Table 2. Comparison of characteristics between IGRA-seropositive and IGRA-seronegative prisoners, Tianjin, China*.
| Characteristic | No. (%) seropositive | No. (%) seronegative | Total | p value by χ2 test |
|---|---|---|---|---|
| Age, y | ||||
| <25 | 14 (2.8) | 60 (13.0) | 74 | <0.01 |
| 25–34 | 197 (39.5) | 226 (49.1) | 423 | |
| 35–44 | 168 (33.7) | 119 (25.9) | 287 | |
|
>45 |
120 (24.0) |
55 (12.0) |
175 |
|
| Ethnicity | ||||
| Han | 470 (94.2) | 443 (96.3) | 913 | 0.13 |
| Other |
29 (5.8) |
17 (3.7) |
46 |
|
| Education level | ||||
| Primary school | 172 (34.5) | 149 (32.4) | 321 | 0.70 |
| Middle school | 233 (46.7) | 216 (47) | 449 | |
| High school |
94 (18.8) |
95 (20.7) |
189 |
|
| Residence | ||||
| Local | 220 (44.1) | 213 (46.3) | 433 | 0.49 |
| Migrant |
279 (55.9) |
247 (53.7) |
526 |
|
| Employment | ||||
| No | 425 (85.2) | 399 (86.7) | 824 | 0.49 |
| Yes |
74 (14.8) |
61 (13.3) |
135 |
|
| BMI† | ||||
| Abnormal: >25–<18.5 | 147 (29.5) | 137 (29.8) | 284 | 0.91 |
| Normal: 18.5–25.0 |
352 (70.5) |
323 (70.2) |
675 |
|
| Contact history | ||||
| No | 415 (83.2) | 388 (84.3) | 803 | 0.62 |
| Yes |
84 (16.8) |
72 (15.7) |
156 |
|
| Concurrent condition‡ | ||||
| No | 403 (80.8) | 395 (85.9) | 798 | 0.03 |
| Yes |
96 (19.2) |
65 (14.1) |
161 |
|
| Mycobacterium bovis BCG scar | ||||
| No | 180 (36.1) | 206 (44.8) | 385 | <0.01 |
| Yes |
319 (63.9) |
254 (55.2) |
573 |
|
| History of incarceration | ||||
| No | 315 (63.1) | 368 (80.0) | 683 | <0.01 |
| Yes |
184 (36.9) |
92 (20.0) |
276 |
|
| Current duration of incarceration, y | ||||
| <3.9 | 227 (45.5) | 236 (51.3) | 463 | 0.07 |
|
>3.9 |
272 (54.5) |
224 (48.7) |
496 |
|
| Facility-specific TB incidence, cases/100,000 persons§ | ||||
| Low | 173 (34.7) | 195 (42.4) | 368 | 0.01 |
| Medium | 220 (44.1) | 197 (42.8) | 417 | |
| High | 106 (21.2) | 68 (14.8) | 174 | |
*BMI, body mass index; TB, tuberculosis. †By World Health Organization standard (13). ‡Chronic diseases, including diabetes, silicosis, hypertension, kidney disease. §The 2 low-incidence prisons reported 603.0 and 649.9 TB cases/100,000 persons, the 2 medium-incidence prisons 892.7 and 944.6 cases/100,000 persons, and the high-background prison 1,945.2 cases/100,000 persons.