Lecture on quality of recreational water for the faculty of Veterinary Medicine, University of Helsinki; Course in Environmental Health

1. RECREATIONAL (SWIMMING) WATER Microbiology hazard

2. LEARNING OUTCOMES
Define RW and identify microbiological health hazards associated with RW
Classify risk factors for the presence of microbial pathogens in RW and the
transmission to human
Review possible epidemiological scenarios of waterborne infections transmitted
through RW

3. RECREATIONAL WATER
- Swimming pools
- Public beaches on lakes, rivers and
sea
- Hot tubs (Spa pools)
- Water parks
- Water play areas
- Interactive fountains

4. ROUTE FOR EXPOSURE TO RECREATIONAL WATER
ILLNESSES (RWIS) AGENTS
Recreational water illnesses (RWIs)
are caused by pathogens present in
contaminated RW which spread to
human by:
- Swallowing à ~100 ml of water enter in
the mouth and nasopharynx in a typical
swimming episode
- Breathing in mists or aerosols à in hot
tube, interactive fountains and showers
- Contact

5. TRANSMISSION PATHWAYS FOR A SELECTION OF
WATERBORNE PATHOGENS
INGESTION INHALATION CONTACT WOUND INFECTIONS
V. cholera Legionella spp. P. aeruginosa V. vulnificus
Salmonella enterica Mycobacterium spp. Aeromonas spp. V. parahaemolyticus
Pathogenic E. coli Mycobacterium spp. Aeromonas spp.
Shigella spp. Leptospira spp. Mycobacterium spp.
Campylobacter spp. Acanthomoeba spp.
Cryptosporidium spp. Naegleria spp.
Norovirus Schistosoma
Hepatovirus
Rotavirus
Enterovirus

6. RWIS CLINICAL PRESENTATIONS
Diarrhea à the most commonly reported RWI
AFRI (Acute febrile respiratory illness)
Keratitis and otitis à bathing, regardless of water quality,
compromises the eye’s immune defenses leading to increased
reporting of symptoms after bathing e.g. in marine waters
Dermatitis and wound infections

7. RWIS CLINICAL PRESENTATIONS
Number of waterborne-disease
outbreaks (n=445) associated with
recreational water by year and
illness
the United States, 1978–2002
Yoder et al. MMWR 2004

8. RWIS CLINICAL PRESENTATIONS
The majority of RWIs are relatively mild and often self-limiting
Certain RW-borne pathogens can cause illnesses with severe outcomes even in
average populations (à 5% of waterborne diseases result in sequelae)
Diseases that are normally mild and self-limiting in the general population can
have severe manifestations in susceptible sub-populations (Children, elderly,
pregnant women, Immunocompromised population, presence of wounds)

9. RISK FACTORS FOR RWIS
Duration of exposure à water contact time is a prime factor influencing
the amount of exposure to pathogens in water
Uses of RW à Some activities are likely to pose greater risk of water
ingestion than others (behaviors of different populations of swimmers)
The personal hygiene of RW users while in the water (which also significantly
alter the quality of the water)
Risk groups à children have greater opportunities for exposure (frequent
users, longer exposure)
Skin abrasions or cuts
Microbiological quality of the water

10. FECAL POLLUTION Acute gastrointestinal illness
(AGI)

11. ACUTE GASTROINTESTINAL ILLNESS (AGI)
There is a 3% to 8% risk of acute gastrointestinal illness (AGI) after swimming
The high-risk groups for AGI are children younger than 5 years & elderly and
immunocompromised patients
The same organisms associated with illness from drinking water are found in swimming
water but in much higher concentrations
- Campylobacter, Salmonella, E. coli, Giardia, Cryptosporidium and enteric viruses

12. FECAL POLLUTION
The concentration of pathogens is
largely determined by fecal
pollution
Fecal contamination from animal or
human: wild animals, human activities
There is an association between
gastrointestinal symptoms, AFRI
and indicator-bacteria concentrations
in recreational waters

13. FECAL POLLUTION
In both coastal and freshwaters the point sources of pollution:
- Domestic sewage discharges
- Riverine discharges
The relative risks to human health from these sources depend on a number
of factors (e.g.):
- Sewage being discharged into an estuary with small tidal versus large tidal interchanges
- Higher concentrations of pathogens in areas where there is more disease or during
disease outbreaks
- Special risk for people coming from low-pathogen circulation environments to high-
pathogen circulation environments.

14. BATHERS AS A SOURCE POLLUTION
Bathers may act as a source of pollution in their own right
People have about 0.14 grams of feces on their bottoms which they shed
during swimming
Increased illness has been also caused by bather to bather transmission via
the water (gastrointestinal illness) and air (respiratory pathogens)
Selected pathogens significantly correlated with both enterococci levels and
bather density à bathers causing re-suspension of bottom sediments, which
resulted in the elevated levels of enterococci and pathogens seen when bather
numbers were high

15. OUTBREAK ASSOCIATED WITH RW IN FINLAND
In June-July 2014 there was a very large number of
bathing water outbreaks (15) à diarrhea
Part of the cause of the disease turned out to be
norovirus
2014 was Finland's second warmest year on
record (50 days of hot summer weather were
recorded between May and August, 14 days more
than average) à overload of bathers in the beaches
(?) Source THL and FMI

16. TAMPERE SWIMMING WATER OUTBREAK 2014
The largest outbreak in Tampere with
~1000 infected people
Good history of water quality (E.
coli and Enterococcus) and no change
during the outbreak
Norovirus or adenovirus not
detected in water
Beaches located on small lakes with
unimportant emission sources
Human to human transmission?
Swimming days
Notification of illness
Unknown
Adults
Children
Unknown
Adults
Children

17. E. COLI O157:H7 SWIMMING WATER OUTBREAK
1997
13 E. coli O157:H7 cases with
bloody diarrhea in Alavus.
Five primary cases fell ill between 5
and 7 July; other 8 occurred 6-10
days after
Ryskööt festival crowding the Tusa
beach during hot summer days
probably resulted in human fecal
contamination of fresh lake water
with E. coli O157:H7
Tusa beach
I cases: young boys with
undeveloped swimming
skills; visited Tusa beach at
the same time
II cases: person-to-person
transmission (32% of
attack rate within families)
Paunio et al. Epidemiol. Infect. 1999

18. NON-FECAL OPPORTUNISTIC
PATHOGEN
Acute febrile respiratory illness
(AFRI), keratitis and otitis

19. NON-FECAL OPPORTUNISTIC PATHOGEN
Swimming pools and spas present special conditions that may result in
different exposures or favor the growth/survival of specific pathogens
Leisure pools and hot tubs may be subject to high bather loads à
increasing the likelihood of water pollution from the bathers themselves and
subsequent person-to-person transmission of disease
In natural water, growth of certain free-living bacteria (Vibrio vulnificus) or
protozoa depends of climatic conditions and showed clear seasonal
variation

20. MYCOBACTERIOSIS
The most significant of the environmental mycobacteria in terms of public
health is the Mycobacterium avium complex (MAC) à M. avium, M.
Intracellulare
M. avium can grow at 45°C and at reduced oxygen levels (drinking water
networks, hot tubes); can grow in brackish and fresh natural waters
The presence of MAC is not routinely investigated
Detection is difficult, time-consuming (up to several months to see colonies in a
plate for MAC) and expensive à no standards methods; species-specific
Advantages of the use of NGS and other DNA based techniques

21. MYCOBACTERIOSIS
MAC infection results from diverse and likely undetectable environmental and
nosocomial exposures
Inhalation steam or microingestion of water – pulmonary disease; contact -
skin and wound infections
Incidence of MAC is ~1 to 2.5/100 000 (might showed geographic clusters)
Incubation time uncertain à ~weeks to months
Infectivity uncertain à 104-107 depending of risk category

22. MYCOBACTERIOSIS - CLINICAL SYMPTOMS
The severity of mycobacterial
diseases varies à depends risk
category
High morbidity and mortality in
AIDS patients
Non-HIV/AIDS patients à mild
cases of hypersensitivity pneumonitis
to life threatening respiratory
infections
Failure to diagnose and treat the
disease may result in lung damage
Source WHO
Symptoms including cough, sputum production, fatigue,
weight loss, sweats, haemoptysis, pleuritic and non-pleuritic
chest pain

23. MYCOBACTERIOSIS AND WATER
Clear evidence for the association
of non-tuberculous Mycobacterium
with RW
Majority of cases associated with
RW: attributed to swimming pools
and hot tubs
Hypersensitivity pneumonitis also
seen in immunocompetent persons
with long aerosol exposure
(lifeguards)
Source WHO

24. PSEUDOMONAS AERUGINOSA – HUMAN HEALTH
Serious pathogen in hospitals setting
Leading cause of illness in immunocompromised individuals: endocarditis,
osteomyelitis, pneumonia, urinary tract infections, gastrointestinal infections,
and meningitis, and is a leading cause of septicemia
Major pathogen in burn and cystic fibrosis (CF) patients àhigh mortality rate
Serious cause of keratitis, especially in patients wearing contact lenses
Mena and Gerba. D.M. Whitacre (ed.), Reviews of Environmental
Contamination and Toxicology Volume 201,

25. PSEUDOMONAS AERUGINOSA – HUMAN HEALTH
The greatest health risks:
- skin exposure in hot tubs
- lung exposure from inhaling aerosols
Aerosol route: 107 cells did cause disease symptoms in mice, and was lethal
in aerosolized doses of 109 cells
Tap water is significant route of transmission in hospitals à infections and
colonization can be significantly reduced by placement of filters on the water
taps
Mena and Gerba. D.M. Whitacre (ed.), Reviews of Environmental
Contamination and Toxicology Volume 201,

26. PSEUDOMONAS AERUGINOSA – HUMAN HEALTH
The oral dose required to establish
colonization in a healthy subject is
very high à after colonization might
not be present evidence of diseases
The risk of colonization from
ingesting P. aeruginosa in drinking
water is low
The risk is slightly higher if the
subject is taking an antibiotic resisted
by P. aeruginosa (Ampicillin)
Mena and Gerba. D.M. Whitacre (ed.), Reviews of Environmental
Contamination and Toxicology Volume 201,

27. P. AERUGINOSA AND RW
Found in whirlpools and hot tubs,
sometimes in 94-100% of those
tested at concentrations of <1 to
2,400 CFU/mL.
Usually found when chlorine
concentrations are low à isolated
up to 3.00 ppm residual free chlorine
Mena and Gerba. D.M. Whitacre (ed.), Reviews of
Environmental Contamination and Toxicology Volume 201,

28. NON-FECAL OPPORTUNISTIC
PATHOGEN
Dermatitis and wound infections

29. HOT-TUBES DERMATITIS
Itchy, bumpy, and red rash.
Symptoms can appear from several
hours to 2 days after contact with the
bacteria
P. aeruginosa is consider the main
cause of the infections
A reported cases of A. hydrophila
folliculitis associated with an
inflatable swimming pool in a child
(mimicking P. aeruginosa Infection) –
Manresa et al Ped. Derm. 2009
44-year-old man presented with papulopustular eruption due to
P. auruginosa infection after returning from a 14-day family
vacation in Sweden (Brauns et al. JDDG. 2013)

30. SWIMMER'S ITCH (CERCARIA DERMATITIS)
Skin rash caused by the larval stage of
a schistosome flatworm like T. ocellata
mistaking a human for their primary host
and burrowing into their skin
Intermediate host is fresh water snail
Väyrynen et al. Ann. Zool. Fennici 2000

31. VIBRIO VULNIFICUS
V. vulnificus is a naturally occurring, free-
living bacterium found in estuarine and
marine environments
Causing necrotizing wound infections, and
primary septicemia
High fatality rate (up to 75%)
Grow preferentially in warm (>15 °C), low-
salinity (<25 ppt NaCl) sea water
Water temperature, which ranged from 18.5
to 33.4°C, is positively correlated with V.
vulnificus concentrations in water but not in
sediments (à do sediment act as reservoir
between heat waves?)
0
2
4
6
8
10
12
14
16
18
20
May June July August September October
2011
2012
2013
2014
2015
Sea surface temperature Finland, Kotka
Salinity gradient
Climate change à increase the risk in the Baltic sea
Preconditioning
conditions
(diabetes,
immunodeficiency,
pre-existing
wound)

32. REPORTED CASES OF VIBRIOSIS IN BALTIC
COUNTRIES
Baker-Austin et al. Nature Climate Change. 2013
A fatal infection with temporal relation to
2 other febrile infections caused by Vibrio
cholerae non-O1, non-O139 (NCV).
All infections were associated with contact
with seawater
All patients had compromising factors.
(Lukinmaa et al. Diagn Microbiol Infect Dis. 2006)

33. AEROMONAS HYDROPHYLA WOUND INFECTIONS
Vally et al. Clin. Infec. Dis. 2004
Reported after accidental puncture of
the skin followed by exposure to
contaminated water or soil
Infections often progress rapidly and
may require surgical debridement or the
amputation of limbs or digits
Fatal wound infections in healthy
adults have also been reported
Outbreak (26 patients)
game of mud football in Collie
In Finland, a 48-y-old female showed
cellulitis, myonecrosis and sepsis after a
prick wound in her hand while boning
freshwater fish. She died in 4 days
(Adamski et al. Scand J Infect Dis. 2006)

34. FAST GROWING MYCOBACTERIUM AND WOUND
INFECTION
Mycobacterium marinum found in salt
water and fresh water
Infection occurs following inoculation of a
skin abrasion or puncture and manifests
as a localized granuloma or
sporotrichotic lymphangitis
Risk factors: trauma to an extremity that
is in contact with an aquarium, salt water,
or marine animals such as fish or turtles