Abstract Objective/Background The diagnostics of latent tuberculosis infection in Poland using the tuberculin skin test is challenging due to the obligatory Bacillus Calmette–Guérin vaccinations. ...Interferon-gamma release assays are still very rarely used for diagnostics. We compared the tuberculin skin test and the QuantiFERON-TB Gold In-Tube test to evaluate the degree of latent tuberculosis infection in at-risk groups for tuberculosis (homeless, close contacts, periodic contacts, nursing-home attendees) and in healthy individuals. Methods QuantiFERON-TB Gold In-Tube tests were carried out on 785 individuals from the homeless ( n = 150), close contacts ( n = 171), periodic contacts ( n = 163), nursing-home attendees ( n = 152), and healthy individuals ( n = 149). The tuberculin skin test was performed on 129, 156, 147, 148, and 121 participants, respectively. We evaluated the (a) correlation between serum concentrations of interferon gamma and the tuberculin-skin-test induration diameter; (b) between the number of QuantiFERON-TB Gold In-Tube-positive results and the tuberculin-skin-test diameter in the studied groups; and (c) agreement between both tests and the kappa coefficient using the tuberculin-skin-test diameters of 5, 10, and 15 mm. Results Larger tuberculin-skin-test induration diameters were associated with elevated serum concentrations of interferon gamma. We found a positive correlation between the number of positive QuantiFERON-TB Gold In-Tube screening results and the tuberculin-skin-test induration diameter. The agreement between QuantiFERON-TB Gold In-Tube and tuberculin-skin-test screening results improved with increasing tuberculin-skin-test induration diameter. Conclusion Based on measures of tuberculin-skin-test induration diameter alone, it is difficult to diagnose latent tuberculosis infection with certainty. The agreement of the QuantiFERON-TB Gold In-Tube test increases with the tuberculin-skin-test diameter. Tuberculin-skin-test diameters larger than 15 mm are more likely to be associated with active infection.
Background: The transmission of tuberculosis may affect the incidence rate of the disease in Poland. Genetic methods are of assistance in tracing the infection transmission, identifying its sources, ...determining the risk groups, and focusing on the preventive actions. Objectives: The objectives of this study lie in an assessment of tuberculosis transmission by genetic methods with the assistance of the standard epidemiologic interview. Methods: The genome DNA of 275 Mycobacterium tuberculosis (Mtb) strains from tuberculosis patients, inhabitants of the city of Krakow, was subjected to a genetic analysis via the spoligotyping method and the IS6110-Mtb1-Mtb2 polymerase chain reaction (PCR) method. If the DNA profiles were identical in both of the PCRs, they were considered identical and classified within one molecular family. Results: Among 275 strains, 104 genetic patterns (spoligotypes) were identified. Two hundred and three strains were divided into 66 molecular families (clusters) and analyzed with the IS6110- Mtb1-Mtb2 PCR method. Eighteen clusters were separated. In the Mtb1-Mtb2 clusters, 21 patients were in the risk groups (the homeless, prisoners, and nursing home residents). We did not confirm any direct or temporary contacts between the patients constituting the Mtb1-Mtb2 clusters (apart from the risk groups). However, the patients in these clusters often lived in the same parts of Krakow. Conclusions: The standard epidemiologic interview in tuberculosis patients should be combined with genetic methods. Active transmission of tuberculosis occurs largely among the individuals maintaining probably periodic contacts. The patients who are in the risk groups may play an important role in the transmission of tuberculosis.
Latent infection with Mycobacterium tuberculosis is defined by a positive IFN-γ release assay (IGRA) result in the absence of active tuberculosis. Only few, mostly monocentric studies have evaluated ...the role of IGRAs to predict the development of tuberculosis in recent contacts in low-incidence countries of tuberculosis.
To analyze IGRA results and the effect of preventive chemotherapy on tuberculosis progression rates among recent contacts.
Results from contact investigations at 26 centers in 10 European countries including testing for latent infection with M. tuberculosis by the QuantiFERON-TB Gold In-Tube (QFT) test or the T-SPOT.TB (TSPOT) were prospectively collected and analyzed.
Among 5,020 contacts of 1,023 index cases, 25 prevalent secondary cases were identified at screening. Twenty-four incident cases occurred among 4,513 contacts during 12,326 years of cumulative follow-up. In those with a positive IGRA result, tuberculosis incidence was 0.2 (QFT) and 0 (TSPOT) per 100 patient-years when contacts received preventive chemotherapy versus 1.2 (QFT) and 0.8 (TSPOT) per 100 patient-years in those not treated (38 and 37 patients needed to be treated to prevent one case, respectively). Positive and negative predictive values were 1.9% (95% confidence interval CI, 1.1-3.0) and 99.9% (95% CI, 99.7-100) for the QFT and 0.7% (95% CI, 0.1-2.6) and 99.7% (95% CI, 99.1-99.9) for the TSPOT.
Tuberculosis rarely developed among contacts, and preventive chemotherapy effectively reduced the tuberculosis risk among IGRA-positive contacts. Although the negative predictive value of IGRAs is high, the risk for the development of tuberculosis is poorly predicted by these assays.
To evaluate the access to comprehensive diagnostics and novel antituberculosis medicines in European countries.
We investigated the access to genotypic and phenotypic Mycobacterium tuberculosis drug ...susceptibility testing and the availability of antituberculosis drugs and calculated the cost of drugs and treatment regimens at major tuberculosis treatment centres in countries of the WHO European region where rates of drug-resistant tuberculosis are the highest among all WHO regions. Results were stratified by middle-income and high-income countries.
Overall, 43 treatment centres from 43 countries participated in the study. For WHO group A drugs, the frequency of countries with the availability of phenotypic drug susceptibility testing was as follows: (a) 75% (30/40) for levofloxacin, (b) 82% (33/40) for moxifloxacin, (c) 48% (19/40) for bedaquiline, and (d) 72% (29/40) for linezolid. Overall, of the 43 countries, 36 (84%) and 24 (56%) countries had access to bedaquiline and delamanid, respectively, whereas only 6 (14%) countries had access to rifapentine. The treatment of patients with extensively drug-resistant tuberculosis with a regimen including a carbapenem was available only in 17 (40%) of the 43 countries. The median cost of regimens for drug-susceptible tuberculosis, multidrug-resistant/rifampicin-resistant tuberculosis (shorter regimen, including bedaquiline for 6 months), and extensively drug-resistant tuberculosis (including bedaquiline, delamanid, and a carbapenem) were €44 (minimum–maximum, €15–152), €764 (minimum–maximum, €542–15152), and €8709 (minimum–maximum, €7965–11759) in middle-income countries (n = 12) and €280 (minimum–maximum, €78–1084), €29765 (minimum–maximum, €11116–40584), and €217591 (minimum–maximum, €82827–320146) in high-income countries (n = 29), respectively.
In countries of the WHO European region, there is a widespread lack of drug susceptibility testing capacity to new and repurposed antituberculosis drugs, lack of access to essential medications in several countries, and a high cost for the treatment of drug-resistant tuberculosis.
Europe has the highest documented caseload and greatest increase in multidrug and extensively drug-resistant tuberculosis (M/XDR-TB) of all World Health Organization (WHO) regions. This survey ...examines how recommendations for M/XDR-TB management are being implemented.
TBNET is a pan-European clinical research collaboration for tuberculosis. An email survey of TBNET members collected data in relation to infection control, access to molecular tests and basic microbiology with drug sensitivity testing.
68/105 responses gave valid information and were from countries within the WHO European Region. Inpatient beds matched demand, but single rooms with negative pressure were only available in low incidence countries; ultraviolet decontamination was used in 5 sites, all with >10 patients with M/XDR-TB per year. Molecular tests for mutations associated with rifampicin resistance were widely available (88%), even in lower income and especially in high incidence countries. Molecular tests for other first line and second line drugs were less accessible (76 and 52% respectively). A third of physicians considered that drug susceptibility results were delayed by > 2 months.
Infection control for inpatients with M/XDR-TB remains a problem in high incidence countries. Rifampicin resistance is readily detected, but tests to plan regimens tailored to the drug susceptibilities of the strain of Mycobacterium tuberculosis are significantly delayed, allowing for further drug resistance to develop.
•M/XDR-TB poses a serious threat to TB control in Europe.•Isolation rooms are insufficient for safe diagnosis.•Drug susceptibility testing results are frequently delayed.•A positive test for rifampicin resistance should lead automatically to tests for other first- and second-line drug resistance.
Abstract
Background: The objective of this study was to assess the prevalence of latent tuberculosis infection (LTBI) in risk groups in Krakow, using the QuantiFERON-TB Gold In-Tube (QFT-GIT) test ...and the tuberculin skin test (TST); we also sought to assess the rate of progression to active disease over 4-5 y of follow-up. Methods: QFT-GIT tests were performed on 785 subjects and the TST on 701 subjects from the risk groups of homeless persons, close contacts, periodic contacts, and residents of long-term care facilities (LTCFs), and subjects from a low risk group. Results: In homeless persons, close contacts, periodic contacts, LTCF residents, and low risk persons, a positive QFT-GIT was found in 36.7%, 27.2%, 27.0%, 21.1%, and 23.7% of subjects, respectively, while a positive TST was found in 55.8%, 47.4%, 47.6%, 43.2%, and 47.9%, respectively. Of 63 homeless subjects, 5 developed active TB over 248 person-y of follow-up (incidence rate (IR) 20 per 1000 person-y, 95% confidence interval (CI) 8.4-48.5); of 148 close contacts, 5 developed active TB over 740 person-y of follow-up (IR 7, 95% CI 2.8-16.2); of 145 periodic contacts, 2 developed active TB over 580 person-y of follow-up (IR 4, 95% CI 0.9-13.8). The IR per 1000 person-y (95% CI) among subjects with a positive QFT-GIT was 30 (9.0-86.1) for homeless subjects, 18 (5.7-54.7) for close contacts, and 13 (3.2-51.3) for periodic contacts. In Poland there is no policy for the provision of LTBI treatment to people with a positive QFT or TST; therefore, the estimated rates of disease progression were analysed amongst untreated subjects. Conclusions: The prevalence of positive QFT-GIT and TST was high in the study risk groups. The best predictor of active TB in the homeless and close contacts groups was a positive QFT-GIT together with a positive TST.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
How patients relate to the experience of their illness has a direct impact over their behavior
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We aimed to assess illness perception in patients with pulmonary tuberculosis (TB) by means of the ...Brief Illness Perception Questionnaire (BIPQ) in correlation with patients’ demographic features and clinical TB score.
Our observational questionnaire based study included series of consecutive TB patients enrolled in several countries from October 2008 to January 2011 with 167 valid questionnaires analyzed. Each BIPQ item assessed one dimension of illness perceptions like the consequences, timeline, personal control, treatment control, identity, coherence, emotional representation and concern. An open question referred to the main causes of TB in each patient’s opinion.
The over-all BIPQ score (36.25 ± 11.054) was in concordance with the clinical TB score (p ≤ 0.001). TB patients believed in the treatment (the highest item-related score for treatment control) but were unsure about the illness identity. Illness understanding and the clinical TB score were negatively correlated (p < 0.01). Only 25% of the participants stated bacteria or TB contact as the first ranked cause of the illness.
For routine clinical practice implementation of the BIPQ is convenient for obtaining fast and easy assessment of illness perception with potential utility in intervention design. This time saving effective personalized approach may improve communication with TB patients and contribute to better behavioral strategies in disease control.
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