WHO: Blood tests for tuberculosis are unreliable

(AP) -- Widely used blood tests to detect tuberculosis are "dangerous" to patients because they are unreliable and can produce wrong results, the World Health Organization warned Sunday.

The U.N. health agency said it will issue an unprecedented recommendation against using such tests for the infectious that affects some 14 million people worldwide. As much as a third of the world's population is thought to harbor the bacteria that causes TB.

"The tests are not reliable and a waste of money and time, putting proper care at risk," said Mario Raviglione, the director of WHO's Stop TB department.

A review of the tests has shown that they produce too many false negative and false positive, according to WHO.

Raviglione told The Associated Press that the blood tests "are in fact dangerous to patients, since some cases will not be detected and some will be called TB when in fact they do not have it,"

The WHO guidance will be issued later this week. It is the first time that WHO has issued a "negative" policy, specifically counseling against the use of a particular method for diagnosing a disease.

The use of TB blood tests is particularly common in such as India, where an estimated 3 million people are infected with the disease.

The Lancet medical journal reported in January that some of the kits used there are made in where such tests aren't licensed. They are ordered by doctors who receive greater commissions for the blood tests than for the older and more reliable sputum microscopy method, the journal reported.

"Many of these tests are used in the private-for-profit sector, charging poor people who do not understand the lack of value of the test," Raviglione said.


Explore further

South Africa to test all HIV patients for TB

©2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Citation: WHO: Blood tests for tuberculosis are unreliable (2011, July 18) retrieved 1 December 2021 from https://medicalxpress.com/news/2011-07-blood-tuberculosis-unreliable.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
 shares

Feedback to editors