Volume 17, Number 3—March 2011
Research
Active Tuberculosis among Homeless Persons, Toronto, Ontario, Canada, 1998–2007
Table 2
Characteristic | All persons, no. (%) | Canada born, no. (%) | Foreign born, no. (%) | p value† | 1998–2002, no. (%) | 2003–2007, no. (%) | p value‡ |
---|---|---|---|---|---|---|---|
Median age, y (IQR) | 47 (38–56) | 49 (42–58) | 38 (30–50) | – | 45 (38–59) | 48 (40–54) | – |
Male sex |
81 (89) |
53 (88) |
25 (89) |
1.00 |
40 (91) |
41 (87) |
0.74 |
Origin | 0.15 | ||||||
Canada born, not Aboriginal | 47 (53) | 47 (78) | NA | 27 (64) | 20 (43) | ||
Canada born, Aboriginal | 13 (15) | 13 (22) | NA | 5 (12) | 8 (17) | ||
Foreign born |
28 (32) |
NA |
28 (100) |
10 (24) |
18 (39) |
||
Case type | 0.43 | 1.00 | |||||
New | 83 (91) | 53 (88) | 27 (96) | 40 (91) | 43 (91) | ||
Re-treated§ |
8 (9) |
7 (12) |
1 (4) |
4 (9) |
4 (9) |
||
Method of detection | – | – | |||||
Signs and symptoms | 51 (56) | 30 (50) | 18 (64) | 23 (52) | 28 (60) | ||
Contact tracing | 19 (21) | 16 (27) | 3 (11) | 11 (25) | 8 (17) | ||
Diagnosis while under care for other condition | 8 (9) | 8 (13) | 0 | 4 (9) | 4 (9) | ||
Immigration screening | 6 (7) | NA | 6 (21) | 6 (14) | 0 | ||
Active case finding (sputum screening) | 3 (3) | 3 (5) | 0 | NA | 3 (6) | ||
Jail | 1 (1) | 1 (2) | 0 | 0 | 1 (2) | ||
Other¶ |
3 (3) |
2 (3) |
1 (4) |
0 |
3 (6) |
||
Site(s) of infection | 1.00 | 0.15 | |||||
Pulmonary only | 67 (74) | 45 (75) | 21 (75) | 33 (75) | 34 (72) | ||
Extrapulmonary only | 21 (23) | 13 (22) | 6 (21) | 8 (18) | 13 (28) | ||
Pulmonary and extrapulmonary |
3 (3) |
2 (3) |
1 (4) |
3 (7) |
0 |
||
Chest radiograph at diagnosis# | 0.08 | ||||||
No abnormalities | 9 (13) | 7 (15) | 2 (9) | 0.86 | 7 (19) | 2 (5) | |
Abnormal without cavitation | 45 (65) | 30 (64) | 15 (68) | 24 (67) | 21 (62) | ||
Abnormal with cavitation |
15 (22) |
10 (21) |
5 (23) |
5 (14) |
11 (32) |
||
Self-reported symptoms | 73 (80) | 50 (83) | 20 (71) | 0.26 | 34 (77) | 39 (83) | 0.60 |
Median time from symptom onset to diagnosis, mo (IQR) |
1.9 (0.6–3.1) |
1.8 (0.6–2.6) |
2.6 (0.8–5.8) |
– |
1.8 (0.6–3.1) |
2.2 (0.6–3.2) |
– |
Sputum smear results at diagnosis** | 0.39 | 0.58 | |||||
Negative | 21 (33) | 12 (29) | 9 (43) | 12 (40) | 9 (27) | ||
Scarce/moderate | 13 (21) | 8 (20) | 5 (24) | 5 (17) | 8 (24) | ||
Numerous |
29 (46) |
21 (51) |
7 (33) |
13 (43) |
16 (49) |
||
Method of diagnosis | 0.59 | 0.18 | |||||
Positive culture | 86 (95) | 55 (92) | 28 (100) | 40 (91) | 46 (98) | ||
Positive AMTD | 3 (3) | 3 (5) | 0 | 3 (7) | 0 | ||
Clinical | 2 (2) | 2 (3) | 0 | 1 (2) | 1 (2) |
*Birthplace information available for 88 persons. IQR, interquartile range; NA, not applicable; –, no statistical test performed; AMTD, amplified Mycobacterium tuberculosis direct test.
†Probability of a significant difference between Canada-born and foreign-born persons for each variable; calculated by using the 2-sided Fisher exact test or χ2 test, as appropriate.
‡Probability of a significant difference between the 2 periods for each variable; calculated by using the 2-sided Fisher exact test or χ2 test, as appropriate.
§Public Health Agency of Canada definition: documented evidence or adequate history of previously active tuberculosis (TB) that was declared cured or treatment completed by current standards, AND at least 6 mo have passed since the last day of previous treatment, AND a diagnosis with a subsequent episode of TB that meets the active TB case definition.
¶Includes shelter screening, routine screening at other centers, and other detection methods.
#Results for only the 70 persons with pulmonary disease.
**Sputum smears available for 63 patients with pulmonary disease.