Recreational Water – Would You Dare Go In for a Dip?

Overview of Recreational Water & Disease

Julie Kinzelman, PhDRacine Health Department, Wisconsin, USA

Why the Public Health Significance?

• Worldwide tourists spend billions of days at coastal recreational areas

• In Racine, beach usage has gone up 300% in the last 5 years

• More usage = More chance for exposure• Public health burden can be in millions of $$• Perceived risks related to poor recreational

water quality may have economic repercussions, i.e. economic loss

Recreational Water Industry Generates Billions Annually

• By 2026 346 million tourists will visit Mediterranean destinations (World Tourism Organization)

• Over 21,500 individuals visited Scottish beaches for 2003 – 2007 (SEPA)

• More than 30 million people in the United States rely on the five Great Lakes—Superior, Michigan, Huron, Erie, and Ontario—as a principal source of their drinking water, recreation, and economic livelihood (US GAO).

• 750,000 individuals, on average, visit Indiana State Park during the bathing season, roughly 152 days (Rabinovici, et al.)

• Racine, WI (population ~ 80,000) had over 50,000 visitors at North Beach in 2007

Lost Spending Beach Advisories

$2.35 millionTotal for all advisories

Lost spending per year

LakeMichigan(Chicago)

Shaikh (2006)

$43,000Per swim banLost spending per event

Lake Michigan(Indiana)

Indiana Dunes State

Park

Study Location Method Description Estimates

Murray and Sohngen(2001)

Lake Erie Lost spending per year

Per Advisory $131,000

Total for all Advisories

$4.91 million

Southern California

Los Angeles &

Orange Co.

Public Health losses

Total for all advisories

$62 million

Cost of Illness (Dwight et al. 2005)• Quantify the health burden from illnesses associated

with exposure to polluted recreational marine waters

• Gastrointestinal illness (GI) = $36.58• Acute respiratory disease = $76.76• Ear ailment = $37.86• Eye ailment = $27.31

• Exposures at Orange County and Huntington Beaches estimated to generate 36,778 GI episodes per year

• 38,000 more illness episodes of other types– respiratory, eye, and ear infections

• Cumulative public health burden = $3.3 million/year

82536652001 - 200242093591999 - 200001000321997 - 1998

No. of Deaths

No. Individuals Affected

No. of Outbreaks

Reporting Period

US Outbreaks of Waterborne Disease -Recreational Water (CDC 2002)

CDC – Surveillance, Waterborne DZ

• Outbreaks Associated with Recreational Water – USA, 2003—2004

• 62 total events– 43 occurred in treated water – 2,446 cases of illness.

• Among the 30 gastroenteritis outbreaks (all waters) – Cryptosporidium was confirmed as the causal agent in 11

(36.7%)– All except one of these outbreaks occurred in treated water

venues• Of the 43 outbreaks associated with treated water that

had an identified etiologic agent: – 14 (32.6%) involved bacteria– 12 (27.9%) involved parasites– 4 (9.3%) involved viruses– 1 (2.3%) involved chemicals

Factors Influencing Health Risk• Nature of the hazard – Derived from human or non-

human sources.

• Characteristics associated with the water body – are conditions right for the persistence and or growth of pathogens?

• Immune status of the user - children, elderly and immune compromised individuals may be more susceptible. – Children ingest twice as much water as adults when

swimming (Frank 2002)

• Lack of immunity to endemic diseases

• Type of exposure – full body or incidental contact

Marine & Fresh Surface Waters

– Gastroenteritis– Acute febrile respiratory illness (ARFI)– Ear and eye infections– Skin rashes– Meningoencephalitis (PAM)– Renal disease– Cardiac and nutritional disorders

Bather Shedding• On average a person has 0.14 grams of feces “with

them” at all times (Gerba)• When you are ill your feces contains millions of germs

that can be rinsed off while swimming• Swimming is essentially communal bathing

– Duration of use each day and number of bathers– Age, health and hygiene behavior of fellow bathers

Bacteria• Campylobacter - frequently isolated but few cases reported via waterborne

transmission

• E. coli O157:H7 – has been proven to cause WBDO; Lake Winnebago, WI 2006

• Helicobacter pylori – has been implicated in WBDO; difficult to isolate from environment

• Legionella – isolated from treated recreational water such as hot tubs

• Mycobacterium avium complex – cases from both healthy and compromised individuals; more frequently associated with treated waters such as hot tubs and pools

• Salmonella typhi – typhoid fever still prevalent in other countries

• Shigella spp– epidemiological evidence exists for association between self-limiting infections and recreational water use

• Plesiomonas shigelloides – most human infections are presumed to be waterborne but healthy individuals may carry this organism as a transient member of their intestinal flora

• Vibrio spp – responsible for gastrointestinal, ear, and wound infections, sepsis

Protozoa• Cryptosporidium parvum – fecal accidents are

implicated in most outbreaks of cryptosporidiosis; Great America, Gurnee, IL 2006

• Giardia duodenalis – recreational water exposure is a proven risk factor for giardiasis

• Naegleria fowleri – can colonize warm, freshwater environments; high risk of death (responsible for all deaths associated with recreational waters for CDC reporting period 1997 - 2002)

Viruses• Human adenovirus – respiratory and GI infections

• Norovirus – GI infections

• Coxsackievirus – few outbreaks associated with recreational waters have been recorded although this virus is frequently isolated

• Echovirus – few published cases but many unreported cases likely

• Hepatitis A – has been isolated from surface water used for recreational purposes; cases documented in recreational water users

• Hepatitis E – has also been isolated from surface waters

Other• Blue-Green Algae (Microcystin toxins)

– Toxin can be as poisonous as snake venom– Human deaths have been attributed to exposure (Madison, WI 2002)

Risks Unrelated to Infection

• Riptides• Marine trauma - Bites• Envenomation• Sun exposure• Drowning• Ingestion of contaminated or improperly

cooked foods

Pools, Spas, Water Features, & Hot Tubs

Accidental Fecal Release (AFR)

Hot Tub Jets = Bidet

Source of Microorganisms•Contaminated source water

•Release of formed stool or diarrhea into the water

•Residual fecal material on swimmers’ bodies

•Non-fecal human shedding (e.g. from vomit, mucus, saliva or skin)

•Free-living aquatic bacteria

• Amoeba

•Outdoor pools may also be subject to micro-organisms derived directly from pets and wildlife, e.g. rodents, birds, dogs

Considerations for Infection Risk

• Quality of the water source • Pool design, including drainage and filters • Operation and maintenance • Type of water treatment or disinfection• Functioning and adequate hygiene facilities (i.e.,

toilets, diaper-changing areas, and showers) in adequate numbers should be located near pools and should provide hot water and hand-washing access

• Pools, etc. can serve as ideal amplification venues for fecal-oral transmission of pathogens

Outdoor Pools

• Leptospirosis– Carriers include rats, cows & pigs– Gain entry to the body through

cuts, abrasions & mucosal surfaces

• Naegleria fowleri– Free-living amoeba present in fresh water and soil– Primary amoebic meningoencephalitis (PAM)– Usually fatal within 3 – 10 days after symptoms

appear

Occurrence of Leptospirosis

• Italy– Drinking water from an open air fountain– Uncommon mode of transmission– 33 cases of leptospirosis

• Non-chlorinated swimming pools– 2 outbreaks – USA - Cockburn et al., 1954– Brazil - de Lima et al., 1990

Occurrence of PAM

• Usti, Czech Republic, 1968 (Cerva & Novak)– 16 cases of PAM – Associated with a public swimming pool – Swimming pool source = river water

• Bath, UK, 1978– 1 case PAM– Associated with Bath Spa – Spa fed by thermal spring

Spas & Hot Tubs• Spas are susceptible to contamination from

persons infected with the same pathogens that cause gastroenteritis in swimming and wading pools

• Spas, hot tubs and whirlpools may not be drained, cleaned or refilled after each use

• High bather load/turnover rate of users in many spas and whirlpools pose an infection risk

• Microorganisms derived from the bathers (past users and those present in the water)

• Warm, nutrient containing, aerobic water provides an ideal environment for the growth of microorganisms (e.g., Pseudomonas and Legionella)

Potential Pathogens• Legionella pneumophila

– Causes ~90% of cases of legionellosis (Legionnaires’ disease)– Pneumonic & non-pneumonic– Pontiac fever (milder)

• Pseudomonas aeruginosa– Causes folliculitis

• Infection of the hair follicles associated with an itchy rash– May accumulate in biofilms– Spa outbreaks are common

• Acanthamoeba– Natural hot spas may contain a species of amoeba that can

cause meningitis• Staphylococcus aureus

– Infections of the ear (otitis externa)– Urinary tract infections– Also respiratory tract, eye and wounds

US Dermatological Outbreaks

• 2003 – 2004

• 8 Pseudomonas outbreaks occurred in treated waters that involved heated spa water– Illness occurred in 274 persons

• Ohio, July 2004 119 cases – Largest bacterial outbreak for this reporting period

• Connecticut, August 2003– Multiple members of a Connecticut college football team were

diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) skin infections (normal human flora)

– A spa at the team's athletic facility, which was disinfected with an unapproved disinfectant was implicated in the outbreak

US Legionellosis Outbreaks• Four outbreaks caused by Legionella

pneumophila were associated with treated recreational water venues (i.e., spas) during 2003—2004– 3/4 Outbreaks

• <5 cases of Legionnaires' disease– 4th Outbreak

• 6 cases of Legionnaires' disease • 101 cases of Pontiac Fever• Occurred at a hotel a weeklong basketball tournament. • The bather load (i.e., maximum occupancy) of the hotel spa

was exceeded• The bromine concentrations in the spa were not adequately

monitored.

Water Features• Fountains• Interactive water play

areas• Shallow pools • Vertical pressure jets • Overhead sprays and

showers • Wet decks

Added Risk Factors

• These features differ from swimming pools in potentially having a greater burden and variety of environmental contamination and requiring a high water turnover that puts a burden on any treatment processes

• The area is usually designed to collect the water from the feature and return it to an underground holding tank

• Interactive water features may suffer from environmental contamination, including domestic and wild animals and birds

Pathogens Assoc. w/ Water Features

• Shigella sonnei– Interactive fountain in Oregon (2003)– 56 cases– Inadequate disinfection– Poor monitoring of water chemistry – Heavy use of the fountain by young diaper-aged children

• Norovirus • Legionella (Legionnaires' disease and Pontiac Fever) • Cryptosporidium

– Seneca State Park, NY spray ground (2005)• interactive water feature• Affected ~3000 people• Cryptosporidium found water storage tanks

Pathogens - Swimming Pools

• Bacteria– Shigella– E. coli O157:H7– Staphylococcus (S. aureus, MRSA)– V. vulnifcus

• Parasites– Giardia– Cryptosporidium

• Most common• Viruses

– Hepatitis A– Adenovirus– Norovirus– Enterovirus

Cryptosporidium

• Cryptosporidium is resistant to the chlorine levels used in pools

• Outbreaks can occur, even in facilities that are well-maintained

• California, 2004– Water park – 336 persons– Traced to ill employees

• Ohio, 2004 – Community pool– 160 individuals

• Kansas, 2003– Multiple pools & nurseries – 617 cases– Largest recreational water

outbreak in US, 2003/04

Viruses• Hepatitis A

– Hungary, 1994 (Solt et al.) • 31 children hospitalized • All reported swimming at a summer camp swimming pool

• Norovirus– Florida, USA, 2004

• 42 cases• Waterslides implicated• Ill child with diarrhea used one of the slides – infected others• Secondary transmission to household contacts also occurred

• Enterovirus– Connecticut, USA, 2003

• Viral meningitis (Echovirus 9)• Aseptic meningitis occurred in 12 of 36 exposed persons

• Adenovirus– USA

• Several outbreaks associated with swim teams• Poor pool maintenance was to blame.

Other Potential Health Risks…• Superficial fungal infections of the hair, fingernails or

skin• Tinea pedis (athletes foot)

– Transmitted through contact with infected skin fragments

Bathing Water EpidemiologyLegislation/Guidelines

Marine & Fresh Waters

Background• Global epidemiological studies have been

& are being conducted– Due to the morbidity and mortality associated

with waterborne diseases several• Many studies have shown a link between

GI symptoms and respiratory illness to bathing water quality.

Epidemiological Studies - US

• American Public Health Association, Simons et al 1922

• United States Public Health Service, Stevenson 1953

• United States Environmental Protection Agency, Cabelli 1982

• United States Environmental Protection Agency, Dufour 1984

• United States Environmental Protection Agency/CDC, NEEAR Study, Wade et al 2005

US EPA Ambient Water Quality Criteria for Bacteria ‐ 1986

• Approved indicators – E. coli or enterococci 

• Single sample limits (E. coli = 235 SS fresh, enterococci = 61 SS fresh, 104 SS marine)

• 5‐day geometric mean (E. coli = 126 GM fresh, enterococci = 35 GM marine, 33 GM fresh)– 8 illness per 1,000 swimmers at fresh water beaches

– 19 illness per 1,000 swimmers at marine beaches

UK/EU Epidemiological Studies• Health Effects of Sea Bathing Study

– 1994-1998 (UK)– 2 sets of studies (Kay & Balarajan, Pike)

• Prospective cohort – Pike• Randomised control - Kay

• Randomised Control Study– 4 UK beaches

• All had passed the EC Mandatory standards • All had sewage pollution problems• Dose-response relationship was seen for GI and acute febrile

respiratory illness • Bathers showed a significant increase in the occurrence of

gastroenteritis when faecal streptococci densities were >32/100ml. • Bathers showed a significant increase in the occurrence of AFRI

when faecal streptococci densities were >60/100ml.• This study forms the basis of the EC standards and the WHO

Guidelines

Translation into Health RiskFrom the dose response graph (derived from the Kay studies) the EU Health Guidelines relate to:

•Waters classified as “Good Quality”:

•5% risk of contracting gastroenteritis

•2.5% risk of contracting AFRI

•Waters classified as “Excellent Quality”:

•3% risk of contracting gastroenteritis

•1% risk of contracting AFRI

•All based on repetitive exposures.

WHO Guideline Values

>10% GI illness risk>3.9% AFRI risk

5-10% GI illness risk1.9-3.9% AFRI risk

1-5% GI illness risk0.3-1.9% AFRI risk

<1% GI illness risk<0.3% AFRI risk

Estimated risk per exposure

There is a greater than 10% chance of GI per single exposure.

>500

This range represents a probability of 1 in 10 to 1 in 20 of GI for a single exposure.

201-500

Where the upper 95th percentile is 200/100ml there is an average probability of 1 case of GI in 20 exposures.

41-200

Relates to an average probability of <1 case of gastroenteritis in every 100 exposures where the upper 95th

percentile value is 40/100ml

</= 40

Interpretation95th percentile value of Intestinal Enterococci/100ml

A Word of Caution!• US epidemiological studies are derived from the

NEEAR project– Only conducted at beaches in proximity to known

human sources of fecal contamination– Only conducted using enterococci

• WHO Guidelines are derived from the epidemiological studies from Kay et al.– These relate to healthy adult bathers in temperate

north European marine waters. – Elderly, children and immune-compromised could

have a lower immunity and might require a higher degree of protection.

– Relate only to gastroenteritis and AFRI

Epidemiological Studies Summary

• Linked environmental exposure to disease• Allowed for standardization of suitable indicator

bacteria– E. coli (fresh water)– Enterococci (marine water)

• Microbiological limits have been established as guidelines and standards for recreational water quality– Based the association of indicator density to an

increase in the rate of illness in exposed populations• These limits are being revised

– US EPA BEACH Act– EU Bathing Water Directive

Why not just test water for pathogens?

• Too many possibilities – Salmonella– Shigella– Campylobacter – Viruses

• Too slow.• Too expensive.

Variation in Testing Schemes

YesWeekly unless non-compliant.E. coliHong Kong

NoDecided by local authorities.E. coliEnterococciFaecal coliforms

Canada

YesWeekly (at least 20 samples per season). Multiple point sampling at large beaches.

E. coliEnterococci

Australia/NZ

Yes5 samples per season for very low, low or very high quality waters.Otherwise 4 replicates per 5 events each season.

Enterococci WHO

NoBased on priority. No less than 5 samples every 30 days. One sample per 500m

E. coliEnterococci

US EPA

YesFortnightly through the bathing season

E. coliEnterococci

EU

Classification scheme

Sampling frequencyIndicator

Variation In Monitoring Frequency between Great Lakes States

StateFrequency

Tier 1 Tier 2 Tier 3Ohio 4 days/wk Twice/mo Once/mo

Wisconsin 4 days/wk 2 days/wk 1 day/wk

Michigan 5x/30 days 5x/30 daysor less

Infrequent or not monitored

Illinois/Chicago 5 days/wk 1 day/wk Twice/mo

Not monitored

Indiana 2 days/wk 2 days/wk Variable

Minnesota 2 days/wk 1 day/wk Not monitoredNew York 1 day/wk Twice/mo Once/mo

Pennsylvania 2 days/wk 1 day/wk Not monitored

Poor Estimation of Health Risk

• Type I errors occur when an advisory is posted but the level of bacterial indicator organisms do not exceed recommended standards or guidelines

• Type II errors occur when no advisory is posted in the presence of elevated bacterial indicator levels

Coastal Bathing Water Quality, England & Wales (1990-2006)

Source: UK Environment Agency

What’s on the Horizon?• Alternative indicators• Real-time testing technology - QPCR• New/ongoing epidemiological studies (EC, US

EPA)• Pathogen studies• Research designed to determine

replication/persistence and host source of bacterial indicators

• Beach Sanitary Surveys (US), Environmental Health and Sanitary Surveys (Canada)

Are You Willing to Take the Risk?

Millennium ParkChicago, IL

Milwaukee County Public PoolMilwaukee, WI

Laurel Clark Memorial FountainRacine, WI

North BeachRacine, WI

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