Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 75
Filtrar
1.
Int J Tuberc Lung Dis ; 26(10): 942-948, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-36163670

RESUMEN

INTRODUCTION The WHO End TB Strategy emphasises early diagnosis and screening of TB in high-risk groups, including migrants. We analysed TB yield data from four large migrant TB screening programmes to inform TB policy.METHODS We pooled routinely collected individual TB screening episode data from Italy, the Netherlands, Sweden and the United Kingdom under the European Union Commission E-DETECT.TB grant, described characteristics of the screened population, and analysed TB case yield.RESULTS We collected data on 2,302,260 screening episodes among 2,107,016 migrants, mostly young adults aged 18-44 years (77.8%) from Asia (78%) and Africa (18%). There were 1,658 TB cases detected through screening, with substantial yield variation (per 100,000): 201.1 for Sweden (95% confidence intervals CI 111.4-362.7), 68.9 (95% CI 65.4-72.7) for the United Kingdom, 83.2 (95% CI 73.3-94.4) for the Netherlands and 653.6 (95% CI 445.4-958.2) in Italy. Most TB cases were notified among migrants from Asia (n = 1,206, 75/100,000) or Africa (n = 370, 76.4/100,000), and among asylum seekers (n = 174, 131.5/100,000), migrants to the Netherlands (n = 101, 61.9/100,000) and settlement visa migrants to the United Kingdom (n = 590, 120.3/100,000).CONCLUSIONS We found considerable variations in yield across programmes, types of migrants and country of origin. These variations may be partly explained by differences in migration patterns and programmatic characteristics.


Asunto(s)
Refugiados , Migrantes , Tuberculosis , Europa (Continente)/epidemiología , Humanos , Tamizaje Masivo/métodos , Tuberculosis/epidemiología , Adulto Joven
2.
Int J Tuberc Lung Dis ; 26(6): 529-536, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35650705

RESUMEN

BACKGROUND: Protection against infection by the bacille Calmette-Guérin vaccine against Mycobacterium tuberculosis remains a subject of controversy. We investigated the association between BCG vaccination at birth and infection by M. tuberculosis.MATERIAL and METHODS: This was a secondary analysis of data from tuberculin skin test (TST) surveys in Vietnamese schoolchildren between 1988 and 2001. We investigated whether a BCG scar was associated with a lower prevalence of TST positivity, adjusting for BCG-induced variation by varying cut-off values for a positive TST.RESULTS: We found a positive association between BCG scar and TST positivity. The strength of the association decreased with increasing TST cut-off values; however, it never inverted significantly, irrespective of geographic region and survey year.CONCLUSION: In Vietnam, BCG vaccination was not associated with reduced M. tuberculosis infection prevalence as measured using TST. This in contrary to a similar study conducted in Tanzania. These contradictory findings may be explained by geographical differences and the relatively high prevalence in Vietnam of the M. tuberculosis Beijing genotype, which is reported to be capable of circumventing BCG-induced immunity.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Ganglionar , Vacuna BCG , Niño , Cicatriz , Humanos , Recién Nacido , Vacunación
3.
Int J Tuberc Lung Dis ; 25(11): 933-938, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34686236

RESUMEN

BACKGROUND: Diagnostic tools to identify incipient or subclinical TB stages will be helpful for preventive intervention. A simple biomarker to predict TB may be the monocytes to lymphocytes ratio (ML ratio) in peripheral blood.METHODS: We assessed the relationship between multiple time-updated ML ratio measurements and incidence of TB in people living with HIV (PLWH) after antiretroviral therapy (ART) was initiated. The ML ratio was updated at least every 6 months. TB incidence with corresponding 95% confidence intervals stratified according to time-updated ML ratio was calculated using ML ratio in quartiles.RESULTS: A total of 1305 PLWH were included in the analyses: 46 had incident TB and 1259 remained TB-free. The TB incidence rate was 10.3 (95% CI 7.1-14.9) cases/1000 patient-years (PYR) among participants with ML ratio ≥0.25 compared with 1.1/1000 PYR (95% CI 0.4-2.9) among those with ML ratio <0.15. At cut-point 0.23, the ML ratio provided a diagnostic area under the receiver operating characteristics curve (AROC) of 0.849 (95% CI 0.784-0.914) and a sensitivity of 85% and specificity of 71%.CONCLUSION: Increased ML ratio was predictive of incident TB among PLWH on or after ART. The ML ratio can be a simple tool to stratify the risk of TB in PLWH.


Asunto(s)
Infecciones por VIH , Tuberculosis , Recuento de Linfocito CD4 , Pruebas Diagnósticas de Rutina , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Incidencia , Linfocitos , Monocitos , Tuberculosis/diagnóstico , Tuberculosis/epidemiología
4.
Int J Tuberc Lung Dis ; 24(5): 477-484, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32398196

RESUMEN

BACKGROUND: Tuberculosis incidence varies seasonally in many settings. However, the role of seasonal variation in reactivation vs. transmission is unclear.METHODS: We reviewed data on TB notifications in Cape Town, South Africa, from 1903 to 2017 (exclusive of 1995-2002, which were unavailable). Data from 2003 onward were stratified by HIV status, age and notification status (new vs. retreatment). We performed seasonal decomposition and time-dependent spectral analysis using wavelets to assess periodicity over time. We estimated monthly peak-to-peak seasonal amplitude of notifications as a percentage of the annual notification rate.RESULTS: A seasonal trend was intermittently detected between 1904 and 1994, particularly during periods of high notification rates, but was consistently and strongly evident between 2003 and 2017, with peaks in September through November, following winter. Among young children, a second, higher seasonal peak was observed in March. Seasonal variation was greater in children (<5 years, 54%, 95% CI 47-61; 5-14 years, 63%, 95% CI 58-69) than in adults (36%, 95% CI 33-39).CONCLUSIONS: Stronger seasonal effects were seen in children, in whom progression following recent infection is known to be the predominant driver of disease. These findings may support increased transmission in the winter as an important driver of TB in Cape Town.


Asunto(s)
Tuberculosis , Adulto , Niño , Preescolar , Ciudades , Humanos , Incidencia , Estaciones del Año , Sudáfrica/epidemiología , Tuberculosis/tratamiento farmacológico , Tuberculosis/epidemiología
5.
Int J Tuberc Lung Dis ; 21(5): 531-536, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28399968

RESUMEN

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is considered to be less transmissible due to the fitness cost associated with drug resistance-conferring mutations in essential genes. OBJECTIVE: To test the hypothesis that TB drug resistance-conferring mutations with fitness cost are more frequent among human immunodeficiency virus (HIV) positive than among HIV-negative patients. DESIGN: We analysed all strains from the two TB drug resistance surveys conducted in Uganda between 2008 and 2011. Strains phenotypically susceptible to rifampicin and/or isoniazid were assumed to be wild-type; in all other cases, we performed whole-genome sequencing. Mutations at the rpoB531 and katG315 codons were considered without fitness loss, whereas other rpoB codons and non-katG were considered with fitness loss. RESULTS: Of the 897 TB patients, 286 (32.1%) were HIV-positive. Mutations with fitness loss in HIV-positive and HIV-negative patients were respectively as follows: non-531 rpoB: 1.03% (n = 3), 0.71% (n = 4) (OR 1.46, 95%CI 0.58-3.68); non-katG: 0.40% (n = 1), 1.0% (n = 6) (OR 0.40, 95%CI 0.07-2.20); rpoB531: 1.49% (n = 4), 0.69% (n = 4) (OR 2.29, 95%CI 0.83-5.77); katG315: 3.86% (n = 11), 2.55% (n = 15) (OR 1.54, 95%CI 0.81-2.90). The odds of mutations with and without fitness cost were higher for patients with a history of previous anti-tuberculosis treatment. CONCLUSIONS: Our data do not support the hypothesis that resistance-conferring mutations with fitness cost are likely to be often present in HIV-positive individuals.


Asunto(s)
Antituberculosos/farmacología , Infecciones por VIH/epidemiología , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Resistente a Múltiples Medicamentos/transmisión , Adolescente , Adulto , Farmacorresistencia Bacteriana Múltiple/genética , Femenino , Genoma Bacteriano , Humanos , Isoniazida/farmacología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Mutación , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/aislamiento & purificación , Rifampin/farmacología , Uganda , Adulto Joven
6.
Int J Tuberc Lung Dis ; 21(4): 446-451, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28284261

RESUMEN

SETTING: Mozambique, one of the world's high tuberculosis (TB) burden countries, has conducted only one national-level drug resistance survey, in 2007-2008. OBJECTIVE: To determine the drug resistance patterns of laboratory-confirmed TB cases. DESIGN: This was a population-level survey conducted over a 1-year period in the district of Manhiça. All laboratory-confirmed cases were evaluated for first-line anti-tuberculosis drug susceptibility testing using liquid culture. RESULTS: Resistance to at least one first-line drug was observed in 44 of 276 isolates (15.9%). Prevalence of drug resistance to each of the five anti-tuberculosis drugs tested was 4.0% for streptomycin, 10.1% for isoniazid (INH), 6.2% for rifampicin, 3.6% for ethambutol and 1.1% for pyrazinamide. The overall prevalence of multidrug-resistant TB (MDR-TB) was 5.1%: 3.8% (95%CI 2.0-7.0) in new and 13.2% (95%CI 5.8-27.3) in retreatment cases. Respectively 4.6% and 2.6% of new and retreatment cases were INH-monoresistant. Previous history of anti-tuberculosis treatment was associated with having MDR-TB (OR 4.3, 95%CI 1.3-14.1). CONCLUSION: The prevalence of drug resistance in the district of Manhiça is slightly higher than, but still compatible with, previous national estimates. INH monoresistance was high, posing the risk of hidden monotherapy in the continuation phase.


Asunto(s)
Antituberculosos/farmacología , Isoniazida/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Adulto , Farmacorresistencia Bacteriana , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Mozambique/epidemiología , Mycobacterium tuberculosis/aislamiento & purificación , Prevalencia , Estudios Prospectivos , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología
7.
BMC Infect Dis ; 16(1): 726, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27905897

RESUMEN

BACKGROUND: Despite improvements in treatment success rates for tuberculosis (TB), current six-month regimen duration remains a challenge for many National TB Programmes, health systems, and patients. There is increasing investment in the development of shortened regimens with a number of candidates in phase 3 trials. METHODS: We developed an individual-based decision analytic model to assess the cost-effectiveness of a hypothetical four-month regimen for first-line treatment of TB, assuming non-inferiority to current regimens of six-month duration. The model was populated using extensive, empirically-collected data to estimate the economic impact on both health systems and patients of regimen shortening for first-line TB treatment in South Africa, Brazil, Bangladesh, and Tanzania. We explicitly considered 'real world' constraints such as sub-optimal guideline adherence. RESULTS: From a societal perspective, a shortened regimen, priced at USD1 per day, could be a cost-saving option in South Africa, Brazil, and Tanzania, but would not be cost-effective in Bangladesh when compared to one gross domestic product (GDP) per capita. Incorporating 'real world' constraints reduces cost-effectiveness. Patient-incurred costs could be reduced in all settings. From a health service perspective, increased drug costs need to be balanced against decreased delivery costs. The new regimen would remain a cost-effective option, when compared to each countries' GDP per capita, even if new drugs cost up to USD7.5 and USD53.8 per day in South Africa and Brazil; this threshold was above USD1 in Tanzania and under USD1 in Bangladesh. CONCLUSION: Reducing the duration of first-line TB treatment has the potential for substantial economic gains from a patient perspective. The potential economic gains for health services may also be important, but will be context-specific and dependent on the appropriate pricing of any new regimen.


Asunto(s)
Antituberculosos/economía , Tuberculosis/tratamiento farmacológico , Tuberculosis/economía , Bangladesh , Brasil , Análisis Costo-Beneficio , Atención a la Salud/economía , Costos de los Medicamentos , Costos de la Atención en Salud , Gastos en Salud , Servicios de Salud/economía , Humanos , Modelos Teóricos , Sudáfrica , Tanzanía , Resultado del Tratamiento
8.
Int J Tuberc Lung Dis ; 20(5): 611-8, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27084814

RESUMEN

INTRODUCTION: The Xpert® MTB/RIF assay is being implemented as a substitute for sputum smear microscopy (SSM) in many low and high tuberculosis (TB) burden countries, including Brazil, a country with low multidrug resistance and moderate human immunodeficiency virus co-infection rates. SETTING: Brazilian National TB Programme (NTP). OBJECTIVE AND DESIGN: We estimated the incremental cost-effectiveness ratio (ICER) of Xpert as a substitute for two SSM tests in the diagnosis of drug-susceptible TB. The costs for confirming each additional case and for avoiding treatment due to false-positive empirical diagnoses were estimated. RESULTS: The ICER was US$943 for each additional TB diagnosis and US$356 for each additional TB diagnosis with bacteriological confirmation, assuming 80% specificity of clinical diagnosis using both strategies. For every 100 000 patients with suspected TB, the NTP would spend an additional US$1.2 million per year to confirm 3344 more TB patients. The model was highly sensitive to specificity of clinical diagnosis after a negative test. CONCLUSION: Although the NTP has no threshold for cost-effectiveness, our model can provide support for decision makers in Brazil and other countries with a low prevalence of drug resistance among TB patients. Financial benefit can potentially be expected if physicians rely more on a negative Xpert result and empirical treatment is reduced.


Asunto(s)
ADN Bacteriano/genética , Farmacorresistencia Bacteriana/genética , Costos de la Atención en Salud , Pulmón/microbiología , Técnicas de Diagnóstico Molecular/economía , Mycobacterium tuberculosis/genética , Reacción en Cadena de la Polimerasa/economía , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/economía , Antibióticos Antituberculosos/uso terapéutico , Automatización de Laboratorios , Brasil , Simulación por Computador , Análisis Costo-Beneficio , ADN Bacteriano/aislamiento & purificación , Técnicas de Apoyo para la Decisión , Árboles de Decisión , Reacciones Falso Positivas , Humanos , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/aislamiento & purificación , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Rifampin/uso terapéutico , Esputo/microbiología , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/microbiología , Procedimientos Innecesarios/economía
9.
Int J Tuberc Lung Dis ; 20(2): 257-60, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26792481

RESUMEN

User-friendly models (UFMs) allow local decision makers to explore relationships and apply results from more detailed models of such outcomes as cost-effectiveness. When developing UFMs, modelers must decide which simplifications may be appropriate, enabling the UFM to retain accuracy while reducing complexity. We use the example of cost-effectiveness analysis (CEA) for novel shortened anti-tuberculosis treatment regimens across four settings to demonstrate how UFMs can allow decision makers to adapt published results to their local context. We simplified a complex model to produce a UFM that provides similar results, the ability to modify key parameter values, and receive customized results in seconds.


Asunto(s)
Antituberculosos/administración & dosificación , Antituberculosos/economía , Técnicas de Apoyo para la Decisión , Costos de los Medicamentos , Tuberculosis/tratamiento farmacológico , Tuberculosis/economía , Simulación por Computador , Análisis Costo-Beneficio , Evaluación de la Discapacidad , Esquema de Medicación , Quimioterapia Combinada , Accesibilidad a los Servicios de Salud , Humanos , Modelos Económicos , Método de Montecarlo , Selección de Paciente , Factores de Tiempo , Resultado del Tratamiento , Tuberculosis/diagnóstico , Tuberculosis/epidemiología
10.
Clin Infect Dis ; 62(7): 887-895, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26757804

RESUMEN

BACKGROUND: Medical treatment for multidrug-resistant (MDR)-tuberculosis is complex, toxic, and associated with poor outcomes. Surgical lung resection may be used as an adjunct to medical therapy, with the intent of reducing bacterial burden and improving cure rates. We conducted an individual patient data metaanalysis to evaluate the effectiveness of surgery as adjunctive therapy for MDR-tuberculosis. METHODS: Individual patient data, was obtained from the authors of 26 cohort studies, identified from 3 systematic reviews of MDR-tuberculosis treatment. Data included the clinical characteristics and medical and surgical therapy of each patient. Primary analyses compared treatment success (cure and completion) to a combined outcome of failure, relapse, or death. The effects of all forms of resection surgery, pneumonectomy, and partial lung resection were evaluated. RESULTS: A total of 4238 patients from 18 surgical studies and 2193 patients from 8 nonsurgical studies were included. Pulmonary resection surgery was performed on 478 patients. Partial lung resection surgery was associated with improved treatment success (adjusted odds ratio [aOR], 3.0; 95% confidence interval [CI], 1.5-5.9; I(2)R, 11.8%), but pneumonectomy was not (aOR, 1.1; 95% CI, .6-2.3; I(2)R, 13.2%). Treatment success was more likely when surgery was performed after culture conversion than before conversion (aOR, 2.6; 95% CI, 0.9-7.1; I(2)R, 0.2%). CONCLUSIONS: Partial lung resection, but not pneumonectomy, was associated with improved treatment success among patients with MDR-tuberculosis. Although improved outcomes may reflect patient selection, partial lung resection surgery after culture conversion may improve treatment outcomes in patients who receive optimal medical therapy.


Asunto(s)
Neumonectomía/estadística & datos numéricos , Tuberculosis Resistente a Múltiples Medicamentos/cirugía , Tuberculosis Pulmonar/cirugía , Adulto , Antituberculosos/uso terapéutico , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología
11.
Int J Tuberc Lung Dis ; 20(1): 24-42, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26688526

RESUMEN

The emergence of drug-resistant strains of Mycobacterium tuberculosis is a challenge to global tuberculosis (TB) control. Although culture-based methods have been regarded as the gold standard for drug susceptibility testing (DST), molecular methods provide rapid information on mutations in the M. tuberculosis genome associated with resistance to anti-tuberculosis drugs. We ascertained consensus on the use of the results of molecular DST for clinical treatment decisions in TB patients. This document has been developed by TBNET and RESIST-TB groups to reach a consensus about reporting standards in the clinical use of molecular DST results. Review of the available literature and the search for evidence included hand-searching journals and searching electronic databases. The panel identified single nucleotide mutations in genomic regions of M. tuberculosis coding for katG, inhA, rpoB, embB, rrs, rpsL and gyrA that are likely related to drug resistance in vivo. Identification of any of these mutations in clinical isolates of M. tuberculosis has implications for the management of TB patients, pending the results of in vitro DST. However, false-positive and false-negative results in detecting resistance-associated mutations in drugs for which there is poor or unproven correlation between phenotypic and clinical drug resistance complicate the interpretation. Reports of molecular DST results should therefore include specific information on the mutations identified and provide guidance for clinicians on interpretation and on the choice of the appropriate initial drug regimen.


Asunto(s)
Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/genética , Antituberculosos/farmacología , Conferencias de Consenso como Asunto , Humanos , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología
12.
BMC Infect Dis ; 15: 473, 2015 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-26503434

RESUMEN

BACKGROUND: Molecular resistance detection (MRD) of resistance to second-line anti-tuberculous drugs provides faster results than phenotypic tests, may shorten treatment and allow earlier separation among patients with and without second-line drug resistance. METHODS: In a decision-analytical model we simulated a cohort of patients diagnosed with TB in a setting where drug resistant TB is highly prevalent and requires initial hospitalization, to explore the potential benefits of a high-throughput MRD-assay for reducing potential nosocomial transmission of highly resistant strains, and total costs for diagnosis of drug resistance, treatment and hospitalization. In the base case scenario first-line drug resistance was diagnosed with WHO-endorsed molecular tests, and second-line drug resistance with culture and phenotypic methods. Three alternative scenarios were explored, each deploying high-throughput MRD allowing either detection of second-line mutations in cultured isolates, directly on sputum, or MRD with optimized markers. RESULTS: Compared to a base case scenario, deployment of high-throughput MRD reduced total costs by 17-21 %. The period during which nosocomial transmission may take place increased by 15 % compared to the base case if MRD had currently reported suboptimal sensitivity and required cultured isolates; increased by 7 % if direct sputum analysis were possible including in patients with smear-negative TB, and reduced by 24 % if the assay had improved markers, but was still performed on cultured isolates. Improved clinical sensitivity of the assay (additional markers) by more than 35 % would be needed to avoid compromising infection control. CONCLUSIONS: Further development of rapid second-line resistance testing should prioritize investment in optimizing markers above investments in a platform for direct analysis of sputum.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Ensayos Analíticos de Alto Rendimiento/métodos , Mutación , Tuberculosis Resistente a Múltiples Medicamentos/genética , Antituberculosos/uso terapéutico , Costos y Análisis de Costo , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/prevención & control , Diagnóstico Precoz , Georgia (República) , Ensayos Analíticos de Alto Rendimiento/economía , Humanos , Control de Infecciones , Persona de Mediana Edad , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/aislamiento & purificación , Esputo/microbiología , Tuberculosis/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/economía
13.
Int J Tuberc Lung Dis ; 18(9): 1012-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25189546

RESUMEN

The landscape of diagnostic testing for tuberculosis (TB) is changing rapidly, and stakeholders need urgent guidance on how to develop, deploy and optimize TB diagnostics in a way that maximizes impact and makes best use of available resources. When decisions must be made with only incomplete or preliminary data available, modelling is a useful tool for providing such guidance. Following a meeting of modelers and other key stakeholders organized by the TB Modelling and Analysis Consortium, we propose a conceptual framework for positioning models of TB diagnostics. We use that framework to describe modelling priorities in four key areas: Xpert(®) MTB/RIF scale-up, target product profiles for novel assays, drug susceptibility testing to support new drug regimens, and the improvement of future TB diagnostic models. If we are to maximize the impact and cost-effectiveness of TB diagnostics, these modelling priorities should figure prominently as targets for future research.


Asunto(s)
Técnicas Bacteriológicas/economía , Costos de la Atención en Salud , Tuberculosis/diagnóstico , Antituberculosos/uso terapéutico , Técnicas Bacteriológicas/normas , Investigación Biomédica/economía , Análisis Costo-Beneficio , Prioridades en Salud/economía , Humanos , Pruebas de Sensibilidad Microbiana/economía , Modelos Económicos , Guías de Práctica Clínica como Asunto , Valor Predictivo de las Pruebas , Pronóstico , Tuberculosis/tratamiento farmacológico , Tuberculosis/economía , Tuberculosis/microbiología
14.
Int J Tuberc Lung Dis ; 18(6): 647-54, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24903933

RESUMEN

BACKGROUND: Drug susceptibility testing (DST) against second-line tuberculosis drugs (SLDs) is essential for improving outcomes among multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) cases. OBJECTIVE: To evaluate the potential cost-effectiveness of rapid DST for SLDs. DESIGN: We constructed a decision analysis model of Xpert MTB/RIF-based TB diagnosis in East and South-East Asia to compare culture-based DST vs. a hypothetical rapid SLD DST system for specimens resistant to rifampin. Our primary outcomes were the effectiveness and incremental cost-effectiveness of a rapid SLD DST assay relative to culture-based DST. RESULTS: For rapid SLD DST to be more effective than culture-based DST, treating individuals with pre-XDR/XDR-TB with a standardized MDR-TB regimen while awaiting culture-based DST must incur at least 30% excess XDR-TB mortality (100% = treatment with first-line drugs); rapid SLD DST should attain an aggregate sensitivity and specificity for all pre-XDR/XDR mutations of 88% and 96%, respectively. The unit cost of the rapid SLD DST assay must approach that of culture to achieve common thresholds for cost-effectiveness in low-income countries. CONCLUSION: Rapid SLD DST has the potential to be cost-effective, but must meet stringent criteria for accuracy and costs, and requires that standardized second-line treatment for pre-XDR/XDR-TB incur substantial excess mortality before the return of culture results.


Asunto(s)
Antituberculosos/uso terapéutico , Análisis Costo-Beneficio , Técnicas de Apoyo para la Decisión , Farmacorresistencia Bacteriana Múltiple , Tuberculosis Extensivamente Resistente a Drogas/tratamiento farmacológico , Costos de la Atención en Salud , Pruebas de Sensibilidad Microbiana/economía , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Algoritmos , Asia , Árboles de Decisión , Costos de los Medicamentos , Tuberculosis Extensivamente Resistente a Drogas/diagnóstico , Tuberculosis Extensivamente Resistente a Drogas/economía , Tuberculosis Extensivamente Resistente a Drogas/microbiología , Tuberculosis Extensivamente Resistente a Drogas/mortalidad , Humanos , Modelos Económicos , Valor Predictivo de las Pruebas , Resultado del Tratamiento , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/economía , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/mortalidad
15.
Int J Tuberc Lung Dis ; 17(11): 1479-85, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24125454

RESUMEN

SETTING: The molecular diagnosis of tuberculosis (TB) in Viet Nam is often based on the detection of insertion sequence (IS) 6110 in Mycobacterium tuberculosis. However, 8-11% of M. tuberculosis strains in South-East Asia do not contain this target and this undermines the validity of these molecular tests. OBJECTIVE: We quantified the frequency of M. tuberculosis strains lacking IS6110 in rural Viet Nam and studied their epidemiological and clinical characteristics. DESIGN: Consecutively diagnosed adult TB patients in rural Southern Viet Nam submitted two sputum samples for culture, IS6110 restriction fragment length polymorphism (RFLP) spoligotyping and 15-loci variable number tandem repeat typing. Polymerase chain reaction (PCR) was performed to confirm the absence of IS6110 elements in strains lacking IS6110 hybridisation in RFLP. RESULTS: Among 2664 TB patient isolates examined, 109 (4.1%) had no IS6110 element. Compared to other strains, these no-copy strains were less often resistant to anti-tuberculosis drugs, particularly to streptomycin (adjusted OR 0.2, 95%CI 0.1-0.5), and showed significant geographic variation. No associations with TB history or demographic factors were found. CONCLUSIONS: Strains without the IS6110 target pose a problem in Viet Nam as regards false-negative molecular TB diagnosis in PCR. Compared to other strains circulating in Viet Nam, no-copy strains are more susceptible to anti-tuberculosis drugs.


Asunto(s)
Elementos Transponibles de ADN , ADN Bacteriano/análisis , Mycobacterium tuberculosis/genética , Tuberculosis Pulmonar/microbiología , Adolescente , Adulto , Anciano , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Antituberculosos/uso terapéutico , Farmacorresistencia Bacteriana , Reacciones Falso Negativas , Femenino , Genotipo , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Repeticiones de Minisatélite , Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis/clasificación , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/aislamiento & purificación , Fenotipo , Polimorfismo de Longitud del Fragmento de Restricción , Valor Predictivo de las Pruebas , Estudios Prospectivos , Salud Rural , Esputo/microbiología , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/transmisión , Vietnam/epidemiología , Adulto Joven
16.
Int J Tuberc Lung Dis ; 17(6): 738-44, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23676155

RESUMEN

OBJECTIVES: To estimate the prevalence of infection with Mycobacterium tuberculosis and the annual risk of tuberculous infection (ARTI) and to compare this with the prevalence of tuberculosis (TB) over study clusters and households. METHODS: A nationwide, stratified cluster sample survey was carried out in 2006-2007 in Viet Nam to assess the prevalence of infection with M. tuberculosis. A representative sample of children aged 6-14 years underwent a tuberculin skin test (TST) using the Mantoux method. RESULTS: Of 23,160 children registered, 21,487 (92.8%) were tested and read and available for analysis. Using a cut-off point of 10 mm, the estimated prevalence of TST positivity was 16.7%, and the ARTI was 1.7% (95%CI 1.5-1.8). Higher infection rates were found in urban than in rural and remote areas, and infection rates increased with age. There was significant association between the prevalence of TB disease and infection at the cluster level (regression coefficient 0.54, 95%CI 0.06-1.01, P = 0.027, correlation coefficient R(2) 0.120). Children with a (recent) case of TB in the household were 1.6 times more likely to be TST-positive than children in households with no recent cases (P < 0.05). CONCLUSION: The estimated nationwide ARTI was 1.7%. TST positivity was associated with the presence of a TB case in the household.


Asunto(s)
Salud de la Familia/estadística & datos numéricos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis/epidemiología , Adolescente , Ageísmo , Niño , Análisis por Conglomerados , Femenino , Humanos , Masculino , Prevalencia , Análisis de Regresión , Población Rural/estadística & datos numéricos , Prueba de Tuberculina , Tuberculosis/diagnóstico , Población Urbana/estadística & datos numéricos , Vietnam/epidemiología
17.
Int J Tuberc Lung Dis ; 16(12): 1625-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23131260

RESUMEN

SETTINGS: Private pharmacies in Hanoi, Viet Nam. OBJECTIVES: To explore the response of health care providers (HCPs) in private pharmacies to suspected tuberculosis (TB) patients. METHODS: A simulated patient method combined with an interview in 128 randomly selected private pharmacies and 10 private pharmacies near TB hospitals. RESULTS: In the simulated patient method and interview, respectively 59 (46%) and 70 (55%) of HCPs referred the TB suspect to general health care. Only 11 (9%) referred the simulated patient to a TB care facility. Fifty-two (42%) of the HCPs identified suspected TB from a fictitious case described on paper; 34 (27%) were aware that free treatment was provided under the National Tuberculosis Programme (NTP). Knowledge about free NTP treatment predicted a higher rate of direct referrals to TB facilities (OR 5.80, 95%CI 1.88-19.62) and greater ability to identify suspected TB from a fictitious case on paper (OR 5.14, 95%CI 2.36-11.73). Pharmacies with Good Pharmacy Practice (GPP) certification were less likely to refer simulated patients to TB facilities than non-GPP pharmacies (OR 0.10, 95%CI ≤0.01-0.79). CONCLUSIONS: Nearly half of HCPs in private pharmacies do not refer TB suspects, possibly contributing to delays in diagnosis and treatment. Knowledge about free NTP treatment predicted better performance of HCPs.


Asunto(s)
Actitud del Personal de Salud , Servicios Comunitarios de Farmacia , Hospitales de Enfermedades Crónicas , Farmacéuticos/psicología , Sector Privado , Competencia Profesional , Derivación y Consulta , Tuberculosis/diagnóstico , Adulto , Antituberculosos/uso terapéutico , Concienciación , Diagnóstico Tardío , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Análisis Multivariante , Programas Nacionales de Salud , Oportunidad Relativa , Simulación de Paciente , Valor Predictivo de las Pruebas , Pronóstico , Encuestas y Cuestionarios , Factores de Tiempo , Tuberculosis/tratamiento farmacológico , Tuberculosis/microbiología , Vietnam , Adulto Joven
18.
Int J Tuberc Lung Dis ; 16(6): 762-7, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22507287

RESUMEN

BACKGROUND: Tuberculosis (TB) prevalence surveys generally rely on a combination of screening methods to identify suspects eligible for sputum culture. OBJECTIVE: To assess the yield of screening methods applied in a recent prevalence survey in Viet Nam and estimate the proportion of TB cases missed due to incomplete participation. METHODS: TB suspects were identified based on self-reported TB history or productive cough by interview and chest X-ray (CXR). We calculated the case yield of these two screening methods by dividing the number of cases detected per method by the total number of cases detected. As not all participants underwent the full screening procedure, we recalculated the maximum yield of the screening methods using multiple imputation methods. RESULTS: The yield from screening by interview and CXR were respectively 38% and 91%. Adjusting for missing data by multiple imputation, we estimated that we missed 9.9% (95%CI 6.8-14.2) of expected TB cases. CONCLUSION: In prevalence surveys, screening by pre-structured interview is insufficient, and should be supplemented with CXR to achieve sufficient identification of TB cases. The effect of incomplete participation in the full screening procedure may be substantial and should be adjusted for in the analysis.


Asunto(s)
Entrevistas como Asunto , Tamizaje Masivo/métodos , Radiografía Torácica , Tuberculosis Pulmonar/epidemiología , Estudios Transversales , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Mycobacterium tuberculosis/aislamiento & purificación , Valor Predictivo de las Pruebas , Prevalencia , Sensibilidad y Especificidad , Esputo/microbiología , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/diagnóstico por imagen , Tuberculosis Pulmonar/microbiología , Vietnam/epidemiología
19.
Trop Med Int Health ; 17(6): 760-6, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22487607

RESUMEN

OBJECTIVE: To review the activities, progress, achievements and challenges of the Zambia Ministry of Health tuberculosis (TB)/HIV collaborative activities over the past decade. METHODS: Analysis of Zambia Ministry of Health National TB and HIV programme documents and external independent programme review reports pertaining to 2000-2010. RESULTS: The number of people testing for HIV increased from 37 557 persons in 2003 to 1 327 995 persons in 2010 nationally. Those receiving anti-retroviral therapy (ART) increased from 143 in 2003 to 344 304 in 2010. The national HIV prevalence estimates declined from 14.3% in 2001 to 13.5% in 2009. The proportion of TB patients being tested for HIV increased from 22.6% in 2006 to 84% in 2010 and approximately 70% were HIV positive. The proportion of the HIV-infected TB patients who: (i) started on ART increased from 38% in 2006 to 50% in 2010; (ii) commenced co-trimoxazole preventive therapy (CPT) increased from 31% in 2006 to 70% in 2010; and (iii) were successfully treated increased to an average of 80% resulting in decline of deaths from 13% in 2006 to 9% in 2010. CONCLUSIONS: The scale-up of TB/HIV collaborative programme activities in Zambia has steadily increased over the past decade resulting in increased testing for TB and HIV, and anti-retroviral (ARV) rollout with improved treatment outcomes among TB patients co-infected with HIV. Getting service delivery points to adhere to WHO guidelines for collaborative TB/HIV activities remains problematic, especially those meant to reduce the burden of TB in people living with HIV/AIDS (PLWHA).


Asunto(s)
Programas de Gobierno/organización & administración , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Promoción de la Salud/organización & administración , Tuberculosis/epidemiología , Tuberculosis/prevención & control , Adolescente , Adulto , Fármacos Anti-VIH/uso terapéutico , Antiinfecciosos/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Antituberculosos/uso terapéutico , Conducta Cooperativa , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Prevalencia , Evaluación de Programas y Proyectos de Salud , Resultado del Tratamiento , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Adulto Joven , Zambia/epidemiología
20.
Trop Med Int Health ; 16(10): 1260-7, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21692960

RESUMEN

OBJECTIVE: To assess health-seeking behaviour among adults with prolonged cough in a population-based, nationally representative sample in Vietnam. METHODS: Cross-sectional survey conducted from September 2006 to July 2007. All inhabitants aged ≥15 years were invited for screening for cough, history of tuberculosis (TB) treatment and chest X-ray (CXR) examination. TB suspects, defined as any survey participant with CXR abnormalities consistent with TB, or productive cough for more than 2 weeks or TB treatment either currently or in the preceding 2 years submitted sputum specimens for smear examination and culture and provided information on health-seeking behaviour in an in-depth interview. RESULTS: Of 94 179 persons participating in the survey, 4.6% had prolonged productive cough. Forty-four percentage of those had sought health care and reported pharmacies (35%), commune health posts (29%), public hospitals (24%) and private physicians (10%) as first point of contact. Only 7% had undergone sputum smear examination. Of TB suspects with prolonged productive cough, 2.9% were diagnosed with TB; 10.2% of these reported smear and 21.9% reported X-ray examination when visiting a health care facility. The average patient delay was 4.1 weeks (95% CI: 3.9-4.4) among cough suspects and 4.0 weeks (95% CI: 3.1-4.9) among TB cases. CONCLUSIONS: In this Vietnamese survey, nearly half of persons with cough for more than 2 weeks had visited a health care provider. The commonest first health facility contacted was the pharmacy. Sputum smears were rarely examined, except in the provincial TB hospital. Our findings highlight the need to improve diagnostic practices by retraining health staff on the performance of sputum examination for TB suspects.


Asunto(s)
Tos/microbiología , Conductas Relacionadas con la Salud , Aceptación de la Atención de Salud/estadística & datos numéricos , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/diagnóstico , Adulto , Anciano , Enfermedad Crónica , Estudios Transversales , Diagnóstico Diferencial , Femenino , Humanos , Conducta en la Búsqueda de Información , Masculino , Persona de Mediana Edad , Población Rural/estadística & datos numéricos , Distribución por Sexo , Encuestas y Cuestionarios , Factores de Tiempo , Población Urbana/estadística & datos numéricos , Vietnam/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA