A new diagnostic tool for rapid and accurate detection of Mycobacterium tuberculosis

Abstract

, acid fast bacilli from the family of , 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 × 10 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.

Innovative Strategies for Developing Tuberculosis Implementation Research in Sudan

“…Sudan population is 32 million according to 2008 census excluding the separated South Sudan. The prevalence of Tuberculosis is very high especially among Eastern states' populations; namely Kassala (2,519,071), Al-Gedarif (2,208,385) and The Red Sea (1,482,053) respectively. These populations were chosen for a survey and/or experiment using World Health Organization recommended Sample Size Calculator and Sampling Spreadsheet (The STEPS) that can assist in rst determining the size of sample and then in drawing a sample from sampling frame (https://www.who.int/ncds/surveillance/steps/resources/sampling/en/).…”

“…Globally, tuberculosis remains one of the top 10 causes of death worldwide. Millions of people continue to fall sick from TB each year (1)(2)(3). The huge biodiversity in Sudan, has a great bacterial record showed variable characteristics of infections and antibiotics susceptibility, this gives an excellent opportunity to nd the effective intervention system (4).…”

Innovative Strategies for Developing Tuberculosis Implementation Research in Sudan

“…Sample Size: Sudan population is 32 million according to 2008 census excluding the separated South Sudan. The prevalence of Tuberculosis is very high especially among Eastern states' populations; namely Kassala (2,519,071), Al-Gedarif (2,208,385) and The Red Sea (1,482,053) respectively. These populations were chosen for a survey and/or experiment using World Health Organization recommended Sample Size Calculator and Sampling Spreadsheet (The STEPS) that can assist in rst determining the size of sample and then in drawing a sample from sampling frame (https://www.who.int/ncds/surveillance/steps/resources/sampling/en/).…”

Dataset of complete genome assembly and analysis of mycobacterium tuberculosis strain SIT745/EAI1-MYS

“…Mycobacterium tuberculosis is an acid-fast bacillus considered to be the causative agent for tuberculosis (TB) [1] . M. tuberculosis strain SIT745/EAI1-MYS was found to be the second most predominant strain in the Kelantan region, Malaysia [2] .…”