Guyana does not use blood tests to detect TB

In light of a warning from the World Health Organization (WHO), the Ministry of Health here says that Guyana does not use blood tests for the diagnosis of tuberculosis.

It however urged the private sector “to discontinue the practice of using these expensive but useless tests”.

The WHO yesterday called for an immediate stop to the use of blood tests to detect active tuberculosis after claims were made that the tests were defective and have left millions of people at risk, Reuters reported.

According to the Reuters news item, the test kits are largely produced by Western companies and they are exported to developing countries since they have not passed regulatory standards in rich nations.

The Reuters article said, “Overwhelming evidence showed that the blood tests produced an unacceptable level of wrong results” and this had led to the misdiagnosis and mistreatment, the United Nations agency said after a year-long analysis.

Studies have proved that at least half the tests detect the disease in patients when it is actually absent or proves to be negative when TB is indeed present. The WHO TB Prevention Chief Mario Raviglione stated, “So they put patients lives in danger”.

Reuters reported that 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.
In a statement yesterday afternoon the, the ministry said that

“Guyana prohibits the use of blood tests for TB diagnosis in its TB Diagnosis and Treatment Guidelines.

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. We note the WHO is urging countries to ban the inaccurate and unapproved blood tests and instead rely on accurate microbiological or molecular tests, as prescribed in our guidelines.”

It noted that here are several steps to diagnosing TB disease, including obtaining the TB case’s history, and conducting a physical examination, mycobacteriological assessment and radiographic examination.

Prior to the press release, Stabroek News spoke to the National Public Health Reference Laboratory. A representative there stated that blood tests for TB are not done in Guyana and the method for testing TB used at the lab is gold standard and thoroughly validated by the WHO.