Tuberculosis diagnosis by BCG inoculation tuberculin tests can be affected. In general the US approach is likely to result in more false positives and more unnecessary treatment with potentially toxic drugs; the UK approach is as sensitive in theory and should also be more specific, because of the use of interferon-γ tests. Under the US recommendations, diagnosis and treatment of latent tuberculosis infection (LTBI) is considered for any BCG-vaccinated person whose skin test is 10 mm or greater, if any of these circumstances are present: These have been reviewed in detail. In 2007, a systematic review of adenosine deaminase by the NHS
BCG vaccine potentially more severe in those with poor immune function. It is not safe for use during pregnancy. The vaccine was originally developed from "Mycobacterium bovis" which is commonly found in cows. While it has been weakened, it is still live. The BCG vaccine was first used medically in 1921. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Between 2011 and 2014 the wholesale price was $0.16 to $1.11 USD a dose in the developing world. In the United States it costs $100 to $200 USD. As