The COVID-19 pandemic may have a negative impact on the proper implementation of TB control programmes and may increase TB incidence rates in the near future. The aim of this study was to perform an epidemiological and molecular analysis of Mycobacterium tuberculosis strains cultured from tuberculosis patients in Poland in 2020 and to compare the results of monitoring drug-resistant tuberculosis in Poland with previous studies in 2012 and 2016. The analysis was based on questionnaires and strains sent by regional laboratories during the 12 months of 2020. Molecular analysis was performed by spoligotyping 20% of the strains sensitive to the four primary antimycobacterial drugs and all of the drug-resistant strains. The number of strains sent for analysis dropped threefold, from 4136 in 2012 to 1383 in 2020. The incidence of tuberculosis among men was higher than among women. There was an increase in strains’ resistance to antimycobacterial drugs in both newly diagnosed patients, from 4.4% in 2012 to 6.1% in 2020, and previously treated patients, from 11.7% to 12.3%. Four-year resistance increased to 1% and 2.1%, respectively. The spoligotype SIT1 was the most abundant among the resistant strains (17%), and SIT53 (13.9%) was the most common among susceptible strains.

The aim of the study was to evaluate the QuantiFERON-TB Gold Plus (QFT-Plus) test usability in the identification of latent tuberculosis infection (LTBI) in children and the determination of features associated with tuberculin skin test (TST) and QFT-Plus-positive results concerning LTBI. Two-hundred thirteen children aged 1–14 were screened for LTBI due to household contact with TB, suspected TB, or were qualified for biological therapy. The objective of this study was to evaluate the QFT-Plus affectivity as a diagnostic test in the absence of a gold standard (GS) test for the diagnosis of LTBI. The children were diagnosed with QFT-Plus, TST, and culture of TB. The QFT-Plus results were analyzed depending on the children’s age, TST size, and type. In children aged 1–4, the positive predictive value of QFT-Plus was 1, the negative predictive value was 0.94, QFT-Plus sensitivity was 75%, and specificity was 100%. It was observed that in children aged 5–14 years, the level of agreement decreased to the substantial, i.e., 87.2%. Moreover, the negative predictive value was 0.83. QFT-Plus sensitivity was 64%, and specificity was 100%. Statistical analysis of QFT-Plus and TST results showed substantial and almost perfect agreements. Our study suggests that QFT-Plus is helpful in a pediatric practice showing good sensitivity and specificity for LTBI. The BCG vaccine, infections, and concomitant morbidities do not affect QFT-Plus results.

According to the World Health Organization (WHO), around 1 million children worldwide are diagnosed with tuberculosis each year. The Bacillus Calmette–Guérin (BCG) vaccine has been used around the world for over 100 years. The complications of the BCG vaccination can occur in about 0,06% of children and include local or systemic adverse reactions. Due to the close analogy between the vaccine strain and other species of the Mycobacterium tuberculosis complex (MTBC), molecular methods are recommended for differential diagnosis of Vaccine adverse events (VAE) after BCG. The ability to quickly and specifically identify BCG is important in view of different treatment regimens. The aim of the study was to assess the usefulness of genetic testing for Mycobacterium bovis BCG in the paraffin-embedded specimens’ methods. We describe two cases of VAE in immune-compromised children presenting with osteoarticular changes that had been clinically suspected of tuberculosis and led to molecular identification through GeneXpert, GenoType MTBC, and Spoligotyping. Results: Mycobacterium bovis BCG was detected in osteoarticular changes embedded in paraffin block of two patients. Conclusion: Genetic tests using paraffin-embedded materials allow for quick identification and differential diagnosis of patients with Tuberculosis and VAE after BCG. This is an important issue, especially in cases where the tissue has only been submitted for histopathological examination without microbiological diagnostics for tuberculosis.

Przez wiele lat podstawowym testem identyfikującym latentne (utajone) zakażenie prątkami gruźlicy (LTBI) była próba tuberkulinowa, posiadająca pewne ograniczenia, które wynikają przede wszystkim z niskiej czułości i specyficzności. Obecnie stosuje się testy IGRA z krwi obwodowej, umożliwiające szybką diagnostykę LTBI poprzez pomiar interferonu gamma (IFN-γ) wydzielanego przez limfocyty T pobudzone swoistymi dla Mycobacterium tuberculosis antygenami. Wykrywanie LTBI ma istotne znaczenie w kontroli osób potencjalnie zagrożonych zachorowaniem na gruźlicę, na przykład przebywających w bliskim kontakcie z chorymi prątkującymi oraz dla pacjentów kwalifikowanych do leczenia lekami biologicznymi. W pracy przedstawiono 3 wybrane sytuacje kliniczne, w których zastosowano testy IGRA. W dwóch przypadkach rozpoznano ostatecznie utajone zakażenie prątkami gruźlicy, a w jednym aktywną gruźlicę.

DOI: 10.20452/pamw.16104, Published online: October 06, 2021, Authors: Dagmara Borkowska-Tatar, Sylwia Brzezińska, Maria Krasińska, Katarzyna Błasińska, Ewa Augustynowicz-Kopeć

Background: Latent tuberculosis infection (LTBI) is an important public health problem and a major source of future active tuberculosis (ATB) cases. In this preliminary study, we sought to identify host biomarkers that could potential differentiate between LTBI and ATB. Methods: A total of 145 plasma samples obtained from antigen tubes of the QuantiFERON‐TB Gold Plus assay were analysed. Concentrations of 20 selected cytokines were determined using a multiplex bead‐based immunoassay (Luminex xMAP Technology). Cytokine profiles were compared between patients with ATB, LTBI, and non‐tuberculosis (TB)/LTBI controls. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis and multivariable logistic regression modelling. Results: Comparison of cytokine profiles showed significant differences in 13 of 20 analysed markers between LTBI and ATB. Among all evaluated biomarkers, interleukin‐7 (IL‐7) demonstrated the highest diagnostic potential in differentiating the two conditions (95.9%), outperforming interferon‐gamma (IFN‐γ), the key component of current IFN‐γ release assay (IGRA) assays. A logistic regression model based on IL‐7 and IFN‐γ achieved high diagnostic accuracy (98.1%) in this study cohort. Conclusion: These preliminary findings suggest that IL‐7, in combination with IFN‐γ, may serve as a promising candidate biomarker signature for distinguishing LTBI from ATB. Nevertheless, these findings are based on a single‐centre dataset and represent internal, non‐externally validated results. Therefore, external validation in independent multicentre cohorts is essential before any clinical application can be considered.