A DHSS (Department
of Health and Social Security-United Kingdom) survey has shown Legionella is present in
big buildings - at least one strain was found in 53% of the
hotels sampled. Continued surveillance has also shown that buildings where
outbreaks have occurred have had further outbreaks in later years.
hotels where the rooms are used infrequently, and where there is static water in the
pipe work. The outbreak is caused when the bacteria starts to multiply because of the lack
of disinfections within the system. It grows in the slime in the pipes. The trouble is
probably due to static water lying around in the pipes for a long time where bacteria has
started to grow like crazy - particularly in hot climates where the pipes get warm.
Warm water-samples (total of 476) were taken from
showers of 119 hotels (predominantly 4-star large buildings): Germany(38), Austria (12),
Italy(28), Spain(20) and the UK(21). According to Tiefenbrunner, F. et al. 1993,
Legionella was identified. More than 50% of the European hotels are contaminated with
Chlorination /ozonation are incapable of eradicating
Legionella for short residual disinfections periods in excess of 3-4 hours for
chlorination and 21 minutes for ozonation.
survey has shown how commonly Legionella is present in hospitals. At least one
strain was found in 70% of the hospitals sampled. An outbreak of Legionnaires disease in
Glasgow hospital in 1990 led to an interesting study of the source of the outbreak. The
cleaning and chlorination of the storage tank failed to eliminate the Legionella organism
in it, and further subsequent sampling showed that Legionella was still present in the
cold water storage tanks and in the hot and cold distributor system.