Table 1.
Demographic Characteristics Among Employees Seropositive and Seronegative for Antibodies Against Francisella tularensis—Devils Tower National Monument, September 2015
| Characteristic | Seropositive (N=3) | Seronegative (N=20) | Pa | OR (exact 95% CI) |
|---|---|---|---|---|
| Male, n (%) | 2 (67) | 11 (55) | 1.000 | 1.6 (0.07–107.1) |
| Age in years,b n (%) | 0.651c | |||
| ≤ 20 | 0 (0) | 1 (5) | ||
| 21–40 | 2 (67) | 14 (60) | ||
| 41–60 | 1 (33) | 1 (5) | ||
| ≥ 61 | 0 (0) | 4 (20) | ||
| Park Housing, n (%) | 1 (33) | 10 (50) | 1.000 | 0.5 (0.01–11.4) |
| Job type, n (%) | ||||
| Permanent full-time | 1 (33) | 4 (20) | 0.539 | 2.0 (0.03–47.0) |
| Term or seasonal | 2 (67) | 11 (55) | 1.000 | 1.6 (0.07–107.1) |
| Volunteer | 0 (0) | 3 (15) | 1.000 | 0.0 (0.0–13.7) |
| Contractor or student | 0 (0) | 2 (10) | 1.000 | 0.0 (0.0–26.1) |
| Division, n (%) | ||||
| Facility Management | 2 (67) | 4 (20) | 0.155 | 8.0 (0.3–500.4) |
| Interpretation | 0 (0) | 1 (5) | 1.000 | 0.0 (0.0–126.7) |
| Visitor and Resource Protection | 0 (0) | 3 (15) | 1.000 | 0.0 (0.0–13.7) |
| Resource Management | 1 (33) | 7 (35) | 1.000 | 0.9 (0.01–21.0) |
| Entrance Station | 0 (0) | 3 (15) | 1.000 | 0.0 (0.0–13.7) |
| Concessions | 0 (0) | 1 (5) | 1.000 | 0.0 (0.0–126.7) |
| Hours worked outdoors per week, median (range) | 38 (31–62) | 25 (8–54)d | 0.109c | |
| Worked for NPS during previous years, n (%) | 3 (100) | 14 (70) | 0.539 | Undefined |
| Held previous outdoor jobs, including NPS, n (%) | 3 (100) | 16 (80) | 1.000 | Undefined |
a
Fisher’s exact test unless otherwise indicated.
b
Presented in age categories to protect identities because of small numbers.
c
Mann–Whitney exact U test.
d
n = 19.
CI, confidence interval; NPS, National Park Service; OR, odds ratio.