Table 3. Advantages and disadvantages of IGRA tests compared to tuberculin tests.

Advantages of an in vitro diagnosis in comparison to TT

Eliminates subjectivity.

Absence of false positives in persons vaccinated with the BCG vaccine or in persons infected by atypical mycobacteria.

Control of false negatives in patients infected by HIV.

Avoids treatment of latent tuberculosis infection.

Disadvantages of an in vitro diagnosis in comparison to TT

More expensive.

Difficult to use in community screenings (issues with blood extraction, transport and conservation).

Note. BCG: bacillus Calmette-Guérin; IGRA: interferon gamma release assay; TT: tuberculin test; HIV: human immunodeficiency virus.