Method For Detection Of Tuberculosis Research Articles

TENDENCIES IN TUBERCULOSIS SITUATION AMONG CHILDREN IN SAKHA REPUBLIC (YAKUTIA) DURING LAST 10 YEARS WHEN OF NEW DIAGNOSTIC TOOLS HAVE BEEN INTRODUCED

Goal of the study: to analyze the tendencies in tuberculosis situation among children in Sakha Republic (Yakutia) for the last ten years when some new diagnostic tools have been introduced. Materials and methods. The analysis included data of official statistic reporting on tuberculosis (Form no. 33) among children in Sakha Republic (Yakutia) from 2005 to 2014. During this period of time tuberculosis was newly diagnosed in 647 children in the age from 0 to 14 years old. Their ethnicity, age, tuberculosis detection methods, clinical forms, frequency of bacillary excretion and types of complications were studied. Results. In 2005-2009 in Sakha Republic (Yakutia) the part of children among all new tuberculosis cases made 11.2% and in 2010-2014 it reduced down to 8.2%. The number of children who developed tuberculosis reduced by 51.5% in 2014 versus 2005 (2014 – 51, 2005 – 105 cases). Among new tuberculosis cases in children the exposure to tuberculosis was identified in 57.9% (2005-2009) and in 73.9% (2010-2014), which provided the evidence of severe burden of tuberculosis in the Republic. The part of children in age from 0 to 2 years old made 20.8% in 2005-2009 and 20.4% in 2010-2014. Children in the age from 7 to 14 years old developed tuberculosis the most often. In 2005-2009 tuberculosis was detected in children mostly by tuberculin tests (70.4%) and in 2010-2014 during examination after exposure to a tuberculosis case (43.6%) and less frequently by tuberculin tests (40.2%).

A Novel Sample Processing Method for Rapid Detection of Tuberculosis in the Stool of Pediatric Patients Using the Xpert MTB/RIF Assay.

BackgroundTuberculosis (TB) is difficult to diagnose in children using molecular tests, because children have difficulty providing respiratory samples. Stool could replace sputum for diagnostic TB testing if adequate sample processing techniques were available.MethodsWe developed a rapid method to process large volumes of stool for downstream testing by the Xpert MTB/RIF (Xpert) TB-detection assay. The method was tested and optimized on stool samples spiked with known numbers of M. tuberculosis colony forming units (CFU), and stools from M. tuberculosis-infected cynomolgus macaques (Macaca fascicularis). Performance was scored on number of positive Xpert tests, the cycle thresholds (Cts) of the Xpert sample-processing control (SPC), and the Cts of the M. tuberculosis-specific rpoB probes. The method was then validated on 20 confirmed TB cases and 20 controls in Durban, South Africa.ResultsThe assay’s analytical limit of detection was 1,000 CFU/g of stool. As much as one gram of spiked stool could be tested without showing increased PCR inhibition. In analytical spiking experiments using human stool, 1g samples provided the best sensitivity compared to smaller amounts of sample. However, in Macaques with TB, 0.6g stool samples performed better than either 0.2g or 1.2g samples. Testing the stool of pediatric TB suspects and controls suggested an assay sensitivity of 85% (95% CI 0.6–0.9) and 84% (95% CI 0.6–0.96) for 0.6g and 1.2g stool samples, respectively, and a specificity of 100% (95% CI 0.77–1) and 94% (95% CI 0.7–0.99), respectively.ConclusionThis novel approach may permit simple and rapid detection of TB using pediatric stool samples.

Evaluation of the analytical performance of the PURE-TB-LAMP assay for tuberculosis detection

Given the prevalence and lethality of tuberculosis (TB) in developing countries, there is an ongoing need for a rapid, simple, and low-cost detection method that is nonetheless sensitive and highly specific. The present study evaluated the basic performance of a novel TB detection method combining procedure for ultra-rapid extraction (PURE) and loop-mediated isothermal amplification for TB (TB-LAMP). The PUER-TB-LAMP assay detected five Mycobacterium tuberculosis complexes and did not show any cross-reactivity with 18 species of non-TB mycobacteria (NTM) or with 10 species of other bacteria that cause respiratory tract infections such as Streptococcus pneumonia, underscoring its high specificity for TB detection. The analytical sensitivity of the assay was 100 CFU/ml for M. tuberculosis strain H37Rv cell and was unaffected by the presence of excess amounts of M. avium cells (a typical NTM species) or human genomic DNA. Moreover, when used with a range of artificial specimens prepared by spiking known amounts of cultured M. tuberculosis cells, the PURE method efficiently removed various inhibitory materials from a variety of samples such as sputum, urine, simulated gastric fluid, and whole blood, demonstrating the applicability of this assay to these samples. These results suggest that the PURE-TB-LAMP assay is a highly effective and accessible TB detection method that can be useful in resource-limited communities.

Pyrosequencing of Mycobacterium tuberculosis drug-resistance gene mutations of detection

Purpose: Application of pyrosequencing technology (pyrosequencing) detection of resistance genes of Mycobacterium tuberculosis (rpoB and gyrA) mutation characteristics, evaluation of its clinical application, created by pyrosequencing method on drug-resistance gene mutations of Mycobacterium tuberculosis detection method. Methods: Through the BACTEC-960 rapid culture and using the pyrosequencing technology, about 110 cases of tuberculosis drug resistance, analyzes the characteristics of gene mutation, and the results were compared with conventional susceptibility, pyrosequencing sensitivity is 96%. Results: 110 strains of Mycobacterium tuberculosis resistance in the rpoB gene of 57 strains of drug-resistant strains, the most common mutation and mutant forms of respectively 531 TCG mutation for TTG, Conclusions: Pyrosequencing technology is a high throughput and high performance method in detecting mutation resistance in Mycobacterium tuberculosis.

Evaluation of AFB smear, culture, real-time PCR methods for detection of tuberculosis

Background: Tuberculosis is the leading cause of mortality worldwide and kill 3 million people every year. It is caused by members of theMycobacterium tuberculosis complex (MTC). Zambia is ranked among the world’s top 10 high incident countries. Lack of routine mulecular characterization of mycobacteria in patients presenting with pulmonary tuberculosis in the country’s health facilities including Ndola Central Hospital has led to non availablity of data on specific species other thanM. tuberculosis that are in circulation. This information is vital for proper patient management, as different species and strains of mycobacteria have varying sensitivies to drugs, pathogenesis as well as their epidemiology. The study was aimed at characterizingmembers of theMTC in patients presenting with pulmonary tuberculosis at Ndola Central Hospital in Zambia from February 2012 to August 2012. Methods & Materials: This was a cross-sectional study targeting symptomatic and clinically suspected pulmonary TB patients attending Ndola Central Hospital. A total of 197 consenting adult patiets were included in the study, from whom a structured questionnaire probing their socioeconomic, HIV status and possible source of the disease status. Additionally, 2 sputum samples were collected fromwhere Microscopy, culture, spoligotyping and deletion analysis were carried out. Results:About 60%of theparticipantsweremale. The total positivity rate on culturewas 65% (N=138). Out of seventy-one samples analysed for IS6110 deletion analysis, 41 sampleswhere confirmed to beM. tuberculosis since theywere positive for RD1, RD4, RD9 and RD12. Four samples were confirmed to be M. canettii as characterized by the absence of RD12 amplification. Among the six clusters obtained by spoligotyping, the SAF1 family was largest comprising 43.5% of the isolates. The study also found four orphan strains which did not match with previously identified strains. Conclusion:Other thanM. tuberculosis,Mcanettii has also been implicated in Tuberculosis infection in Ndola.

Tuberculosis Screening Using a T-Cell Interferon-<i>γ</i> Release Assay in Japanese Medical Students and Non-Japanese International Students

Screening of medical students and international students for tuberculosis (TB) at the time of admission is a key strategy to control and prevent the spread of infection on university campus and teaching hospitals because of the high risk of exposure to TB patients. The Mycobacterium tuberculosis antigen-specific T-cell interferon-γ release assays (IGRAs) are specific latent tuberculosis detection methods used in such groups. Currently, in Japan, there are no guidelines and no baseline data on IGRAs to evaluate the risk of TB in these high-risk groups. In order to evaluate TB risk at the time of admission in university campus and medical schools in Japan, a retrospective study was conducted. A total of 969 students (585 Japanese students and 384 international students) were screened for TB using the IGRAs at the time of admission. Eight Japanese students (0.9%) were positive for IGRAs, but none were diagnosed with active TB at the follow-up. In contrast, 30 international students (7.8%) were positive for IGRAs, including two students diagnosed with active TB during follow up. Positive ratio of IGRAs in international students was significantly higher than that of medical students at the time of admission. Here we propose a standard approach for TB screening with IGRAs at the time of admission for medical students and international students in Japan.

A NANOSCALE POROUS SILICON MICROCAVITY BIOSENSOR FOR NOVEL LABEL-FREE TUBERCULOSIS ANTIGEN–ANTIBODY DETECTION

One third of the world population is estimated to have Mycobacterium tuberculosis infection. It is urgent to develop a rapid, inexpensive and convenient diagnostic method for detection of tuberculosis. Porous silicon material has taken more and more attention in recent years for biosensing applications and some useful results have been obtained. In this paper, we report the feasibility of applying porous silicon microcavity biosensor in a novel and relatively rapid serodiagnostic approach. Nowadays, most of serodiagnostic tests are based on labeled detection. Applying label-free detection methods can help develop fast and efficient tuberculosis diagnostic tools, which can meet the current demand. In this study, we use this label-free sensing platform (i.e., porous silicon microcavity) to detect the interaction between 16 kDa antigen and anti-16 kDa antibody. Through a series of experiments, we verify the specificity and examine the sensitivity of this new diagnostic technique. The results show that it is feasible to apply porous silicon microcavity in the tests of tuberculosis.

Tuberculin diagnostics in pulmonary tuberculosis combined with HIV-infection

Aim. To evaluate the sensitivity to tuberculin in patients with infiltrative pulmonary tuberculosis in combination with an infection, caused by the human immunodeficiency virus (HIV), using various different tests. Methods. Examined were patients with infiltrative pulmonary tuberculosis with HIV infection (134 patients, the main group) and without HIV infection (100 patients, control group). Tuberculin diagnostics included an intradermal Mantoux test with 2 tuberculin units, the skin prick test with a 100% solution of PPD-L and the intradermal test «Diaskintest». Results. In the main group, a positive reaction to the Mantoux test with 2 tuberculin units was reported significantly less frequently (56.0%) than in the comparison group (89.0%), the diagnostic value of the test decreased with a decrease in the number of CD4+ lymphocytes. The prick test was characterized by a complete correlation with the results of the Mantoux test, although having a number of advantages. The sensitivity of the «Diaskintest» in the main group was 48.3%, and in the control group - 84.6%, at the same time the sensitivity of the «Diaskintest» decreased to 17% in cases of pronounced immunodeficiency. Conclusion. The skin prick test can be used as a screening method for early detection of tuberculosis in HIV-infected individuals with CD4+ lymphocyte count of 300 cells in 1 ml or more with the aim of forming risk groups, followed by screening for tuberculosis.

OL-008 Molecular method for the rapid detection of tuberculosis from clinical specimens at UKM Malaysia

OL-008 Molecular method for the rapid detection of tuberculosis from clinical specimens at UKM Malaysia

To investigate the clinical diagnostic value of four mycobacteria tuberculosis detection methods

目的 探讨转录酶主导基因TB-RNA扩增法、噬菌体裂解法、3D培养法和涂片法4种实验室检测方法对结核病临床诊断的应用价值.方法 用以上4种方法对临床每份送检标本同时进行同步检测.其中痰液110份、胸腔积液54份、咽拭子37份、支气管冲洗液31份、脑脊髓液13份、尿液12份、颈部淋巴液8份和其他体液(包括腹腔积液、血液、心包积液、脓性分泌物和大便等)20份以及妇科标本(包括白带、经血等)6份等共计291份.最后对上述4种方法检测结果进行评估.结果 291份送检标本中,转录酶主导基因TB-RNA扩增法的总阳性率为37.1%,噬菌体裂解法为28.9%,3D培养法为27.5%和涂片法为10.3%;4种方法检测的敏感度、特异度分别依次为:54.3%和100%、41.7%和98.9%、31.7%和83.5%以及14.6%和98.9%.结论 转录酶主导基因TB-RNA扩增法对结核病临床诊断有较高的应用价值;涂片法阳性率低但其成本低廉且能在实验室中广泛开展;噬菌体裂解法的阳性率略高于培养法;而培养法阳性率远低于转录酶主导基因TB-RNA扩增法和略低于噬菌体裂解法,且需时较长,但培养出的分枝杆菌可做药物敏感性试验和菌型鉴定。

TUBERCULOSIS OF MALE GENITAL SYSTEM – MYTH OR REALITY IN 21ST CENTURY

To review literature and our clinical experience with tuberculosis (TBC) of male genital tract. To analyze the localization of the specific process, association with other forms of TBC and its impact on fertility. The study comprises 69 male patients, average age 40.32 +/- 1.64 years who were diagnosed to have TBC of genital system. All laboratory, imaging, immunological and biological methods for detection of TBC were used as well as sperm count in patients with fertile problems. Time to set up of the diagnosis was 1 day to 19 years (median 26.82 +/- 6.76 months). TBC of the epididymis was found to be present in 78.26% of all cases. In 68.12%, unilateral affection was evident and involvement of left and right sites were similar. In 40.58% of patients, different grade of sperm quality alterations were diagnosed. Almost one-third of cases showed co-morbidity and 36.24% association with TBC of other organs and systems. TBC of male genital tract has a considerable impact on fertility and still remains a challenging medical problem. There is a growing body of evidence that regardless of all measures we should ring the bell about the possibility of a new widespread of TBC. Strong efforts are mandatory especially in developing countries and countries in transition like Eastern European Countries. Management of the disease should involve measures in health promotion programs, medical education health policy makers, and international cooperation.

Evaluation of a safe sputum processing method for detecting tuberculosis.

To evaluate a safe sputum processing method for detection of tuberculosis in developing countries. A sample processing method was developed in which acid fast bacilli were killed with 1% sodium hypochlorite and concentrated by flotation on a layer of xylene before staining by the Ziehl Neelsen or auramine O methods. Best results were obtained by auramine O staining after flotation. Staining by the Ziehl Neelsen method after flotation gave better results than direct Ziehl Neelsen staining without flotation. The flotation method with Ziehl Neelsen staining offers advantages for smear preparation in the tuberculosis control programmes of developing countries.

Assessment of Tuberculin Screening in an Urban Pediatric Clinic

The American Lung Association (ALA) and Center for Disease Control (CDC) have stated that routine screening of children is an inefficient and ineffective method for detection of tuberculosis in the United States. This is at variance with prior recommendations. Our objective, therefore, was to assess prospectively tuberculin screening for our urban, primarily low socioeconomic, clinic population. A prior chart review revealed that only 36% of tuberculin tests had written documentation of results. The following improvements were made: (1) One trained technician administered all tests and recorded data. (2) One hospital mail box was used for receiving tuberculin test postcard results. (3) Telephone follow-up was begun. This resulted in an increase of results documented to 84% (P .001). After these improvements, we prospectively studied the next 1,233 routine screening tests over a period of eight months. The written documentation rate during the study was 90%. Thirteen positive tuberculin tests were found. Three patients had subsequent negative tuberculin tests. One patient received Calmette-Guérin bacillus (BCG) as an infant and had multiple positive tuberculin tests in the past. One patient was lost to follow-up. Eight positive patients were confirmed as new converters. Of these eight patients, six had histories of prior positive tuberculin tests, recent TB exposure, foreign travel, or symptoms. We conclude that: (1) Prior to the study, recording of tuberculin tests was severely deficient. (2) Reorganization significantly increased the documentation rate. (3) Of 1,233 consecutive tests, eight unsuspected cases were found. This is below the 1% conversion rate recommended by the CDC for routine TB screening in children. (4) The data support the ALA-CDC statement regarding the low yield of routine tuberculin testing of healthy children. (5) However, abandoning tuberculin screening of healthy children would leave undetected a few children with unsuspected tuberculosis infection, who would then be in danger of developing serious illness.

"Multiphasic" screening tests.

The extensive employment of mass methods for detection of tuberculosis, syphilis, diabetes and other diseases by official and voluntary health agencies has led quite logically to the idea that it might be advantageous to combine various diagnostic screening tests, instead of organizing separate campaigns, each with a single test. Thus, multiple screening proposes to provide a series of rapid, highly technical diagnostic facilities for large groups of adults, at low cost and, for the most part, at community expense. Various types of tests have been suggested for inclusion in the screening unit. They are conducted in series. Registration, chiefly for identification, is the first step, with a record of age, sex, marital status, weight and height. No detailed history is provided for. The blood pressure, diastolic and systolic, is taken. A urine sample is procured, to be tested for albumin, sugar, sediment and, perhaps, urobilinogen. A