Tuberculosis (TB)

New WHO recommendations on use of commercial TB Interferon-Gamma Release Assays (IGRAs) in low- and middle-income countries

Above: blood being drawn; below: tuberculin skin test.
US CDC

24 October 2011 | Geneva | WHO's Stop TB Department has published new recommendations related to the use of IGRAs as a replacement of the tuberculin skin test (TST) to detect latent TB in low- and middle-income countries (the recommendations are not intended for high-income countries or to supersede existing national guidelines in these countries). The key recommendations are:

  • IGRAs and the TST cannot accurately predict the risk of infected individuals developing active TB disease;
  • Neither IGRAs nor the TST should be used for the diagnosis of active TB disease;
  • IGRAs are more costly and technically complex to do than the TST. Given comparable performance but increased cost, replacing the TST by IGRAs, as a public health intervention in resource-constrained settings, is not recommended.

The WHO policy statement follows an extensive evaluation of evidence by WHO and an independent Expert Group. Also published today is the Expert Group's meeting report and a WHO fact sheet on the use of IGRAs in low- and middle-income countries.