Table 2 Univariate Analysis of Risk Factors for MTB infection of TB Contacts
From: Surveillance of close contacts of patients with infectious tuberculosis: a prospective cohort study
Risk factor | Negative IGRAs | Positive IGRAs | Total | P value |
|---|---|---|---|---|
(n = 97) | (n = 87) | (n = 184) | ||
Sex | 0.685 | |||
Male | 34 (35.1%) | 33 (37.9%) | 67 (36.4%) | |
Female | 63 (64.9%) | 54 (62.1%) | 117 (63.6%) | |
Age | *0.013 | |||
5–20 years | 5 (5.2%) | 10 (11.5%) | 15 (8.2%) | |
20–60 years | 80 (82.5%) | 55 (63.2%) | 135 (73.4%) | |
> 60 years | 12 (12.4%) | 22 (25.3%) | 34 (18.5%) | |
Residence a | *0.016 | |||
Local | 68 (70.1%) | 46 (52.9%) | 114 (62.0%) | |
Migrant | 29 (29.9%) | 41 (47.1%) | 70 (38.0%) | |
Ethnic | 0.845 | |||
Han nationality | 91 (93.8%) | 81 (93.1%) | 172 (93.5%) | |
other nationality | 6 (6.2%) | 6 (6.9%) | 12 (6.5%) | |
Education | 0.641 | |||
Junior high school and below | 26 (26.8%) | 28 (32.2%) | 54 (29.3%) | |
high school | 20 (20.6%) | 19 (21.8%) | 39 (21.2%) | |
College degree and above | 51 (52.6%) | 40 (46.0%) | 91 (49.5%) | |
BMI (kg/m2) b | 0.604 | |||
< 18.5 | 6 (6.2%) | 8 (9.2%) | 14 (7.6%) | |
18.5–24 | 39 (40.2%) | 30 (34.5%) | 69 (37.5%) | |
> 24 | 52 (53.6%) | 49 (56.3%) | 101 (54.9%) | |
HIV | 0.697 | |||
Negative | 20 (20.6%) | 20 (23.0%) | 40 (21.7%) | |
Unknown | 77 (79.4%) | 67 (77.0%) | 144 (78.3%) | |
Comorbidity | **0.006 | |||
No | 84 (86.6%) | 61 (70.1%) | 145 (78.8%) | |
Yes | 13 (13.4%) | 26 (29.9%) | 39 (21.2%) | |
Frequency of colds | 0.291 | |||
0–1 | 72 (74.2%) | 70 (80.5%) | 142 (77.2%) | |
2–3 | 25 (25.8%) | 16 (18.4%) | 41 (22.3%) | |
≥ 4 | 0 (0.0%) | 1 (1.1%) | 1 (0.5%) | |
BCG scar | **0.005 | |||
No | 16 (16.5%) | 30 (34.5%) | 46 (25.0%) | |
Yes | 81 (83.5%) | 57 (65.5%) | 138 (75.0%) | |
History of tuberculosis | 0.065 | |||
No | 97 (100.0%) | 84 (96.6%) | 181 (98.4%) | |
Yes | 0 (0.0%) | 3 (3.4%) | 3 (1.6%) | |
History of tuberculosis in family | 0.192 | |||
No | 2 (2.1%) | 5 (5.7%) | 7 (3.8%) | |
Yes | 95 (97.9%) | 82 (94.3%) | 177 (96.2%) | |
Relationship with the index case | 0.252 | |||
Conjugal | 29 (29.9%) | 29 (33.3%) | 58 (31.5%) | |
Children | 43 (44.3%) | 38 (43.7%) | 81 (44.0%) | |
Grandchildren | 12 (12.4%) | 4 (4.6%) | 16 (8.7%) | |
Other | 13 (13.4%) | 16 (18.4%) | 29 (15.8%) | |
Degree of closeness | 0.358 | |||
≤ 1 h per day | 18 (18.6%) | 12 (13.8%) | 30 (16.3%) | |
1–3 h per day | 13 (13.4%) | 19 (21.8%) | 32 (17.4%) | |
3–5 h per day | 17 (17.5%) | 13 (14.9%) | 30 (16.3%) | |
5–8 h per day | 6 (6.2%) | 2 (2.3%) | 8 (4.3%) | |
≥ 8 h per day | 43 (44.3%) | 41 (47.1%) | 84 (45.7%) | |
Medication | 0.912 | |||
No | 95 (97.9%) | 85 (97.7%) | 180 (97.8%) | |
Yes | 2 (2.1%) | 2 (2.3%) | 4 (2.2%) | |
Degree of Xpert (Index cases) | **0.000 | |||
Lowc | 44 (45.4%) | 35 (40.2%) | 79 (42.9%) | |
Medium | 48 (49.5%) | 39 (44.8%) | 87 (47.3%) | |
High | 5 (5.1%) | 13 (14.9%) | 18 (9.8%) | |
Index Situation | ||||
Subclinical TBd | 9 (9.3%) | 8 (9.2%) | 17 (9.2%) | 1.000 |
Active TB | 88 (90.7%) | 79 (90.8%) | 167 (90.8%) |