The primary objective of this clinical research study is to demonstrate performance of the normalized TB specific lymphocyte response in identifying patients with active TB disease. The secondary exploratory objective is to demonstrate that active TB cannot be identified using an antigen-to-mitogen ratio derived from an ELISA-based IGRA.

The target number of subjects is 100 active TB and 100 active TB excluded . This study will enroll up to 680 subjects (based on previous enrolment rates of approximately 300-350 subjects enrolled for 50 active TB and 50 active TB excluded).

Study Duration: 6 months

All subjects enrolled in this study will be men or women, aged 18 years or older.

Inclusion Criteria: Cohort 1a and 1b

• • Must be at least 18 years of age

  • Must be able to provide informed consent
  • Must be able to provide a minimum of 10 mL of whole blood at each visit (16mL for immunocompromised i.e. HIV+)
  • Must be T-SPOT.TB positive
  • First visit suspect TB subjects with no prior history of TB diagnosis Inclusion Criteria: Cohort 2a and 2b
  • Must be at least 18 years of age
  • Must be able to provide informed consent
  • Must be able to provide a minimum of 10 mL of whole blood at each visit (16mL for immunocompromised i.e. HIV+)
  • Must be T-SPOT.TB positive
  • No prior history of TB diagnosis

Exclusion Criteria: Cohort 1a and 1b

• • Negative in the T-SPOT.TB test

  • Previous or pre-existing confirmed TB diagnosis
  • On anti-TB treatment for more than 1 week*
  • Not meeting inclusion criteria Exclusion Criteria: Cohort 2a and 2b
  • Negative T-SPOT.TB test
  • Previous or pre-existing confirmed TB diagnosis
  • On anti-TB treatment
  • Symptoms of active TB
  • Not meeting inclusion criteria

Male and Female 18 years of age and older.