Table 2.
Characteristics of TB cases, Group 1 and Group 2, 1986–2004
| Group 1 Epidemic t0 < 1920 |
Group 2 Epidemic t0 > 1920 |
P valuea | |
|---|---|---|---|
| Total number of TB cases | 228 | 1243 | |
| Age category, number (%) | <0.001 | ||
| <5 years | 82 (36) | 456 (37) | |
| 5–9 | 26 (11) | 184 (15) | |
| 10–34 | 47 (21) | 434 (35) | |
| 35–64 | 49 (22) | 122 (10) | |
| ≥65 | 24 (11) | 47 (4) | |
| Median age (range) | 11 (4mo-84y) | 9 (2mo-88y) | <0.001 |
| Male, number (%) | 124 (54) | 649 (52) | 0.48 |
| Disease category, number (%)b | 0.21 | ||
| pulmonary | 164 (80) | 931 (85) | |
| extra-pulmonary | 29 (14) | 133 (12) | |
| disseminated | 11 (5) | 36 (3) | |
| Cavitary pneumonia (%)c | 13/206 (6) | 90/1117 (8) | 0.92 |
| Relapse or reinfection (%)d | 13 (6) | 100 (8) | 0.22 |
| Documented reinfection (new strain)e | 0 | 4 | |
| History of LTBI treatment (%)f | 5 (2) | 26 (2) | 0.95 |
| History of BCG (%) | 108 (47) | 700 (56) | 0.01 |
| Sputum smear positive (%)g | 44/104 (42) | 231/513 (45) | 0.44 |
| Culture positive (%)h | 81/180 (45) | 475/1042 (46) | 0.88 |
| Medical risk factor identified (%)i | 19 (8) | 9 (0.7) | <0.001 |
| Identified by screening (%)j | 99/227 (44) | 580/1240 (47) | 0.31 |
Wilcoxon rank-sum or chi-square test. Unless otherwise indicated, the denominator for the proportions is the total number of TB cases in each group. Detailed descriptions of variables are in Methods and SOM.
Disease category data (pulmonary, extra-pulmonary, or disseminated) were available from 204 of the Group 1 cases and 1100 of the Group 2 cases. Percentages reported are proportion of cases from which disease classification data were available.
Cavity identified on chest X ray/cases for which chest X ray results were available.
History of discrete tuberculosis disease episode a minimum of 2 years prior to the current diagnosis
Bacteria with ≥ 2 distinct RFLP types isolated from a single individual during distinct disease episodes. RFLP types differed by ≥5 bands. Denominator is the total number of cases within the group for which RFLP typing data were available.
History of treatment for latent tuberculosis infection
Number of sputum smear specimens with acid fast bacilli/number of sputum smear examinations recorded
Number of patient specimens with M.tuberculosis identified in culture/number of tests recorded (≤1 specimen/case)
Risk factor for tuberculosis identified in medical history. Risk factors included HIV infection, malignancy, renal failure, diabetes mellitus, and treatment with corticosteroids. No data were recorded regarding use of tobacco, alcohol or other recreational drugs.
Case identified during through active surveillance, such as contact tracing investigations, tuberculin skin testing surveys, or population-based screens for tuberculosis disease. Denominator is number of cases for which these data were available.