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1.
BMJ Glob Health ; 8(Suppl 8)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37813445

RESUMO

Fiscal policies to improve diet are a promising strategy to address the increasing burden of non-communicable disease, the leading cause of death globally. Sugar-sweetened beverage taxes are the most implemented type of fiscal policy to improve diet. Yet taxes on food, if appropriately structured and applied across the food supply, may support a larger population-level shift towards a healthier diet. Designing these policies and guiding them through the legislative process requires evidence. Equity-oriented cost-effectiveness analyses that estimate the distribution of potential health and economic gains can provide this critical evidence. Taxes on less healthy foods are rarely modelled in low-income and middle-income countries.We describe considerations for modelling the effect of a food tax, which can provide guidance for food tax policy design. This includes describing issues related to the availability, reliability and level of detail of national data on dietary habits, the nutrient content of foods and food prices; the structure of the nutrient profile model; type of tax; tax rate; pass-through rate and price elasticity. Using the Philippines as an example, we discuss considerations for using existing data to model the potential effect of a tax, while also taking into account the political and food policy context. In this way, we provide a modelling framework that can help guide policy-makers and advocates in designing a food policy to improve the health and well-being of future generations in the Philippines and elsewhere.


Assuntos
Países em Desenvolvimento , Alimentos , Humanos , Filipinas , Reprodutibilidade dos Testes , Impostos
2.
Biomolecules ; 12(11)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36421707

RESUMO

Pseudoexfoliation glaucoma (XFG) is an aggressive form of secondary open angle glaucoma, characterised by the production of exfoliation material and is estimated to affect 30 million people worldwide. Activation of the TGF-ß pathway by TGF-ß1 has been implicated in the pathogenesis of pseudoexfoliation glaucoma. To further investigate the role of TGF-ß1 in glaucomatous changes in the trabecular meshwork (TM), we used RNA-Seq to determine TGF-ß1 induced changes in the transcriptome of normal human trabecular meshwork (HTM) cells. The main purpose of this study was to perform a hypothesis-independent RNA sequencing analysis to investigate genome-wide alterations in the transcriptome of normal HTMs stimulated with TGF-ß1 and investigate possible pathophysiological mechanisms driving XFG. Our results identified multiple differentially expressed genes including several genes known to be present in exfoliation material. Significantly altered pathways, biological processes and molecular functions included extracellular matrix remodelling, Hippo and Wnt pathways, the unfolded protein response, oxidative stress, and the antioxidant system. This cellular model of pseudoexfoliation glaucoma can provide insight into disease pathogenesis and support the development of novel therapeutic interventions.


Assuntos
Glaucoma de Ângulo Aberto , Glaucoma , Humanos , Malha Trabecular/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Glaucoma de Ângulo Aberto/genética , Glaucoma de Ângulo Aberto/metabolismo , RNA/metabolismo , Glaucoma/genética , Glaucoma/metabolismo , Análise de Sequência de RNA
3.
J Clin Hypertens (Greenwich) ; 24(10): 1285-1292, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36172888

RESUMO

The purpose of this paper is to evaluate the quality of information and guidance on dietary sodium reduction available on consumer-facing websites. Google Trends was used to identify the five most-used search terms related to dietary sodium reduction. For each term, websites on the first two pages were collected (n = 18-20). Of 93 websites collected, 24 were excluded due to defective links, duplicate websites, or not being consumer-focused. The remaining 69 websites were evaluated using a novel instrument, JHU-SALT, that includes 14 questions on topics related to salt reduction. The questions are grouped into three domains ("information," "guidance," and "accuracy"). For each question, websites were scored using a 3-step ordinal scale ("topic not addressed," "topic somewhat addressed," or "topic addressed adequately"). Only three of 14 JHU-SALT questions were addressed adequately by a majority of websites. Many websites provided information on the adverse health effects of a high sodium diet (74%, n = 51) or mentioned intake recommendations (64%, n = 44). Information on fundamental concepts was largely missing. The majority of websites (80%, n = 55) provided information on lifestyle strategies to reduce blood pressure, but most did not provide guidance to help implement those strategies. While missing information was common, misinformation was uncommon. The DISCERN questionnaire was utilized as well. Consumers seeking information and guidance on dietary sodium reduction will find that most available websites provide accurate but limited information, and insufficient guidance on how to lower sodium intake. Websites that provide both relevant information and guidance are needed to help consumers effectively reduce dietary sodium.


Assuntos
Informação de Saúde ao Consumidor , Hipertensão , Sódio na Dieta , Humanos , Hipertensão/epidemiologia , Hipertensão/prevenção & controle , Inquéritos e Questionários , Sódio , Internet
4.
Nutrients ; 13(9)2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34579080

RESUMO

Excess sodium consumption and insufficient potassium intake contribute to high blood pressure and thus increase the risk of heart disease and stroke. In low-sodium salt, a portion of the sodium in salt (the amount varies, typically ranging from 10 to 50%) is replaced with minerals such as potassium chloride. Low-sodium salt may be an effective, scalable, and sustainable approach to reduce sodium and therefore reduce blood pressure and cardiovascular disease at the population level. Low-sodium salt programs have not been widely scaled up, although they have the potential to both reduce dietary sodium intake and increase dietary potassium intake. This article proposes a framework for a successful scale-up of low-sodium salt use in the home through four core strategies: availability, awareness and promotion, affordability, and advocacy. This framework identifies challenges and potential solutions within the core strategies to begin to understand the pathway to successful program implementation and evaluation of low-sodium salt use.


Assuntos
Dieta Hipossódica , Promoção da Saúde , Hipertensão/dietoterapia , Potássio na Dieta/administração & dosagem , Sódio na Dieta/administração & dosagem , Hipertensão/prevenção & controle , Cloreto de Sódio na Dieta/administração & dosagem
6.
Nutrients ; 13(4)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33804870

RESUMO

In China, a major source of sodium is salt added during cooking. In this context, use of a salt-restriction spoon (SRS) has been promoted in public health campaigns and by health care providers. To describe use of and factors associated with SRS use, knowledge of correct use, and actual correct use. This study is a population-based, representative survey of 7512 residents, aged 18 to 69 years, of China's Zhejiang Province. The survey, which was conducted in 2017 using a multistage random sampling strategy, collected demographic information, SRS use, and physical measurements; a 24-h urine collection was obtained from 1,496 of the participants. The mean age of the participants was 44.8 years, 50.1% were females, and over 1/3 (35.3%) were classified as hypertensive. Mean 24-h urinary sodium and potassium excretions were 167.3(72.2) mmol/24 h and 38.2(18.2) mmol/24 h, respectively. Only 12.0% (899/7512) of participants once used or were currently using SRS; of the 899 users, 73.4% knew how to use the SRS correctly, and just 46.5% actually used it correctly. SRS use was more commonly associated with behavioral factors rather than socio-demographic factors. Initiation of SRS use by health care providers was associated with correct technical knowledge of SRS. Lower sodium-to-potassium ratio was associated with SRS use, while SRS use was not associated with urinary sodium and potassium excretion. Use of SRS was uncommon in Zhejiang Province of China. Given that a common source of sodium in China is salt added during cooking, use of SRS is an appealing strategy, ideally as part of a multi-component campaign.


Assuntos
Utensílios de Alimentação e Culinária/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Potássio/urina , Cloreto de Sódio na Dieta/administração & dosagem , Cloreto de Sódio na Dieta/urina , Sódio/urina , Adolescente , Adulto , Idoso , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
J Clin Hypertens (Greenwich) ; 22(2): 273-279, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31967732

RESUMO

High salt (sodium chloride) intake raises blood pressure and increases the risk of developing hypertension, a major risk factor for cardiovascular disease. Little is known about salt intake in Nepal, and no study has estimated salt consumption from 24-hour urinary sodium excretion. Participants (n = 451) were recruited from the Community-Based Management of Non-Communicable Diseases in Nepal (COBIN) cohort in 2018. Salt intake was estimated by analyzing 24-hour urinary sodium excretion. Multivariate linear regression was used to estimate differences in salt intake. The mean (±SD) age and salt intake were 49.6 (±9.8) years and 13.3 (±4.7) g/person/d, respectively. Higher salt intake was significantly associated with male gender (ß for female = -2.4; 95% CI: -3.3, -1.4) and younger age (ß10 years  = -1.4; 95% CI: -1.4, -0.5) and higher BMI (ß = 0.1; 95% CI: 0.0, 0.2). A significant association was also found between increase in systolic blood pressure and higher salt intake (ß = 0.3; 95% CI: 0.0, 0.7). While 55% reported that they consumed just the right amount of salt, 98% were consuming more than the WHO recommended salt amount (<5 g/person/d). Daily salt intake in this population was over twice the limit recommended by the WHO, suggesting a substantial need to reduce salt intake in this population. It also supports the need of global initiatives such as WHO's Global Hearts Initiative SHAKE technical package and Resolves to Save Lives for sodium reduction in low- and middle-income countries like Nepal.


Assuntos
Cloreto de Sódio na Dieta/administração & dosagem , Cloreto de Sódio na Dieta/urina , Adulto , Pressão Sanguínea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nepal/epidemiologia , Coleta de Urina
8.
Adv Nutr ; 11(3): 677-686, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31904809

RESUMO

Excess salt intake contributes to hypertension and increased cardiovascular disease risk. Efforts to implement effective salt-reduction strategies require accurate data on the sources of salt consumption. We therefore performed a systematic review to identify the sources of dietary salt around the world. We systematically searched peer-reviewed and gray literature databases for studies that quantified discretionary (salt added during cooking or at the table) and nondiscretionary sources of salt and those that provided information about the food groups contributing to dietary salt intake. Exploratory linear regression analysis was also conducted to assess whether the proportion of discretionary salt intake is related to the gross domestic product (GDP) per capita of a country. We identified 80 studies conducted in 34 countries between 1975 and 2018. The majority (n = 44, 55%) collected data on dietary salt sources within the past 10 y and were deemed to have a low or moderate risk of bias (n = 75, 94%). Thirty-two (40%) studies were judged to be nationally representative. Populations in Brazil, China, Costa Rica, Guatemala, India, Japan, Mozambique, and Romania received more than half of their daily salt intake from discretionary sources. A significant inverse correlation between discretionary salt intake and a country's per capita GDP was observed (P < 0.0001), such that for every $10,000 increase in per capita GDP, the amount of salt obtained from discretionary sources was lower by 8.7% (95% CI: 5.1%, 12%). Bread products, cereal and grains, meat products, and dairy products were the major contributors to dietary salt intake in most populations. There is marked variation in discretionary salt use around the world that is highly correlated with the level of economic development. Our findings have important implications for the type of salt-reduction strategy likely to be effective in a country.


Assuntos
Cloreto de Sódio na Dieta , Brasil , China , Humanos , Índia , Japão
9.
Hypertension ; 75(2): 266-274, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31838902

RESUMO

Use of salt substitutes containing potassium chloride is a potential strategy to reduce sodium intake, increase potassium intake, and thereby lower blood pressure and prevent the adverse consequences of high blood pressure. In this review, we describe the rationale for using potassium-enriched salt substitutes, summarize current evidence on the benefits and risks of potassium-enriched salt substitutes and discuss the implications of using potassium-enriched salt substitutes as a strategy to lower blood pressure. A benefit of salt substitutes that contain potassium chloride is the expected reduction in dietary sodium intake at the population level because of reformulation of manufactured foods or replacement of sodium chloride added to food during home cooking or at the dining table. There is empirical evidence that replacement of sodium chloride with potassium-enriched salt substitutes lowers systolic and diastolic blood pressure (average net Δ [95% CI] in mm Hg: -5.58 [-7.08 to -4.09] and -2.88 [-3.93 to -1.83], respectively). The risks of potassium-enriched salt substitutes include a possible increased risk of hyperkalemia and its principal adverse consequences: arrhythmias and sudden cardiac death, especially in people with conditions that impair potassium excretion such as chronic kidney disease. There is insufficient evidence regarding the effects of potassium-enriched salt substitutes on the occurrence of hyperkalemia. There is a need for additional empirical research on the effect of increasing dietary potassium and potassium-enriched salt substitutes on serum potassium levels and the risk of hyperkalemia, as well as for robust estimation of the population-wide impact of replacing sodium chloride with potassium-enriched salt substitutes.


Assuntos
Dieta Hipossódica/métodos , Hipertensão , Cloreto de Potássio/farmacologia , Cloreto de Sódio na Dieta/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Humanos , Hipertensão/metabolismo , Hipertensão/prevenção & controle , Medição de Risco , Equilíbrio Hidroeletrolítico/fisiologia
10.
J Clin Hypertens (Greenwich) ; 21(6): 739-748, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31026125

RESUMO

High salt/sodium intake is associated with an increased risk of hypertension, which is a major risk factor for cardiovascular diseases. This paper aims to examine the association between salt consumption and salt-related knowledge, attitudes, and practices (KAP) in Nepal. The cross-sectional data used in this study were collected as part of the community-based management of non-communicable diseases project (COBIN) to understand the amount and KAP related to salt consumption in Nepal. Multivariate hierarchical logistic regression was performed to assess the association of salt-related KAP and determinants of high salt consumption in Nepal. The mean per capita salt intake was 8.0 (±3.7) g/day, with 81.6% of the population reporting higher intake than the WHO recommendation of <5 g/day. People of upper castes [adjusted odds ratio (aOR) = 0.7; 95% confidence interval (CI): 0.5-0.9], people in large families (aOR = 0.6; 95% CI: 0.5-0.7), respondents who were advised to lower salt intake (aOR = 0.6; 95% CI: 0.4-0.9) and who checked salt/sodium labels in food (aOR = 0.6; 95% CI: 0.4-0.9) were less likely to consume higher amounts of salt. Similarly, people who added extra salt to their food at the table (aOR = 1.4; 95 CI: 1.1-1.9) and who reported consuming high amounts of salt (aOR = 1.5; 95% CI: 1.1-2.3) were more likely to have high salt intake. High salt intake was documented in this population. This study suggests the need for culturally tailored community-based behavior modification through health education and dietary counseling to effectively reduce salt consumption and thereby support a reduction in hypertension and cardiovascular diseases in Nepal.


Assuntos
Comportamento Alimentar/psicologia , Conhecimentos, Atitudes e Prática em Saúde/etnologia , Hipertensão/prevenção & controle , Doenças não Transmissíveis/prevenção & controle , Cloreto de Sódio na Dieta/efeitos adversos , Adulto , Doenças Cardiovasculares/epidemiologia , Estudos de Casos e Controles , Serviços de Saúde Comunitária/normas , Estudos Transversais , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Nepal/epidemiologia , Doenças não Transmissíveis/epidemiologia , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Cloreto de Sódio na Dieta/administração & dosagem , Cloreto de Sódio na Dieta/urina
11.
Carbohydr Polym ; 181: 1194-1205, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29253949

RESUMO

Hyaluronic acid (HA) is a natural linear polysaccharide that has been used extensively in the biomedical field as it is a biocompatible, biodegradable, nontoxic and non-immunogenic polymer with high water affinity. Besides, the presence of multiple acid and hydroxyl groups in the HA molecule makes it an ideal candidate for chemical modification. The present paper describes the synthesis and characterization of HA-based hydrogels. For this purpose, aqueous mixtures containing 5% (w/w) of HA and different concentrations of Gantrez S97 (GAN) (1, 3 and 5% w/w) were used to prepare HA-based hydrogels. The mixtures were dried and the hydrogels were obtained after heating the solid material at 80°C for 24h. GAN is the acid form of an methylvinylether and maleic anhydride copolymer and contains multiple acid groups that can form ester bonds when reacting with the multiple hydroxyl groups present in HA chains. The method described here present potential to be applied for the preparation of HA-based biomaterials with a defined form as the crosslinking reaction between HA and the crosslinker takes place in solid phase. Besides, the method can be considered an environmental-friendly process as no organic solvents or potentially toxic substances were used. The esterification reaction was confirmed by infrared spectroscopy and dynamic scanning calorimetry measurements. The loading and release capabilities of the hydrogels were evaluating by using methylene blue (MB) as a model molecule. The hydrogels showed a high affinity for MB showing loadings up to 0.35mg MB per mg of hydrogel. Moreover, the hydrogels were capable of sustaining the MB release over two days. The use of microwave radiation was evaluated to reduce the crosslinking time from 24h to 1h, but this procedure needs to be optimized in future studies. As the crosslinking procedure takes place in solid state, the HA/GAN hydrogels were used to prepare micro-engineered device, microneedle arrays. Finally, the antimicrobial properties of the hydrogels were evaluated. The results showed that the hydrogels presented anti-infective properties.


Assuntos
Tecnologia Biomédica/métodos , Reagentes de Ligações Cruzadas/química , Ácido Hialurônico/síntese química , Hidrogéis/síntese química , Solventes/química , Aderência Bacteriana/efeitos dos fármacos , Liberação Controlada de Fármacos , Ácido Hialurônico/química , Hidrogéis/química , Maleatos/química , Azul de Metileno/farmacologia , Testes de Sensibilidade Microbiana , Micro-Ondas , Agulhas , Polivinil/química , Proteus/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Água/química
14.
Clin Vaccine Immunol ; 16(2): 260-76, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19052159

RESUMO

Serological antibody detection tests for tuberculosis may offer the potential to improve diagnosis. Recent meta-analyses have shown that commercially available tests have variable accuracies and a limited clinical role. We reviewed the immunodiagnostic potential of antigens evaluated in research laboratories (in-house) for the serodiagnosis of pulmonary tuberculosis and conducted a meta-analysis to evaluate the performance of comparable antigens. Selection criteria included the participation of at least 25 pulmonary tuberculosis patients and the use of purified antigens. Studies evaluating 38 kDa, MPT51, malate synthase, culture filtrate protein 10, TbF6, antigen 85B, alpha-crystallin, 2,3-diacyltrehalose, 2,3,6-triacyltrehalose, 2,3,6,6'-tetraacyltrehalose 2'-sulfate, cord factor, and TbF6 plus DPEP (multiple antigen) were included in the meta-analysis. The results demonstrated that (i) in sputum smear-positive patients, sensitivities significantly >or=50% were provided for recombinant malate synthase (73%; 95% confidence interval [CI], 58 to 85) and TbF6 plus DPEP (75%; 95% CI, 50 to 91); (ii) protein antigens achieved high specificities; (iii) among the lipid antigens, cord factor had the best overall performance (sensitivity, 69% [95% CI, 28 to 94]; specificity, 91% [95% CI, 78 to 97]); (iv) compared with the sensitivities achieved with single antigens (median sensitivity, 53%; range, 2% to 100%), multiple antigens yielded higher sensitivities (median sensitivity, 76%; range, 16% to 96%); (v) in human immunodeficiency virus (HIV)-infected patients who are sputum smear positive, antibodies to several single and multiple antigens were detected; and (vi) data on seroreactivity to antigens in sputum smear-negative or pediatric patients were insufficient. Potential candidate antigens for an antibody detection test for pulmonary tuberculosis in HIV-infected and -uninfected patients have been identified, although no antigen achieves sufficient sensitivity to replace sputum smear microscopy. Combinations of select antigens provide higher sensitivities than single antigens. The use of a case-control design with healthy controls for the majority of studies was a limitation of the review. Efforts are needed to improve the methodological quality of tuberculosis diagnostic studies.


Assuntos
Anticorpos Antibacterianos/sangue , Antígenos de Bactérias , Tuberculose Pulmonar/diagnóstico , Antígenos de Bactérias/isolamento & purificação , HIV , Humanos , Sensibilidade e Especificidade , Testes Sorológicos/métodos
15.
Postgrad Med J ; 83(985): 705-12, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17989270

RESUMO

Conventional diagnostic tests for tuberculosis have several limitations and are often unhelpful in establishing the diagnosis of extrapulmonary tuberculosis. Although commercial serological antibody based tests are available, their usefulness in the diagnosis of extrapulmonary tuberculosis is unknown. A systematic review was conducted to assess the accuracy of commercial serological antibody detection tests for the diagnosis of extrapulmonary tuberculosis. In a comprehensive search, 21 studies that reported data on sensitivity and specificity for extrapulmonary tuberculosis were identified. These studies evaluated seven different commercial tests, with Anda-TB IgG accounting for 48% of the studies. The results showed that (1) all commercial tests provided highly variable estimates of sensitivity (range 0.00-1.00) and specificity (range 0.59-1.00) for all extrapulmonary sites combined; (2) the Anda-TB IgG kit showed highly variable sensitivity (range 0.26-1.00) and specificity (range 0.59-1.00) for all extrapulmonary sites combined; (3) for all tests combined, sensitivity estimates for both lymph node tuberculosis (range 0.23-1.00) and pleural tuberculosis (range 0.26-0.59) were poor and inconsistent; and (4) there were no data to determine the accuracy of the tests in children or in patients with HIV infection, the two groups for which the test would be most useful. At present, commercial antibody detection tests for extrapulmonary tuberculosis have no role in clinical care or case detection.


Assuntos
Anticorpos Antibacterianos/sangue , Tuberculose/diagnóstico , Humanos , Sensibilidade e Especificidade , Testes Sorológicos/métodos
16.
Thorax ; 62(10): 911-8, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17675320

RESUMO

Conventional diagnostic tests for tuberculosis have several limitations and are often unhelpful in establishing the diagnosis of extrapulmonary tuberculosis. Although commercial serological antibody based tests are available, their usefulness in the diagnosis of extrapulmonary tuberculosis is unknown. A systematic review was conducted to assess the accuracy of commercial serological antibody detection tests for the diagnosis of extrapulmonary tuberculosis. In a comprehensive search, 21 studies that reported data on sensitivity and specificity for extrapulmonary tuberculosis were identified. These studies evaluated seven different commercial tests, with Anda-TB IgG accounting for 48% of the studies. The results showed that (1) all commercial tests provided highly variable estimates of sensitivity (range 0.00-1.00) and specificity (range 0.59-1.00) for all extrapulmonary sites combined; (2) the Anda-TB IgG kit showed highly variable sensitivity (range 0.26-1.00) and specificity (range 0.59-1.00) for all extrapulmonary sites combined; (3) for all tests combined, sensitivity estimates for both lymph node tuberculosis (range 0.23-1.00) and pleural tuberculosis (range 0.26-0.59) were poor and inconsistent; and (4) there were no data to determine the accuracy of the tests in children or in patients with HIV infection, the two groups for which the test would be most useful. At present, commercial antibody detection tests for extrapulmonary tuberculosis have no role in clinical care or case detection.


Assuntos
Antígenos de Bactérias/sangue , Testes Sorológicos/normas , Tuberculose/diagnóstico , Área Sob a Curva , Ensaio de Imunoadsorção Enzimática/normas , Humanos , Imunoglobulinas/sangue , Sensibilidade e Especificidade
17.
PLoS Med ; 4(6): e202, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17564490

RESUMO

BACKGROUND: The global tuberculosis epidemic results in nearly 2 million deaths and 9 million new cases of the disease a year. The vast majority of tuberculosis patients live in developing countries, where the diagnosis of tuberculosis relies on the identification of acid-fast bacilli on unprocessed sputum smears using conventional light microscopy. Microscopy has high specificity in tuberculosis-endemic countries, but modest sensitivity which varies among laboratories (range 20% to 80%). Moreover, the sensitivity is poor for paucibacillary disease (e.g., pediatric and HIV-associated tuberculosis). Thus, the development of rapid and accurate new diagnostic tools is imperative. Immune-based tests are potentially suitable for use in low-income countries as some test formats can be performed at the point of care without laboratory equipment. Currently, dozens of distinct commercial antibody detection tests are sold in developing countries. The question is "do they work?" METHODS AND FINDINGS: We conducted a systematic review to assess the accuracy of commercial antibody detection tests for the diagnosis of pulmonary tuberculosis. Studies from all countries using culture and/or microscopy smear for confirmation of pulmonary tuberculosis were eligible. Studies with fewer than 50 participants (25 patients and 25 control participants) were excluded. In a comprehensive search, we identified 68 studies. The results demonstrate that (1) overall, commercial tests vary widely in performance; (2) sensitivity is higher in smear-positive than smear-negative samples; (3) in studies of smear-positive patients, Anda-TB IgG by enzyme-linked immunosorbent assay shows limited sensitivity (range 63% to 85%) and inconsistent specificity (range 73% to 100%); (4) specificity is higher in healthy volunteers than in patients in whom tuberculosis disease is initially suspected and subsequently ruled out; and (5) there are insufficient data to determine the accuracy of most commercial tests in smear microscopy-negative patients, as well as their performance in children or persons with HIV infection. CONCLUSIONS: None of the commercial tests evaluated perform well enough to replace sputum smear microscopy. Thus, these tests have little or no role in the diagnosis of pulmonary tuberculosis. Lack of methodological rigor in these studies was identified as a concern. It will be important to review the basic science literature evaluating serological tests for the diagnosis of pulmonary tuberculosis to determine whether useful antigens have been described but their potential has not been fully exploited. Activities leading to the discovery of new antigens with immunodiagnostic potential need to be intensified.


Assuntos
Anticorpos Antibacterianos/sangue , Ensaio de Imunoadsorção Enzimática , Mycobacterium tuberculosis/imunologia , Kit de Reagentes para Diagnóstico , Tuberculose Pulmonar/diagnóstico , Adulto , Testes de Aglutinação , Preservação de Sangue , Western Blotting , Criança , Comorbidade , Países em Desenvolvimento , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Infecções por HIV/epidemiologia , Humanos , Imunoglobulina G/sangue , Caulim , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/isolamento & purificação , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Projetos de Pesquisa , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/imunologia
18.
Lancet Infect Dis ; 6(10): 664-74, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17008175

RESUMO

In low-income and middle-income countries, direct (unconcentrated) sputum smear microscopy is the primary method for diagnosing pulmonary tuberculosis. The method is fast, inexpensive, and specific for Mycobacterium tuberculosis in high incidence areas. The main limitations of direct microscopy are its relatively low sensitivity, especially in individuals co-infected with HIV, and variable quality of the test in programme conditions. Thus, there is a need to identify methods to improve the sensitivity of microscopy. Physical and chemical sputum processing methods, including centrifugation, sedimentation, and bleach, have been studied and found to show promise. We did a systematic review to assess the ability of different processing methods to improve the sensitivity of microscopy. By searching many sources, we identified 83 studies. Overall, by comparison with direct smears, the results suggested that centrifugation with any of several chemical methods (including bleach) is more sensitive, that overnight sedimentation preceded by chemical processing is more sensitive, and that specificity is similar. There were insufficient data to determine the value of sputum processing methods in patients with HIV infection. Operational studies are needed to determine whether the increased sensitivity provided by processing methods is sufficient to offset their increased cost, complexity, and potential biohazards, and to examine their feasibility.


Assuntos
Técnicas Bacteriológicas , Microscopia , Escarro/microbiologia , Tuberculose/diagnóstico , Humanos , Sensibilidade e Especificidade , Manejo de Espécimes
19.
Lancet Infect Dis ; 6(9): 570-81, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16931408

RESUMO

Most of the world's tuberculosis cases occur in low-income and middle-income countries, where sputum microscopy with a conventional light microscope is the primary method for diagnosing pulmonary tuberculosis. A major shortcoming of conventional microscopy is its relatively low sensitivity compared with culture, especially in patients co-infected with HIV. In high-income countries, fluorescence microscopy rather than conventional microscopy is the standard diagnostic method. Fluorescence microscopy is credited with increased sensitivity and lower work effort, but there is concern that specificity may be lower. We did a systematic review to summarise the accuracy of fluorescence microscopy compared with conventional microscopy. By searching many databases and contacting experts, we identified 45 relevant studies. Sensitivity, specificity, and incremental yield were the outcomes of interest. The results suggest that, overall, fluorescence microscopy is more sensitive than conventional microscopy, and has similar specificity. There is insufficient evidence to determine the value of fluorescence microscopy in HIV-infected individuals. The results of this review provide a point of reference, quantifying the potential benefit of fluorescence microscopy, with which the increased cost and technical complexity of the method can be compared to determine the possible value of the method under programme conditions.


Assuntos
Escarro/microbiologia , Tuberculose/diagnóstico , Citodiagnóstico/economia , Humanos , Renda , Microscopia de Fluorescência/economia , Reprodutibilidade dos Testes , Tuberculose/patologia
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