Lessons learned from 30 years of Legionella
SCI/RSC/Water Management Society conference, 12-13 July 2006, Birmingham, UK
Legionella: 30 years on, an international conference held in Birmingham, UK, in June, gave a global view of Legionella with details of a number of major outbreaks in the UK, Spain and the Netherlands. All of the presentations underlined the lessons learned from each of the outbreaks, with the incident in Spain the biggest ever reported with 449 confirmed cases (around 800 suspected cases in total). An outbreak at a Dutch flower show infected more than 200 people leading to more than 30 deaths. Experiences in Australia were also considered.
Discussion on treatment processes and strategies centred on issues associated with spa baths; Legionella water analysis developments (it is now possible to obtain a result within three hours of receiving a sample); and future research needs, with a presentation from Steve Copping of the UK Health and Safety Executive (HSE) entitled ‘The future direction of legislation’. Currently in the UK, Legionella is not a notifiable disease
In Australia, approximately
half of Legionella infections
originate from potting compost,
which now carries warnings
on its packaging. Most
cooling tower incidents in Australia
are associated with
smaller cooling towers of less
than 500kW, with the risk
being compounded by stagnant
water, nutrient availability,
deficiencies in the cooling
water system and location and
access of cooling towers. Evidence
was presented at the
conference indicating that
infection could be transmitted
up to 8km from a badly
infected cooling tower under
appropriate weather transmission
conditions.
 The first recorded outbreak
in Philadelphia in 1976
resulted in 200 cases with 13
deaths. It took six months to
ascertain the cause as
Legionella. Evidence from preserved
lung tissue has shown
that Legionella outbreaks had
occurred as far back as 1944
and this would indicate that
the disease had occurred
before this but had not been
identified.
It was recommended that to
avoid outbreaks, architects,
engineers, chemists and microbiologists
should liaise when
designing new buildings, and
once any water systems are
commissioned a robust maintenance
plan should be put in
place.
Almost 200 delegates and
speakers attended the conference
and associated trade exhibition
with 14 stands. Speakers
from Spain, Australia, the
Netherlands and the UK took
part. There were presentations
from the UK Health Protection
Agency, the HSE, the London
School of Hygiene & Tropical
Medicine, the Royal Liverpool,
Broadgreen and University hospitals,
and Liverpool, Basildon
and Thurrock NHS trusts, as
well as some major water treatment
companies.
Clive Thompson
Environment Group
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