scholarly journals Diagnosis and Risk Factors of Latent Tuberculosis Infection among Healthcare Workers Using Whole Blood Human Interferon-gamma Release Assay and Tuberculin Skin Testing

Author(s):  
A. N. Umo ◽  
O. J. Akinjogunla ◽  
N. O. Umoh ◽  
G. E. Uzono

This study established the diagnosis and risk factors of latent tuberculosis infection (LTBI) among health-care workers in an endemic population using Tuberculin skin test (TST) and Quantiferon TB-gold. A total of 609 Healthcare workers from tuberculosis treatment facilities in Akwa Ibom State, Nigeria were studied. The Interferon-gamma release assay was performed using 3ml of whole blood by ELISA according to the manufacturer’s instruction (Cellestis Ltd., Carnegie, Australia) after which 0.1 ml of 5 tuberculin units of Purified Protein Derivative (PPD) was administered intra-dermally to each subject. TST results were read after 72 hours by measuring the size of indurations in millimetres. Data were analysed using SPSS version 17 (SPSS Inc., Chicago, Illinois). At the threshold of 10 mm, the prevalence of LTBI by TST was 45.8% and 24.8% at the IGRA diagnostic value of ≥ 0.351 IU. Laboratory staff and ward orderlies as well as being in service for >10 years, were more significantly associated with LTBI. A moderate agreement of 76.7%, k = 0.51 was obtained between TST at 10 mm, and QFT. Neither previous exposure to TST nor BCG vaccination affected the prevalence of LTBI in the study population. The difference of 54% prevalence of LTBI between TST and QFT may be due to non-tuberculous mycobacterium (NTM) since TST is non-specific. This may have grave implications of drug toxicity and development of resistance to anti-TB drug among individuals harbouring NTM, but receiving anti-TB medication. The 76.7% agreement between the two tests is an indication that the 10 mm cut-off induration for TST is still relevant in the diagnosis of LTBI.

2021 ◽  
Author(s):  
Allyson Guimaraes Costa ◽  
Brenda K.S. Carvalho ◽  
Mariana Araujo-Pereira ◽  
Hiochelson N.S. Ibiapina ◽  
Renata Spener-Gomes ◽  
...  

Background: Interferon-gamma release assay (IGRA) has emerged as a useful tool in identifying latent tuberculosis infection (LTBI). This assay can be performed through testing platforms, such as QuantiFERON-TB Gold Plus (QFT-Plus). This in vitro test has been incorporated by several guidelines worldwide and has recently been considered for the diagnosis of LTBI by the World Health Organization (WHO). The possibility of systematically implementing IGRAs such as QFT-Plus in centers that perform LTBI screening has been accelerated by the decreased availability of tuberculin skin testing (TST) in several countries. Nevertheless, the process to implement IGRA testing in routine clinical care has many gaps. Methods: The study utilized the expertise acquired by the laboratory teams of the Regional Prospective Observational Research in Tuberculosis (RePORT)-Brazil consortium during study protocol implementation of LTBI screening of TB close contacts. Results: RePORT-Brazil includes clinical research sites from Brazilian cities and is the largest multicenter cohort of TB close contacts to date in the country. Operational and logistical challenges faced during IGRA implementation in all four study laboratories are described, as well as the solutions that were developed and led to the successful establishment of IGRA testing in RePORT-Brazil. Conclusions: The problems identified and resolved in this study can assist laboratories implementing IGRAs, in addition to manufacturers of IGRAs providing effective technical support. This will facilitate the implementation of IGRA testing in countries with a high TB burden, such as Brazil.


2012 ◽  
Vol 161 (4) ◽  
pp. 632-638 ◽  
Author(s):  
Elena Critselis ◽  
Virginia Amanatidou ◽  
Garyfallia Syridou ◽  
Nikos P. Spyridis ◽  
Mersini Mavrikou ◽  
...  

2019 ◽  
Vol 36 (2) ◽  
Author(s):  
Rabia Sadaf ◽  
Tehmina Munir ◽  
Sheroze Farrukh ◽  
Saleem Abbasi

Objective: To determine the prevalence of latent tuberculosis infection (LTBI) in healthcare workers in tertiary care hospitals of Rawalpindi, using interferon gamma release assay. Methods: It was a cross-sectional study. The samples were collected from pulmonology and microbiology departments of three hospitals; i) Military Hospital, Rawalpindi, ii) Fauji Foundation Hospital, Rawalpindi and iii) Pakistan Institute of Medical Sciences, Islamabad. The study was completed in one year from January 2017 to January 2018. Fifty-five asymptomatic healthcare workers of both genders between the ages of 18-50 years with a working tenure of at least one year in concerned departments were included and those with active tuberculosis were excluded from the study. Whole blood from subjects was collected and plasma was checked for interferon gamma value by IGRA(Interferon gamma release assay). Results: In this study of total 55 healthcare workers a high prevalence 22 (40.0%) of latent tuberculosis was found. When LTBI distribution was analyzed within occupational categories, the most frequently affected were sanitary workers 3 (100.0%), nurses 5 (50.0%), doctors 6 (43%) and nursing assistants 2 (40%). Conclusion: The prevalence of LTBI in healthcare workers is alarmingly high in our local healthcare settings. doi: https://doi.org/10.12669/pjms.36.2.936 How to cite this:Sadaf R, Munir T, Farrukh S, Abbasi S. Prevalence of latent tuberculosis infection in healthcare workers in tertiary care hospitals of Pakistan. Pak J Med Sci. 2020;36(2):---------. doi: https://doi.org/10.12669/pjms.36.2.936 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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