WHO says TB blood tests faulty, must be stopped

GENEVA,  (Reuters) – The World Health Organisation  (WHO) called yesterday for an immediate halt to the use of  blood tests to detect active tuberculosis, saying they were  faulty and leave millions of people at risk.
Production of the test kits, WHO officials said, was largely  by Western companies which export them to developing countries  because they have not passed regulatory standards in rich  nations.
“Overwhelming evidence showed that the blood tests produced  an unacceptable level of wrong results” which led to  misdiagnosis and mistreatment, the United Nations agency said  after a year-long analysis.
Studies showed that at least half the tests find the disease  in patients when it is absent or give the all-clear when TB is  present. “So they put patients lives in danger,” said WHO TB  prevention chief Mario Raviglione.
At least two million of the tests are carried out each year  in some 17 poorer nations — including China and India — almost  exclusively by doctors and health workers in the private or  semi-private sector, according to the WHO.
“The WHO is urging countries to ban the inaccurate and  unproved blood tests and instead rely on accurate  microbiological or molecular tests, as recommended by the WHO,”  a statement from the agency said.
WHO TB specialist Karin Weyer told a news conference to  announce the highly unusual move by the agency that it had been  asked by the government of India to launch a detailed analysis  of the tests — on sale since the mid-1990s.
The WHO had never recommended their use. The tests “are  often targeted at countries with weak regulatory mechanisms for  diagnostics, where questionable marketing incentives can  override the interests of patients”, Weyer said.
“It is a multi-million dollar business centred on selling  sub-standard tests with unreliable results.”
Most of the tests were manufactured in Europe and North  America — including France, Italy, Germany, the Netherlands and  the United States — “even though the blood tests are not  approved by any regulatory body”, the WHO statement said.
The WHO warning, which has been passed on to several  governments, is the first time it has issued an explicit  “negative” policy recommendation against a practice that is used  in the care of TB — which kills 1.7 million people a year.
The tests, of which there are at least 18 available on the  market, “must be stopped immediately and everywhere”, Raviglione  told the news conference.

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