|
  
|
世卫组织建议不要使用不准确的活动性结核病血液检测
不合标准且结果不可靠的检测工具
世卫组织建议不要使用不准确的活动性结核病血液检测
不合标准且结果不可靠的检测工具
新闻稿
2011年7月20日 | 日内瓦 - 世界卫生组织（世卫组织）在今天公布的一项政策建议中指出，使用目前市面上商业性血液（血清学）检测手段诊断活动性结核病，常常导致误诊和不当治疗，进而损害公众健康。世卫组织敦促各国采用世卫组织推荐的准确的微生物或分子检测方法，禁止使用不准确的和未经批准的血液检测方法。
结核病被误诊
通过检测血液中的抗体或抗原，极难检测活动性结核病。患者可产生不同的抗体反应，即使没有活动性结核病，有时抗体反应却显示患有活动性结核病。抗体还可能对其他生物体产生反应，错误显示患有活动性结核病。此外，不同生物体可能有相同抗原，因此检测结果很不可靠。这些因素可能会导致无法捡出结核病或误诊。
通过验血诊断活动性结核病是不良做法
世卫组织控制结核病司司长Mario Raviglione博士说，“出于对私立和公共卫生部门结核病患者和医护者最佳利益的考虑，世卫组织呼吁停止使用这些血清学检测方法来诊断结核病。”他说，“通过验血诊断活动性结核病是不良做法。检测结果不一致，不准确，这可能会危及患者生命。”
今天发布的政策建议针对的是活动性结核病血液检测。世卫组织目前正在审查对非活动性结核感染（也称休眠或潜伏性结核）的血液检测。
认真分析证据后提出的新建议
这项新建议是在世卫组织和全球卫生专家历经12个月认真分析有关证据后提出的。总共评估了94项研究，其中67项是肺结核病研究，27项是肺外结核病（即其它器官的结核病）研究。大量证据表明，与世卫组织推荐的检测方法相比，验血产生大量假阳性或假阴性的错误结果。
误诊导致的后果
研究显示，商业性血液检测“敏感度低”，大量患者被误诊，呈假阴性，即虽然实际上患有活动性结核病，但未被检出。这可能会导致结核病传至他人，或甚至结核病患者因未获治疗而死亡。研究结果还显示“低特异性”，大量患者被误诊，呈假阳性，即虽然实际上未患活动性结核病，但却被诊断患有此病。这些患者随后可能会接受不必要的治疗，而实际病因仍不明，这也可能导致过早死亡。
不准确的血液检测花费大量资金
每年共有100多万例不准确的活动性结核病血液检测，患者往往花费大量资金。许多患者的验血费高达30美元。市场上至少有18种血液检测方法。其中大部分检测工具是欧洲和北美产品，但未获任何正规监管机构批准。
销售不合标准且结果不可靠的检测工具
世卫组织控制结核病司结核病诊断工具和强化实验室处处长Karin Weyer博士说，“结核病血液检测工具通常针对的是诊断工具监管机制薄弱的国家，在这些国家中，可疑的营销激励手段可能会压倒患者利益。这是一项涉及大量资金的业务，靠的是销售不合标准且结果不可靠的检测工具。”
这是世卫组织首次在政策建议中明确反对结核病防治领域中广泛使用的一项做法。它显示世卫组织决心在强有力证据的基础上向各国政府提供明确的政策建议。
结核病每年导致170万人死亡，是艾滋病毒感染者的主要杀手。世卫组织和国际结核病医务界的一项优先任务是，必须采取行动，增强对结核病的早期和有效诊断，确保挽救更多人的生命。目前正在开展结核病研究，努力开发更好、更快速、简便、有效和准确的检测方法。
如欲获取更多信息，请联系：
日内瓦世卫组织
控制结核病司
通讯联络高级顾问
Glenn Thomas
电话：+41 79 509 0677
电子邮件：thomasg@who.int
http://www.who.int/mediacentre/n ... 10720/en/index.html
WHO warns against the use of inaccurate blood tests for active tuberculosis
A substandard test with unreliable results
News release
20 July 2011 | GENEVA - The use of currently available commercial blood (serological) tests to diagnose active tuberculosis (TB) often leads to misdiagnosis, mistreatment and potential harm to public health, says WHO in a policy recommendation issued today. WHO is urging countries to ban the inaccurate and unapproved blood tests and instead rely on accurate microbiological or molecular tests, as recommended by WHO.
TB can be wrongly diagnosed
Testing for active TB disease through antibodies or antigens found in the blood is extremely difficult. Patients can have different antibody responses suggesting that they have active TB even when they do not. Antibodies may also develop against other organisms which again could wrongly indicate they have active TB. In addition, different organisms share the same antigens, making tests results unreliable. These factors can result in TB disease not being identified or wrongly diagnosed.
A blood test for diagnosing active TB disease is bad practice
"In the best interests of patients and caregivers in the private and public health sectors, WHO is calling for an end to the use of these serological tests to diagnose tuberculosis," said Dr Mario Raviglione, Director of WHO Stop TB Department. "A blood test for diagnosing active TB disease is bad practice. Test results are inconsistent, imprecise and put patients' lives in danger."
Today's policy recommendation applies to blood tests for active TB. Blood tests for inactive TB infection (also known as dormant or latent TB) are currently under review by WHO.
New recommendation after 12 months of rigorous analysis
The new recommendation comes after 12 months of rigorous analysis of evidence by WHO and global experts. Ninety-four studies were evaluated - 67 for pulmonary tuberculosis (TB in the lungs) and 27 for extrapulmonary tuberculosis (TB elsewhere in other organs). Overwhelming evidence showed that the blood tests produced an unacceptable level of wrong results - false-positives or false-negatives - relative to tests endorsed by WHO.
Problems of misdiagnosis
The research revealed "low sensitivity" in commercial blood tests which leads to an unacceptably high number of patients wrongly being given the 'all clear' (i.e. a false-negative when in reality they have active TB). This can result in the transmission of the disease to others or even death from untreated tuberculosis. It also revealed "low specificity", which leads to an unacceptably high number of patients being wrongly diagnosed with TB (i.e. a false-positive when in reality they do not have active TB). Those patients may then undergo unnecessary treatment, while the real cause of their illness remains undiagnosed, which may then also result in premature death.
The inaccurate blood tests are costly
More than a million of these inaccurate blood tests are carried out annually to diagnose active TB, often at great financial cost to patients. Many patients pay up to US$ 30 per test. There are at least 18 of these blood tests available on the market. Most of these tests are manufactured in Europe and North America, even though the blood tests are not approved by any recognized regulatory body.
Selling substandard tests with unreliable results
"Blood tests for TB are often targeted at countries with weak regulatory mechanisms for diagnostics, where questionable marketing incentives can override the welfare of patients," said Dr Karin Weyer, Coordinator of TB Diagnostics and Laboratory Strengthening for the WHO Stop TB Department. "It's a multi-million dollar business centred on selling substandard tests with unreliable results."
This is the first time WHO has issued an explicit "negative" policy recommendation against a practice that is widely used in tuberculosis care. It underscores the Organization's determination to translate strong evidence into clear policy advice to governments.
Tuberculosis kills 1.7 million people every year, and is the major killer of people living with HIV. Improving the early and effective diagnosis of TB to ensure more lives are saved is a priority action for WHO and the international TB community. TB research is currently underway to bring better and more rapid tests that are easy to administer, effective and accurate.
For more information, please contact:
Glenn Thomas
Senior Communications Adviser
Stop TB Department
WHO, Geneva
Telephone: +41 79 509 0677
E-mail: thomasg@who.int |
|
发表于 2011-10-24 16:36
|