Table 1.
Description of the study population and univariate analysis of risk factors for latent tuberculosis infection
| Characteristic | Total | QGTB+ | QGTB− | OR | P-value* | |||
|---|---|---|---|---|---|---|---|---|
| n | % | N | % | n | % | |||
| Total | 61 | 100 | 7 | 11.5 | 54 | 88.5 | – | – |
| Age (years) | ||||||||
| ≤ 9 | 17 | 27.9 | 0 | 0 | 17 | 100 | Reference | – |
| 10–19 | 19 | 31.1 | 0 | 0 | 19 | 100 | NA | 0.26 |
| 20–29 | 4 | 6.6 | 0 | 0 | 4 | 100 | NA | 0.1 |
| 30–39 | 8 | 13.1 | 2 | 25 | 6 | 75 | 8.3 (0.45–348.5) | 0.08 |
| 40–49 | 6 | 9.8 | 1 | 16.7 | 5 | 83.3 | 5.2 (0.09–277.4) | 0.19 |
| ≥ 50 | 7 | 11.5 | 4 | 57.1 | 3 | 42.9 | 29.5 (1.65–2,351) | 0.01 |
| Gender | ||||||||
| Male | 24 | 39.3 | 3 | 12.5 | 21 | 87.5 | 1.18 (0.15–7.7) | > 0.99 |
| Female | 37 | 60.7 | 4 | 10.8 | 33 | 89.2 | Reference | – |
| Education | ||||||||
| Elementary school or less | 32 | 52.5 | 5 | 15.6 | 27 | 84.4 | Reference | – |
| Middle school | 19 | 31.1 | 2 | 10.5 | 17 | 89.5 | 0.64 (0.06–4.48) | 0.95 |
| High school or more | 10 | 16.4 | 0 | 0 | 10 | 100 | 0.65 (0.01–7.30) | > 0.99 |
| BMI† | ||||||||
| Underweight | 8 | 13.1 | 0 | 0 | 8 | 100 | 2.7 (0.05–150.5) | 0.27 |
| Normal | 22 | 36.1 | 0 | 0 | 22 | 100 | Reference | – |
| Overweight | 19 | 31.1 | 6 | 31.6 | 13 | 68.4 | 14.9 (1.23–972.3) | 0.014 |
| Obese | 12 | 19.7 | 1 | 8.3 | 11 | 91.7 | 3.2 (0.03–327.4) | 0.53 |
| Living in overcrowded conditions | ||||||||
| Yes | 52 | 85.2 | 4 | 7.7 | 48.0 | 92.3 | 0.17 (0.02–1.47) | 0.07 |
| No | 9 | 14.8 | 3 | 33.3 | 6.0 | 66.7 | Reference | – |
| BCG scar | ||||||||
| Yes | 57 | 93.4 | 4 | 7.0 | 53 | 93.0 | 0.03 (0.001–0.33) | 0.004 |
| No | 4 | 6.6 | 3 | 75.0 | 1 | 25.0 | Reference | – |
| Caregiver | ||||||||
| Yes | 17 | 27.9 | 3 | 17.6 | 14 | 82.4 | 2.14 (0.28–14.27) | 0.39 |
| No | 44 | 72.1 | 4 | 9.1 | 40 | 90.9 | Reference | – |
| Time of exposure | ||||||||
| ≥ 12 hours/day | 42 | 68.9 | 5 | 11.9 | 37 | 88.1 | 1.15 (0.17–13.1) | > 0.99 |
| < 12 hours/day | 19 | 31.1 | 2 | 10.5 | 17 | 89.5 | Reference | – |
| Smear status of source case | ||||||||
| Positive | 19 | 32.2 | 2 | 10.5 | 17 | 89.5 | 0.82 (0.07–5.71) | > 0.99 |
| Negative | 40 | 67.8 | 5 | 12.5 | 35 | 87.5 | Reference | – |
BCG = Bacillus Calmette-Guerin; BMI = body mass index; NA = not applicable; QGTB = quantiferon gold. Underweight: < 18.5 kg; normal: ≥ 18.5 kg and < 23 kg; overweight: ≥ 23 kg and < 27.5 kg; obese: ≥ 27.5 kg. Bold values resulted statistically significant at P < 0.005.
* Fisher exact test P-value (two-tailed).
† For ages 2–20 years, we used CDC growth charts for boys and girls.