A more reliable PCR for detection of Mycobacterium tuberculosis in clinical samples

Diagnostic techniques based on PCR have two major problems: false-positive reactions due to contamination with DNA fragments from previous PCRs (amplicons) and false-negative reactions caused by inhibitors that interfere with the PCR. We have improved our previously reported PCR based on the amplification of a fragment of the Mycobacterium tuberculosis complex-specific insertion element IS6110 with respect to both problems. False-positive reactions caused by amplicon contamination were prevented by the use of uracil-N-glycosylase and dUTP instead of dTTP. We selected a new set of primers outside the region spanned by the formerly used primers to avoid false-positive reactions caused by dTTP-containing amplicons still present in the laboratory. With this new primer set, 16 copies of the IS6110 insertion element, the equivalent of two bacteria, could be amplified 10(10) times in 40 cycles, resulting in a mean efficiency of 77% per cycle. To detect the presence of inhibitors of the Taq polymerase, which may cause false-negative reactions, part of each sample was spiked with M. tuberculosis DNA. The DNA purification method using guanidinium thiocyanate and diatoms effectively removed most or all inhibitors of the PCR. However, this was not suitable for blood samples, for which we developed a proteinase K treatment followed by phenol-chloroform extraction. This method permitted detection of 20 M. tuberculosis bacteria per ml of whole blood. Various laboratory procedures were introduced to reduce failure or inhibition of PCR and avoid DNA cross contamination. We have tested 218 different clinical specimens obtained from patients suspected of having tuberculosis. The samples included sputum (n=145), tissue biopsy samples (n=25), cerebrospinal fluid (n=15), blood (n=14), pleural fluid (n=9), feces, (n=7), fluid from fistulae (n=2), and pus from a wound (n=1). The results obtained by PCR were consistent with those obtained with culture, which is the "gold standard." We demonstrate that PCR is a useful technique for the rapid diagnosis of tuberculosis at various sites.

La hospitalización terapéutica obligatoria en el control de la tuberculosis

Este trabajo describe las acciones de los servicios de salud pública de la ciudad de Barcelona para evitar la transmisión de la tuberculosis por pacientes bacilíferos incumplidores utilizando las posibilidades de la Ley 3/1986. Se basan en la resolución de la autoridad sanitaria de la necesidad de su localización y hospitalización terapéutica obligatoria para administrar el tratamiento, movilizando la colaboración policial, comunicándolo a la persona afectada y pidiendo al Juzgado de lo Contencioso Administrativo su ratificación. Se describen el proceso y las características de los casos. Desde julio de 2006 hasta junio de 2015, a lo largo de 9 años, se ha activado sólo en 12 ocasiones. Se valora que se ha usado con prudencia y proporcionalidad, y que ha permitido tratar a pacientes que comportaban riesgo en su entorno, reduciendo así la transmisión de la infección.

Second worldwide proficiency study on variable number of tandem repeats typing of Mycobacterium tuberculosis complex

Global Network for the Molecular Surveillance of Tuberculosis 2010: A. Miranda (Tuberculosis Laboratory of the National Institute of Health, Porto, Portugal)

Cribado de la tuberculosis

Hay pruebas de que el cribado universal de la infección tuberculosa latente (ITBL) en zonas de baja incidencia tiene un rendimiento pobre, un número elevado de falsos positivos y no es coste-efectivo. Hay evidencias de que el cribado de la ITBL en los grupos que tienen riesgo elevado de desarrollar una infección tuberculosa activa (ITBA) mejora el rendimiento de las pruebas diagnósticas, el balance beneficio-riesgo y debe formar parte de las estrategias para disminuir el impacto de la tuberculosis. Sobre el dilema de cuál de las tres estrategias (prueba cutánea de la tuberculina ENT#091;PCTENT#093; sola, determinación de la liberación de interferón gamma ENT#091;IGRAENT#093; solo o PCT seguida de IGRA) para el diagnóstico de la ITBL es la que ofrece mejor rendimiento, existe variabilidad tanto en las recomendaciones de las guías de práctica clínica (GPC) y las instituciones como en las conclusiones de los estudios sobre el tema, aunque la mayoría de las recomendaciones van en el mismo sentido que las que proponemos en este documento. La prueba cutánea de la tuberculina sigue siendo el test diagnóstico con mejor rendimiento para realizar el cribado de la infección tuberculosa latente en niños y adolescentes. Recomendaciones de PrevInfad (GRADE): 1. Se recomienda no realizar el cribado universal de la infección tuberculosa latente en los niños y adolescentes de nuestro país. 2. Se recomienda realizar el cribado de la infección tuberculosa latente en los niños y adolescentes que pertenecen a grupos de riesgo. 3. Se sugiere el uso de la prueba cutánea de la tuberculina (PCT) como primera prueba para el cribado de la infección tuberculosa latente en niños y adolescentes de nuestro país. 4. Se sugiere utilizar los IGRA para los niños y adolescentes de cinco o más años con PCT positiva y antecedente de vacunación con bacilo de Calmette-Guérin (BCG) para mejorar la especificidad de la prueba de cribado.

Programa de intervención para mejorar conocimientos y actitudes sobre la tuberculosis y captar sintomáticos respiratorios. Area 1 de Salud del Cañar. 2007

Con el objetivo de aplicar un programa de capacitación personal para mejorar conocimientos y prácticas sobre el control de la tuberculosis y mejorar la captación de sintomáticos respiratorios. Materiales y métodos: con un diseño cuasi experimental se incluyeron 63 profesionales sanitarios: 33 médicos, 17 odontólogos, 11 enfermeras y 2 obstetrices, distribuidos en 29 unidades operativas; 2 Centros de Salud, 16 subcentros de Salud y 12 puestos de Salud, pertenecientes al Ministerio de Salud Pública. Se aplicó un tes de 20 preguntas para evaluar conocimientos y prácticas antes de la intervención y otro de igual numero para medir el efecto de la intervención después de cumplir el programa de capacitación. Resultados: antes de la intervención, el promedio de respuestas correctas fue de 35,8 ± 4,3 (entre 23 y 56). El incremento de conocimientos fue significativo (p= 0,0001). La captación de sintomáticos respiratorios se incrementó en un 17% en los dos trimestres posteriores a la capacitación, RR 7,8 (IC95% 1,8-32,9) P=0,0003. En cuarto trimestre descendió a los valores pre intervención. Implicaciones: un programa de capacitación permanente sobre control de la Tuberculosis es una estrategia válida para mejorar los conocimientos y las prácticas sanitarias tendientes a incrementar la captación de sintomáticos respiratorios como la mejor medida para detectar la enfermedad

Paradoxical Deterioration During Anti-Tuberculous Therapy in Non-HIV-Infected Patients with Pleural Tuberculosis: A Pragmatic Approach

We report a case of paradoxical deterioration. A male patient diagnosed with pleural tuberculosis, but who was not infected with human immunodeficiency virus (HIV), experienced clinical deterioration 3 weeks after the initiation of anti-tuberculous treatment. After other diagnoses were ruled out, a paradoxical response to treatment was established and the patient was started on systemic corticosteroids. Paradoxical response to treatment should be considered in patients with clinical deterioration after they start on anti-tuberculous treatment.

Endometrial tuberculosis simulating an ovarian cancer

Female genital tuberculosis remains a major health problem in developing countries and is an important cause of infertility. As symptoms, laboratory data and physical fndings are non-specifc, its diagnosis can be diffcult. We describe a case of a 39-year-old woman suffering from peri-umbilical pain and increased abdominal size for one year, anorexia, asthenia, weight loss, occasionally dysuria and dyspareunia, and four months amenorrhea. Laboratory data revealed cancer antigen 125 (CA-125) level of 132.3 U/mL, erythrocyte sedimentation rate of 42 mm/h, and gamma-globulins of 2.66 g/dL. Computer Tomography scan showed loculated ascites. It was initially suspected a carcinomatous origin, but ascites evaluation was negative for malignant cells. Magnetic Resonance Imaging from another hospital showed endometrial heterogeneity. Therefore, an endometrial biopsy was performed demonstrating an infammatory infltrate with giant cells of type Langhans and bacteriological culture identifed Mycobacterium tuberculosis

Thyroid function in multidrug-resistant tuberculosis patients with or without human immunodeficiency virus (HIV) infection before commencement of MDR-TB drug regimen.

Background: Mycobacterium tuberculosis and human immunodeficiency virus (HIV) are known to cause abnormal thyroid function. There is little information on whether HIV infection aggravates alteration of thyroid function in patients with MDRTB. Objectives: This study was carried out to determine if HIV co-infection alters serum levels of thyroid hormones (T3, T4) and thyroid stimulating hormone (TSH) in patients with MDR-TB patients and to find out the frequency of subclinical thyroid dysfunction before the commencement of MDR-TB therapy. Methods: This observational and cross-sectional study involved all the newly admitted patients in MDR-TB Referral Centre, University College Hospital, Ibadan, Nigeria between July 2010 and December 2014. Serum levels of thyroid stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were determined using ELISA. Results: Enrolled were 115 patients with MDR-TB, out of which 22 (19.13%) had MDR-TB/HIV co-infection. Sick euthyroid syndrome (SES), subclinical hypothyroidism and subclinical hyperthyroidism were observed in 5 (4.35%), 9 (7.83%) and 2 (1.74%) patients respectively. The median level of TSH was insignificantly higher while the median levels of T3 and T4 were insignificantly lower in patients with MDR-TB/HIV co-infection compared with patients with MDRT-TB only. Conclusion: It could be concluded from this study that patients with MDR-TB/HIV co-infection have a similar thyroid function as patients having MDR-TB without HIV infection before commencement of MDR-TB drug regimen. Also, there is a possibility of subclinical thyroid dysfunction in patients with MDR-TB/HIV co-infection even, before the commencement of MDR-TB therapy.

Profile and treatment outcomes of patients with tuberculosis in Northeastern Ethiopia: a cross sectional study.

Background: Data on the epidemiology of tuberculosis and its treatment outcomes were incomplete in the study area and this study was done to fill this gap. Methods: Institution based cross sectional study was conducted from January 2011 to December 2014. A total of 949 TB patients who were on treatment in North Eastern Ethiopia, Eastern Amhara region were included. Data was analyzed using SPSS version 20. Frequency, percentages and means were used to present data. To assess the associations of treatment outcomes with sex, age, type of TB and human immunodeficiency virus (HIV), logistic regression was used. Results: The proportion of smear positive and negative pulmonary TB, and extra pulmonary TB were 187/949 (19.7%), 322/949 (33.9%) and 440/949 (46.4%), respectively. Treatment success rate was 853/949 (89.9%). Smear positive pulmonary TB and TB/HIV co-infections were significantly associated with unsuccessful treatment outcome, P≤ 0.002. Conclusion: Extra pulmonary TB was the most prevalent types of TB followed by smear negative pulmonary TB. Treatment success rate was above the WHO target of 85%. The causes for the high proportion of smear negative PTB and EPTB should be further investigated. Special emphasis should be put on smear positive PTB patients and TB/HIV co-infected patients to decrease unsuccessful treatment outcome and TB transmissions.

Diabetes mellitus among tuberculosis patients: a cross sectional study from Pakistan

Background: The co-occurrence of diabetes mellitus (DM) and tuberculosis (TB) is largely associated with high frequency of morbidity. Objective: To determine the prevalence of DM among TB patients and describe the socio-demographic and behavioral factors associated with TB-DM co-occurrence . Methods: We enrolled 500 TB patients from September, 2014 to August 2015 at four major public sector hospitals of Lahore, Pakistan. A questionnaire was used to collect information regarding associated socio-demographic and behavioral factors of the patients. We monitored the fasting blood sugar of each patient by using a semi automated clinical chemistry analyzer followed by an HbA1c level check of all hyperglycemic patients. Results: The prevalence of TB-DM co-occurrence was 14.8%. The prevalence of TB-DM was higher (62.2%) among males. The >57 year age group had the highest proportion of patients (35.1%), with co-existent TB-DM. Most were illiterate (73.0%) and unemployed (48%). Moreover, among the 74 patients positive for TB-DM had a history of smoking. Age and education level were significantly associated with DM-TB while gender, occupation and smoking were not associated. Conclusion: The study revealed a 14.8% prevalence of DM among TB patients. This was associated with several socio-demographic factors, including age, unemployment, literacy and polluted environment. Thus, poor and unhealthy lifestyles were the factors associated with DM among immunologically compromised individuals due to TB.

Proteína C reactiva, marcador inflamatorio asociado con ANCA en tuberculosis pulmonar

Antecedentes: la proteína C reactiva es uno de los marcadores inflamatorios denominados “reactantes de fase aguda” que se produce en el hígado en respuesta a procesos infecciosos o inflamatorios. En los pacientes con tuberculosis se ha descrito la formación de anticuerpos anticitoplasma de neutrófi los (ANCA). Objetivo: determinar la concentración de proteína C reactiva, evaluar su comportamiento como marcador de la respuesta inflamatoria y analizar su correlación con los ANCA en los pacientes con tuberculosis pulmonar, antes y después de iniciar el tratamiento antifímico. Pacientes: se eligieron pacientes con sospecha de tuberculosis pulmonar. Una vez confirmado el diagnóstico, se obtuvieron las muestras de suero para analizar los datos clínicos y de laboratorios. La determinación de ANCA se realizó con estuches comerciales de inmunofluorescencia y la de proteína C reactiva con ELISA, antes y después de iniciar el tratamiento antifímico. Resultados: se obtuvieron 50 muestras de suero de pacientes con tuberculosis pulmonar. En la primera (94%) y segunda obtención (90%) de los sueros se registró un valor de proteína C reactiva menor de 5 mg/L. El valor promedio de proteína C reactiva fue de 3.05 ± 8.27 mg/L en la primera muestra y de 4.49 ± 11.2 mg/L en la segunda (p = 0.46). Los pacientes positivos a ANCA tuvieron valores más altos de proteína C reactiva en su segunda muestra (p = 0.001). Discusión: existe una asociación entre la proteína C reactiva y la producción de anticuerpos anticitoplasma de neutrófilos en un subgrupo de pacientes con tuberculosis pulmonar. Su significación es incierta, pero quizá desempeñan alguna función patogénica en la respuesta inflamatoria pulmonar.

Prevalencia de brucelosis bovina en el periodo 2004-2012 y tuberculosis bovina en el periodo 2006-2012 en hatos lecheros del Cantón Mejía

Brucelosis y tuberculosis bovina son dos enfermedades que causan importantes pérdidas productivas y reproductivas en la ganadería local, nacional e internacional. En el Ecuador, desde hace varios años se viene trabajando en un programa para el control y erradicación de estas dos enfermedades. En el año 2006, por primera vez, siete predios de producción lechera consiguieron la certificación de predio libre de Brucelosis bovina, otorgada por el Servicio Ecuatoriano de Sanidad Animal (SESA) de ese entonces (Paredes 2014, comunicación personal). La Asociación Holstein Friesian del Ecuador (AHFE) inicia en el año 2004 el Programa de Control y Erradicación de Brucelosis bovina y en el año 2006 el Programa de Control y Erradicación de Tuberculosis bovina. Sin embargo, los datos de ambos programas no han sido analizados para determinar el estado de estas dos enfermedades en los periodos comprendidos entre los años 2004 a 2012 y periodo 2006 a 2012, respectivamente.

Transient hyperglycemia in patients with tuberculosis in Tanzania: implications for diabetes screening algorithms.

BACKGROUND: Diabetes mellitus (DM) increases tuberculosis risk while tuberculosis, as an infectious disease, leads to hyperglycemia. We compared hyperglycemia screening strategies in controls and patients with tuberculosis in Dar es Salaam, Tanzania. METHODS: Consecutive adults with tuberculosis and sex- and age-matched volunteers were included in a case-control study between July 2012 and June 2014. All underwent DM screening tests (fasting capillary glucose [FCG] level, 2-hour CG [2-hCG] level, and glycated hemoglobin A1c [HbA1c] level) at enrollment, and cases were tested again after receipt of tuberculosis treatment. Association of tuberculosis and its outcome with hyperglycemia was assessed using logistic regression analysis adjusted for sex, age, body mass index, human immunodeficiency virus infection status, and socioeconomic status. Patients with tuberculosis and newly diagnosed DM were not treated for hyperglycemia. RESULTS: At enrollment, DM prevalence was significantly higher among patients with tuberculosis (n = 539; FCG level > 7 mmol/L, 4.5% of patients, 2-hCG level > 11 mmol/L, 6.8%; and HbA1c level > 6.5%, 9.3%), compared with controls (n = 496; 1.2%, 3.1%, and 2.2%, respectively). The association between hyperglycemia and tuberculosis disappeared after tuberculosis treatment (adjusted odds ratio [aOR] for the FCG level: 9.6 [95% confidence interval {CI}, 3.7-24.7] at enrollment vs 2.4 [95% CI, .7-8.7] at follow-up; aOR for the 2-hCG level: 6.6 [95% CI, 4.0-11.1] vs 1.6 [95% CI, .8-2.9]; and aOR for the HbA1c level, 4.2 [95% CI, 2.9-6.0] vs 1.4 [95% CI, .9-2.0]). Hyperglycemia, based on the FCG level, at enrollment was associated with tuberculosis treatment failure or death (aOR, 3.3; 95% CI, 1.2-9.3). CONCLUSIONS: Transient hyperglycemia is frequent during tuberculosis, and DM needs confirmation after tuberculosis treatment. Performance of DM screening at tuberculosis diagnosis gives the opportunity to detect patients at risk of adverse outcome.

Safety assessment in primary Mycobacterium tuberculosis smear microscopy centres in Blantyre Malawi: a facility based cross sectional survey

Introduction Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is transmitted mainly through aerosolization of infected sputum which puts laboratory workers at risk in spite of the laboratory workers’ risk of infection being at 3 to 9 times higher than the general public. Laboratory safety should therefore be prioritized and optimized to provide sufficient safety to laboratory workers. Objective To assess the safety for the laboratory workers in TB primary microscopy centres in Blantyre urban. Methodology TB primary microscopy centers in Blantyre urban were assessed in aspects of equipment availability, facility layout, and work practice, using a standardized WHO/AFRO ISO 15189 checklist for the developing countries which sets the minimum safety score at ≥80%. Each center was graded according to the score it earned upon assessment. Results Only one (1) microscopy center out nine (9) reached the minimum safety requirement. Four (4) centers were awarded 1 star level, four (4) centers were awarded 2 star level and only one (1) center was awarded 3 star level. Conclusion In Blantyre urban, 89% of the Tuberculosis microscopy centers are failing to provide the minimum safety to the laboratory workers. Government and other stake holders should be committed in addressing the safety challenges of TB microscopy centres in the country to ensure safety for the laboratory workers. Recommendations It is recommended that the study be conducted at the regional or national level for both public and private laboratories in order to have a general picture of safety in Tb microscopy centres possibly across the country.