540. Household contact tracing of Adult Pulmonary TB patients in India: Prevalence of TB disease and Infection
Session: Poster Abstract Session: Tuberculosis Epidemiology and Diagnosis
Thursday, October 27, 2016
Room: Poster Hall
  • ID Week 2016 Poster Prevalence of TB Disease and Infection.pdf (708.2 kB)
  • Background: WHO recommends systematic screening of high risk populations, including household contacts (HHCs) of adult pulmonary TB patients, as a key strategy for elimination of tuberculosis (TB). QuantiFERON-TB Gold In-Tube (QGIT) and tuberculin skin test (TST) are commonly used tools for the detection of tuberculosis infection (TBI) but may yield differential results, impacting eligibility for TB preventive therapy.

    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).

    Table 1: Age specific prevalence of TBI by the two tests




    < 18 years

    n=168 (%)

    18 - 45 yrs,

    n=229 (%)

    > 45 yrs,

    n = 64 (%)


    193 (42)

    63 (38)

    96 (42)

    34 (53)


    267 (58)

    87 (52)

    140 (61)

    40 (63)


    63 (14)

    21 (13)

    32 (14)

    10 (16)


    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.

    Padmapriyadarasini Chandrasekaran, MD1, Vidya Mave, MD, MPH2, Kannan Thiruvengadam, MSc, Mphil3, Sushant Meshram, MD4, Nikhil Gupte, PhD5, Luke Elizabeth Hannah, PhD6, Soumya Swaminathan, MD7 and Amita Gupta, MD, MHS2, (1)Clinical Research, National Institute for Research in Tuberculosis, Chennai, India, (2)Johns Hopkins University School of Medicine, Baltimore, MD, (3)National Institute for Research in Tuberculosis, Chennai, India, (4)Byramjee Jeejeebhoy Government Medical College, Pune, India, (5)Johns Hopkins University School of Medicine, Pune, MD, (6)HIV Labs, National Institute for Research in Tuberculosis, Chennai, India, (7)Indian Council of Medical Research, New Delhi, India


    P. Chandrasekaran, None

    V. Mave, None

    K. Thiruvengadam, None

    S. Meshram, None

    N. Gupte, None

    L. E. Hannah, None

    S. Swaminathan, None

    A. Gupta, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.