In summary, we found that the T-SPOT.TB, QTF and TST
were highly discordant in adults and children in recent
household contacts. The T-SPOT.TB correlated better with
high exposure levels in young child contacts. Larger communitybased
longitudinal studies with serial assessment of discordant
results and accurate long-term outcome measures are essential
to assess the predictive value of IGRAs for infection and disease
in HIV-uninfected and infected children and adults. Further
studies should also assess age-related individual IGRA antigen
responses and the use of more comprehensive exposure
gradients as a surrogate measure of infection.