Volume 10, Number 3—March 2004
Research
Legionella Infection Risk from Domestic Hot Water
Paola Borella*
, M. Teresa Montagna†, Vincenzo Romano-Spica‡§, Serena Stampi¶, Giovanna Stancanelli#, Maria Triassi**, Rachele Neglia*, Isabella Marchesi*, Guglielmina Fantuzzi*, Daniela Tatò†, Christian Napoli†, Gianluigi Quaranta‡, Patrizia Laurenti‡, Erica Leoni¶, Giovanna De Luca§, Cristina Ossi#, Matteo Moro#, and Gabriella Ribera D’Alcalà**
, M. Teresa Montagna†, Vincenzo Romano-Spica‡§, Serena Stampi¶, Giovanna Stancanelli#, Maria Triassi**, Rachele Neglia*, Isabella Marchesi*, Guglielmina Fantuzzi*, Daniela Tatò†, Christian Napoli†, Gianluigi Quaranta‡, Patrizia Laurenti‡, Erica Leoni¶, Giovanna De Luca§, Cristina Ossi#, Matteo Moro#, and Gabriella Ribera D’Alcalà**Table 3
Characteristics of Legionella contamination in the examined domestic hot water
| Characteristic | Legionella spp. total | L. pneumophila serogroup 1 | L. pneumophila serogroups 2–14 | Other Legionella species |
|---|---|---|---|---|
| Positive samples
n (%) |
33/146 (22.6) |
6/33 (18.2) |
19/33 (57.6) |
8/33 (24.2) |
| Count (CFU/L) | ||||
| Geometric mean | 1.17 × 103 | 0.96 × 103 | 0.94 × 103 | 2.30 × 103 |
| Median | 1.85 × 103 | 0.89 × 103 | 1.85 × 103 | 3.16 × 103 |
| 5th percentile | 54 | 100 | 25 | 100 |
| 95th percentile |
4.1 × 104 |
5 × 103 |
3 × 104 |
8.8 × 104 |
| Distribution n (%) | ||||
| 1–9.9×102 CFU/L | 15/33 (45.4) | 3/6 (50.0) | 9/19 (47.4) | 3/8 (37.5) |
| 103–9.9 × 103 CFU/L | 15/33 (45.4) | 3/6 (50.0) | 8/19 (42.1) | 4/8 (50.0) |
| >104 CFU/L | 3/33 (9.2) | 0/6 (0.0) | 2/19 (10.5) | 1/8 (12.5) |
