North Carolina TB guide update

North Carolina has recently sent out a memo advising TB nurses of Changes to the 2007 TB Policy Manual. In particular interferon gamma release assays (IGRA) are discussed here. In essence they say that

The Mantoux tuberculin skin test is the most accurate skin test for determining TB infection and is the only skin test recommended by TB Control.

Fair enough, they are only talking about skin tests. When it comes to IGRAs there are all the usual caveats and uncertainties however they have recommended that IGRA be used for screening

• at sites where tuberculin skin testing is not frequently performed
• if the patient is unlikely or unwilling to return for reading of the tuberculin skin test
• in populations with sub optimal health care access/utilisation (eg. the homeless, drug users, migrant workers)
• in contact situations of children +5 years of age and adults

In general they have emphasised that with TB testing

Medicine is constantly changing, and IGRAs are a very active area of research. Clinical judgment based on the latest scientific evidence, with emphasis on how a given test will affect patient management, should always be used in deciding to order any diagnostic test and in interpreting the results

.