Table 2.
Results of environmental investigation of potential sources linked to LD patients. (Source: Database National Legionella Outbreak Detection Programme, National Reference Laboratory for Legionella in Haarlem, The Netherlands)
| Type of source sampled | Number of sources sampled | P value | Positive sampled sources | P value | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Epidemic group* | Non-epidemic group* | Epidemic group | Non-epidemic group | |||||||
| Private house | 24 | (30·4%) | 105 | (38·2%) | 0·20 | 5 | (20·8%) | 28 | (26·7%) | 0·55 |
| Hospital or healthcare setting | 8 | (10·1%) | 22 | (8·0%) | 0·55 | 4 | (50%) | 12 | (54·5%) | 0·83 |
| Garden centre | 14 | (17·7%) | 27 | (9·8%) | 0·05 | 1 | (7·1%) | 2 | (7·4%) | 1·00 |
| Wellness centre | 1 | (1·3%) | 16 | (5·8%) | 0·14 | 1 | (100%) | 13 | (81·3%) | 1·00 |
| Accommodation† | 9 | (11·4%) | 14 | (5·1%) | 0·05 | 1 | (11·1%) | 2 | (14·3%) | 1·00 |
| Cooling tower | 3 | (3·8%) | 17 | (6·2%) | 0·58 | 1 | (33·3%) | 9 | (52·9%) | 1·00 |
| Car wash | 4 | (5·1%) | 18 | (6·5%) | 0·79 | 0 | — | 2 | (11·1%) | 1·00 |
| Place of work | 2 | (2·5%) | 14 | (5·1%) | 0·54 | 1 | (50%) | 2 | (14·3%) | 0·35 |
| Other | 14 | (17·7%) | 42 | (15·3%) | 0·60 | 3 | (21·4%) | 6 | (14·3%) | 0·40 |
| Total no. of sources sampled | 79 | (100%) | 275 | (100%) | — | 17 | (21·5%) | 76 | (27·6%) | 0·28 |
*
Epidemic group: domestic cases with onset disease in weeks 32–38 (2010). Non-epidemic group: domestic cases with onset of disease in 2008, 2009, and 2010, excluding weeks 32–38 (2011).
†
Accommodation: hotel, campsite or holiday home.