
Methods: In a prospective cohort study (CTRIUMPH) adult pulmonary TB patients and their HHCs were recruited at BJMC Pune and NIRT Tiruvallur, India. HHCs underwent QGIT (Qiagen) and TST (PPD SPAN 2TU/5TU). A positive QGIT was defined as > 0.35 IU/ml and a positive TST as an induration of >5mm. Proportion positive by either or both assays, discordant positive, and discordant negative was calculated; test concordance was assessed using %agreement and Kappa statistics.Results: Of 461 HHCs enrolled, median age was 26 years (IQR: 13-40); 14 (3%) were children < 6 years. 12 (2%) were diagnosed with active TB. TBI prevalence by QGIT was 58% (95%CI 53 - 65), by TST was 42% (95% CI 37 - 47), by either was 72% and by both was 28% (95% CI 24 - 33). QGIT+/TST- discordance was 30% and QGIT -/TST + was 13% (57% agreement, kappa 0.16 - poor agreement). In multivariable analyses, there were no significant risk factors for QGIT positivity while age and BMI remained significant for TST positivity. HHCs between 18-45 years had higher odds of having a discordant QGIT/TST result (aOR 4.2, 95% CI 1.4 – 12.9).
|
Overall n(%) |
< 18 years n=168 (%) |
18 - 45 yrs, n=229 (%) |
> 45 yrs, n = 64 (%) |
TST+ |
193 (42) |
63 (38) |
96 (42) |
34 (53) |
QGIT+ |
267 (58) |
87 (52) |
140 (61) |
40 (63) |
TST+/QGIT- |
63 (14) |
21 (13) |
32 (14) |
10 (16) |
TST-/QGIT+ |
137 (30) |
45 (27) |
76 (33) |
16 (25) |
Conclusion: A high prevalence of TBI was noted among HHCs of adult pulmonary TB patients in India, with more than half of them being QGIT positive. Active HHC tracing, TBI screening, and targeted TB preventive therapy should be implemented to achieve global TB elimination goals.

P. Chandrasekaran,
None
K. Thiruvengadam, None
S. Meshram, None
N. Gupte, None
L. E. Hannah, None
S. Swaminathan, None
A. Gupta, None