TABLE 2.
Association of hot water distribution systems and hotel characteristics with Legionella contamination by univariate analysis
| Characteristic | No. (%) of samples:
|
RR (95% CI) | |
|---|---|---|---|
| With Legionella spp. | Without Legionella spp. | ||
| No. of rooms, ≥80 | 31 (27.0) | 49 (18.2) | 1.5 (1.0-2.2)a |
| Hotel age, ≥30 yr | 34 (17.2) | 42 (28.0) | 0.6 (0.4-0.9)a |
| Boiler age, ≥20 yr | 5 (20.8) | 58 (22) | 0.9 (0.4-2.1) |
| Apartments | 73 (21.2) | 6 (23.1) | 0.9 (0.4-1.9) |
| Bungalows | 11 (44) | 68 (19.8) | 2.2 (1.3-3.6)b |
| Seasonal operation | 16 (42.1) | 58 (18.4) | 2.3 (1.5-3.5)b |
| Water source, municipal supply | 70 (20.5) | 10 (23.3) | 0.8 (0.5-1.6) |
| Water source, well | 3 (25.0) | 77 (20.6) | 1.2 (0.4-3.3) |
| Water tank | 30 (27.5) | 44 (17.1) | 1.6 (1.0-2.4)a |
| Operation temp, ≥55°C | 15 (27.3) | 58 (19.0) | 1.4 (0.9-2.3) |
| Thermal insulation of system | 50 (20.4) | 19 (19.4) | 1.0 (0.6-1.7) |
| Steel plumbing | 5 (26.3) | 75 (20.5) | 1.2 (0.6-2.8) |
| Cu-PVC plumbing | 3 (23.1) | 77 (20.7) | 1.1 (0.4-3.0) |
| Cu plumbing | 32 (21.1) | 48 (20.6) | 1.0 (0.7-1.5) |
| PVC plumbing | 9 (24.3) | 71 (20.4) | 1.2 (0.6-2.2) |
| Independent disinfection system | 9 (10.8) | 245 (29.3) | 0.4 (0.2-0.7)c |
| Independent water filtration | 10 (23.8) | 49 (21.6) | 1.1 (0.6-2.0) |
| Water storage tank protected | 22 (30.1) | 3 (18.8) | 1.6 (0.4-4.7) |
| Oil heat | 55 (25.1) | 25 (15.1) | 1.7 (1.0-2.5)a |
| Electric heat | 8 (14.8) | 72 (21.8) | 0.6 (0.3-1.3) |
| Solar heat | 8 (17.4) | 72 (21.2) | 0.8 (0.4-1.6) |
a
P = 0.01 to 0.03.
b
P = 0.001 to 0.007.
c
P = 0.00001.