WHAT’S in the PIPELINE? Tobias van Reenen CSIR Building Design and Engineering Approaches to Airborne Infection Control WHAT’S in the PIPELINE? Tobias van Reenen CSIR

OVERVIEW BACKGROUND STANDARDS & LEGISLATION DESIGN MANAGEMENT 2

BACKGROUND LEGIONELLA:- Mesophilic Bacteria naturally occurring in low numbers in aquatic environments Thrives in man-made water distribution and storage systems (20-50°C) ~ Half of the species cause Legionellosis Legionella Pneumophila is responsible for 90% of cases Within endemic regions, about 4% to 5% of pneumonia are caused by L. pneumophila -Robert-Koch-Institut Legionella Pneumophila can also be divided into sub groups. These sub groups are referred to as Sero-Groups. There are 16 different Sero-groups of Legionella Pneumophila, and Serogroup 1 is associated with most cases of Legionnaires Disease (it is also associated with the majority of fatalities from Legionnaires Disease, but not all).

BACKGROUND LEGIONELLA PNEUMOPHILA:- >70 °C : Disinfection range At 66 °C  : Legionellae die within 2 minutes At 60 °C  : They die within 32 minutes At 55 °C  : They die within 5 to 6 hours 50 °C  : They can survive but do not multiply 35 to 46 °C : Ideal growth range 20 to 50 °C : Growth range Below 20 °C : They can survive but are dormant

BACKGROUND LEGIONELLA PNEUMOPHILA:- 35 to 46 °C : Ideal growth range 20 to 50 °C : Growth range Legionella coincidently likes water at the same temperatures that we do.

BACKGROUND LEGIONELLA RISK ENVIRONMENTS Cooling towers and evaporative condensers Hot and Cold water systems especially showers Spa baths Water Features / Fountains Machinery Spray-Cooling Systems Water misting systems HVAC Systems Emergency Showers & Fire Hoses Sprinkler systems and hose reels Portable room humidifiers In other words “do nothing”

BACKGROUND BACKGROUND Biofilm:- a thin layer of microorganisms adhering to the surface of a structure, which may be organic or inorganic, together with the polymers that they secrete –http://medical-dictionary.thefreedictionary.com Biofilm development can result in cyclical system contamination, complicating trouble-shooting

BACKGROUND 4 EASY STEPS TO CONTRACTING LEGIONELLOSIS Contamination & Colonisation of Water Systems Growth & Proliferation Aerosolisation Inhalation Exposure (Duration x Susceptibility) In other words “do nothing”

STANDARDS & LEGISLATION STANDARDS & LEGISLATION SOUTH AFRICA:- Occupational Health and Safety Act, 1993 Regulations For Hazardous Biological Agents – pg24 SANS 11731: - Detection and enumeration of Legionella Act No. 36, 1998 National Water Act Act No. 108, 1997 Water Services Act SANS 893 (1&2) Risk Management and Control of Legionella in Water Systems (Committee Draft for Comment)

DESIGN Biofilm colonises stagnant or low-flow water in piping. Legionella risk increases with over-supply of Hand Wash Basins Over-use of alcohol based hand sanitizers = stagnation in unused basins (Dead Legs) DESIGN Avoid stagnation of water at the wrong temperatures!

DESIGN Avoid “dead legs” in distribution piping and fittings. A “dead leg” is a leg length >2x the diameter of the piping. DESIGN WHO Supplementary Training Modules: Validation, Water, Air Handling Systems - Water for Pharmaceutical Use (Part 2): Water Purification Engineering

DESIGN Point-of-use “RO filters” ? Filters eradicate concentrate organisms Point-of-use carbon filters? Breading grounds for Bio-film Aerosolizing/ Low flow faucets? Increase inhalation risk Pillar taps? Open standing dead-legs Automatic Faucets? Internal bio-film Maintenance burden http://www.shea-online.org/View/ArticleId/71/Electronic-Faucets-Unsafe-for-Use-in-High-Risk-Patient-Hospital-Settings-Study-Shows-Automatic-Fauce.aspx DESIGN

DESIGN Avoid warm water circulation or storage Keep COLD loops <20°C Keep HOT loops >55°C Avoid storing too much water Use of many smaller cisterns reduces stagnation Avoid long pipe runs Longer runs = Greater heat gain in cold water systems Greater heat loss in hot water systems Cisterns should be insulated from heat sources DESIGN

DESIGN Mixing devices should provide 55°C at upper limit of range A geyser is the “gatekeeper” to your distribution system. >55°C prevents colonisation of HW systems. Geysers should be set to 60°C Solar geysers can fail to maintain >45°C year round. DESIGN

MANAGEMENT 1. Risk Assessment and Management Plan Identify Risks Hygiene risks Safety risks (>55°C water) Operational protocols Thermostatic mixing Define competency and responsibility (Hygiene & Safety) Planners, Designers & Operators Implement program MANAGEMENT

MANAGEMENT 2. Disinfection Poor Water Supply Quality? Dispersive Disinfection Chlorination Free Chlorine Chloromines Chlorine Dioxide Silver & Copper ionisation Thermal Pasteurisation Site Disinfection Ozone & UV Not effective with downstream colonies MANAGEMENT Free chlorine may be associated with the formation of carcenogens in the presence of natural organic residues Ionisation can result in pitting corrosion

MANAGEMENT 3. Maintenance and Cleaning Develop and Implement Cleaning program Maintenance Policy Record keeping 4. Training, Monitoring and Review Training & Skills Matrix Develop monitoring program Updated asset register Effective logbook Engineering Change Control Safety and Hygiene Risks MANAGEMENT

REFERENCES & FURTHER READING http://www.ecosafe.co.za/legionella-background-information Water Systems: HTM 04-01 The control of Legionella , hygiene, “safe” hot water, cold water and drinking water. Part A & B ASHRAE White Paper : Position Paper on Legionellosis, 1995 World Health Organization – Legionella and the Control of Legionellosis – 2007 – ISBN 92 4 156297 8 SANS 893 (1&2) Risk Management and Control of Legionella in Water Systems (Committee Draft for Comment) REFERENCES