Targeted tuberculin testing and treatment of latent tuberculosis infection. This official statement of the American Thoracic Society was adopted by the ATS Board of Directors, July 1999. This is a Joint Statement of the American Thoracic Society (ATS) and the Centers for Disease Control and Prevention (CDC). This statement was endorsed by the Council of the Infectious Diseases Society of America. (IDSA), September 1999, and the sections of this statement

Pulmonary Immunocompromise in Chronic and High-dose Steroid Therapy

Glucocorticoid (GC) use is often the mainstay of treatment in many pulmonary, autoimmune, allergic, and oncologic diseases, along with organ transplantation. Short-term and long-term GC use is estimated to be around 1% to 2% worldwide. It has been associated with significant infectious complications such as streptococcus and influenza, mycobacterial infections, and opportunistic infections, specifically Pneumocystis pneumonia, invasive fungal infections, and strongyloidiasis. It is important to use minimal effective dose for the shortest duration to minimize complications. This review summarizes the prevalence of steroid prescriptions, mechanisms, manifestations, and mitigation strategies of pulmonary immunocompromise in patients on chronic and high-dose steroid therapies.

Tuberculosis in the US Kidney Failure Population

Background:

People with chronic kidney disease (CKD) have a higher risk for progression to tuberculosis disease following infection with Mycobacterium tuberculosis. We produced a nationwide incidence estimate and description of tuberculosis among people with kidney failure.

Methods:

We completed a cross-sectional descriptive analysis of people with a reported case of tuberculosis in the United States between 2010 and 2021. We stratified all people with tuberculosis by reported kidney failure status. The primary outcome was tuberculosis incidence among people with kidney failure. We also compared characteristics of people with tuberculosis by reported kidney failure status.

Results:

Approximately 3% of people (2,892 of 111,155) diagnosed with tuberculosis between 2010 and 2021 also had kidney failure. Annual tuberculosis incidence ranged from 26.1 to 45.4 per 100,000 people with kidney failure and 2.1 to 3.5 per 100,000 people without kidney failure. Among people with kidney failure, 924 (32%) had extrapulmonary tuberculosis only, and nearly 40% died: 286 were diagnosed with tuberculosis after death, and 792 died during treatment. People with tuberculosis and kidney failure had approximately twice the prevalence of a false-negative tuberculin skin test result (39%) compared to people with tuberculosis alone (20%).

Conclusions:

Tuberculosis incidence among people with kidney failure between 2010 and 2021 in the United States was 10-fold that among people without kidney failure.

Diagnosis and Treatment of Latent Tuberculosis Infection in Adults in South Korea

Latent tuberculosis infection (LTBI) is characterized by immune responses to Mycobacterium tuberculosis antigens without clinical symptoms or evidence of active tuberculosis. Effective LTBI management is crucial for tuberculosis elimination, requiring accurate diagnosis and treatment. In South Korea, LTBI guidelines have been updated periodically, the latest being in 2024. This review discusses the recent changes in the Korean guideline for the diagnosis and treatment of LTBI in adults.

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.

A multistage Sendai virus vaccine incorporating latency-associated antigens induces protection against acute and latent tuberculosis

One-quarter of the world's population is infected with Mycobacterium tuberculosis (Mtb). After initial exposure, more immune-competent persons develop asymptomatic latent tuberculosis infection (LTBI) but not active diseases, creates an extensive reservoir at risk of developing active tuberculosis. Previously, we constructed a novel recombinant Sendai virus (SeV)-vectored vaccine encoding two dominant antigens of Mtb, which elicited immune protection against acute Mtb infection. In this study, nine Mtb latency-associated antigens were screened as potential supplementary vaccine candidate antigens, and three antigens (Rv2029c, Rv2028c, and Rv3126c) were selected based on their immune-therapeutic effect in mice, and their elevated immune responses in LTBI human populations. Then, a recombinant SeV-vectored vaccine, termed SeV986A, that expresses three latency-associated antigens and Ag85A was constructed. In murine models, the doses, titers, and inoculation sites of SeV986A were optimized, and its immunogenicity in BCG-primed and BCG-naive mice were determined. Enhanced immune protection against the Mtb challenge was shown in both acute-infection and latent-infection murine models. The expression levels of several T-cell exhaustion markers were significantly lower in the SeV986A-vaccinated group, suggesting that the expression of latency-associated antigens inhibited the T-cell exhaustion process in LTBI infection. Hence, the multistage quarter-antigenic SeV986A vaccine holds considerable promise as a novel post-exposure prophylaxis vaccine against tuberculosis.

Immune correlates of protection as a game changer in tuberculosis vaccine development

The absence of validated correlates of protection (CoPs) hampers the rational design and clinical development of new tuberculosis vaccines. In this review, we provide an overview of the potential CoPs in tuberculosis vaccine research. Major hindrances and potential opportunities are then discussed. Based on recent progress, it is reasonable to anticipate that success in the ongoing efforts to identify CoPs would be a game-changer in tuberculosis vaccine development.

Isoniazid-historical development, metabolism associated toxicity and a perspective on its pharmacological improvement

Despite the extraordinary anti-tubercular activity of isoniazid (INH), the drug-induced hepatotoxicity and peripheral neuropathy pose a significant challenge to its wider clinical use. The primary cause of INH-induced hepatotoxicity is in vivo metabolism involving biotransformation on its terminal -NH2 group owing to its high nucleophilic nature. The human N-acetyltransferase-2 enzyme (NAT-2) exploits the reactivity of INH's terminal -NH2 functional group and inactivates it by transferring the acetyl group, which subsequently converts to toxic metabolites. This -NH2 group also tends to react with vital endogenous molecules such as pyridoxine, leading to their deficiency, a major cause of peripheral neuropathy. The elevation of liver functional markers is observed in 10%-20% of subjects on INH treatment. INH-induced risk of fatal hepatitis is about 0.05%-1%. The incidence of peripheral neuropathy is 2%-6.5%. In this review, we discuss the genesis and historical development of INH, and different reported mechanisms of action of INH. This is followed by a brief review of various clinical trials in chronological order, highlighting treatment-associated adverse events and their occurrence rates, including details such as geographical location, number of subjects, dosing concentration, and regimen used in these clinical studies. Further, we elaborated on various known metabolic transformations highlighting the involvement of the terminal -NH2 group of INH and corresponding host enzymes, the structure of different metabolites/conjugates, and their association with hepatotoxicity or neuritis. Post this deliberation, we propose a hydrolysable chemical derivatives-based approach as a way forward to restrict this metabolism.

Tuberculin skin test repetition after TNF-α inhibitors in patients with chronic inflammatory arthritis: a long-term retrospective cohort in endemic area

OBJECTIVES

To evaluate the tuberculin skin test (TST) conversion in chronic inflammatory arthropathies (CIA) patients on TNFα inhibitors (TNFi) and without previous latent tuberculosis infection (LTBI) treatment.

METHODS

Patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) with negative LTBI were retrospectively evaluated for TST conversion and active tuberculosis (TB) after six months of exposition to TNFi. Two groups were compared: patients who repeated TST (TST-repetition) during the follow-up and patients who did not (non-TST-repetition).

RESULTS

A total of 355 CIA patients on TNFi were screened and 138 (38.9%) did not fulfill the inclusion criteria. Of the remaining 217 CIA patients, 81 (37.3%) repeated TST during TNFi treatment. TST conversion rate was observed in 18 (22.2%) patients without significant differences among CIA (p = 0.578). The number of TB cases was low (n = 10; 4.6%) and was similar in TST-repetition and non-TST-repetition groups [2 (2.5%) vs. 8 (5.9%), p = 0.328]. Of note, 30% of active TB occurred early (6-12 months of TNFi exposure) and the median (full range) time to incident TB was 1.3 (0.6-10.6) years, whereas the median (full range) time to TST repetition was later [3.3 (0.5-13.4) years]. The incidence of active TB was lower among RA patients than AS patients [342 (95% CI 41 - 1446) vs. 1.454 (95% CI 594-2993)/100,000 patient-years, p = 0.049].

CONCLUSION

These results indicate that TST repetition is associated with a high conversion rate, suggesting the need for recommended treatment. The delayed repetition of TST and low number of active TB cases hampered the evaluation of this strategy effectiveness to prevent active infection. Larger studies with systematic repetition patterns are necessary. In addition, the study highlights the need for a greater surveillance for TB in AS patients.

Giant lung cavity due to three different pathogens in a patient receiving inhaled salmeterol plus fluticasone propionate for asthma

INTRODUCTION

High-dose and long-term use of inhaled corticosteroids may cause systemic and local side effects such as opportunistic infections. Here we report a patient with asthma who developed a giant cavity in the lung while using inhaled salmeterol plus fluticasone propionate.

CASE STUDY

A 57-year-old female patient presented with a three-week history of cough, hemoptysis, and dyspnea. She had a diagnosis of asthma for 4 years and was using an inhaled salmeterol plus fluticasone treatment intermittently for 2 years. A giant cavity was detected in the patient's chest X-ray. As a result of further investigations, three different microorganisms were isolated from the samples of sputum, bronchial lavage and lung biopsy.

RESULTS

Staphylococcus aureus was the first microorganism that was isolated from the sputum and the bronchial lavage. Afterwards, Candida albicans was detected in both the bronchial lavage fluid and the histologic examination of the tissue samples obtained by percutaneous lung biopsy. Appropriate antibiotics and antifungals were prescribed. Moderate clinical and radiological response to the treatment was obtained. During the outpatient follow-up, Mycobacterium tuberculosis growth which was sensitive to all of the major anti-tuberculosis drugs was reported in the mycobacterial culture, and the patient was started on anti-tuberculosis treatment.

CONCLUSION

Tuberculosis and other opportunistic infections are a potential consequences of inhaled corticosteroids. Clinicians overseeing such patients need to be vigilant about the need for timely investigations about tuberculosis before and during prescribing medications containing inhaled corticosteroids.

Latent tuberculosis diagnostics: current scenario and review

This review presents a comprehensive examination of the contemporary landscape pertaining to latent tuberculosis infection (LTBI) diagnostics, with a particular emphasis on the global ramifications and the intricacies surrounding LTBI diagnosis and treatment. It accentuates the imperative of bolstering diagnostic, preventive, and treatment modalities for tuberculosis (TB) to fulfill the ambitious targets set forth by the World Health Organization aimed at reducing TB-related mortalities and the incidence of new TB cases. The document underscores the significance of addressing LTBI as a means of averting the progression to active TB, particularly in regions burdened with high TB prevalence, such as India. An in-depth analysis of the spectrum delineating latent and active TB disease is provided, elucidating the risk factors predisposing individuals with LTBI to progress towards active TB, including compromised immune functionality, concurrent HIV infection, and other immunosuppressive states. Furthermore, the challenges associated with LTBI diagnosis are elucidated, encompassing the absence of a definitive diagnostic assay, and the merits and demerits of tuberculin skin testing (TST) and interferon-γ release assays (IGRAs) are expounded upon. The document underscores the necessity of confronting these challenges and furnishes a meticulous examination of the advantages and limitations of TST and IGRAs, along with the intricacies involved in interpreting their outcomes across diverse demographics and settings. Additionally, attention is drawn towards the heritability of the interferon-γ response to mycobacterial antigens and the potential utility of antibodies in LTBI diagnosis.

Incidence and risk factors of active tuberculosis among older individuals with latent tuberculosis infection: a cohort study in two high-epidemic sites in eastern China

Background

The influencing factors of the process from latent tuberculosis infection (LTBI) to the onset of active tuberculosis (TB) remain unknown among different population groups, especially among older individuals in high-incidence areas. This study aimed to investigate the development of active TB among older adults with LTBI and identify groups in greatest need of improved prevention and control strategies for TB.

Methods

In 2021, we implemented an investigation among older individuals (≥ 65 years old) in two towns in Zhejiang Province with the highest incidence of TB. All participants underwent assessment using standardized questionnaires, physical examinations, interferon-gamma release assays, and chest radiography. All the participants with suspected TB based on the clinical symptoms or abnormal chest radiography results, as well as those with LTBI, were referred for diagnostic investigation in accordance with the national guidelines. Those with an initial diagnosis of TB were then excluded, whereas those with LTBI were included in a follow-up at baseline. Incident patients with active TB were identified from the Chinese Tuberculosis Management Information System, and a multivariate Cox regression model was used to estimate the incidence and risk of TB among those with LTBI.

Results

In total, 667 participants with LTBI were followed up for 1,315.3 person-years, revealing a disease density of 1,292.5 individuals/100,000 person-years (17/1,315.3). For those with LTBI, chest radiograph abnormalities had adjusted hazard ratios for active TB of 4.9 (1.6-15.3).

Conclusions

The presence of abnormal chest radiography findings increased the risk of active TB among older individuals with LTBI in high-epidemic sites in eastern China.

Natural products in anti-tuberculosis host-directed therapy

Given that the disease progression of tuberculosis (TB) is primarily related to the host's immune status, it has been gradually realized that chemotherapy that targets the bacteria may never, on its own, wholly eradicate Mycobacterium tuberculosis, the causative agent of TB. The concept of host-directed therapy (HDT) with immune adjuvants has emerged. HDT could potentially interfere with infection and colonization by the pathogens, enhance the protective immune responses of hosts, suppress the overwhelming inflammatory responses, and help to attain a state of homeostasis that favors treatment efficacy. However, the HDT drugs currently being assessed in combination with anti-TB chemotherapy still face the dilemmas arising from side effects and high costs. Natural products are well suited to compensate for these shortcomings by having gentle modulatory effects on the host immune responses with less immunopathological damage at a lower cost. In this review, we first summarize the profiles of anti-TB immunology and the characteristics of HDT. Then, we focus on the rationale and challenges of developing and implementing natural products-based HDT. A succinct report of the medications currently being evaluated in clinical trials and preclinical studies is provided. This review aims to promote target-based screening and accelerate novel TB drug discovery.

Accuracy of QuantiFERON in active tuberculosis suspects with comorbidities and nontuberculous mycobacterial infection in Northern California

The QuantiFERON-TB Gold (QFT) is routinely utilized in North American health systems to detect a cellular immune response to Mycobacterium tuberculosis antigens in symptomatic and asymptomatic patients. The sensitivity of QFT in tuberculosis (TB) patients with comorbidities is not well established and the specificity of QFT in patients with nontuberculous mycobacteria (NTM) infections is incompletely understood. Between 2012 and 2023, all patients with culture-positive TB and patients with NTM infection per the expert diagnostic guidelines or biopsy-proven NTM infection who had a concurrent QFT test were included in this study. The sensitivity and specificity of QFT were measured in TB and NTM patients, respectively. In 109 patients with active TB, the overall sensitivity of QFT was 78.0% (85/109; 95% CI: 70.1, 85.7). The sensitivity was 86.0% (49/57; 95% CI: 76.6, 94.8) and 69.2% (36/52; 95% CI: 56.7, 81.8) in immunocompetent and immunocompromised patients, respectively. The overall specificity of QFT in 88 patients with NTM infection was 76.1% (67/88; 95% CI: 67.2, 85.0). After the exclusion of 17 NTM patients with risk factors for latent TB infection, the specificity was 94.4% (67/71; 95% CI: 89.1, 99.7). Two patients had NTM species known to cross-react with QFT. In two NTM patients infected with species (Mycobacterium intracellulare subsp. intracellulare and Mycobacterium intracellulare subsp. chimaera) not known to cross-react, whole genome sequencing did not detect ESAT-6 or CFP-10. In Northern California, the QFT assay demonstrated moderately low to moderately high sensitivity in TB patients and very high specificity in NTM patients, thus ruling out concerns for cross-reactivity with NTM.

Ocular manifestations and diagnosis of tuberculosis involving the uvea: a case series

BACKGROUND

Ocular tuberculosis (TB) affects 1-2% of patients with TB, with TB uveitis being the most common. This series aims to look at different manifestations of tuberculosis associated uveitis and the different tests used to make a presumptive or definitive diagnosis.

METHODS

Patients diagnosed with TB related uveitis in Hong Kong SAR between 2017 and 2020 were reviewed. Demographics, clinical features, investigations and treatments of patients were collected.

RESULTS

Fifteen eyes in 10 patients with a mean age 57.30 ± 10.17 years were included. The ocular manifestations on presentation included anterior uveitis (50%), posterior uveitis (40%) and panuveitis (10%), where 70% of them were unilateral and 30% were bilaterally infected; on subsequent visits the manifestations further developed into posterior uveitis (40%), panuveitis (40%) and anterior uveitis (20%), where 50% of them were unilateral and 50% bilateral infected. Tuberculosis tests were positive in 5 out of 7 Mantoux tests, 4 out of 4 T-SPOT TB tests, 3 out of 4 QuantiFERON-TB gold tests, 1 out of 1 lymph node biopsy, 0 out of 9 chest x-rays, and no aqueous fluid polymerase chain reaction (PCR) was tested. Vision impairing complications were seen in 6 patients where retinal vasculitis was most commonly seen. With anti-TB treatment prescribed in 9 patients, side effects occurred in 5 patients, including ocular hypertension, disc swelling, and hepatitis.

CONCLUSIONS

Ocular TB infections may manifest in various forms, and can involve different parts of the eye. Bilateral involvement of TB is commonly presented, and both eyes should be evaluated at every follow up. When TB is suspected in a patient, diagnostic confirmation requires multimodal investigations where a negative chest x-ray is not useful in ruling out ocular TB infections, especially in an endemic region like Hong Kong. In these patients, it is crucial to have a high index of suspicion for TB, even when they do not demonstrate classical respiratory signs and symptoms of TB.

[Recommendations for Contact Tracing for Tuberculosis - Update 2023]

The aim of contact tracing for tuberculosis is in addition to active case finding the detection of chains of infection and the prevention of the further spread of the disease. In this context, a careful selection of contact persons is necessary, depending on the type and duration of contact, to identify persons who are recently infected and therefore to increase the benefit of a preventive therapy and to avoid unnecessary testing of persons who are not at risk of infection. Since the last update of the recommendations on contact tracing, data on the use of interferon-y release assays (IGRAs) in children has been improved markedly. These are the preferred test in contact tracing of adults. For children, both IGRAs and the tuberculin skin test can be used equivalently. Rifampicin for 4 months, rifampicin and isoniazid for 3 months, or isoniazid for 9 months are recommended as preventive therapy in cases of confirmed infection.The implementation of the contact tracing in different age groups as well as legal framework conditions and socio-medical aspects and challenges are dealt with in detail. In addition, special cases, such as environmental screening in day-care centers, schools, or other community facilities, are discussed separately.

[Recommendations for contact tracing for tuberculosis - update 2023]

The aim of contact tracing for tuberculosis is in addition to active case finding the detection of chains of infection and the prevention of the further spread of the disease. In this context, a careful selection of contact persons is necessary, depending on the type and duration of contact, to identify persons who are recently infected and therefore to increase the benefit of a preventive therapy and to avoid unnecessary testing of persons who are not at risk of infection. Since the last update of the recommendations on contact tracing, data on the use of interferon-y release assays (IGRAs) in children has been improved markedly. These are the preferred test in contact tracing of adults. For children, both IGRAs and the tuberculin skin test can be used equivalently. Rifampicin for 4 months, rifampicin and isoniazid for 3 months, or isoniazid for 9 months are recommended as preventive therapy in cases of confirmed infection.The implementation of the contact tracing in different age groups as well as legal framework conditions and socio-medical aspects and challenges are dealt with in detail. In addition, special cases, such as environmental screening in day-care centers, schools, or other community facilities, are discussed separately.

CNS tuberculoma in an immunocompetent patient: A case report of multi-drug hypersensitivity to RIPE therapy

Background

Tuberculosis (TB) is the second leading cause of death due to an infectious disease worldwide (World Health Organization, 2022 [1]). The first line treatment of TB involves the concurrent use of four drugs: rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE). Given the rising threat of multidrug resistant TB, it is crucial to understand how TB can be treated when first line treatment is not an option.

Case presentation

We report a rare case of multi-drug hypersensitivity to RIPE therapy in an immunocompetent patient with an unusual presentation of CNS tuberculoma. The patient presented to an outside hospital four months prior with weakness, numbness, imbalance, and speech difficulties. A CT of the head revealed a mass in the left parietal lobe that demonstrated chronic necrotizing granulomatous inflammation with positive cultures for M. tuberculosis. The patient was started on a regimen of rifampin 600 mg daily, isoniazid 300 mg daily, pyrazinamide 2000 mg daily, ethambutol 1200 mg daily, and pyridoxine 50 mg daily. However, the patient developed drug hypersensitivity reactions to both rifampin and ethambutol with subsequent failed desensitization to rifabutin. She was ultimately discharged from the hospital on a regimen of isoniazid, pyridoxine, pyrazinamide, and moxifloxacin with plans for outpatient follow-up.

Conclusions

This case highlights a rare clinical presentation of multiple drug hypersensitivity in the setting of a CNS tuberculoma and the importance of identifying the offending agents early in the course of treatment and adjusting the drug regimen accordingly. Desensitization should be attempted, but if ineffective, then alternative drug regimens should be formulated on a case-by-case basis.

Incidence and risk factors of tuberculosis in systemic lupus erythematosus patients: a multi-center prospective cohort study

Objectives

Both burdens of tuberculosis (TB) and systemic lupus erythematosus (SLE) in China are ranked as top three in the world. SLE patients are at high risk for TB, but so far, there are no guidelines for TB prevention and management targeting this population in China. This study aims to investigate the incidence of active tuberculosis (ATB) and to explore the risk factors for developing ATB in SLE patients, and to provide evidence for TB prevention and management for SLE patients in China.

Methods

A multi-center prospective cohort study was conducted. SLE patients were enrolled from clinics and wards of 13 tertiary hospitals in Eastern, Middle, and Western China from September 2014 to March 2016. Baseline demographic features, TB infection status, clinical information, and laboratory data were collected. ATB development was examined during follow-up visits. Kaplan-Meier method was applied to plot survival curves, and Log-rank test was used to evaluate differences. Cox proportional-hazards model was used to explore the risk factors for ATB development.

Results

With a median follow-up time of 58 months [interquartile range (IQR): 55-62], 16 out of 1361 SLE patients developed ATB. The 1-year incidence of ATB was 368 [95% confidence interval (CI): 46-691] per 100,000. Over a 5-year period, the cumulative incidence of ATB was 1141 [95% CI: 564-1718] per 100,000, and the incidence density was 245 per 100,000 person-years. Cox regression models were constructed with maximum daily dose of glucocorticoids (GCs) as a continuous variable and a categorical variable, respectively. In model 1, maximum daily dose of GCs (pills per day) [adjusted hazard ratio (aHR)=1.16, 95%CI: 1.04-1.30, p=0.010] and TB infection (aHR=8.52, 95%CI: 3.17-22.92, p<0.001) were independent risk factors for ATB development. In model 2, maximum daily dose of GCs≥30 mg/d (aHR =4.81, 95%CI: 1.09-22.21, P=0.038) and TB infection (aHR=8.55, 95%CI: 3.18-23.00, p<0.001] were independent risk factors for ATB development.

Conclusions

SLE patients had a higher incidence of ATB compared to the general population. The risk of developing ATB was even higher with increased daily dose of GCs or in a status of TB infection, in which case TB preventive treatment should be considered.

Treatment strategies for the latent tuberculosis infections

This study investigates the dynamics of tuberculosis transmission through mathematical modeling, incorporating exogenous reinfections and different treatment approaches for latent tuberculosis infections. We examine three types of treatment rates: saturated, unsaturated, and mass screening-then-treatment. Our results reveal that both saturated treatment and mass screening-then-treatment can lead to a backward bifurcation, while unsaturated treatment does not. To determine the global dynamics of the models, we employ a persistent approach that avoids classifying the steady mode. By applying the models to China, we demonstrate that the data favors the use of unsaturated treatment. If unsaturated treatment is not feasible, the optimal strategy is to screen high-risk groups, identify LTBIs, and administer unsaturated treatment. Saturated treatments are not recommended.

Fulminant pulmonary tuberculosis in a previously healthy young woman from the Marshall Islands: Potential risk factors

A 19-year-old woman originally from the Republic of the Marshall Islands presented with diffuse pneumonia and acute hypoxemic respiratory failure. She dies one month into her hospitalization but the diagnosis of pulmonary tuberculosis (TB) was not made until one day before her demise. A contact investigation screened a total of 155 persons with 36 (23%) found to have latent TB infection and seven (4.5%) with active pulmonary TB. This unfortunate case provided the opportunity to analyze the epidemiology of TB in the state of Washington in the context of those who emigrated from the Marshall Islands. The development of fulminant pulmonary TB in this previously healthy young woman also provides a segue to discuss potential risk factors for TB in the index case that include: (i) foreign-born in a TB-endemic country; (ii) race and genetic factors; (iii) age; (iv) body habitus; (v) pregnancy; and (vi) use of glucocorticoids.

Determining the Need for Additional Testing With Quantiferon TB Gold in Patients With Positive Tuberculin Skin Tests and a History of BCG Vaccination

OBJECTIVE

 To determine if the QuantiFERON-TB Gold (QFT) testing can be obviated for the diagnosis of latent tuberculosis infection (LTBI) in patients with a positive tuberculin skin test (TST) and a history of Bacillus Calmette-Guerin (BCG) vaccination by identifying high-risk features in patients with positive TST and a history of BCG vaccination who are associated with positive QFT.

METHODS

 Retrospective chart review was done for 76 adult patients by dividing them into two groups. Group 1 consisted of true positive TST patients who had BCG vaccination and were positive for QFT. Group 2 consisted of false positive TST patients who had BCG vaccination but were negative for QFT. The two groups were compared to determine if the high-risk features of TST induration diameter of 15mm and more, TST induration of 20mm and more, recent immigration to the US, the advanced age of more than 65 years, country of origin with high TB burden, known exposure to active TB, and smoking history were more prevalent in Group 1 compared to Group 2.

RESULTS

 Group 1 had 23 patients and Group 2 had 53 patients. Group 1 had a higher prevalence of patients with PPD induration of more than 10mm than Group 2, which was statistically significant with a P value of 0.03. Other risk factors of advanced age, exposure to active TB and smoking did not show statistically significant differences between Groups 1 and 2.  Conclusion: This study also confirms that if the TST induration is more than 10mm in patients with a history of BCG vaccination, the TST induration is likely because of LTBI and is less likely because of cross-reaction with BCG vaccination.

Bacterial Infections Associated with Immunosuppressive Agents Commonly Used in Patients with Interstitial Lung Diseases

There are about 200 different types of interstitial lung disease (ILD), and a crucial initial step in the assessment of a patient with suspected ILD is achieving an appropriate diagnosis. Some ILDs respond to immunosuppressive agents, while immunosuppression can be detrimental in others, hence treatment is based on the most confident diagnosis with consideration of a patient's risk factors. Immunosuppressive medications have the potential to result in substantial, and perhaps life-threatening, bacterial infections to a patient. However, data on the risk of bacterial infections from immunosuppressive treatment specifically in patients with interstitial lung disease is lacking. We hereby review the immunosuppressive treatments used in ILD patients excluding sarcoidosis, highlight their risk of bacterial infections, and discuss the potential mechanisms that contribute to the increased risk of infections.

Latent Tuberculosis in India: An Overview

Treatment of latent tuberculosis infection (LTBI) is essential for tuberculosis (TB) eradication. LTBI patients serve as a reservoir for active TB cases. The WHO's End TB Strategy now prioritises the detection and treatment of LTBI. A comprehensive approach focused on integrated LTBI control is required to accomplish this goal. This review aims to summarise what we know about LTBI in the existing literature, its prominence, diagnostic strategies, and new interventions to alert people of its occurrence and symptoms. We used Medical Subject Heading (MeSH) phrases to search for published publications on the English language in PubMed, Scopus, and Google Scholar. To provide clarity and impact, we examined several government websites to identify the most effective and current treatment regimens. LTBI is a spectrum of infections, such as intermittent, transitory, or progressive, with early, subclinical, and ultimately active TB cases. The global burden of LTBI cannot be firmly established because no "gold-standard" test exists. Screening is advised for high-risk individuals, such as immigrants, occupants and staff members of congregate living facilities, and those who are HIV-positive. The most reliable form of LTBI screening is still the targeted tuberculin skin test (TST). Although LTBI therapy is challenging, for India to become TB-free, it must first focus on testing and treating LTBI. The government should focus on generalising the new diagnostic criteria and adopting a more specific treatment known to all to eliminate TB once and for all.

Tuberculosis Infection in Children and Adolescents

The burden of tuberculosis (TB) in children and adolescents remains very significant. Several million children and adolescents are infected with TB each year worldwide following exposure to an infectious TB case and the risk of progression from TB infection to tuberculosis disease is higher in this group compared to adults. This review describes the risk factors for TB infection in children and adolescents. Following TB exposure, the risk of TB infection is determined by a combination of index case characteristics, contact features, and environmental determinants. We also present the recently recommended approaches to diagnose and treat TB infection as well as novel tests for infection. The tests for TB infection have limitations and diagnosis still relies on an indirect immunological assessment of cellular immune response to Mycobacterium tuberculosis antigens using immunodiagnostic testing. It is recommended that TB exposed children and adolescents and those living with HIV receive TB preventive treatment (TPT) to reduce the risk of progression to TB disease. Several TPT regimens of similar effectiveness and safety are now available and recommended by the World Health Organisation.

2022 EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in adults with autoimmune inflammatory rheumatic diseases

Objectives

To develop EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in patients with autoimmune inflammatory rheumatic diseases (AIIRD).

Methods

An international Task Force (TF) (22 members/15 countries) formulated recommendations, supported by systematic literature review findings. Level of evidence and grade of recommendation were assigned for each recommendation. Level of agreement was provided anonymously by each TF member.

Results

Four overarching principles (OAP) and eight recommendations were developed. The OAPs highlight the need for infections to be discussed with patients and with other medical specialties, in accordance with national regulations. In addition to biologic/targeted synthetic disease-modifying antirheumatic drugs (DMARDs) for which screening for latent tuberculosis (TB) should be performed, screening could be considered also before conventional synthetic DMARDs, glucocorticoids and immunosuppressants. Interferon gamma release assay should be preferred over tuberculin skin test, where available. Hepatitis B (HBV) antiviral treatment should be guided by HBV status defined prior to starting antirheumatic drugs. All patients positive for hepatitis-C-RNA should be referred for antiviral treatment. Also, patients who are non-immune to varicella zoster virus should be informed about the availability of postexposure prophylaxis should they have contact with this pathogen. Prophylaxis againstPneumocystis jiroveciiseems to be beneficial in patients treated with daily doses >15–30 mg of prednisolone or equivalent for >2–4 weeks.

Conclusions

These recommendations provide guidance on the screening and prevention of chronic and opportunistic infections. Their adoption in clinical practice is recommended to standardise and optimise care to reduce the burden of opportunistic infections in people living with AIIRD.

Interferon-gamma release assays in tuberculous uveitis: a comprehensive review

Tuberculous uveitis (TBU) comprises a broad clinical spectrum of ocular manifestations, making its diagnosis challenging. Ophthalmologists usually require evidence from investigations to confirm or support a clinical diagnosis of TBU. Since direct isolation of the causative organism from ocular specimens has limitations owing to the small volume of the ocular specimens, resultant test positivities are low in yield. Immunodiagnostic tests, including the tuberculin skin test and interferon-gamma release assays (IGRAs), can help support a clinical diagnosis of TBU. Unlike the tuberculin skin test, IGRAs are in vitro tests that require a single visit and are not affected by prior Bacillus Calmette-Guerin vaccination. Currently, available IGRAs consist of different techniques and interpretation methods. Moreover, newer generations have been developed to improve the sensitivity and ability to detect active tuberculosis. This narrative review collates salient practice points as a reference for general ophthalmologists, such as evidence for the utilization of IGRAs in patients with suspected TBU, and summarizes basic knowledge and details of clinical applications of these tests in a clinical setting.

Biomarkers to identify Mycobacterium tuberculosis infection among borderline QuantiFERON results

BACKGROUND

Screening for tuberculosis (TB) infection often includes QuantiFERON-TB Gold Plus (QFT) testing. Previous studies showed that two-thirds of patients with negative QFT results just below the cut-off, so-called borderline test results, nevertheless had other evidence of TB infection. This study aimed to identify a biomarker profile by which borderline QFT results due to TB infection can be distinguished from random test variation.

METHODS

QFT supernatants of patients with a borderline (≥0.15 and <0.35 IU·mL-1), low-negative (<0.15 IU·mL-1) or positive (≥0.35 IU·mL-1) QFT result were collected in three hospitals. Bead-based multiplex assays were used to analyse 48 different cytokines, chemokines and growth factors. A prediction model was derived using LASSO regression and applied further to discriminate QFT-positive Mycobacterium tuberculosis-infected patients from borderline QFT patients and QFT-negative patients RESULTS: QFT samples of 195 patients were collected and analysed. Global testing revealed that the levels of 10 kDa interferon (IFN)-γ-induced protein (IP-10/CXCL10), monokine induced by IFN-γ (MIG/CXCL9) and interleukin-1 receptor antagonist in the antigen-stimulated tubes were each significantly higher in patients with a positive QFT result compared with low-negative QFT individuals (p<0.001). A prediction model based on IP-10 and MIG proved highly accurate in discriminating patients with a positive QFT (TB infection) from uninfected individuals with a low-negative QFT (sensitivity 1.00 (95% CI 0.79-1.00) and specificity 0.95 (95% CI 0.74-1.00)). This same model predicted TB infection in 68% of 87 patients with a borderline QFT result.

CONCLUSIONS

This study was able to classify borderline QFT results as likely infection-related or random. These findings support additional laboratory testing for either IP-10 or MIG following a borderline QFT result for individuals at increased risk of reactivation TB.

The challenge of tuberculosis diagnosis and management in the era of the COVID-19 pandemic and diabetes mellitus

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A Rare Case of Latent Tuberculosis Reactivation Secondary to a COVID-19 Infection

Coronavirus disease 2019 (COVID-19) and tuberculosis (TB) are currently the two leading causes of death among infectious diseases. As we progress towards a “new normal”, more information is required regarding post-COVID-19 syndromes. We present a case of latent tuberculosis reactivation 3 months after a successful inpatient treatment of COVID-19. A 74-year-old female from the Philippines presented with a new left mid-lung infiltrate with worsening shortness of breath and lethargy for one week prior to admission. The clinical course of the patient deteriorated despite broad-spectrum antibiotics, diuretics, and high-dose steroid therapy requiring intubation and mechanical ventilation. Her sputum culture yielded the microbiological diagnosis of TB. Anti-tubercular medications were started and the patient had a favorable clinical outcome. Our case demonstrates that immunosuppression secondary to COVID-19 and its treatments may promote the development of an active TB infection from a latent infection. It is important to be aware of this potential increase in risk during and after a COVID-19 treatment. This is especially important in high-risk populations to ensure an early diagnosis and prompt management as well as to reduce transmission.

Effect of different interventions for latent tuberculosis infections in China: a model-based study

BACKGROUND

Tuberculosis (TB) has a serious impact on people's health. China is one of 30 countries that has a high TB burden. As the currently decreasing speed of the incidence of TB, the WHO's goal of "End TB Strategy" is hard to achieve by 2035. As a result, a SEIR model that determines the impact of different tuberculosis preventive treatments (TPTs) in different age groups, and the effect of different interventions on latent TB infections (LTBIs) in China is developed.

METHODS

A Susceptible-Exposed-Infectious-Recovered (SEIR) model was established. Goodness-of-fit tests were used to assess model performance. Predictive analysis was used to assess the effect of different interventions on LTBIs and achieving the goals of the "End TB Strategy".

RESULTS

The Chi-square test indicated the model provided a good statistical fit to previous data on the incidence of TB (χ² = 0.3085, p > 0.999). The 1HP treatment regimen (daily rifapentine + isoniazid for 4 weeks) was most effective in reducing the number of TB cases by 2035. The model indicated that several strategies could achieve the 2035 target of the "End TB Strategy": completion of active case finding (ACF) for LTBI and TPT nation-wide within 5 years; completion of ACF for LTBIs and TPT within 2 years in high-incidence areas; completion of TPT in the elderly within 2 years; or introduction of a new vaccine in which the product of annual doses and vaccine efficiency in the three age groups above 14 years old reached 10.5 million.

CONCLUSION

The incidence of TB in China declined gradually from 2005 to 2019. Implementation of ACF for LTBIs and TPT nation-wide or in areas with high incidence, in the elderly, or administration of a new and effective vaccine could greatly reduce the number of TB cases and achieve the 2035 target of the "End TB Strategy" in China.

Use of Isoniazid Monotherapy in Comparison to Rifamycin-Based Regimen for the Treatment of Patients With Latent Tuberculosis: A Systematic Review

Tuberculosis (TB) is a common infectious disease that is present all around the world. This insidious disease needs drastic measures for its eradication. One of the actions contributing to it is the timely diagnosis and offering suitable treatment options for latent tuberculosis patients. In this review, we will discuss and compare the variety of options available for this purpose. We searched PubMed/Medline, Cochrane library, Google Scholar, and Science Direct to find articles regarding the effectiveness, safety, and completion of any of the five regimens available for latent tuberculosis infection. These options are the most classic and standard nine months of isoniazid given daily, which is now more commonly given as six months course, three months of daily isoniazid and rifampin, three months of weekly isoniazid and rifapentine, and four months of daily rifampin. We looked into free full-text studies published from 2011 to 2021 available in English language and human studies. After applying inclusion/exclusion criteria and removing duplicates and screening, 34 articles were shortlisted for quality assessment check, after which we finalized nine studies. Cochrane risk-of-bias assessment tool was used for quality check of randomized control trials, New-Castle Ottawa tool for observational studies, and assessment of multiple systematic reviews (AMSTAR) tool for systematic reviews. Efficacy was checked by tracking down the new cases of TB in the sample population that took the treatment for latent tuberculosis infection. New rifamycin-based regimens were almost equal in effectiveness to isoniazid regimens. The side effect profile is different for both regimens, but short-duration courses tend to have a higher chance of completion.

Reactivation of latent tuberculosis in a COVID-19 patient on corticosteroid treatment

Though the COVID-19 pandemic has made international headlines since 2020, behind the scenes, tuberculosis (TB) has remained a leading cause of global mortality. According to the WHO, TB is 1 of the top 10 causes of death globally, with about one-quarter of the world’s population infected. This case report highlights a female patient who presented to the emergency department with signs and symptoms of COVID-19 and was admitted to hospital. When the patient demonstrated minimal clinical improvement after initiating treatment for COVID-19, further investigations uncovered concomitant reactivated TB. This case is helpful in underscoring the potential implications of the COVID-19 pandemic and current treatment guidelines on the global burden of TB, which could subsequently impact how practitioners approach screening and management of latent TB infection.

Tuberculin skin test before biologic and targeted therapies: does the same rule apply for all?

This study aimed to compare Tuberculin Skin Test (TST) and QuantiFERON®-TB Gold In-Tube (QFT-GIT) test in rheumatoid arthritis (RA) and spondyloarthritis (SpA) patients scheduled for biological and targeted synthetic disease modifying anti-rheumatic drugs (DMARDs) in a Bacillus Calmette-Guérin-vaccinated population. Adult RA (n = 206) and SpA (n = 392) patients from the TReasure database who had both TST and QFT-GIT prior to initiation of biological and targeted synthetic DMARDs were included in the study. Demographic and disease characteristics along with pre-biologic DMARD and steroid use were recorded. The distribution of TST and performance with respect to QFT-GIT were compared between RA and SpA groups. Pre-biologic conventional DMARD and steroid use was higher in the RA group. TST positivity rates were 44.2% in RA and 69.1% in SpA for a 5 mm cutoff (p < 0.001). Only 8.9% and 15% of the patients with RA and SpA, respectively, tested positive by QFT-GIT. The two tests poorly agreed in both groups at a TST cutoff of 5 mm and increasing the TST cutoff only slightly increased the agreement. Among age, sex, education and smoking status, pre-biologic steroid and conventional DMARD use, disease group, and QFT-GIT positivity, which were associated with a 5 mm or higher TST, only disease group (SpA) and QFT-GIT positivity remained significant in multiple logistic regression. TST positivity was more pronounced in SpA compared to that in RA and this was not explainable by pre-biologic DMARD and steroid use. The agreement of TST with QFT-GIT was poor in both groups. Using a 5 mm TST cutoff for both diseases could result in overestimating LTBI in SpA.

Identification and Contribution of Inflammation-Induced Novel MicroRNA in the Pathogenesis of Systemic Lupus Erythematosus

Recently microRNAs (miRNAs) have been recognized as powerful regulators of many genes and pathways involved in the pathogenesis of inflammatory diseases including Systemic Lupus Erythematosus (SLE). SLE is an autoimmune disease characterized by production of various autoantibodies, inflammatory immune cells, and dysregulation of epigenetic changes. Several candidate miRNAs regulating inflammation and autoimmunity in SLE are described. In this study, we found significant increases in the expression of miR21, miR25, and miR186 in peripheral blood mononuclear cells (PBMCs) of SLE patients compared to healthy controls. However, miR146a was significantly decreased in SLE patients compared to healthy controls and was negatively correlated with plasma estradiol levels and with SLE disease activity scores (SLEDAI). We also found that protein levels of IL-12 and IL-21 were significantly increased in SLE patients as compared to healthy controls. Further, our data shows that protein levels of IL-12 were positively correlated with miR21 expression and protein levels of IL-21 positively correlated with miR25 and miR186 expression in SLE patients. In addition, we found that levels of miR21, miR25, and miR186 positively correlated with SLEDAI and miR146a was negatively correlated in SLE patients. Thus, our data shows a dynamic interplay between disease pathogenesis and miRNA expression. This study has translational potential and may identify novel therapeutic targets in patients with SLE.

Plasma Concentrations of sTREM-1 as Markers for Systemic Adverse Reactions in Subjects Treated With Weekly Rifapentine and Isoniazid for Latent Tuberculosis Infection

Background

A regimen of once-weekly rifapentine plus isoniazid for 3 months (3HP) is an effective treatment for subjects with latent tuberculosis infection; however, no reliable biomarker exists for predicting systemic adverse reactions (SARs) to 3HP treatment.

Methods

This prospective, multi-center study evaluated the plasma concentrations of soluble triggering receptors expressed on myeloid cells (sTREM)-1 and sTREM-2 in subjects undergoing 3HP treatment and examined the associations between these biomarkers and SARs.

Results

This study enrolled 80 consecutive subjects receiving 3HP treatment, 25 of whom had SARs and 55 of whom did not. Subjects with SARs presented higher concentrations of sTREM-1 at baseline than those without SARs (240.1 ± 19.1 vs. 176.7 ± 9.4 pg/mL, P = 0.001). The area under the receiver operating characteristic curves revealed that day 1 plasma levels of sTREM-1 (0.708, 95% CI, 0.584–0.833, P = 0.003) and sTREM-2 (0.343, 95% CI, 0.227–0.459, P = 0.025) as well as the sTREM-1/sTREM-2 ratio (0.748, 95% CI, 0.638–0.858, P = 0.001) had modest discriminative power pertaining to the development of SARs. An sTREM-1 level exceeding the cut-off value (>187.4 pg/mL) (hazard ratio [HR], 6.15; 95% CI 1.67–22.70, P = 0.006) and a sTREM-2 below the cut-off value (<237.2 pg/mL) (HR, 4.46; 95% CI 1.41–14.1, P = 0.011) were independent predictors of SARs after controlling for other variables.

Conclusions

Plasma sTREM-1 and sTREM-2 levels are useful biomarkers for predicting SARs during 3HP treatment.

Clinical trial government

NCT04655794

Latent Tuberculosis Testing Through the Ages: The Search for a Sleeping Killer

Tuberculosis has been present in the world’s population for as long as there has been written language. It is a disease known to the ancient Egyptians, Greeks, Romans, and Hebrews, but its etiology eluded the world for thousands of years. Even after the germ theory was accepted and early scientists hypothesized a pathogen as the cause, the identity of the sleeping killer in society remained a mystery. That is until Robert Koch was able to grow and visualize Mycobacterium tuberculosis. Koch introduced his Old Tuberculin solution as a diagnostic therapy of tuberculosis (TB), with the intent to reduce the number of infected persons and stop its spread. Old Tuberculin’s ability to treat TB proved minimal, but its diagnostic potential paved the way for more effective tests from von Pirquet, Calmette, Wolff-Eisner, and Mantoux. Florence Seibert set out to identify and purify the active principle in Koch’s Old Tuberculin and ended up creating purified protein derivative (PPD) tuberculin which is still used as the standard for the tuberculin skin test (TST). Interferon-γ release assays (IGRAs) are a more modern diagnostic tool for detecting latent TB infection that offer some benefits (and some disadvantages) to TST. TSTs and IGRAs can determine if an individual has been infected with M. tuberculosis but are equally unable to predict progression to active tuberculosis, the diagnosis of which relies on assessment of clinical symptoms, radiographic imaging, and sample culture.

Analysis of the Research Hotspot of Drug Treatment of Tuberculosis: A Bibliometric Based on the Top 50 Cited Literatures

Objective

The objective of the current study was to analyze the research hotspot of drug treatment for tuberculosis via top literatures.

Materials and Methods

A retrospective analysis was performed on June 7th, 2021. Literatures were searched on the Web of Science Core Collection to identify the top 50 cited literatures related to drug treatment of tuberculosis. The characteristics of the literatures were identified. The outcomes included authorship, journal, study type, year of publication, and institution. Cooccurrence network analysis and visualization were conducted using the VOS viewer (Version 1.6.16; Leiden University, Leiden, The Netherlands).

Results

The top 50 cited literatures were cited 308 to 2689 times and were published between 1982 and 2014. The most studied drugs were the first-line drugs such as isoniazid and rifampicin (n = 22), and drug-resistant tuberculosis was most frequently reported (n = 16). They were published in 18 journals, and the New England Journal of Medicine published the most literatures (n = 18), followed by the American Journal of Respiratory and Critical Care Medicine (n = 7), and the Lancet (n = 6). The authors were from 13 countries, and the authors from the USA published most of the literatures (n = 30), while authors from other countries published less than five literatures. The CDC in the USA (n = 4), the World Health Organization (WHO) (n = 3), and the American Philosophical Society (n = 3) were the leading institutions, and only two authors published at least two top-cited literatures as first authors.

Conclusions

This study provides insights into the development and most important literatures on drug therapy for tuberculosis and evidence for future research on tuberculosis treatment.

Descriptive analysis of a tuberculosis outbreak from a northern Saskatchewan First Nations community-December 2018 to May 2019

Background

The tuberculosis (TB) incidence rate for northern Saskatchewan First Nations on-reserve is 1.5 higher than the national average. In December 2018 a member of one of these communities was diagnosed with 4+ smear-positive TB, spurring an outbreak investigation.

Objectives

To describe the public health response to TB outbreak investigation and highlight the risk factors associated with TB transmission in northern Saskatchewan; and to highlight the relevance of social network contact investigation tool in outbreak management.

Methods

Descriptive analysis included active TB cases and latent TB infection (LTBI) cases linked by contact investigation to the index case. Data were collected from active TB case files. Statistical analyses were performed and social network analysis conducted using household locations as points of contact between cases.

Results

A total of eight active TB cases and 41 LTBI cases were identified as part of the outbreak between December 2018 and May 2019. Half of the cases (4/8) were 25 to 34 years old, and five were smear negative. One-third of the people with LTBI were 15 to 24 years old, and about a half tested positive to the new tuberculin skin test (TST). The commonly reported risk factors for TB and LTBI cases were alcohol use, cigarette use, marijuana use, previous TB infection and homelessness. Social network analysis indicated a relationship between increased node centrality and becoming an active case.

Conclusion

Real-time social network contact investigation used in active-case finding was very successful in identifying cases, and enhanced nursing support, mobile clinics and mobile X-ray worked well as a means of confirming cases and offering treatment. TB outbreaks in northern Saskatchewan First Nations on-reserve communities are facilitated by population-specific factors. Efforts to implement context-specific interventions are paramount in managing TB outbreaks and preventing future transmission.

Differential Diagnosis of Latent Tuberculosis Infection and Active Tuberculosis: A Key to a Successful Tuberculosis Control Strategy

As an ancient infectious disease, tuberculosis (TB) is still the leading cause of death from a single infectious agent worldwide. Latent TB infection (LTBI) has been recognized as the largest source of new TB cases and is one of the biggest obstacles to achieving the aim of the End TB Strategy. The latest data indicate that a considerable percentage of the population with LTBI and the lack of differential diagnosis between LTBI and active TB (aTB) may be potential reasons for the high TB morbidity and mortality in countries with high TB burdens. The tuberculin skin test (TST) has been used to diagnose TB for > 100 years, but it fails to distinguish patients with LTBI from those with aTB and people who have received Bacillus Calmette–Guérin vaccination. To overcome the limitations of TST, several new skin tests and interferon-gamma release assays have been developed, such as the Diaskintest, C-Tb skin test, EC-Test, and T-cell spot of the TB assay, QuantiFERON-TB Gold In-Tube, QuantiFERON-TB Gold-Plus, LIAISON QuantiFERON-TB Gold Plus test, and LIOFeron TB/LTBI. However, these methods cannot distinguish LTBI from aTB. To investigate the reasons why all these methods cannot distinguish LTBI from aTB, we have explained the concept and definition of LTBI and expounded on the immunological mechanism of LTBI in this review. In addition, we have outlined the research status, future directions, and challenges of LTBI differential diagnosis, including novel biomarkers derived from Mycobacterium tuberculosis and hosts, new models and algorithms, omics technologies, and microbiota.

Malignant Peritoneal Mesothelioma with Latent Tuberculosis Infection

Malignant peritoneal mesothelioma (MPM) is a rare malignant tumor with peritoneal thickening. Tuberculous peritonitis also shows peritoneal thickening, so differentiating between the two is important but difficult if latent tuberculosis infection (LTBI) is present. We herein report a patient with MPM and LTBI. A 79-year-old man was diagnosed with peritoneal thickening on computed tomography. Interferon gamma release assay (IGRA) results were positive, suggesting tuberculous peritonitis. He underwent a laparoscopic omental biopsy and was diagnosed with MPM, which can occur together with LTBI. If peritoneal thickening is observed, an IGRA should be performed early, and the possibility of LTBI should be considered.

Prevalence and risk factors associated with latent tuberculosis infection among household contacts of smear positive pulmonary tuberculosis patients in South India

OBJECTIVE

We aimed to determine the prevalence and find the risk factors associated with latent tuberculosis infection (LTBI) among the household contacts (HHC) of pulmonary TB patients.

METHODS

This cohort study was conducted from 2014 to 2019. Pretested standardised questionnaires and tools were used for data collection. The prevalence of LTBI among HHCs of TB patients was summarised as proportion with 95% confidence interval (CI). Mixed-effects generalised linear modelling function (meglm) in STATA with family Poisson and log link was performed to find the factors associated with LTBI.

RESULTS

In total, 1523 HHC of pulmonary TB patients were included in the study. Almost all HHC shared their residence with the index case (IC) for more than a year; 25% shared the same bed with the IC. The prevalence of LTBI among the HHC of TB patients was 52.6% (95% CI: 50.1-55.1%). In an adjusted model, we found that among HHC belonging to the age group of 19-64 years (aIRR = 1.2; 95% CI: 1.1-1.3; p-value: 0.02), to the age group >65 years (aIRR = 1.4, 95% CI: 1.1-1.9, p-value: 0.02) and sharing the same bed with the IC (aIRR = 1.2, 95% CI: 1.1-1.3, p value: 0.04) were independent determinants of LTBI among the HHC.

CONCLUSION

One in two household contacts of TB patients have latent tuberculosis infection. This underscores the need of targeted contact screening strategies, effective contact tracing and testing using standardised methods in high TB burden settings.

Frequency of positivity of the tuberculin intradermorreaction test in a cohort of patients with rheumatoid arthritis

Introduction: Rheumatoid arthritis is an autoimmune, chronic, and deforming condition associated with disability. Patients are immunosuppressed and at high risk of developing tuberculosis. The tuberculin skin test is used to screen candidates for biological therapy. Objective: To evaluate the frequency of positivity of the tuberculin skin test in a cohort of Colombian patients with rheumatoid arthritis. Materials and methods: We conducted a descriptive cross-sectional study including patients with rheumatoid arthritis receiving the tuberculin skin test prior to the start or at the time of the change of biological therapy. The patients’ condition was moderate or severe and they were candidates for initiation or change of biological therapy. We defined the value of ≥6 mm as the cut-off point for a positive tuberculin skin test and performed a descriptive analysis for each of the variables considered. Results: In total, 261 patients with rheumatoid arthritis were included, 92 % of whom were women; the average age was 55 years (SD=13.92) and the time from diagnosis, 12.3 years (SD=8.54). The frequency of positive tuberculin skin tests was 15.71% (n=41). Of the 41 positive patients, nine had previously had the test (1 to 6 years before), all of them with negative results; 18 of these were receiving glucocorticoids (43.9%) and all of them (100%) were being treated with methotrexate. Conclusions: The frequency of positivity of the tuberculin skin test in these Colombian patients diagnosed with rheumatoid arthritis was around 16%. We reco0mmend optimizing strategies aimed at an optimal detection of this condition and the timely initiation of treatment to reduce the risk of tuberculosis reactivation.

Risk of tuberculosis in patients with cancer treated with immune checkpoint inhibitors: a nationwide observational study

BACKGROUND

While some recent studies have reported the development of tuberculosis (TB) in patients exposed to immune checkpoint inhibitors (ICIs), there is limited evidence to date. Therefore, we evaluated the risk of TB in patients with cancer exposed to ICIs using the National Health Insurance claims data in South Korea.

METHODS

Patients with diagnostic codes for non-small cell lung cancer, urothelial carcinoma or melanoma between August 2017 and June 2019 were identified. The incidence rate and standardized incidence ratio (SIR) of TB were calculated for both the ICI exposure and non-exposure groups. The risk of TB according to ICI exposure was assessed using a multivariable Cox regression model.

RESULTS

During the study period, 141 550 patients with cancer and 916 new TB cases were identified. Among the 5037 patients exposed to ICIs, 20 were diagnosed with TB at a median of 2.2 months after the ICI was initiated. The crude incidence rate of TB per 100,000 person-years was 675.8 (95% CI 412.8 to 1043.8) for the ICI exposure group and 599.1 (95% CI 560.5 to 639.6) for the non-exposure group. The SIR for TB was 8.1 (95% CI 8.0 to 8.2) in the ICI exposure group. After adjusting for potential confounding factors, ICI treatment was not significantly associated with an increased risk of TB (HR: 0.73; 95% CI 0.47 to 1.14).

CONCLUSIONS

While the incidence of TB in cancer patients exposed to ICIs was eightfold higher than in the general population, the risk of patients with cancer developing TB did not significantly differ according to ICI exposure.

Latent Tuberculosis Infection Screening and Treatment in Congregate Settings (TB FREE COREA): Demographic Profiles of Interferon-Gamma Release Assay Cohort

In 2017, the Korean government launched an unprecedentedly large-scaled latent tuberculosis infection (LTBI) screening project which covered more than a million individuals in congregate settings. A total of 1,047,689 participants of source population (n = 2,336,157) underwent LTBI testing from 2017 to 2018. The overall LTBI test uptake rate during this project was 44.8%. Workers in daycare centers (83.5%) and kindergartens (78.9%) showed high participation rate. A total of 1,012,206 individuals with valid results of interferon-gamma release assay (IGRA) were selected to constitute the IGRA cohort. Most of the enrolled participants in the IGRA cohort were in their working age. Approximately, three-quarters of total enrolled population were female. Investigating the LTBI prevalence, stages of LTBI care cascade, natural history of LTBI, efficacy of LTBI treatment and cost-effectiveness of LTBI screening are feasible within this IGRA cohort.

Predictors for tuberculosis co-infection in people living with HIV/AIDs

Background/aim

Tuberculosis (TB) is one of the most common chronic infectious conditions causing mortality and severe outcomes, particularly in people living with HIV/AIDS (PLWHA). In this study, we aimed to determine the prevalence and predictors of TB among PLWHA.

Materials and Methods

We conducted a retrospective and single-center study of adults (≥18 years) PLWHA registered at our tertiary teaching and research hospital between 2000 and 2016.

Results

A total of 711 PLWHA were included. Of whom, 633 (89.0%) were male. Mean age was 36.53 ±11.55 years (range, 17–79). Thirty-eight (5.3%) patients were diagnosed with active TB. TB development was associated with low CD4+ lymphocyte count (p<0.001), high viral load (p=0.040) and alcohol consumption (p=0.004) but no association with age (p=0.392), gender (p=0.928) and duration since anti-retroviral therapy initiation (p=0.788) was found. Also, a receiver operating characteristic analysis showed that the area under the curves of CD4+ lymphocyte count as a predictor for TB development in PLWHA was 0.717 (p<0.001).

Conclusion

There are still clinical challenges to predict TB diagnosis. However, CD4+ lymphocyte count and viral load may be considered as valuable predictors for TB development. Also, community strategies to reduce harmful effect of alcohol use should be developed.

Monitoring frequency of interferon gamma release assay for tuberculosis surveillance following infliximab therapy in patients with Crohn's disease

OBJECTIVE

To characterize the pattern of positive conversion of interferon gamma release assay (IGRA) in patients with Crohn's disease (CD) during infliximab therapy in China, which has a high burden of tuberculosis.

METHODS

Eligible patients with CD who received serial IGRA screening during infliximab therapy from January 2015 to March 2020 were retrospectively included. The positive conversion rate of IGRA and the risk of subsequent tuberculosis of the patients were analyzed.

RESULTS

A total of 128 patients with CD were included, and the median time from the initiation of IFX treatment to positive conversion or the last follow-up test of IGRA was 43.6 weeks. At baseline 3.9% of the patients were positive for IGRA and received prophylactic anti-tuberculosis treatment. In the other 123 patients with negative IGRA at baseline, 6.5% had IGRA positive conversion during infliximab treatment, and one (12.5%) who was exposed to Mycobacterium tuberculosis was diagnosed as having active tuberculosis. The conversion rate at 40 weeks, 2 years and 3 years after treatment were 10.0% (6/60), 2.2% (1/46) and 5.9% (1/17), respectively. Age, sex, history of smoking and alcohol consumption, disease severity (Crohn's disease activity index score) and immunosuppressive therapy were not significantly associated with latent tuberculosis test conversion.

CONCLUSIONS

Positive conversion of IGRA occurs early during treatment with infliximab for CD and the monitoring frequency of IGRA should be appropriately increased at the early stage of treatment. Physicians should pay attention to patient's history of tuberculosis exposure and carry out surveillance in a timely fashion.

Health Maintenance Consensus for Adults With Inflammatory Bowel Disease

BACKGROUND

With the management of inflammatory bowel disease (IBD) becoming increasingly complex, incorporating preventive care health maintenance measures can be challenging. The aim of developing these updated recommendations is to provide more specific details to facilitate their use into a busy clinical practice setting.

METHOD

Fifteen statements were formulated with recommendations regarding the target, timing, and frequency of the health maintenance interventions in patients with IBD. We used a modified Delphi method and a literature review to establish a consensus among the panel of experts. The appropriateness of each health maintenance statement was rated on a scale of 1 to 5 (1-2 as inappropriate, and 4-5 as appropriate) by each panelist. Interventions were considered appropriate, and statements were accepted if ≥80% of the panelists agreed with a score ≥4.

RESULTS

The panel approved 15 health maintenance recommendations for adults with IBD based on the current literature and expert opinion. These recommendations include explicit details regarding specific screening tools, timing of screening, and vaccinations for adults with IBD.

CONCLUSIONS

Patients with IBD are at an increased risk for infections, malignancies, and other comorbidities. Given the complexity of caring for patients with IBD, this focused list of recommendations can be easily incorporated in to clinical care to help eliminate the gap in preventative care for patients with IBD.