A new diagnostic tool for rapid and accurate detection of Mycobacterium tuberculosis
| Autor: | Abolfazl Fateh, Morteza Ghazanfari, Farid Abdolrahimi, Farzam Vaziri, Seyed Davar Siadat, Shamsi Yari, Ahmadreza Bahrmand, S. Pourazar, Alireza Hadizadeh Tasbiti, Ali Nour-Neamatollahi, Nayereh Ebrahimzadeh |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty Pathology Diagnostic methods Tuberculosis 030106 microbiology Communicable diseases Diagnostic tools Article Mycobacterium tuberculosis 03 medical and health sciences Internal medicine medicine lcsh:QH301-705.5 Kappa value Communicable disease Diagnostic techniques biology Agricultural and Biological Sciences(all) business.industry Pulmonary tuberculosis Sputum medicine.disease biology.organism_classification Sensitivity and specificity lcsh:Biology (General) Diagnostic tests Test performance medicine.symptom General Agricultural and Biological Sciences business |
| Zdroj: | Saudi Journal of Biological Sciences, Vol 25, Iss 3, Pp 418-425 (2018) |
| Popis: | Mycobacterium tuberculosis, acid fast bacilli from the family of Mycobacteriaceae, is the causative agent of most cases of tuberculosis. Tuberculosis, as a communicable disease, remains a serious public health threat, killing more than one million people globally every year. Primary diagnosis of tuberculosis bacilli (TB) relies mainly on microscopic detection of acid fast bacilli (AFB), but the method suffers from low sensitivity and the results largely depend on the technician’s skill. New diagnostic tools are necessary to be introduced for rapid and accurate detection of the bacilli in sputum samples. We, in collaboration with Anda Biologicals, have developed a new platform, named as “Patho-tb”, for rapid detection of AFB with high sensitivity and with low dependence on human skills. Evaluation of Patho-tb test performance was done in two settings: (1) primary field study conducted using 38 sputa from high TB prevalence area of Iran (Zabol city near to the Afghanistan border), and (2) main study conducted using 476 sputa from Tehran, capital of Iran. Patho-tb was applied for processed sputum samples in parallel with routine diagnostic methods (including AFB microscopy, culture and PCR). All test results were compared to final clinical diagnostic state of an individual and diagnostic sensitivity (DSe), specificity, positive predictive value, negative predictive value and accuracy of each test results were calculated using standard formulations. Analytical sensitivity and specificity of the Patho-tb test were also determined. Calculated values for five above mentioned parameters are as follows: for field study: AFB (DSe: 29.6, DSp: 81.8, PPV: 80, NPV: 23.1, AC: 44.7), Patho-tb (DSe: 63, DSp: 72.7, PPV: 85, NPV: 44.4, AC: 65.8), and for main study: AFB (DSe: 86.1, DSp: 99.4, PPV: 98.5, NPV: 93.9, AC: 95.2), Patho-tb (DSe: 97.4, DSp: 92.9, PPV: 86.5, NPV: 98.7, AC: 94.3). Reproducibility of Patho-tb test results were near to 100% (Cohen’s kappa value between 0.85 and 1). The detection limit of Patho-tb test with 100% positivity rate was 3 × 103 cells/ml of sputum. In the field study, Patho-tb test was 33.4% more sensitive than AFB microscopy, while the improvement was only 11.3% during the main study. Patho-tb results are easy to interpret and the test can be merged with other screening tests, like AFB. Totally, Patho-tb test alone or in conjunction with AFB microscopy is a useful screening tool for TB detection especially in poor geographical lab conditions. Keywords: Mycobacterium tuberculosis, Diagnostic tests, Communicable diseases, Diagnostic techniques, Sensitivity and specificity, Sputum, Pulmonary tuberculosis |
| Databáze: | OpenAIRE |
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