WHO warns all countries to stop using TB blood tests

The World Health Organization recently warned all countries to stop using blood tests to diagnose active tuberculosis because of the potential risk for errors.

Instead, the WHO is urging that doctors rely on WHO-recommended microbiological or molecular tests, according to MedicalNewsToday.com. This is the first time the United Nations health agency has issued a negative policy recommendation regarding TB.

The new recommendation warns that the available commercial blood tests are unreliable and inaccurate because they attempt to find antibodies or antigens in the blood, which is notoriously difficult to do. The tests often return false negative results or misidentify antibodies to other diseases as those of TB.

"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," Dr. Mario Raviglione, director of the WHO’s Stop TB Department, said, MedicalNewsToday.com reports. "A blood test for diagnosing active TB disease is bad practice. Test results are inconsistent, imprecise and put patients' lives in danger."

The new policy recommendation currently only applies to blood tests for active TB. The WHO is conducting research on blood tests for latent TB.

The WHO announcement follows a year of analysis that evaluated 94 studies, including 67 for pulmonary TB.