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Colliers International warns against the potential outbreak of Legionnaires’ disease as workers return to the office

15 06 20 Potential outbreak of Legionnaires disease hero

Preventing the outbreak of Legionnaires’ disease is a key consideration for landlords and property managers across the country as the workforce begins returning to the office.

Mark Jarrett, head of the Investment Property Management team at Colliers International comments: “There have been so many unexpected consequences from COVID-19 for landlords, property managers and occupiers. Legionnaires’ disease is one of these and with so many offices and buildings standing empty, the risk of legionella in poorly maintained buildings can be huge.

“In mothballed or low occupancy buildings water systems are not being used and there is the potential for bacteria, in particular legionella, growth within these systems.By turning on a tap or a shower you could be potentially exposing yourself to another deadly disease.”

Legionnella is a bacteria which grows in stagnant water, and can cause a type of pneumonia called Legionnaires’ disease.

Mark continues: “At Colliers we have given the potential risk from legionella a very high priority and have taken all the necessary precautions. In mobilising for the return to the office, it is important that firms put extra resources towards preventing any spread and ensuring water systems are cleaned and thoroughly flushed.

“There are several simple steps that can be taken to mitigate risk; reviewing the water risk assessment for the building, flushing all the outlets on a regular basis and the sampling of water when necessary. At our managed buildings we had already implemented these actions for low occupancy or where mothballed, and have continued following them throughout the crisis.

“It is of crucialimportance that property managers, occupiers and landlords are all aware of the potential growth of legionella bacteria so that that measures and steps can be taken now, before the return to the office kicks in in earnest.”

Colliers notes that guidance has been issued by Health and Safety Executive and the Legionella Control Association regarding re-commissioning of buildings on lockdown. There is a legal requirement to maintain the safety of all workplaces, including the water that is supplied to employees.

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Mark Jarrett

Head of Professional Services

Investment Property Management

London - West End

Mark joined Colliers International in 2001

Mark is Head of the Investment Property Management Department

Mark is Head of the Professional Services Division


Charles Church (residential developers) 1988-1990

Barnett Baker & Co 1990 - 1995

CBRE (formally St Quintin) 1996 - 2001


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Rebecca Allen

PR Manager

Marketing & Communications

London - West End

I have been working in commercial property communications for over 10 years  having previously worked at CBRE and Savills.

In my role at Colliers I am responsible for the PR of National Capital Markets, London Offices and Investment Property  Management teams as well as Scotland.

My role includes:

  • Creating and exectuing PR plans for business lines that span press, marketing and digital channels
  • Media monitoring and reporting
  • Advising on brand, tone of voice and profile raising 
  • Journalist relationship building through face to face meetings, phone calls day to day assistance with stories
  • Reputation management of the Colliers brand



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