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FEDECAI ConferenceFEDECAI Conference

Legionella – A British Perspective

Presented by

David Handley

of Healthy Buildings International

On 24th October 2002 in Valencia

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What isWhat is Legionnaires Legionnaires’ Disease ?’ Disease ? Potentially fatal form of pneumonia

Affects anybody, but some individuals are particularly susceptible

Contracted by inhalation of legionella bacteria from contaminated water

High fever, chills, headache & muscular pain

200 –250 reported cases each year

Fatal in approximately 12% of cases

Legionellosis – range of illnesses cased by legionella bacteria

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What are Legionella?What are Legionella?

Types of bacteria

Found in water at temperatures 6°C to 55°C

Requires nutrients to multiply

40 different types of legionella

Legionella pneumophila – 16 serogroups

Legionella pneumophila sg1 is the causative bacterium for 90% of Legionnaires’ Disease

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Where are legionella found?Where are legionella found?

Found in environmental water sources

Colonises manufactured water systemsCooling towers

Hot and cold water systems

Air handling plant

Other plant that uses or stores water

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History of Legionnaires’ DiseaseHistory of Legionnaires’ Disease

1976 Philadelphia» Clinical samples pre 1930

1985 Staffordshire Hospital

1986 BBC London

2002 Barrow-in Furness

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Legionella - LegislationLegionella - Legislation

Health and Safety at Work Act 1988

The Control of Substances Hazardous to Health 1994 (COSHH)

Approved Code of Practice (ACoP L8)» Launched 8th January 2001

» Replaced HS(G) 70, ACoP L8 (Rev) & MISC 150

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Requirements of the ACoPRequirements of the ACoP

Identify & Assess Sources of Risk

Prepare a Scheme for Preventing or Controlling the Risk

Implement & Manage the Precautions

Keep Records of the Precautions Implemented

Appoint a Person to be Managerially Responsible

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Changes in the New ACoP Changes in the New ACoP (1)(1)

A New Title» Legionnaires’ Disease, The Control of Legionella

Bacteria in Water Systems

Previously» The prevention or control of legionellosis

(including legionnaires’ disease)

Aim » to directly identify the subject matter and avoid

confusion

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Changes in the New ACoP Changes in the New ACoP (2)(2)

The New ACoP is Split (Part 1 and Part 2)

» Part 1 – The ACoP

» Part 2 – Guidance on Control

Includes Guidance in Part 1

Aim » to make clear the Employers duty under the

COSHH Regs to control legionella

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Changes in the New ACoP Changes in the New ACoP (3)(3)

Use of Risk Systems HAS TO BE AVOIDED in so far as is reasonably practicable

» Previously SHOULD BE

» Must assess practicality of removal of risk system

Now requires that you CONTROL the Risk

» Previously MINIMISE the Risk

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Changes in the New ACoP Changes in the New ACoP (4)(4)

Now has a requirement to have access to competent help when conducting a risk assessment

Code of Conduct for organisations providing water treatment services

» Water Management Society

» British Association of Chemical Specialities

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Changes in the New ACoP Changes in the New ACoP (5)(5)

Greatly expanded section on Managing the Risk - gives advice on competence & training for those:

» Developing, managing & conducting the risk assessment

» Implementing controls

» Managing external Contractors

• Including detailed lines of communication

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Changes in the New ACoP Changes in the New ACoP (6)(6)

Emphasises the duty of suppliers of products and services to:

» Carry out work effectively

» Liase with Duty Holders about deficiencies

» Clearly define limitations of work undertaken

» Ensure staff have necessary ability, training, information, resources etc.

Code of Conduct

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Design RequirementsDesign Requirements

Design requirements of L8» Ensure that risk is reasonably avoided

or, where not reasonably practicable;

» Ensure that the plant or water system is so designed as to be safe and without risk when used

» Provide on handover information as to safe usage. Such information should be updated as applicable.

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Changes in the Part 2 Guidance Changes in the Part 2 Guidance (1)(1)

Cooling Towers Much greater detail on regimes of control

Routine quarterly testing of cooling towers for the presence of Lp (records kept for 5 yrs)

Table 1 – details weekly, monthly & quarterly tests for make-up water and cooling water

Action levels for Lp & aerobic bacterial counts outlined in Table 2

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Part 2 Guidance Part 2 Guidance

Cooling Towers

Must have regular programme of visual inspection

Particular attention is paid to:

» Tower Pack

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Part 2 Guidance Part 2 Guidance

Cooling Towers

Must have regular programme of visual inspection

Particular attention is paid to:

» Tower Pack

» Drift Reducers

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Part 2 Guidance Part 2 Guidance

Cooling Towers

Must have a programme of water treatment effective against:

» Corrosion

» Scale formation

» Fouling

» Microbiological Activity

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Part 2 Guidance Part 2 Guidance (2)(2)

Cooling Towers

Weekly

» Conductivity

» Oxidising Biocide Reserve

» pH

» Microbiological Activity (Dip Slide)

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Changes in the Part 2 GuidanceChanges in the Part 2 Guidance

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Part 2 Guidance Part 2 Guidance (2)(2)

Cooling Towers

Monthly» Hardness - Ca, Mg & Total !!

» Oxidising Biocide Reserve

» pH

» Microbiological Activity (Dip Slide)

» Chloride

» Inhibitor Treatment Level

» Concentration Factor

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Part 2 Guidance Part 2 Guidance (2)(2)

Cooling Towers

Quarterly

» Legionella

» Total Alkalinity & Sulphate

» Suspended Solids

» Soluble & Total Iron

» Temperature

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Part 2 Guidance Part 2 Guidance (2)(2)

Cooling Towers

Cleaning & Disinfection

» Before tower first commissioned

» After shutdown of more than one month

» If any mechanical work undertaken

» If cleanliness is in doubt

» If microbial test results show a problem

» Temperature

» Every six months

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Microbial Monitoring – Action LevelsMicrobial Monitoring – Action Levels

Aerobic Count at 30°C (cfu/ml)

Legionella Bacteria (cfu/l)

Action

10,000 or less 100 or less System under control

>10,000 and up to 100,000

>100 and up to 1,000

Review Programme

>100,000 More than 1,000 Corrective Action

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Changes in the Part 2 Guidance Changes in the Part 2 Guidance (2)(2)

Domestic Hot & Cold Water Systems Removal of the limit of 300 litres for DHW

TMVs given recognition and procedures outlined

Table 3 & Checklist 2 introduced as guides to monitoring

Sentinel outlets introduced

Temperature measurement on DHW return

Annual tap temps reduced to “representative”

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Changes in the Part 2 GuidanceChanges in the Part 2 Guidance

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Changes in the Part 2 Guidance Changes in the Part 2 Guidance (3)(3)

Showers

Now included!!

Procedures outlined for showers served by TMVs (include hot supply as sentinel outlet)

Checklist 2 gives guide to monitoring

Shower heads – quarterly or as necessary

Flush little-used outlets weekly

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Changes in the Part 2 Guidance Changes in the Part 2 Guidance (4)(4)

Other Risk Systems Checklist 3 includes:

» Water misting systems

» Air washers & wet scrubbers

» Dental equipment

» Car/bus washes

» Fountains & water features

» Etc.

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Part 2 GuidancePart 2 Guidance

Hot & Cold Water Systems

Monthly

» Calorifier Temperatures – Flow & Return

» Sentinel Taps (Nominal Nearest & Furthest)

» Supplies to Thermostatic Mixing Valves

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Part 2 GuidancePart 2 Guidance

Hot & Cold Water Systems

Annual

» All Monthly Tests

» Representative Number of Hot Water Outlets

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Part 2 Guidance – Control LimitsPart 2 Guidance – Control Limits

Hot & Cold Water Systems

Calorifier Temperatures » Flow >60°C & Return <50°C

Taps » Hot >50°C within 1 minute

» Cold <20°C after 2 mins

Supplies to Thermostatic Mixing Valves» Same as Taps

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Legionella Monitoring – Action LevelsLegionella Monitoring – Action Levels

Legionella Bacteria (cfu/l) Action

100 or less System under control

>100 and up to 1,000 Review Programme

More than 1,000 Corrective Action

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Legionella Risk Assessment Legionella Risk Assessment Risk at Source

» Condition

» Accessibility

Cultivation Conditions» Temp & pH

» Microbe Count & Water Change Rate

Exposure» Period and Type

» Exposed Population

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Precautions & Control SchemePrecautions & Control Scheme

Prepare a Suitable System of Control

Manual» Details

• Written Scheme• Regime of Maintenance & Control• Responsible Persons• Reporting Procedures• Risk Assessments

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Lp High Risk SystemsLp High Risk Systems

Cooling Towers» Diligent Water Treatment Programme

» Quarterly Lp Testing

» Once or Twice Weekly Water Treatment Tests

Showers» Minimum Quarterly Clean/Descale of Shower

Head

» Weekly Flush Through of Low Usage Systems

» Annual Lp Testing

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Implement & Manage the PrecautionsImplement & Manage the Precautions

Log Book» Water Treatment Results

» Lp Tests

» Temperature Measurements

» Cleanliness of systems

» Disinfection certificates etc

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Record KeepingRecord Keeping

Keep Records

» Manual (incl. Risk Assessments)

• 2 Years

» Log Book Records• 5 Years

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Responsible PersonResponsible Person

Manage the Control Scheme

Training

Regular Reviews

Communication

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The Barrow Outbreak The Barrow Outbreak (1)(1)

Britain’s Biggest Ever Outbreak of LD» 131 confirmed cases

» Trawl of GPs nationwide shows 10 more suspected cases

» 41 people still in hospital – 8 in intensive care

» Majority of victims aged 55-75 - none <15yrs old

» 4 Fatalities - 3 Women, 1 Man – all >50 yrs old

» Mortality Rate 3.1%. Lower than norm - due to rapid diagnosis & more effective antibiotics

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The Barrow Outbreak The Barrow Outbreak (2)(2)

Identifying the Source» Epidemiological link to centre of Barrow-in-Furness

» HSE checked 132 locations in immediate area

» Most rapidly eliminated – just 4 cooling towers

» 3 proved negative for legionella spp

» Causative organism identified as Legionella pneumophila serogroup 1 – subtype Benidorm

» Strain isolated from some patients and the Forum 28 Arts Centre cooling tower

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The Barrow Outbreak The Barrow Outbreak

The Forum 28 Arts Centre

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The Barrow Outbreak The Barrow Outbreak

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The Barrow Outbreak The Barrow Outbreak (3)(3)

The Arts Centre Cooling System» 30 yrs old and in poor condition

» Local Council responsible for site maintenance

» Biocide dosing system malfunctioning?

» Discharging “discoloured steam” into alleyway

» Part of system not used, but not decommissioned

» 6-monthly disinfection being done for free!

» System believed to have been operating badly for some time

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The Barrow OutbreakThe Barrow Outbreak

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The Barrow Outbreak The Barrow Outbreak (4)(4)

Action Being Taken» Technical Manager of Local Council has been

suspended on full pay “to minimise contact”

» A meeting has been held between affected people and firm of solicitors

» Cumbria Police have 20 Officers investigating the deaths

» Maintenance Records have been seized

» Police investigations include “negligence, recklessness and corporate manslaughter”