M. tuberculosis infection among medical and nursing students starting clinical training in Bandung, Indonesia using interferon-γ release assay (IGRA) QuantiFERON-TB Gold Plus. IGRA-negative students had a repeat test after 1 y and logistic regression was used to identify factors associated with IGRA positivity or conversion.

RESULTS

There were 379 students included in this study: 248 (65.4%) were medical students and 131 (34.6%) were nursing students. Of 379 students, 70 (18.5%) were IGRA positive at baseline. Of 293 IGRA-negative students with 1-y results, 26 (8.9%) underwent IGRA conversion. Being a medical student (adjusted relative risk [ARR] 5.15 [95% confidence interval {CI} 1.82 to 14.59], p=0.002) and participation in sputum collection or bronchoscopy were associated with IGRA conversion (ARR 2.74 [95% CI 1.29 to 5.79], p=0.008).

CONCLUSIONS

Medical and nursing students entering clinical training are at high risk of M. tuberculosis infection and need improved infection prevention and control strategies.

Serial testing of health care workers for tuberculosis infection: A prospective cohort study

Health Care Workers (HCW) may have an occupational risk of latent tuberculosis infection (LTBI) and TB disease. The objective of this study was to evaluate the performance of the 2-step strategy: tuberculin skin test (TST) followed by confirmation with Interferon (IFN)-γ- release assays (IGRAs) in HCW. A secondary objective was to determine the factors related to conversions and reversions. HCW at risk of occupational exposure who attended the Occupational Department of the Hospital Germans Trias i Pujol were included during the study period (2013-2016). All professionals testing negative for LTBI were included in a cohort study. These workers were followed up with the administration of a TST and an IGRA quantification at least one year after inclusion in the study. Workers with positive TST, regardless of the results of the IGRA tests, were followed-up with an IGRA. 255 workers were enrolled in the study and 108 workers from the same cohort were followed up. During the follow-up period, seven workers presented TST test conversion. One of these conversions was also confirmed by an IGRA test. There were 2 conversions of cases only testing positive with the IGRA. There have been only 2 reversions of cases testing negative with the IGRA. In this study, not all TST conversions were confirmed when using the IGRA test, which highlights the importance of the 2-step strategy. We have detected a low number of conversions and reversions. Our conclusions should be confirmed in studies with a longer follow-up time.

Risk Analysis of Latent Tuberculosis Infection among Health Workers Compared to Employees in Other Sectors

Latent tuberculosis infection (LTBI) represents a work-related risk for health workers (HWs). Tuberculosis remains the second most common occupational infectious disease among HWs in Germany. Comparative figures on LTBI prevalence in the general population are missing because testing is only carried out in the context of an outbreak situation. The objective of this study is to investigate whether HWs are at greater risk of LTBI than workers in other sectors. This study is based on two samples. The first sample is a database of HWs who were examined by the German Occupational Physicians Network using an interferon-gamma release assay (IGRA). The second sample consists of general employees (non-health workers, non-HWs) from Hamburg who had no professional contact with the health care system. Propensity score matching (PS matching) was performed to ensure better comparability of the groups. The differences in the prevalence of positive test results from IGRAs were examined using univariate and multivariate analyses. After the PS matching of 1:10, 100 test subjects in the non-HW group and 1000 HWs remained to form the analysis collective. The HWs tended to exhibit higher IGRA values than non-HWs. The univariate analysis showed an odds ratio (OR) of 3.86 for the HWs (95% confidence interval (CI): 0.99 to 32.5; p = 0.056) with respect to a positive test result. The multivariate analysis produced an OR of 4.92, (95% CI: 1.3 to 43.7; p = 0.013) for HWs born in Germany. Despite the declining tuberculosis incidence rates in Germany, a comparison with non-exposed professional groups showed that HWs are at greater risk of LTBI. Preventive medical check-ups still seem to be indicated.

Current Guidelines for Protecting Health Workers from Occupational Tuberculosis Are Necessary, but Not Sufficient: Towards a Comprehensive Occupational Health Approach

Health workers globally are at elevated occupational risk of tuberculosis infection and disease. While a raft of guidelines have been published over the past 25 years on infection prevention and control (IPC) in healthcare, studies in different settings continue to show inadequate implementation and persistence of risk. The aim of this commentary is to argue, based on the literature and our own research, that a comprehensive occupational health approach is an essential complement to IPC guidelines. Such an approach includes a health system framework focusing on upstream or mediating components, such as a statutory regulation, leadership, an information system, and staff trained in protective disciplines. Within the classical prevention framework, primary prevention needs to be complemented by occupational health services (secondary prevention) and worker's compensation (tertiary prevention). A worker-centric approach recognises the ethical implications of screening health workers, as well as the stigma perceived by those diagnosed with tuberculosis. It also provides for the voiced experience of health workers and their participation in decision-making. We argue that such a comprehensive approach will contribute to both the prevention of occupational tuberculosis and to the ability of a health system to withstand other crises of infectious hazards to its workforce.

Prevalence of positive TST among healthcare workers in high-burden TB setting in Peru

Background

Tuberculosis (TB) transmission has long been recognized as an important occupational hazard for healthcare workers (HCWs). HCWs have a 5.8% annual risk of exposure and three times greater risk of developing active TB than the general population.

Methods

We conducted an observational cross-sectional study between September 2014 and March 2015 among HCWs in a high-burden TB setting in Lima to estimate the prevalence of positive Tuberculin Skin Test (TST) and to investigate factors associated with a positive TST.

Results

Two hundred forty participants were included in the analysis; TST was administered to 190 (79.2%) while the rest were exempt due to a previous positive TST result, history of TB, or test refusal. A positive TST result was found among 56.2% of participants to whom the TST was applied (95% CI: 49.22–63.55%). When considering those who had a previous positive TST result and those with a history of TB, the prevalence of a positive TST result was 64.3% (95% CI: 57.8–70.3%). No significant differences were observed between clinical/paramedical and administrative staff in the health center. The use of N95 masks during work hours was reported by 142 (69.9%) participants. Prevalence ratios (PR) show that workers with more than 120 months as a HCW were 1.44 times more likely to be TST positive. The multivariate analysis found that HCWs with over 10 years of service were 1.52 times more likely to be TST positive.

Conclusion

This study supports previous reports that TB infection is an occupational hazard for HCWs. Prevention of TB transmission through control measures, as well as timely diagnosis of LTBI in this particular high-risk group, is critical for individual and public health.

Awareness and perspectives on expansion of latent TB management among public-sector physicians and medical trainees in Delhi, India

More than one in two healthcare workers (HCWs) in developing countries have latent tuberculosis infection (LTBI), an asymptomatic condition signifying persistent tubercular infection in absence of disease.

OBJECTIVE

to evaluate the physician attitude towards LTBI preventive therapy and their perspectives regarding the potential expansion of latent TB management under the RNTCP.

MATERIAL AND METHODS

We conducted a cross-sectional analysis among 60 participants of a continuing medical education program during October' 2019 in a medical college in Delhi, India.

RESULTS

We enrolled a total of 30 medical officers, 15 resident doctors and 15 medical interns, comprising 27 (45%) males and 33 (55%) females. Only 9 (15%) participants were aware of existing RNTCP guidelines for programmatic management of LTBI. The median (IQR) self-rated willingness of the participants in receiving treatment for LTBI after confirmation of diagnosis on a 10 point continuous rating scale was 6 (5.8). The principal reason attributed to the treatment hesitancy were concerns over drug side effects 19 (31.7%), emergence of drug resistance 11 (18.3%) and the likelihood of reinfection 4 (6.7%). Support for expansion of preventive therapy among household TB contacts was varied, with maximum (41.2%) participants wanting it only for the comorbid patients.

CONCLUSION

LTBI preventive treatment is associated with considerable side effects and lack of long-term benefits by a majority of Indian physicians despite significant personal health concerns in treating pulmonary TB cases.

Perceived Health System Barriers to Tuberculosis Control Among Health Workers in South Africa

Background

The healthcare workforce in high tuberculosis burden countries such as South Africa is at elevated risk of tuberculosis infection and disease with adverse consequences for their well-being and productivity. Despite the availability of international guidelines on protection of health workers from tuberculosis, research globally has focused on proximal deficiencies in practice rather than on health system barriers.

Objective

This study sought to elicit perceptions of informed persons within the health system regarding health system barriers to protecting health workers from tuberculosis.

Methods

Semi-structured interviews were conducted with 18 informants active in spheres related to workplace tuberculosis prevention and management in South Africa. Interviews were audio recorded and transcribed verbatim, validated and analysed to derive emergent themes. Responses were analysed using the World Health Organization building blocks as core elements of a health system bearing on protection of its health workforce.

Findings

The following health system barriers were identified by informants: leadership and governance were "top-down" and fragmented; lack of funding was a major barrier; there were insufficient numbers of staff trained in infection prevention and control and occupational health; occupational health services were not comprehensively available and the ability to sustain protective technologies was questioned. A cross-cutting barrier was lack of priority afforded to workforce occupational health associated with lack of accurate information on cases of TB among health workers.

Conclusions

We conclude that deficiencies in implementation of recommended infection control and tuberculosis management practices are unlikely to be corrected until health system barriers are addressed. More committed leadership from senior health system management and greater funding are needed. The process could be assisted by the development of indicators to characterise such barriers and monitor progress.

Risk of Occupational Latent Tuberculosis Infection among Health Personnel Measured by Interferon-Gamma Release Assays in Low Incidence Countries-A Systematic Review and Meta-Analysis

Healthcare workers (HCWs) have increased risk for latent tuberculosis infection (LTBI) and tuberculosis (TB) disease due to their occupational exposure. For some years now, interferon-γ release assays (IGRAs) have replaced the tuberculin skin test for the diagnosis of LTBI in many countries. This review examined the occupational risk of LTBI in HCWs with IGRA testing in low incidence countries. A systematic review and meta-analysis of studies from 2005 onwards provide data regarding the prevalence of LTBI in HCWs. In addition, the pooled effect estimates were calculated for individual regions and occupational groups. 57 studies with 31,431 HCWs from four regions and a total of 25 countries were analysed. The prevalence of LTBI varied from 0.9 to 85.5%. The pooled estimation found the lowest prevalence of LTBI for North American and West Pacific countries (<5%), and the highest prevalence for Eastern Mediterranean countries (19.4%). An increased risk for LTBI was found only for administrative employees. Studies on the occupational risk of LTBI continue to show increased prevalence of HCWs, even in low-incidence countries. Good quality studies will continue to be needed to describe occupational exposure.

Is latent tuberculosis infection challenging in Iranian health care workers? A systematic review and meta-analysis

Background

The high chances of getting latent tuberculosis infection (LTBI) among health care workers (HCWs) will an enormous problem in low and upper-middle-income countries.

Method

Search strategies were done through both national and international databases include SID, Barakat knowledge network system, Irandoc, Magiran, Iranian national library, web of science, Scopus, PubMed/MEDLINE, OVID, EMBASE, the Cochrane library, and Google Scholar search engine. The Persian and the English languages were used as the filter in national and international databases, respectively. Medical Subject Headings (MeSH) terms was used to controlling comprehensive vocabulary. The search terms were conducted without time limitation till January 01, 2019.

Results

The prevalence of LTBI in Iranian’s HCWs, based on the PPD test was 27.13% [CI95%: 18.64–37.7]. The highest prevalence of LTBI in Iranian’s HCWs were estimated 41.4% [CI95%: 25.4–59.5] in the north, and 33.8% [CI95%: 21.1–49.3] in the west. The lowest prevalence of LTBI was evaluated 18.2% [CI95%: 3.4–58.2] in the south of Iran. The prevalence of LTBI in Iranian’s HCWs who had work-experience more than 20 years old were estimated 20.49% [CI95%: 11–34.97]. In the PPD test, the prevalence of LTBI in Iranian’s HCWs who had received the Bacille Calmette–Guérin (BCG) was estimated 15% [CI95%: 3.6–47.73]. While, in the QFT, the prevalence of LTBI in Iranian’s HCWs in non-vaccinated was estimated 25.71% [CI95%: 13.96–42.49].

Conclusions

This meta-analysis shows the highest prevalence of LTBI in Iranian’s HCWs in the north and the west probably due to neighboring countries like Azerbaijan and Iraq, respectively. It seems that Iranian’s HCWs have not received the necessary training to prevent of TB. We also found that BCG was not able to protect Iranian’s HCWs from TB infections, completely.

The global prevalence of latent tuberculosis: a systematic review and meta-analysis

In 1999, the World Health Organization (WHO) estimated that one-third of the world's population had latent tuberculosis infection (LTBI), which was recently updated to one-fourth. However, this is still based on controversial assumptions in combination with tuberculin skin test (TST) surveys. Interferon-γ release assays (IGRAs) with a higher specificity than TST have since been widely implemented, but never used to estimate the global LTBI prevalence.We conducted a systematic review and meta-analysis of LTBI estimates based on both IGRA and TST results published between 2005 and 2018. Regional and global estimates of LTBI prevalence were calculated. Stratification was performed for low, intermediate and high TB incidence countries and a pooled estimate for each area was calculated using a random effects model.Among 3280 studies screened, we included 88 studies from 36 countries with 41 IGRA (n=67 167) and 67 TST estimates (n=284 644). The global prevalence of LTBI was 24.8% (95% CI 19.7-30.0%) and 21.2% (95% CI 17.9-24.4%), based on IGRA and a 10-mm TST cut-off, respectively. The prevalence estimates correlated well to WHO incidence rates (Rs=0.70, p<0.001).In the first study of the global prevalence of LTBI derived from both IGRA and TST surveys, we found that one-fourth of the world's population is infected. This is of relevance, as both tests, although imperfect, are used to identify individuals eligible for preventive therapy. Enhanced efforts are needed targeting the large pool of latently infected individuals, as this constitutes an enormous source of potential active tuberculosis.

The high-quality health system 'revolution': Re-imagining tuberculosis infection prevention and control

The Lancet Commission on High-Quality Health Systems called for a 'revolution' in the quality of care provided in low- and middle-income countries. We argue that this provides a helpful framework to demonstrate how effective tuberculosis infection prevention and control (TB IPC) implementation should be linked with health system strengthening, moving it from the silo of the national TB programmes. Using this framework, we identify and discuss links between TB IPC implementation and patient safety, human resources for health, prioritising person-centred care, building trust in health systems and refining the tools used to measure TB IPC implementation. Prioritising patient experience has been a recent addition to the definition of high-quality care. In high TB burden settings, the encounter with TB IPC measures may be a TB patient's initial contact with the healthcare system and may cause feelings of stigmatisation. We advocate for re-imagining the way we implement TB IPC, by drawing on the principles of person-centred care through incorporating the experiences of people using healthcare services. Health workers who developed occupational TB also offer a unique perspective: they have both experienced TB IPC and have played a role in implementing it in their workplace. They can be powerful advocates for person-centred TB IPC implementation. Through framing TB IPC as part of health system strengthening and consciously including person-centred perspectives in TB IPC design, measurement and guidelines, we hope to influence future TB IPC research and practice.

Evaluating Latent Tuberculosis Infection Test Performance Using Latent Class Analysis in a TB and HIV Endemic Setting

BACKGROUND

Given the lack of a gold standard for latent tuberculosis infection (LTBI) and paucity of performance data from endemic settings, we compared test performance of the tuberculin skin test (TST) and two interferon-gamma-release assays (IGRAs) among health-care workers (HCWs) using latent class analysis. The study was conducted in Cape Town, South Africa, a tuberculosis and human immunodeficiency virus (HIV) endemic setting Methods: 505 HCWs were screened for LTBI using TST, QuantiFERON-gold-in-tube (QFT-GIT) and T-SPOT.TB. A latent class model utilizing prior information on test characteristics was used to estimate test performance.

RESULTS

LTBI prevalence (95% credible interval) was 81% (71-88%). TST (10 mm cut-point) had highest sensitivity (93% (90-96%)) but lowest specificity (57%, (43-71%)). QFT-GIT sensitivity was 80% (74-91%) and specificity 96% (94-98%), and for TSPOT.TB, 74% (67-84%) and 96% (89-99%) respectively. Positive predictive values were high for IGRAs (90%) and TST (99%). All tests displayed low negative predictive values (range 47-66%). A composite rule using both TST and QFT-GIT greatly improved negative predictive value to 90% (range 80-97%).

CONCLUSION

In an endemic setting a positive TST or IGRA was highly predictive of LTBI, while a combination of TST and IGRA had high rule-out value. These data inform the utility of LTBI-related immunodiagnostic tests in TB and HIV endemic settings.

Tuberculosis infection risk, preventive therapy care cascade and incidence of tuberculosis disease in healthcare workers at Maputo Central Hospital

BACKGROUND

Mozambican healthcare workers have high rates of latent and active tuberculosis, but occupational screening for tuberculosis is not routine in this setting. Furthermore, the specificity of tuberculin skin testing in this population compared with interferon gamma release assay testing has not been established.

METHODS

This study was conducted among healthcare workers at Maputo Central Hospital, a public teaching quaternary care hospital in Mozambique. With a cross sectional study design, risk factors for tuberculosis were assessed using multivariable logistic regression. The care cascade is reported for participants who were prescribed six months of isoniazid preventive therapy for HIV or highly reactive testing for latent tuberculosis infection. The agreement of interferon-gamma release assay results with positive tuberculin skin testing was calculated.

RESULTS

Of 690 screened healthcare workers, three (0.4%) had active tuberculosis and 426 (61.7%) had latent tuberculosis infection. Less education, age 35-49, longer hospital service, and work in the surgery department were associated with increased likelihood of being tuberculosis infected at baseline (p < 0.05). Sex, Bacillus Calmette-Guerin vaccination, HIV, outside tuberculosis contacts, and professional category were not. Three new cases of active tuberculosis developed during the follow-up period, two while on preventive therapy. Among 333 participants offered isoniazid preventive therapy, five stopped due to gastrointestinal side effects and 181 completed treatment. For HIV seropositive individuals, the agreement of interferon gamma release assay positivity with positive tuberculin skin testing was 50% among those with a quantitative skin test result of 5-10 mm, and among those with a skin test result ≥10 mm it was 87.5%. For HIV seronegative individuals, the agreement of interferon gamma release assay positivity with a tuberculin skin test result of 10-14 mm was 63.6%, and for those with a quantitative skin test result ≥15 mm it was 82.2%.

CONCLUSIONS

There is a high prevalence of tuberculosis infected healthcare workers at Maputo Central Hospital. The surgery department was most heavily affected, suggesting occupational risk. Isoniazid preventive therapy initiation was high and just over half completed therapy. An interferon gamma release assay was useful to discern LTBI from false positives among those with lower quantitative tuberculin skin test results.