84 research outputs found

    A field evaluation of the Hardy TB MODS Kit™ for the rapid phenotypic diagnosis of tuberculosis and multi-drug resistant tuberculosis.

    Get PDF
    BACKGROUND: Even though the WHO-endorsed, non-commercial MODS assay offers rapid, reliable TB liquid culture and phenotypic drug susceptibility testing (DST) at lower cost than any other diagnostic, uptake has been patchy. In part this reflects misperceptions about in-house assay quality assurance, but user convenience of one-stop procurement is also important. A commercial MODS kit was developed by Hardy Diagnostics (Santa Maria, CA, USA) with PATH (Seattle, WA, USA) to facilitate procurement, simplify procedures through readymade media, and enhance safety with a sealing silicone plate lid. Here we report the results from a large-scale field evaluation of the MODS kit in a government service laboratory. METHODS & FINDINGS: 2446 sputum samples were cultured in parallel in Lowenstein-Jensen (LJ), conventional MODS and in the MODS kit. MODS kit DST was compared with conventional MODS (direct) DST and proportion method (indirect) DST. 778 samples (31.8%) were Mycobacterium tuberculosis culture-positive. Compared to conventional MODS the sensitivity, specificity, positive, and negative predictive values (95% confidence intervals) of the MODS Kit were 99.3% (98.3-99.8%), 98.3% (97.5-98.8%), 95.8% (94.0-97.1%), and 99.7% (99.3-99.9%). Median (interquartile ranges) time to culture-positivity (and rifampicin and isoniazid DST) was 10 (9-13) days for conventional MODS and 8.5 (7-11) for MODS Kit (p<0.01). Direct rifampicin and isoniazid DST in MODS kit was almost universally concordant with conventional MODS (97.9% agreement, 665/679 evaluable samples) and reference indirect DST (97.9% agreement, 687/702 evaluable samples). CONCLUSIONS: MODS kit delivers performance indistinguishable from conventional MODS and offers a convenient, affordable alternative with enhanced safety from the sealing silicone lid. The availability in the marketplace of this platform, which conforms to European standards (CE-marked), readily repurposed for second-line DST in the near future, provides a fresh opportunity for improving equity of access to TB diagnosis and first and second-line DST in settings where the need is greatest

    Detecting Mutations in the Mycobacterium tuberculosis Pyrazinamidase Gene pncA to Improve Infection Control and Decrease Drug Resistance Rates in Human Immunodeficiency Virus Coinfection.

    Get PDF
    Hospital infection control measures are crucial to tuberculosis (TB) control strategies within settings caring for human immunodeficiency virus (HIV)-positive patients, as these patients are at heightened risk of developing TB. Pyrazinamide (PZA) is a potent drug that effectively sterilizes persistent Mycobacterium tuberculosis bacilli. However, PZA resistance associated with mutations in the nicotinamidase/pyrazinamidase coding gene, pncA, is increasing. A total of 794 patient isolates obtained from four sites in Lima, Peru, underwent spoligotyping and drug resistance testing. In one of these sites, the HIV unit of Hospital Dos de Mayo (HDM), an isolation ward for HIV/TB coinfected patients opened during the study as an infection control intervention: circulating genotypes and drug resistance pre- and postintervention were compared. All other sites cared for HIV-negative outpatients: genotypes and drug resistance rates from these sites were compared with those from HDM. HDM patients showed high concordance between multidrug resistance, PZA resistance according to the Wayne method, the two most common genotypes (spoligotype international type [SIT] 42 of the Latino American-Mediterranean (LAM)-9 clade and SIT 53 of the T1 clade), and the two most common pncA mutations (G145A and A403C). These associations were absent among community isolates. The infection control intervention was associated with 58-92% reductions in TB caused by SIT 42 or SIT 53 genotypes (odds ratio [OR] = 0.420, P = 0.003); multidrug-resistant TB (OR = 0.349, P < 0.001); and PZA-resistant TB (OR = 0.076, P < 0.001). In conclusion, pncA mutation typing, with resistance testing and spoligotyping, was useful in identifying a nosocomial TB outbreak and demonstrating its resolution after implementation of infection control measures

    Microscopic-observation drug-susceptibility assay for the diagnosis of TB.

    Get PDF
    BACKGROUND: New diagnostic tools are urgently needed to interrupt the transmission of tuberculosis and multidrug-resistant tuberculosis. Rapid, sensitive detection of tuberculosis and multidrug-resistant tuberculosis in sputum has been demonstrated in proof-of-principle studies of the microscopic-observation drug-susceptibility (MODS) assay, in which broth cultures are examined microscopically to detect characteristic growth. METHODS: In an operational setting in Peru, we investigated the performance of the MODS assay for culture and drug-susceptibility testing in three target groups: unselected patients with suspected tuberculosis, prescreened patients at high risk for tuberculosis or multidrug-resistant tuberculosis, and unselected hospitalized patients infected with the human immunodeficiency virus. We compared the MODS assay head-to-head with two reference methods: automated mycobacterial culture and culture on Löwenstein-Jensen medium with the proportion method. RESULTS: Of 3760 sputum samples, 401 (10.7%) yielded cultures positive for Mycobacterium tuberculosis. Sensitivity of detection was 97.8% for MODS culture, 89.0% for automated mycobacterial culture, and 84.0% for Löwenstein-Jensen culture (P<0.001); the median time to culture positivity was 7 days, 13 days, and 26 days, respectively (P<0.001), and the median time to the results of susceptibility tests was 7 days, 22 days, and 68 days, respectively. The incremental benefit of a second MODS culture was minimal, particularly in patients at high risk for tuberculosis or multidrug-resistant tuberculosis. Agreement between MODS and the reference standard for susceptibility was 100% for rifampin, 97% for isoniazid, 99% for rifampin and isoniazid (combined results for multidrug resistance), 95% for ethambutol, and 92% for streptomycin (kappa values, 1.0, 0.89, 0.93, 0.71, and 0.72, respectively). CONCLUSIONS: A single MODS culture of a sputum sample offers more rapid and sensitive detection of tuberculosis and multidrug-resistant tuberculosis than the existing gold-standard methods used

    Exhaled Nitric Oxide is Not a Biomarker for Pulmonary Tuberculosis.

    Get PDF
    To reduce transmission of tuberculosis (TB) in resource-limited countries where TB remains a major cause of mortality, novel diagnostic tools are urgently needed. We evaluated the fractional concentration of exhaled nitric oxide (FeNO) as an easily measured, noninvasive potential biomarker for diagnosis and monitoring of treatment response in participants with pulmonary TB including multidrug resistant-TB in Lima, Peru. In a longitudinal study however, we found no differences in baseline median FeNO levels between 38 TB participants and 93 age-matched controls (13 parts per billion [ppb] [interquartile range (IQR) = 8-26] versus 15 ppb [IQR = 12-24]), and there was no change over 60 days of treatment (15 ppb [IQR = 10-19] at day 60). Taking this and previous evidence together, we conclude FeNO is not of value in either the diagnosis of pulmonary TB or as a marker of treatment response

    Rationing tests for drug-resistant tuberculosis - who are we prepared to miss?

    Get PDF
    BACKGROUND: Early identification of patients with drug-resistant tuberculosis (DR-TB) increases the likelihood of treatment success and interrupts transmission. Resource-constrained settings use risk profiling to ration the use of drug susceptibility testing (DST). Nevertheless, no studies have yet quantified how many patients with DR-TB this strategy will miss. METHODS: A total of 1,545 subjects, who presented to Lima health centres with possible TB symptoms, completed a clinic-epidemiological questionnaire and provided sputum samples for TB culture and DST. The proportion of drug resistance in this population was calculated and the data was analysed to demonstrate the effect of rationing tests to patients with multidrug-resistant TB (MDR-TB) risk factors on the number of tests needed and corresponding proportion of missed patients with DR-TB. RESULTS: Overall, 147/1,545 (9.5%) subjects had culture-positive TB, of which 32 (21.8%) had DR-TB (MDR, 13.6%; isoniazid mono-resistant, 7.5%; rifampicin mono-resistant, 0.7%). A total of 553 subjects (35.8%) reported one or more MDR-TB risk factors; of these, 506 (91.5%; 95% CI, 88.9-93.7%) did not have TB, 32/553 (5.8%; 95% CI, 3.4-8.1%) had drug-susceptible TB, and only 15/553 (2.7%; 95% CI, 1.5-4.4%) had DR-TB. Rationing DST to those with an MDR-TB risk factor would have missed more than half of the DR-TB population (17/32, 53.2%; 95% CI, 34.7-70.9). CONCLUSIONS: Rationing DST based on known MDR-TB risk factors misses an unacceptable proportion of patients with drug-resistance in settings with ongoing DR-TB transmission. Investment in diagnostic services to allow universal DST for people with presumptive TB should be a high priority

    La Imagen y la Narrativa como Herramientas para el Abordaje Psicosocial en Escenarios de Violencia. Municipio de Fusagasugá y Arbeláez.

    Get PDF
    La Imagen y la Narrativa como Herramientas para el Abordaje Psicosocial en Escenarios de Violencia. Municipio de Fusagasugá y Arbeláez.En el siguiente informe, se encontrará los diferentes temas desarrollados en el Diplomado de Profundización Acompañamiento Psicosocial en Escenarios de violencia, donde se revisa el material propuesto, encontrándose diferentes relatos de sobrevivientes que atravesaron diferentes historias de violencia causadas por el conflicto armado de nuestro país. La principal prioridad de la Atención Psicosocial deberá corresponder a esa capacidad de los profesionales desde el trabajo interdisciplinario por construir de manera empalmada con la víctima o las víctimas, acciones psicoeducativas; aquellas que les permitan continuar trabajando sobre sus proyectos de vida personales y poder reconocerse como sobrevivientes. Por consiguiente, desde el estudio de caso de las comunidades de la Cacarica se propone brindar nuevas direccionalidades a los abordajes de intervención en donde las acciones psicosociales puedan humanizarse y ampliarse desde el propio sentir del y de los individuos. Pues lo que se espera tras los procesos de intervención a nivel profesional es garantizar a los sujetos pautas psicoeducativas que les faciliten trabajar desde la propia experiencia sin que lo mismo signifique quedarse en calidad de víctima. Es importante que la atención psicosocial de primera instancia no se reduzca al momento inmediato; la misma debe extenderse a esta segunda etapa de atención, con el propósito mismo de poder reducir las afectaciones psico-emocionales y poder trabajar desde lo profesional a favor de la salud mental de los seres humanos.In the following report, you will find the different topics developed in the Diploma of Deepening Psychosocial Accompaniment in Scenarios of violence, where the proposed material is reviewed, finding different stories of survivors who went through different stories of violence caused by the armed conflict in our country. One of the priorities of the Psychosocial Attention must correspond to that capacity of the professionals from the interdisciplinary work to co-construct in a spliced way with the victim or the victims, psychoeducational actions; those that allow them to continue working on their personal life projects and be able to recognize themselves as survivors. Therefore, from the case study of the Communities of the Cacarica, it is proposed to offer new directions to the intervention approaches in which the psychosocial actions can be humanized and extended from the own senses of the individuals. What is expected after the intervention processes at a professional level is to guarantee the subjects psychoeducational guidelines that will facilitate them to work from their own experience without the same being to remain as a victim. It is important that psychosocial care of the first instance is not reduced to the immediate moment; it must be extended to this second stage of attention, with the purpose of reducing psychoemotional affectations and being able to work from the professional in favor of the mental health of human beings

    Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens

    Get PDF
    RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Bleach-sedimentation may improve microscopy for diagnosing tuberculosis by sterilising sputum and concentrating Mycobacterium tuberculosis. We studied gravity bleach-sedimentation effects on safety, sensitivity, speed and reliability of smear-microscopy. Methods This blinded, controlled study used sputum specimens (n = 72) from tuberculosis patients. Bleach concentrations and exposure times required to sterilise sputum (n = 31) were determined. In the light of these results, the performance of 5 gravity bleach-sedimentation techniques that sterilise sputum specimens (n = 16) were compared. The best-performing of these bleach-sedimentation techniques involved adding 1 volume of 5% bleach to 1 volume of sputum, shaking for 10-minutes, diluting in 8 volumes distilled water and sedimenting overnight before microscopy. This technique was further evaluated by comparing numbers of visible acid-fast bacilli, slide-reading speed and reliability for triplicate smears before versus after bleach-sedimentation of sputum specimens (n = 25). Triplicate smears were made to increase precision and were stained using the Ziehl-Neelsen method. Results M. tuberculosis in sputum was successfully sterilised by adding equal volumes of 15% bleach for 1-minute, 6% for 5-minutes or 3% for 20-minutes. Bleach-sedimentation significantly decreased the number of acid-fast bacilli visualised compared with conventional smears (geometric mean of acid-fast bacilli per 100 microscopy fields 166, 95%CI 68-406, versus 346, 95%CI 139-862, respectively; p = 0.02). Bleach-sedimentation diluted paucibacillary specimens less than specimens with higher concentrations of visible acid-fast bacilli (p = 0.02). Smears made from bleach-sedimented sputum were read more rapidly than conventional smears (9.6 versus 11.2 minutes, respectively, p = 0.03). Counting conventional acid-fast bacilli had high reliability (inter-observer agreement, r = 0.991) that was significantly reduced (p = 0.03) by bleach-sedimentation (to r = 0.707) because occasional strongly positive bleach-sedimented smears were misread as negative. Conclusions Gravity bleach-sedimentation improved laboratory safety by sterilising sputum but decreased the concentration of acid-fast bacilli visible on microscopy, especially for sputum specimens containing high concentrations of M. tuberculosis. Bleach-sedimentation allowed examination of more of each specimen in the time available but decreased the inter-observer reliability with which slides were read. Thus bleach-sedimentation effects vary depending upon specimen characteristics and whether microscopy was done for a specified time, or until a specified number of microscopy fields had been read. These findings provide an explanation for the contradictory results of previous studies.Peer Reviewe

    La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia en la ciudad de Bogotá

    Get PDF
    El siguiente trabajo presenta preocupaciones en base a los distintos escenarios de violencia vividos en nuestro territorio colombiano el cual se evidencia por medio del diplomado de acompañamiento Psicosocial en Escenarios de Violencia, presenta diferentes eventos Psicosociales traumático de estas víctimas de violencia vista y analizada desde una perspectiva Psicológica, por medio de relatos de violencia y desplazamiento forzoso, lo que da como respuesta unos emergentes psicosociales como la pérdida de identidad, la estigmatización, daños a nivel físico y emocional. Es aquí donde la narrativa y la imagen son una herramienta fundamental para el abordaje psicosocial en estos escenarios de violencia persiguiendo el entendimiento de la dimensión psicosocial, la problematización de los fenómenos de violencia e identificación de habilidades para la intervención en crisis y recursos de afrontamiento, la resiliencia a nivel personal y comunitario así poder tener una mejor calidad de vida. En este trabajo se evidencia el análisis de dos relatos de violencia a causa del conflicto armado, el caso de Camilo y el caso de Peñas coloradas. En el caso de Camilo se hace una reflexión detallada de los impactos psicosociales, las voces que se encuentran evidentes en el relato, que revelan un posicionamiento subjetivo desde el lugar de víctima o sobreviviente; también da vista de significados alternos respecto a imágenes dominantes de la violencia y los impactos naturalizados como apartes que revelan un posicionamiento resiliente frente a las imágenes de horror de la violencia. Se elaboran una serie de preguntas circulares, reflexivas y estratégicas que le brindaran a la víctima la oportunidad de reconocer sus valores, oportunidades permitiéndole encontrar recursos necesarios para que pase de ser víctima a sobreviviente y así tener un futuro más seguro y sólido ante la situación vivida. En el caso de peñas coloradas se plantean unas acciones y estrategias, que permiten darle sentido a su vida, elaborar los momentos traumáticos llegando a sanar las emociones, encontrar el valor que tienen como personas, empoderarse de sus orígenes y construir un nuevo proyecto de vida, donde se genere una meta y objetivos claros desde lo que se tiene en el presente y llegue a brindarles una mejor calidad de vida.The following work presents concerns based on the different scenarios of violence experienced in our Colombian territory, which is evidenced through the Diploma of Psychosocial accompaniment in Violence Scenes, presents different traumatic Psychosocial events of these victims of violence seen and analyzed from a perspective Psychological, through stories of violence and forced displacement, which responds to psychosocial emergencies such as loss of identity, stigmatization, physical and emotional damage. It is here where the narrative and the image are a fundamental tool for the psychosocial approach in these violence scenarios, pursuing the understanding of the psychosocial dimension, the problematization of the phenomena of violence and the identification of skills for intervention in crisis and coping resources. resilience at a personal and community level, thus being able to have a better quality of life. This work shows the analysis of two accounts of violence due to the armed conflict, the case of Camilo and the case of Peñas coloradas. In the case of Camilo, a detailed reflection is made of the psychosocial impacts, the voices that are evident in the story, which reveal a subjective position from the place of victim or survivor; it also provides a view of alternate meanings with respect to dominant images of violence and impacts naturalized as aside that reveal a resilient position in the face of horror images of violence. A series of circular, reflective and strategic questions are elaborated that will give the victim the opportunity to recognize their values, opportunities that allow them to find the necessary resources to go from being a victim to a survivor, which gives them a more secure and solid future before the situation experienced. In the case of peñas coloradas, some actions and strategies are proposed that allow them to give meaning to their lives, elaborate traumatic moments, healing their emotions, finding the value they have as people, empowering themselves from their origins and building a new life project, where a clear goal and objectives are generated from what we have in the present and come to provide them with a better quality of life

    Dynamics of Cough Frequency in Adults Undergoing Treatment for Pulmonary Tuberculosis.

    Get PDF
    Background: Cough is the major determinant of tuberculosis transmission. Despite this, there is a paucity of information regarding characteristics of cough frequency throughout the day and in response to tuberculosis therapy. Here we evaluate the circadian cycle of cough, cough frequency risk factors, and the impact of appropriate treatment on cough and bacillary load. Methods: We prospectively evaluated human immunodeficiency virus-negative adults (n = 64) with a new diagnosis of culture-proven, drug-susceptible pulmonary tuberculosis immediately prior to treatment and repeatedly until treatment day 62. At each time point, participant cough was recorded (n = 670) and analyzed using the Cayetano Cough Monitor. Consecutive coughs at least 2 seconds apart were counted as separate cough episodes. Sputum samples (n = 426) were tested with microscopic-observation drug susceptibility broth culture, and in culture-positive samples (n = 252), the time to culture positivity was used to estimate bacillary load. Results: The highest cough frequency occurred from 1 pm to 2 pm, and the lowest from 1 am to 2 am (2.4 vs 1.1 cough episodes/hour, respectively). Cough frequency was higher among participants who had higher sputum bacillary load (P < .01). Pretreatment median cough episodes/hour was 2.3 (interquartile range [IQR], 1.2-4.1), which at 14 treatment days decreased to 0.48 (IQR, 0.0-1.4) and at the end of the study decreased to 0.18 (IQR, 0.0-0.59) (both reductions P < .001). By 14 treatment days, the probability of culture conversion was 29% (95% confidence interval, 19%-41%). Conclusions: Coughs were most frequent during daytime. Two weeks of appropriate treatment significantly reduced cough frequency and resulted in one-third of participants achieving culture conversion. Thus, treatment by 2 weeks considerably diminishes, but does not eliminate, the potential for airborne tuberculosis transmission
    corecore