How to Control Legionella andPseudomonas Species and Remain Legal
Legionella• Legionnaires disease is a form of pneumonia caused by the legionella bacterium. The majority of cases are reported as single (isolated) cases but outbreaks can occur. All ages can be affected but the disease mainly affects people over 50 years of age, and generally men more than women. Smokers and the immunocompromised are at a higher risk.• The bacteria are widely distributed in the environment. They can live in all types of water including both natural sources such as rivers and streams, and artificial water sources such as water towers associated with cooling systems, hot and cold water systems and spa pools.
Method of InfectionInhaled in infected aerosol droplets or drop nuclei
Legionnaires’ disease medical profileMost people will not develop Legionnaires’ diseaseand may only show flu-like symptomsStatistically approximately 12% of identified casesare fatalThere are high risk groups that are more likely tobecome infected and less likely to recoverSmokers, alcoholics, diabetics, immune suppressedpeople
Pseudomonas Species• Pseudomonas species are Gram-negative rod shaped bacterium commonly found in soil and ground water and often associated with biofilm.• P. aeruginosa is increasingly important clinically as it is a major cause of both healthcare-associated infections and chronic lung infections in people with cystic fibrosis.
Method of Infection• P. aeruginosa is one of the more common causes of healthcare- associated infections and is increasingly resistant to many antibiotics. In hospitals the organism contaminates moist/wet reservoirs such as respiratory equipment and indwelling catheters and infections can occur in almost every body site but are particularly serious in the bloodstream (bacteraemia).• If it enters lung tissue, for example in a cystic fibrosis patient, it can cause a form of pneumonia.• Infection of a skin wound or burn can lead to extensive tissue damage or even septic shock.• If the bacterium infects the gastro-intestinal system of a vulnerable patient, then a condition called "necrotising enterocolitis" can follow, which again causes severe tissue damage.
Pseudomonas infections medical profile• Latest figures suggest that the number of Pseudomonas infections is fairly steady, with between 3,700 and 4,000 cases reported to the Health Protection Agency each year.• Nine out of 10 of these were the P. aeruginosa strain.• Rates were highest in the London region, and the majority of cases were in the elderly and babies under one year old.• The bacterium appears to have an inbuilt resistance to antibiotics, as well as the ability to mutate into new, even more resistant forms.
Controlling the risk• Control and prevention of the disease is through treatment of the source of the infection, i.e. by treating the contaminated water systems, and good design and maintenance to prevent growth in the first place
Preventative measures• System Design, materials, installation and testing• Procedures and best practice• Training, responsibility and awareness• Monitoring and recording• Treatment and control• Maintenance• Environmental considerations• Guidance Documents and legislation• Identify and assess the risk and apply appropriate actions
Managing the risk• Are conditions suitable for multiplication of the organisms (for example temperatures between 20°C and 45°C and stagnant water)• Is the presence of Legionella in sufficient numbers• Is there a source of nutrients (for example sludge, scale, rust, protozoa, algae and other organic matter);• Is there a means of creating and disseminating fine droplets (for example cooling towers, showers and most other water draw-offs that are capable of creating a spray or causing splashing)• Is there the presence of people who may be exposed to contaminated aerosols, especially those who are vulnerable to Legionella infection (for example those with compromised immune or respiratory systems, and transplant patients
What does the Approved Code of Practice & Guidance L8 cover The control of legionella bacteria in water systems Issued by The Health and Safety Commission and came into force 8th January 2001 It has legal status under: Health and Safety at Work Act. Control of Substances Hazardous Health Regulations
HTM-04• The Health Technical Memorandum (HTM) outlines the principles involved in the design, installation and testing of hot and cold-water supply, storage and distribution systems in healthcare premises.• It is applicable to new and existing premises
Training Academy Courses• Level 3 endorsed Award in Legionella Control for Responsible Persons suitable for Statutory Duty Holders, Responsible People, and managers involved in legionella control. The focus being on why legionella presents a risk, legislation, Approved Code of Practice L8, HTM04:01, roles of individuals, record keeping, and appointment of competent staff.• Level 2 accredited Award in Principles of Legionella Awareness suitable for Statutory Duty Holders, Responsible People, Managers, Deputies and all staff involved in legionella control on site. This course covers the topics above also but it’s main focus is on the actions required to control legionella in specific systems.
Regulatory Factors• Biocidal Products Directive/Regulations (BPD/R)• Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)• Regulation 31(4)A of the Water Supply (Water Quality) Regulations 2000• Water Regulations Advisory Scheme (WRAS)• World Health Organisation (WHO)
What are Biocidal Products?Biocidal products contain or generate active substances and are used againstharmful organisms such as pests and bacteria.They are used both to protect human and animal health. They includehousehold products such as disinfectants, rodenticides, repellents, andinsecticides.Others are used in more industrial applications as wood and materialpreservatives, anti-fouling paints, and embalming products to avoid damageto natural or manufactured products.
What is the Objective of the Biocidal Products Regulations?Due to their intrinsic properties and uses, biocidal products may themselvespose health risks and be harmful to the environment.It is vital therefore to ensure that only biocidal products safe for use areplaced on the marketThe EU Biocidal Products Regulations provide the legal framework to regulatebiocidal products on the marketIn the UK the HSE is the Competent Authority
How will this impact the market?• Only those actives which have been notified for a particular product type (application) can be used legally within the EEC• If an active is not supported then it must be withdrawn from the market, for example copper was not supported so for biocidal use a withdrawal notice was published on 1st Feb 2012 in order to enable removal of copper electrodes by 1st February 2013• This means the use of copper as a biocide will be illegal within the EEC from 1st Feb 2013
What if my site still has a Copper Silver Generator?• The HSE is taking a pragmatic response as organisations have a responsibility to manage the risks from legionella and it is essential that these duties continue to be met and that legionella control is not compromised.• The HSE encourages users of silver/copper ionisation water treatment systems to contact the manufacturer/maintainer of their system to discuss how to achieve this.• A wide range of supported alternative treatments are available
WHO Guidelines• Copper is included in the plan of work of the rolling revision of the WHO Guidelines for Drinking-water Quality.• Recent studies in rabbits have suggested a link between copper in drinking-water and Alzheimer disease. Levels in the rabbits’ drinking- water were well below the current WHO guideline of 2 mg/litre, based on acute gastrointestinal effects; however, it has not been established whether rabbits are an appropriate model. In addition, a communication received by WHO Headquarters suggested the need to review the guideline value and text on copper with regard to toxicity in the preparation of formula for bottle-fed infants.
What Products are Legal to Use?• Many active manufactures have notified their actives for the relevant product types which are PT5 for (Drinking Water Disinfectants ) and PT11 for Process Water (Preservatives for Liquid Cooling)• There are over 20 Actives notified for PT5 however not all are being supported for drinking water for human consumption as PT5 also covers drinking water for animals• Use of such actives must also comply with EU Drinking water legislation such as Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption and meet national requirements
Actives Supported for PT5 Human Consumption• Chlorine Dioxide• Active Chlorine• Calcium Hypochlorite• Sodium Hypochlorite• Chlorine
Chlorine Dioxide• At ambient temperature and pressure Chlorine dioxide is a yellowish- green gas that is readily soluble in water and is an excellent oxidising biocide.• It has more than 2.5 times the oxidising capability than chlorine and requires a lower contact time than chlorine.• Chlorine dioxide is effective in alkaline conditions (pH <10) whereas biocide such as sodium hypochlorite lose activity quickly as the pH rises and are not suitable for use at pH >8.• Chlorine dioxide does not generally react with other water treatment chemicals or with nitrogen compounds including ammonia and naturally occurring organic materials such as organic acids.
Chlorine Dioxide• Chlorine dioxide is a gas that explosively decomposes into chlorine and oxygen so for this reason it should always be used as a dissolved gas in water at relatively low concentrations.• Chlorine dioxide is therefore generated situ. Precursor chemicals react inside the generator to produce a solution of chlorine dioxide• For potable water the application of Chlorine Dioxide is limited to 0.5 ppm as ClO2,Chlorite and Chlorate at the point of application, this can result in inadequate control in large systems
Chlorine• Chlorine has been used as a disinfectant for over 200 years and remains one of the most effective treatments for microbial control.• Within water the principle species are Hypochlorous Acid (HOCl) and Hypochlorite. The HOCl is the most efficacious species as its neutral electrochemical charge and small molecular size enables rapid penetration through the negatively charged cell walls and slime layers of microbes.• Chlorine is less effective in alkali conditions as they favour hypochlorite species over HOCl• Chlorine has wide regulatory approvals and is supported by an extensive toxicological package via the Euro Chlor Consortium
Non Chemical• UV light at certain wavelengths is mutagenic towards bacteria as it breaks the molecular bonds of microbial DNA. Efficacy depends on the power, exposure time, particles which can protect the microbes and ability to withstand exposure. Also there is no residual effect• Filtration via point of use filters can be an effective solution especially in high risk areas. There are concerns that this is a short term fix and low pressure, tap design, cost and disposal are further issues.• Flushing and water movement reduce the opportunity for microbes to multiply however dead legs can harbour microbes• Temperature control is effective as water temperatures in the range 20°C to 45°C seem to favour growth. Legionella do not appear to multiply below 20°C and will not survive above 60°C.
Latest Developments?• HTM - 04 Addendum (March 2013)• Biocidal Products Regulations (September 2013)• L8 update (Late 2013)• Greater public awareness via multimedia• Evaluating a new products
What is the Ideal Biocide?• Excellent efficacy against all microbes• Low use concentrations• Easy to apply• Simple to measure electronically/test kits• Low hazard classification• Cost effective product and equipment• Wide range of regulatory approvals• Broad in use compatibility• Single dose system• Good environmental profile
Stable Active HalogenHigh performance stable active halogen solutions which areextremely efficacious against planktonic and sessilemicroorganisms at very low concentrations
Stable Active Halogens• Infection Control• Water Treatment• Wound Care• Animal Health• Surface Sanitisation• High Level Disinfection• Laundry Treatment• Fruit and Vegetable washing• Seed Priming• Pool and Spa
NHS Healthcare Case Study• Building only 4 years old• B & V took over in 2008 -site not fully occupied• Several hundred outlets, with some low/no usage, and low turnover of water• Legionella problems from day 1• Flushing and high temperature pasteurisation did not eliminate the problem• Cold – TVCs and Pseudomonas species problems• Hot – Legionella (~1/3), TVC and Pseudomonas species problems
The Trial• Dosing equipment installed• Shock dosed for 2 days• Down to maintenance dose after 48 hrs• Technical team regularly visited for 3 months – chemical monitoring and samples carried out on 4 CW and 6 HW points• Quarterly positive outlets added to sampling (total=18)
Outcome• All Legionella eliminated from trial points• 1 rogue outlet picked up on additional sampling– GP49• Requires more than chemical solution -working with site to find an engineering/scheduling solution• All Pseudomonas species and TVCs reduced to zero• Abulox has brought the micro problems under control and has been adopted
Food Company Case Study• Recirculating hot water system• Continuous Legionella issues• Numerous chlorinations with Chlorine Dioxide, SuPerSil and Chlorine with little effect• Abulox trialled at maintenance dose of 0.5 – 1.0 ppm• Initial shock of 5 ppm for 3 days
Case Study – Legionella Results Legionella Results Removal of Biofilm 5 4.5 4 3.5 Mens 4th floor hot 3 Ladies Ground floor hotLog 2.5 Reduced Visitors hot to Zero Mens cloakroom hot 2 Ladies cloakroom hot 1.5 Ladies 2nd floor hot 1 Ladies 2nd floor hot 0.5 Ladies cloakroom hot Mens cloakroom hot 0 Visitors hot 01.04.11 Ladies Ground floor hot 04.04.11 05.04.11 06.04.11 Mens 4th floor hot 08.04.11 13.04.11 Sample Date 15.04.11 19.04.11
Case Study – TVC Results TVCResults 6 5 Mens 4th floor hot 4 Ladies Ground floor hot Visitors hot Mens cloakroom hotLog 3 Ladies cloakroom hot Ladies 2nd floor hot 2 L Cloakroom shower LHF hot L Cloakroom shower RHF hot L Cloakroom shower RHF hot 1 L Cloakroom shower LHF hot Ladies 2nd floor hot Ladies cloakroom hot Mens cloakroom hot 0 Visitors hot 01.04.11 Ladies Ground floor hot 04.04.11 05.04.11 06.04.11 Mens 4th floor hot 08.04.11 13.04.11 15.04.11 Sample Date 19.04.11
Case Study – Pseudomonas Species Results Pseudomonas Results 3.5 3 2.5 Mens 4th floor hot 2 Ladies Ground floor hotLog Visitors hot 1.5 Mens cloakroom hot Ladies cloakroom hot 1 Ladies 2nd floor hot 0.5 Ladies 2nd floor hot Ladies cloakroom hot Mens cloakroom hot 0 Visitors hot 01.04.11 Ladies Ground floor hot 04.04.11 05.04.11 06.04.11 Mens 4th floor hot 08.04.11 13.04.11 15.04.11 Sample Date 19.04.11
Government Organisation Case Study• Under capacity building with poor quality incoming mains• Traditional liquid and dual powder pack chlorine dioxide treatment & chlorinations were not able to solve the problem• System shock dosed for 48hrs and chemical maintained at 1.5ppm Cl2
Case Study – TVC 22 Results TVC 22140012001000 800 600 GF Quiet/First Aid Room CWS 400 Zero 200 0 Incoming Mains Chlorine Chlorine Abulox Dioxide 1 Dioxide 2
Case Study – Pseudomonas Results Pseudomonas 1400 1200 1000 800 GF Accessible Shower 600 400 Zero 200 0 Incoming Mains Chlorine Dioxide 1Chlorine Dioxide 2 Abulox
Case Study – Legionella Results Legionella1200010000 8000 6000 GF Accessible Toilet CWS 4000 2000 Zero 0 Chlorine Dioxide 1 Chlorine Dioxide 2 Abulox
NHS Hospital• Legionella concerns at up to 8000 cfu/litre in the pre and post flush samples at various points within the hospital• Shock dosed Abulox for 3 days followed by a maintenance dose at 0.5 to 1.0 ppm Cl2• Pre and Post Flushing samples taken at 5 key points defined by the NHS Trust• Samples tested by external UKAS accredited laboratory
NHS Hospital• Legionella completely eliminated by day 2 of treatment in all post flush samples and virtually eliminated in all pre flush samples• Pseudomonas eliminated in post flush samples• Trial continuing to form part of a technical paper
Performance Summary• High level of microbial control and biofilm removal• Fast rate of kill and no resistance• Low use concentration• Simple to apply and measure• Long term stable solutions• Good safety and Environmental Profile• Wide range of packs• Regulatory Approvals• Cost effective
Regulatory• Drinking Water Inspectorate Approval (Number DWI 56.4.1074) under Regulation 31(4)A of the Water Supply (Water Quality) Regulations 2000 SI No 3184 & The Water Supply (Water Quality) Regulations 2010 SI No 994 (W.99)• WRAS approved dosing components• All chemical constituents are BS EN Listed• Active ingredient notified for PT5 Drinking Water for Human consumption plus PT’s 2, 3, 4 and 11• WHO recommended limit of 5 ppm Cl2 for potable water• Use in accordance with Council Directive 98/83/EC• Manufactured under ISO13485, ISO 9001 and ISO14001