Legionella Awareness

Size: px

Start display at page:

Download "Legionella Awareness"

Ezra Bruce
6 years ago
Views:

1 Presents Legionella Awareness Presented by Matt Round M.W.M.Soc, TechIOSH

2 HISTORICAL REVIEW The first outbreak occurred following a convention of American Legionnaires (hence the name), in the Bellevue-Stratford Hotel in Philadelphia, USA. 182 people confirmed infected 29 people died

3 HISTORICAL REVIEW Legionella Pneumophila was identified as the causative agent for the first time

4 HISTORICAL REVIEW The oldest known case of legionnaires disease, following retrospective analysis of isolates

5 HISTORICAL REVIEW The oldest isolated case identified in the UK from Nottingham

6 HISTORICAL REVIEW The first case identified as Legionnaires Disease in the UK was in Corby

7 HISTORICAL REVIEW First recognised UK hospital outbreak in Kingston

8 HISTORICAL REVIEW The WHO recommend screening for Legionella infection in all admitted cases of pneumonia

9 HISTORICAL REVIEW Major outbreak at Stafford Hospital 175 confirmed cases 28 deaths

10 HISTORICAL REVIEW Major outbreak at BBC Broadcasting House, increasing public awareness 70 confirmed cases 3 deaths

11 HISTORICAL REVIEW Copthorne Hotel, Cardiff 70 confirmed cases 3 deaths

12 HISTORICAL REVIEW Westfriese Flower Show Netherlands 242 confirmed cases 22 deaths

13 HISTORICAL REVIEW Murcia in Spain 449 confirmed cases 6 deaths

14 HISTORICAL REVIEW Barrow in Furness 131 confirmed cases 7 deaths Design Services Manager charged with negligence

15 HISTORICAL REVIEW Merthyr Tydfil, Wales 22 confirmed cases 2 deaths

16 HISTORICAL REVIEW Playboy Mansion 200 confirmed cases 0 deaths

17 HISTORICAL REVIEW Edinburgh 50 confirmed cases 3 deaths Stoke-on-Trent 19 confirmed cases 1 death

LEGIONNAIRES OCCURRENCE Legionella bacteria are common and can be found naturally in environmental water sources Typically 200 to 250 cases reported annually (underestimated!

18 LEGIONNAIRES OCCURRENCE Legionella bacteria are common and can be found naturally in environmental water sources Typically 200 to 250 cases reported annually (underestimated!) Around 50% of cases associated with travel abroad Cases of Legionnaires disease have occurred among staff in the workplace (factories, offices, shops and hospitals); visitors (delivery drivers) and members of the public (patients, hotel guests or passers-by) people die annually due to Legionnaires Disease However, there are approximately 180,000 pneumonia cases each year in the UK

TRANSMISSION The primary route of infection is the inhalation of aerosols contaminated with legionella bacteria. So for legionnaires disease to develop, the bacteria needs to get into the lungs.

19 TRANSMISSION The primary route of infection is the inhalation of aerosols contaminated with legionella bacteria. So for legionnaires disease to develop, the bacteria needs to get into the lungs. Anything that may aid in that process (eg. smoking) will increase that persons susceptibility to legionnaires disease. Legionnaires disease cannot be contracted from another person infected with the disease. A second method has been described recently called "Aspiration. Aspiration is the inhalation of secretions in the mouth into the lung instead of to the stomach which is normally due to decreased or absent gag reflex.

SUSCEPTIBILITY Patients with increased susceptibility Diabetes Respiratory Disease Cancer Kidney Disease Immunosuppressant Drugs (steroids etc)

20 SUSCEPTIBILITY Patients with increased susceptibility Diabetes Respiratory Disease Cancer Kidney Disease Immunosuppressant Drugs (steroids etc) Alcoholism Patients with very high susceptibility Head/Neck Cancer Bone Marrow Transplant Renal Dialysis Leukaemia Organ Transplant AIDS Smokers Over 45s

WHAT LEGIONELLA NEEDS Before legionella becomes a problem, it needs some of the following to help it proliferate and to spread; Stagnation Nutrients Temperature between

21 WHAT LEGIONELLA NEEDS Before legionella becomes a problem, it needs some of the following to help it proliferate and to spread; Stagnation Nutrients Temperature between o C Oxygen Protective Environments Aerosolisation The 6 faces of the cube When looking at any water system, look at it for the potential for any of the above to occur.

22 CONFIRMED SOURCES Domestic Water Systems Cooling towers Spa Baths Humidifiers Dental Chairs Drilling/grinding machines Misting machines Ornamental fountains

23 EFFECT OF FAILIURE

24 UK LAW AND WHERE L8 FITS IN LAW MUST DO EVIDENCE BASED BEST PRACTICE INFO GUIDANCE

Practice L8, along with what practices have proven efficacy (i.e. best practice).

25 UK LAW AND WHERE L8 FITS IN There are 4 main statutes which are relevant to the control of legionella bacteria; All of the above have been considered by the Health and Safety Commission when writing the Approved Code of Practice L8, along with what practices have proven efficacy (i.e. best practice). The L8 is not however legislation. If you were to be prosecuted, it would probably be under HSWA as it is this which gives the ACoP L8 it s bite.

26 UK LAW AND WHERE L8 FITS IN 2013 ACoP L8 (revised)..and supporting guidance HSG274 in early 2014

27 LEGALLY WHAT YOU MUST DO Identify & Assess Risks Write a Scheme of Precautions Keep a Record Implement Precautions

28 RESPONSIBILITY AND COMMUNICATION Key Responsibilities Statutory Duty Holder Responsible Person Nominated Deputy Competent Help Person in control of the premises and water systems. Typically a Chief Executive, Managing Director or General Manager. They have ultimate responsibility for health and safety matters. Manager, Director or someone who has similar status and sufficient authority, competence and knowledge who has been delegated managerial responsibility for the control of legionella Someone of sufficient competence and knowledge so that someone can always be contacted The Legionella Control Association is a voluntary organisation and consists of both product suppliers and independent consultants. Potential conflict of interest should be considered when choosing a contractor. It is essential that there are clearly defined responsibilities in writing which are understood by all those involved.

29 RISK MANAGEMENT A foreseeable risk of exposure to Legionella Bacteria therefore exists in: cooling towers evaporative condensers hot and cold water systems humidifiers, air washers, softeners, emergency showers, sprinklers / hose reels, lathe coolants, spas, horticultural misting, dentistry, car washes & indoor water features any other water system where the water temperature may exceed 20 C and a spray or aerosol be released during operation or maintenance.

30 RECORD KEEPING Schematics

Design & Construction COLD WATER SYSTEMS Cold water storage systems should be designed to avoid the conditions favouring

Tanks should comply with the Water Supply (Water Fittings) Regulations 1999 (old byelaw 30) and should therefore have;

insulation Insect screens fitted to the vent, overflow and warning pipe preventing foreign objects and debris entering the

Important note : A great way to eliminate the risks presented by cold water storage in open tanks and large volumes, is by

31 Design & Construction COLD WATER SYSTEMS Cold water storage systems should be designed to avoid the conditions favouring growth of Legionella and to allow easy cleaning and disinfection and inspection. Tanks should comply with the Water Supply (Water Fittings) Regulations 1999 (old byelaw 30) and should therefore have; Storage capacity of less than 24 hours A tight fitting lid with inspection hatch allowing inspection without damaging the insulation Insect screens fitted to the vent, overflow and warning pipe preventing foreign objects and debris entering the system. Important note : A great way to eliminate the risks presented by cold water storage in open tanks and large volumes, is by moving to mains pressure systems, with Reduced Pressure Zone (RPZ) valves replacing tanks. The inlet opposite the outlet, ensuring a good flow of water through the tank preventing stagnation hotspots. Insulation all over to prevent greater than 2 C heat gain A good working drain fitted

32 COLD WATER SYSTEMS Operation & Monitoring Cold water should be below 20 o C at all times The incoming cold water inlet temperature should be measured at least once in the winter and once in the summer. Cold water storage tanks should be visually inspected annually and should be cleaned and disinfected if necessary and any faults rectified. See slide on cleaning & disinfection later Record the total water consumption over a typical day and whenever the building use changes, this should be repeated. Check nearest and furthest cold water outlet temperatures are below 20 o C within 2 mins. flow on a monthly basis. A representative number of cold water outlets should also be tested on a rotational basis once a year. Install high use outlets upstream of lower use outlets to maintain flow. Review cold water circuit plans annually and remove redundant outlets

33 Operation & Monitoring HOT WATER SYSTEMS Calorifiers on standby use or out of service for >7 days should be thermally disinfected at 60 o C for on hour AVOID TEMPERATURES BETWEEN 20 o C AND 50 o C Store hot water >60 o C and distribute >50 o C Where scalding is a risk, use thermostatic mixing valves Remove dead-legs and cut back redundant outlets Infrequently used outlets and particularly showers, should be flushed weekly for several minutes to prevent stagnation Calorifiers should be drained and inspected annually. The system should then be cleaned and disinfected Flow and return temperatures should be logged monthly. Building Management Systems (B.M.S.) may be used to automate this task Check that the nearest and furthest hot water outlet temperatures are above 50 o C within 1 min flow on a monthly basis and a representative number of other outlets once a year

34 If it s not logged, it s not done! RECORD KEEPING Record systems should include the following information: Details of the risk assessment this must be current, including schematics and clearly defined lines of communication Details of precautionary measures implemented this is the information detailed in the written scheme Monitoring, inspection, test and check results a record of all results including signatures, dates and what was actioned when out of specification a record of analyses (as appropriate) an asset inspection record, including subsequent remedial actions a record of cleaning and disinfection, including details of chlorination levels, temperatures (during pasteurisation) and certification personnel training records - including this course! Risk assessments & control schemes should be kept whilst current & for 2 years after that period. Monitoring results should be retained for 5 years.

35 COOLING PROCESS Types of Cooling Tower Forced Draught Moist Air Moist Air drift eliminators reduce the aerosol spray released to atmosphere The hot water falls through the packing & cools in the air stream distribution system ensures even flow of water over the tower AIR IS FORCED THROUGH THE TOWER BY THE FAN After cascading through the packing the water is collected in a sump or pit

36 COOLING PROCESS Types of Cooling Tower Induced Draught Moist Air THE FAN SUCKS AIR THROUGH THE TOWER The hot water falls through the packing & cools in the air stream The hot water falls through the packing & cools in the air stream

37 Types of Cooling Tower Evaporative Condensers COOLING PROCESS Medium to be cooled The volume of cooling water in this type of system is very small as it is only in the sump and pipework. Air in Evaporative condensers do not have any packing inside them. Instead they have tubes which carry a secondary medium which requires cooling.

wet cooling systems and hot and cold water systems - please

38 If in doubt The HSE Approved Code of Practice L8 and HSG274 provides detailed guidance on the operation and management of wet cooling systems and hot and cold water systems - please consult this document for further guidance. IF IN DOUBT - SEEK EXPERT ADVICE

LEGIONELLA MANAGEMENT PROCEDURE

LEGIONELLA MANAGEMENT PROCEDURE This procedure sets out the aims and objectives of the school and outlines responsibilities for managing the risk of exposure to legionella. General Statement of Intent