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The World Health Organization (WHO, 2002) recommends that in order to
avoid the multiplication of
Legionella
, water is kept flowing at a temperature,
preferably, below 15 °C or, then, at a temperature above 55 °C. Hrubá (2009)
also found in his work that the temperature of the water must be above 55
°C, but viable cells of
Legionella pneumophila
were found in samples of water
that were between 55 and 60 °C. Fliermans
et al
. (1981) noted the occurrence
of
Legionella pneumophila
among temperatures varying from 5.7 to 63 °C.
Hrubá (2009) verified yet that the highest levels of colonization by
Legionella
pneumophila
occurred when the water was at a temperature between 30 and
35 °C. However, Lin
et al
. (1994) declare that the ideal range of temperature
for the multiplication of
Legionella
in reservoirs of hot water in hospitals is
between 45 °C and 50 °C. Other authors indicated in the work of Lasheras
et al
. (2006) declare that the ideal range for the growth of
Legionella
is wider,
varying between 25 and 45 °C, but the presence of
Legionella
and amoebae
is not verified at the interior of the water distribution systems when water is
circulating and at a temperature above 58.8 °C.
Figure 1
– Relation between decimal reduction times and temperature for
Legionella
pneumophila
(adapted from the data of Schulze-Röbbecke and Buchholtz, 1992, Sanden
et al
., 1989, Stout
et al
., 1986 and Dennis
et al
., 1984).
0,1
1
10
100
1000
10000
40 45 50 55 60 65 70
Decimal Eeduction Times (min)
Temperature (°C)
