BACKGROUND: Tuberculosis (TB) is a major public health problem and a leading cause of death worldwide. Latent
tuberculosis infection (LTBI) is a condition of persistent immune response to infection by Mycobacterium tuberculosis.
Household contacts of active TB cases need to be investigated for the presence of LTBI for detection and management.
OBJECTIVE : Detection of Latent TB Infection(LTBI) by Interferon Gamma Release Assay (IGRA) from close contacts of TB
cases in Tiruvallur District.
METHODS : Blood samples of 1200 Household contacts of Pulmonary TB Patients from Tiruvallur District were collected
and referred to State Public Health Laboratory for diagnosis of LTBI by Interferon Gamma Release Assay (IGRA).
RESULTS : Among the 1200 Household contacts of TB cases tested for IGRA, a total 520 (43%) were positive for LTBI and
female was predominantly positive (62.3%) than male (37.7%). 59% of the LTBI was observed between 15-44 Age Group.
CONCLUSION : Early Diagnosis and treatment of Latent TB infection among the household contacts of TB patients are very
important to reduce the TB disease burden in the community.