20 July 2011 - WHO has called for countries to ban the use of serological (blood) tests to diagnose active TB disease in a policy issued today, which described the results from these blood tests as inaccurate and a major risk to the health of patients.
Despite the wide use of these blood tests, evidence reviewed by a WHO expert group and published today concluded that "commercial serological tests provide inconsistent and imprecise estimates" and that "it is strongly recommended that these tests not be used for the diagnosis of pulmonary and extra-pulmonary TB."
More than a million TB blood tests (also known as serodiagnostic or serological tests) are carried out every year, usually at a substantial cost to patients.
Today's recommendation does not apply to serological tests for latent TB infection, currently under review by WHO and findings expected to be released next month.
http://www.who.int/tb/features_archive/20july11_end_to_inaccurate_tb_blood_tests/en/index.html