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Volume 10, Number 3—March 2004


Legionella Infection Risk from Domestic Hot Water

Paola Borella*Comments to Author , 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**
Author affiliations: *University of Modena and Reggio E., Modena, Italy; †University of Bari, Bari, Italy; ‡Catholic University in Rome, Rome, Italy; §University Institute of Physics Sciences, Rome, Italy,; ¶University of Bologna, Bologna, Italy; #S. Raffaele Hospital, Milan, Italy; **University Federico II of Naples, Naples, Italy

Main Article

Table 7

Differences in some water parameters according to Legionella species

Characteristic L. pneumophila serogroup 1 (n = 6) Mean ± SD L. pneumophila serogroups 2–14 (n = 19) Mean ± SD Legionella other species (n = 8) Mean ± SD F score (p)
Sampling temperature (°C)
29.4 ± 11.8
48.9 ± 4.4a
31.2 ± 15.5
15.17 (<0.001)
Operating temperature (°C)
43.3 ± 12.1a
53.7 ± 5.9
57.0 ± 4.4
6.91 (<0.005)

Geometric mean
Geometric mean
Geometric mean

Free chlorine (μg/L)
7.86 (<0.002)
Pseudomonas spp. (CFU/100 mL) 0.4 19.1b 0.6 3.31 (<0.05)

ap < 0.05 versus the other two groups.
bp < 0.05 versus Legionella other species.

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