Table 5.
Relationship Between Various Baseline/Clinical Characteristics and Risk of Mycobacterium tuberculosis Infection Among Schoolchildren in Various Tibetan Schools in Himachal Pradesh, India, 2017
| Characteristics of Schoolchildren | Schoolchildren With TB Infection, n/N (%) |
Risk of TB Infection (Univariate Analysis), OR (95% CI) |
P Value | Risk of TB Infection (Multivariable Analysis), OR (95% CI) |
P Value |
|---|---|---|---|---|---|
| Age range, y | |||||
| ≥5–9 | 77/1121 (6.9) | Referent | … | Referent | … |
| 10–14 | 365/2398 (15.2) | 2.4 (1.9–3.2) | < .001 | 2.4 (1.9–3.1) | < .001 |
| 15–19 | 458/1621 (28.3) | 5.3 (4.1–6.9) | < .001 | 5.4 (4.2–7.0) | < .001 |
| 20–24 | 30/92 (32.6) | 6.6 (4.0–10.8) | < .001 | 6.5 (4.0–10.7) | < .001 |
| Sex | |||||
| Female | 414/2625 (15.8) | Referent | … | Referent | … |
| Male | 516/2609 (19.8) | 1.3 (1.1–1.5) | < .001 | 1.4 | < .001 |
| Body weight, kg | |||||
| ≤24 | 44/595 (7.4) | Referent | … | Referent | … |
| 25–39 | 201/1751 (11.5) | 1.6 (1.2–2.3) | .005 | 1.1 (.8–1.6) | .540 |
| 40–54 | 386/1874 (20.6) | 3.2 (2.3–4.5) | < .001 | 1.5 (.97–2.2) | .071 |
| 55–69 | 261/877 (29.8) | 5.3 (3.8–7.5) | < .001 | 1.9 (1.2–2.9) | .006 |
| ≥70 | 38/136 (27.9) | 4.9 (3.0–7.9) | < .001 | 1.6 (.9–2.8) | .113 |
| Recent exposure (<2 y) to a TB casea | |||||
| Yes | 433/1430 (30.3) | 2.9 (2.5–3.4) | < .001 | 2.0 (1.7–2.4) | < .001 |
| No | 497/3802 (13.1) | Referent | … | Referent | … |
| Exposure setting in school | |||||
| Classroom | 146/578 (25.3) | Referent | … | Referent | … |
| Dormitory/hostel | 168/497 (33.8) | 1.5 (1.2–2.0) | .002 | 1.4 (1.1–1.9) | .010 |
| Both dormitory/hostel & classroom | 76/197 (38.6) | 1.9 (1.3–2.6) | < .001 | 1.7 (1.2–2.4) | .005 |
| Other unspecified setting | 17/68 (25) | 1.0 (.6–1.8) | .963 | 0.9 (.5–1.7) | .831 |
| Exposure to TB case at homeb | |||||
| No | 873/5078 (17.2) | Referent | < .001 | Referent | < .001 |
| Yes | 57/156 (36.5) | 2.8 (2.0–3.9) | … | 2.3 (1.6–3.2) | … |
| Multiple exposures | |||||
| No history of exposure | 498/3807 (13.1) | Referent | … | Referent | … |
| Contact with 1 case | 216/871 (24.8) | 2.2 (1.8–2.6) | < .001 | 1.7 (1.4–2.1) | < .001 |
| Contact with ≥2 cases | 216/556 (38.9) | 4.2 (3.5–5.1) | < .001 | 2.7 (2.2–3.4) | < .001 |
| BCG vaccine status | |||||
| No | 46/214 (21.5) | Referent | … | Referent | … |
| Yes | 880/5012 (17.6) | 0.8 (.6–1.1) | .141 | 1.4 (.96–1.9) | .078 |
Abbreviations: BCG, Bacille Calmette-Guérin; CI, confidence interval; OR, odds ratio; TB, tuberculosis.
aSchoolchildren were considered to be exposed to Mycobacterium tuberculosis if they were sharing a classroom or residential quarters with another student at the time of the latter’s TB diagnosis. Students diagnosed with lung or pleural TB were considered index TB cases.
bExposure at home was identified in the schoolchildren by asking them during the screening process whether anyone in their family had TB while they were at home in the last 2 years. Exposure at home was assessed for children in sixth grade or higher.