The primary objective of this clinical research study is to demonstrate performance of the normalized TB specific lymphocyte response (NTBSLR) 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.

This study will enroll up to 202 subjects (assumes 15 % exclusion/drop-out rate). The target number of subjects is 75 active TB (recruited from subjects presenting at TB clinics) and 100 active TB excluded (recruited from subjects in the community).

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

Duration: 1 year

Subject 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
• Must be T-SPOT.TB positive
• First visit suspect TB subjects with no prior history of TB diagnosis Subject 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 less than 1 week*
• Not meeting inclusion criteria

Subject 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
• Must be T-SPOT.TB positive
• No prior history of TB diagnosis

Subject 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