The use of risk management as best practice to reduce outbreaks of recreational water illnesses in disinfected swimming facilities and spas Roy Vore, Ph.D., NSPF I, CPO Vore & Associates, LLC Email: Roy.D.Vore@gmail.com CIPHI Annual Educational Conference, Sept 16-19, 2012, Blue Mountains, ON
Recreational water illnesses (RWIs) can be transmitted in three ways Ingesting water Contact with water Air If you are in or near a pool or hot tub that is contaminated you will be exposed and subject to infection or illness. (C) 2012 Vore & Associates LLC 2
Recreational water illnesses: infection vs. venues Illness Pools Spas Gastro-intestinal Dermal Respiratory E coli O157:H7 Shigella Norovirus Hepatitis A Cryptosporidium Giardia Ps. aeruginosa Chloramines (DBPs) Chloramines (DBPs) (indoor pools) Minimal most users do not swallow enough water for infection Ps. aeruginosa Bromamines (DBPs) Legionella Bromamines (DBPs) (C) 2012 Vore & Associates LLC 3
Should we adopt a risk management approach to RWIs? What we know with confidence: Different facilities have different outbreak patterns Variables include type of microbe involved, route of exposure, and infective dose This type of pattern can be analyzed using risk assessment (C) 2012 Vore & Associates LLC 4
The Risk Assessment Equation Where: R = H x E x DR R = Risk of ill illness H = Hazard E = Exposure DR = Dose Response To reduce risk reduce one or more factors to zero (C) 2012 Vore & Associates LLC 5
Application of Risk Management Use existing disinfection regulations for general control Identify control points for increased emphasis Where are historical system failures? What are the warning signs of potential outbreaks? What can be used by inspectors to avoid outbreaks without changing regulations or adding cost? (C) 2012 Vore & Associates LLC 6
Recreational water illnesses: overview of infections Illness type Gastrointestinal Causative agent(s) Bacteria Viruses parasites Frequency of illness Rare Press coverage Very high Dermal Pseudomonas Very common Very low Disinfection byproducts Very common Very low Respiratory Legionella Rare High Disinfection byproducts Common esp. indoors Very low (C) 2012 Vore & Associates LLC 7
Sources of infective agents Illness type Gastrointestinal Dermal Respiratory Source of microbes Bathers (swimmers) Sloughed from the biofilm Sloughed from the biofilm (C) 2012 Vore & Associates LLC 8
CT values for microbes (clump free cells circulating in the water, not attached cells inside a biofilm) Group Organism CT value for free chlorine Bacteria E. coli (including O157:H7) ~1 Shigella ~1 Pseudomonas aeruginosa ~1 Legionella pneumophila ~1 Virus Adenovirus 20-45 Norovirus 20-45 Parasites Giardia 45 Cryptosporidium 15,3000 (C) 2012 Vore & Associates LLC 9
Gastrointestinal illness - overview Gastrointestinal illness is the most reported type of RWI Symptoms are more severe, more likely to seek treatment Most acute gastrointestinal illness agents are on the CDC reportable agent list Microbes in water are shed by ill bathers Shed for up to 14 days after last symptoms Bathers have a strong tendency to swim while symptoms persist or resume as soon as they end Average bather swallows 30 ml of water every 30 minutes (C) 2012 Vore & Associates LLC 10
The germs that gastrointestinal RWIs have very, very low infective doses Organism E coli O157:H7 Norovirus Giardia Cryptosporidium Dose that will cause disease 10 cells 10 particles 10 100 cysts 10 cysts (C) 2012 Vore & Associates LLC 11
Gastrointestinal illness A hypothetical case A fecal accident happens in a 75,000 gallon pool Person is infected and releases 1 billion E. coli O157:H7 cells (it could also be 1 billion Crypto oocysts) Assume all fecal matter is uniformly mixed and none is removed by filtration Every 30 ml (1 ounce) will contain 105.8 infective units 30 ml is a small swallow of water Swallowing as little as 3 ml (0.1 ounce) will cause diarrhea in sensitive individuals This amount of E coli O157:H7 can be fatal to toddlers Imagine this in a 5000 gallon wading pool! (C) 2012 Vore & Associates LLC 12
The seasonal pattern of Crypto MMWR September 7, 2012 / 61(SS05);1-12 (C) 2012 Vore & Associates LLC 13
Control points for acute gastrointestinal illnesses Exposure factors Swimming (not spas) Late summer Local outbreaks Swim teams or mobile users Poor training Poor maintenance Poor system control Crypto is hard to kill Dose Response factors Kids swallow more water Infective doses 10-100 cells/cysts (C) 2012 Vore & Associates LLC 14
Age distribution of Crypto cases MMWR September 7, 2012 / 61(SS05);1-12 (C) 2012 Vore & Associates LLC 15
CDC Model Aquatic Health Code on Crypto Crypto is the only pathogen not readily controlled by 1-5 ppm free chlorine in a reasonable time frame New increased risk facilities must install a secondary disinfection system in addition to chlorine/bromine Any venue designed primarily for diaper-aged children (children <5 years old), such as wading POOLS, water activity POOLS, interactive water features with no standing water, SPRAY PADs, and Therapy pools Currently accepted systems are UV and ozone (C) 2012 Vore & Associates LLC 16
Dermal disease - overview We do not know the frequency of disease Rashes are not a reportable disease Few bathers link skin infections to pools or spas Evidence suggests rashes are extremely common Earaches are one of the leading causes of visits to pediatricians during swimming season Chemical reactions may affect >5% of bathers and produce short term rashes Rashes likely out-number GI disease by 100s or 1000s of times Most incidents cause discomfort but not serious illness Many swimmers continue to swim with some minor rashes (C) 2012 Vore & Associates LLC 17
Dermal disease: Sequence of a typical Pseudomonas aeruginosa outbreak 1. P aeruginosa becomes established in biofilm 2. Sanitizer drops below critical level (bromine or chlorine <1 ppm) and allows P aeruginosa to survive in the water 3. Person stays in water >15 minutes 4. Warm water dilates pores in the skin 5. Bacteria enter the pores in the skin 6. Bacteria reproduce in the pores 7. Bacteria secrete toxins that cause allergic reactions 8. Immune system overcomes infection and toxins in about 8 days (C) 2012 Vore & Associates LLC 18
Distinguishing causes of dermal RWIs How long did it take for the first symptoms to appear? What does the rash look like? How long do the symptoms persist? What impact does reexposure to water have on the symptoms? Contact dermatitis (response to chemical exposure) Less than 24 hours, can be less than 10 minutes Red itchy rash Days to weeks Progressively worse Bacterial infection >24 hours, often >2 days and can be up to 14 days Red rash (like bug bites) <14 days, usually 8 days No change Medical treatment Not usually required Not usually required (C) 2012 Vore & Associates LLC 19
Control points for dermal illnesses Exposure factors Water contact (spas +) Duration Age (kids +) Gender (female +) Poor training Poor maintenance Poor HOCl control Cloudy water Dose Response factors Pre-existing skin conditions Fair complexion Biofilm DBPs (C) 2012 Vore & Associates LLC 20
Respiratory disease Not as well documented as gastrointestinal illness Respiratory RWIs currently receiving the most research attention Two categories: Bacterial infections: Legionella Chemical induced reactions: DBPs Severe illness and fatalities are possible (C) 2010 Roy Vore 21
Respiratory disease: sequence of a typical Legionella spa outbreak 1. Legionella pneumophila becomes established in biofilm 2. Bacteria break free of the biofilm 3. Chlorine level <1 ppm allows Legionella pneumophila to survive in the water 4. Bubbles trap Legionella pneumophila 5. Air bubbles break the surface and burst 6. Fine droplets float in the breathing zone 7. Droplets are inhaled into the lungs 8. Bacteria enter White Blood Cells in the lungs 9. Bacteria reproduce inside the White Blood Cells 10. Outcome either Legionnaire s Disease or Pontiac Fever Legionellosis is not spread by person-to-person contact (C) 2012 Vore & Associates LLC 22
Control points for respiratory illnesses Exposure factors Aerosols/mists (spas +) Warm water facilities Poor training Poor maintenance Poor HOCl control Biofilm DBPs Indoor facilities Dose Response factors Pre-existing conditions Lung disease Smoker Alcoholic Diabetic Older or elderly (C) 2012 Vore & Associates LLC 23
The National Swimming Pool Foundation released their RWI manual in June 2012. This is currently the most comprehensive single manual on RWIs in treated water venues. An on-line course is also available. (C) 2012 Vore & Associates LLC 24
Additional information National Swimming Pool Foundation @ www.nspf.org 2012 manual and on-line course on RWIs Schedule and location of Certified Pool/Spa Operator CPO classes Videos for previous World Aquatic Health Conferences CDC Healthy Swimming @ http://www.cdc.gov/healthywater/swimming/ Information on RWIs Accident response protocols Model Aquatic Health Code (MAHC) (C) 2012 Vore & Associates LLC 25
Acknowledgment This seminar was sponsored by Lowry & Associates, Newmarket, ON For additional information on testing please contact Michael Lowry: mlowry@lowryassociates.ca 905-836-0505 (C) 2011 Vore & Associates 26