PRIMARY OBJECTIVES

1.To determine sensitivity and specificity of new diagnostics to diagnose prevalent TB earlier with a special focus on subclinical disease.

2.To evaluate novel diagnostics for detection of developing, minimal TB that would cause infectious disease in the future.

3.To enhance diagnostic performance by simulating testing algorithms coupled with a risk estimate from a mathematical model.

PROCEDURE

Additionally, at the baseline visit, we will:

1. Get the participant's written consent.

2. Answer a socio-demographic questionnaire.

3. Take a medical history.

4. Collect spontaneous and induced sputum samples.

At all visits, we will:

1. Measure the participant's vital signs.

2. Update the participant's contact information.

3. Perform a WHO symptom screen on the participant.

4. Perform a digital CXR on the participant.

5. If symptoms screen or CXR are positive,

a sputum sample will be tested for TB.

6. Collect various blood and urine samples for analysis.

SECONDARY OBJECTIVES

1. To determine the proportion of HHC with M.tb infection and during follow-up using an immunological assay.

2. To establish a bio-repository of samples from individuals with and without prevalent and incident TB to be used for future diagnostic test development and validation.

SUB-STUDY OBJECTIVES

A sub-study may be pursued in a selection of sites/participants only, exploring elements shaping adoption of new TB detection technologies among asymptomatic members of community.

THE PARTICIPANTS

The participants will be household contacts (HHC). HHCs are individuals who have had substantial exposure to a TB index case. This means they occupy the same household and have had regular contact with the case.

In addition to being a household contact, participants must meet additional inclusion criteria:

1. They must be over the age of 10.

2. They need to provide written, informed consent.

3. If they are HIV negative, they cannot be on preventative therapy.

4. They must also be able to stand while performing a

chest X-ray.

Index cases are people who are known to have TB and are the most likely source of infection for our participants. Their eligibility criteria are:

1. They are over the age of 18.

2. They have been diagnosed with active pulmonary TB in the

last 4 weeks.

3. They have taken less than 7 daily doses of anti-TB treatment

since diagnosis.