A quantitative survey was performed to understand the annual and diurnal profiles of Cryptosporidium and Giardia, representative waterborne infectious protozoans, in river water which is used for drinking water sources in Japan. To investigate the annual profiles, 84 river water samples were collected at 7 sites in the tributary rivers of the Tone River basin in Japan from June 2008 to February 2010. Cryptosporidium and Giardia were detected in 59 (70%) and 64 (76%) out of the 84 samples (10 liters each), showing the highest concentration of 344 oocysts/10 L and 144 cysts/10 L, respectively. Annual variation of the concentrations of Cryptosporidium and Giardia was high. The ratio of the maximum concentration to the mean value at each sampling site ranged from 2–8 except for one sampling site in which the frequency of detection was extremely low. To investigate diurnal profiles, 15 river water samples were collected at 3 sites in the tributary rivers of the Tone River on October 9th, 2008. The maximum concentrations of Cryptosporidium and Giardia in some sampling sites were approximately 10-fold higher than the lowest value. The correlation between the anaerobic spore-forming bacteria and these infectious protozoans was stronger than other microbial indicators (total coliforms, Escherichia coli and heterotrophic bacteria
Trang 1Address correspondence to Naohiro Kishida, Water Management Sector, Department of Environmental Health, National Institute of Public Health, Email: kishida@niph.go.jp
Annual and Diurnal Profiles of Cryptosporidium and
Giardia in River Water in Japan
Naohiro KISHIDA*, Masayuki NAKANO*, Kyungju KIM*, Eiji HARAMOTO**, Shigemitsu MORITA***, Mari ASAMI*, Michihiro AKIBA*
*Division of Water Management, Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama 351-0197, Japan
**Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
***School of Environmental Science, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan
ABSTRACT
A quantitative survey was performed to understand the annual and diurnal profiles of
Cryptosporidium and Giardia, representative waterborne infectious protozoans, in river water
which is used for drinking water sources in Japan To investigate the annual profiles, 84 river water samples were collected at 7 sites in the tributary rivers of the Tone River basin in Japan
from June 2008 to February 2010 Cryptosporidium and Giardia were detected in 59 (70%) and
64 (76%) out of the 84 samples (10 liters each), showing the highest concentration of 344 oocysts/10 L and 144 cysts/10 L, respectively Annual variation of the concentrations of
Cryptosporidium and Giardia was high The ratio of the maximum concentration to the mean
value at each sampling site ranged from 2–8 except for one sampling site in which the frequency
of detection was extremely low To investigate diurnal profiles, 15 river water samples were collected at 3 sites in the tributary rivers of the Tone River on October 9 th , 2008 The maximum
concentrations of Cryptosporidium and Giardia in some sampling sites were approximately
10-fold higher than the lowest value The correlation between the anaerobic spore-forming bacteria and these infectious protozoans was stronger than other microbial indicators (total
coliforms, Escherichia coli and heterotrophic bacteria)
Keywords: cryptosporidiosis, Cryptosporidium, drinking water, Giardia, giardiasis
INTRODUCTION
Cryptosporidium and Giardia are enteric protozoans that cause diarrheal disease and
significant adverse health effects in humans (Fayer, 2004; Craun et al., 2005; Sunderland et al., 2007) These parasites are widely distributed throughout the world
and transmitted through contaminated water and food Waterborne cryptosporidiosis and giardiasis are particularly important because their transmissive stages, i.e., oocysts and cysts, respectively, are resistant to disinfectants (such as chlorine) commonly used for
water treatment (Peeters et al., 1989; Carpenter et al., 1999) The most notorious
waterborne outbreak occurred in Milwaukee, Wisconsin, in 1993 where more than 400,000 suspected and 5,000 confirmed cases of clinical cryptosporidiosis were
reported (MacKenzie et al., 1995; Cicirello et al., 1997; Corso et al., 2003) In Japan, an
outbreak occurred in Ogose Town, Saitama Prefecture, in 1996 where more than 8,800 suspected cases were reported, accounting for approximately 70% of population of the town
Cryptosporidium oocysts and Giardia cysts are shed in large numbers in the feces of
infected humans and animals (Castro-Hermida et al., 2008) Due to their high resistance
Trang 2to environmental stressors, they are ubiquitous in the environment Many investigators
have reported that these protozoans exist in surface waters all over the world (Rose et
al., 1991; Castro-Hermida et al., 2009; Mons et al., 2009) In Japan, several surveys on
these protozoans in surface waters for drinking water sources have been conducted since
1996 (Ono et al., 2001; Masago et al., 2006) However, there is little information
available on annual and diurnal variations in these protozoan concentrations, which makes it difficult to estimate the health risk of protozoan diseases via water supply systems
The specific objective of this study is to investigate the annual and diurnal profiles of
Cryptosporidium and Giardia in river water which is used for drinking water sources
For this purpose, frequent monitoring of protozoans was performed in tributary rivers of the Tone River basin in Japan where the surface water is utilized for the main production of drinking water for people living in the Tokyo metropolitan area In addition, the relationship between microbial indicators and protozoans was investigated
MATERIALS AND METHODS
Collection of River Water Samples
To investigate the annual profiles of protozoans, a total of 84 river water samples were collected at 7 sites (sites A-G) in tributary rivers of the Tone River basin in Japan from June 2008 to February 2010 (Fig 1) Although the water sampling was performed under
a normal weather condition, heavy rainfall was observed at the upper area of Tone River basin on the day before the sampling date in June 2009, which increased river flow rates
at sites A and B To investigate the diurnal profiles, a total of 15 river water samples were collected at 3 sites (sites H-J) in tributary rivers of the Tone River on October 9th,
2008 The Tone River has a total length of 322 km and a catchment area of 16,840 km2, with approximately 800 tributary rivers There are many livestock production facilities (cow and pig farms) in the catchment area, especially in the Koyama River and River X basins Sites A and B are located along the main Tone River Site B is located near the Tone Diversion Weir, where the surface water is utilized for the production of drinking water for people living in the Tokyo metropolitan area Sites C and D are located along the Koyama River, which meets the main river between sites A and B, whereas sites E-J are located along the River X, which meets the main river between sites C and D Sites
H and I are located in the area where many livestock production facilities exist, while site J is located closely on the discharge point of treated sewage wastewater
Tone River
Tone Diversion Weir
Site C
Site D
River X
Treated sewage wastewater
Sampling sites for investigating annual profiles Sampling sites for investigating diurnal profiles
Site A
Site E
Koyama River
Site F Site G Site J Site H Site I
Fig 1 - Sampling sites in tributary rivers of Tone River basin
Trang 3All samples were stored in plastic bottles on ice and delivered to the laboratory within two days of collection As soon as the samples arrived, microbial tests were conducted
Detection of Cryptosporidium Oocyst and Giardia Cyst
Samples were analyzed according to the Japanese standard procedure for the detection
of Cryptosporidium and Giardia in water supply systems (MHLW, 2007) This procedure was adapted from the U.S EPA method 1623 for the detection of Giardia and
Cryptosporidium in water by filtration, immunomagnetic separation and fluorescent
assay (U.S EPA, 2001) Briefly, 10 L samples were filtered through a hydrophilic polytetrafluoroethylene (PTFE) type membrane filter (1 μm pore size) (Advantec Toyo, Ltd, Japan) Retained oocysts and cysts were eluted by a 50 mL solution containing sodium pyrophosphate (0.02%), Tween 80 (0.01%) and trisodium EDTA (0.03%), and then centrifuged at 1050 × g for 10 min Oocysts and cysts in the pellet were purified by
immunomagnetic separation (IMS) using Cryptosporidium and Giardia specific
antibody-coated magnetic beads according to the manufacturer’s protocol (Dynabeads GC-Combo, Invitrogen, USA)
The IMS-purified oocysts and cysts were stained on a PTFE membrane filter (0.8 μm pore size) (Advantec Toyo Ltd, Japan) on a glass slide by FITC conjugated antibodies (EasyStain™, BTF Pty Ltd, Australia) and the nuclear fluorochrome 40, 60-diamidino-2-phenylindole (DAPI) Slides were examined using differential interference contrast (DIC) and epifluorescence microscopy at 400 × or 1000 × magnification Oocysts and cysts were identified when the size, shape, fluorescence, and morphology agree with control parasite suspensions The number of oocysts and cysts in the whole area of the filter was counted Results were expressed as oocyst and cyst counts per 10 L
Bacterial Analysis
Concentrations of 4 types of microbial (fecal) indicators (total coliforms, Escherichia
coli, anaerobic spore-forming bacteria, heterotrophic bacteria) were measured in this
study Total coliforms and E coli were enumerated on Chromocult® Coliform agar (Merck, USA) following incubation for 20 h at 37oC Blue colonies were counted as E
coli, while both blue and red colonies were counted as total coliforms Anaerobic
spore-forming bacteria were enumerated on modified Handford Agar (Eiken Chemical Co., LTD, Japan) following incubation for 24 h at 42oC Heterotrophic bacteria were enumerated on R2A (Difco, BD, USA) following incubation for 7 d at 20oC Results were expressed as colony-forming units (CFU) per 100 mL of sample
Statistical Analysis
Spearman rank order correlation coefficients (rs) were calculated to evaluate the correlation among the concentrations of microbial indicators and protozoans Analysis was performed using Excel Statistics 2010 (SSRI, Tokyo, Japan) Probability value was set at 0.01 This analysis is often used for evaluating the relationship among the
concentrations of microorganisms (Mons et al., 2009) In addition, regression analysis
was performed All the microbial analysis data during annual surveys (n = 84) were used for statistical analysis
Trang 4RESULTS AND DISCUSSION
Annual Profiles of Cryptosporidium Oocyst and Giardia Cyst
Concentrations of Cryptosporidium oocysts and Giardia cysts during the survey period are summarized in Fig 2 Cryptosporidium and Giardia were detected in 59 (70%) and
64 (76%) out of the 84 samples (10 liters each), respectively Although it has been reported that the frequency of two protozoans in some river basins was significantly
different (Mons et al., 2009), the frequency in Tone River basin was almost the same Actually, Giardia was detected in 53 out of 59 (90%) river water samples in which
Cryptosporidium was detected
0 5 10 15 20 25
Cryptosporidium Giardia
Site A
(a) Tone River
Site B
Storm runoff
Storm runoff
0 5 10 15 20 25 30 35 40
Cryptosporidium Giardia
Site C
(b) Koyama River
Site D
Fig 2 - Annual profiles ofthe concentrations of Cryptosporidium and Giardia in river water
0 50 100 150 200 250 300 350
Cryptosporidium Giardia
Site E
(c) River X
Site F
Site G
Trang 5The protozoan concentration in main rivers increased after the confluence of tributary rivers, which indicates that the main river water is contaminated due to the confluence
of tributary rivers In River X, the protozoan concentration at site F was much higher than that at site E This is because a lot of livestock production facilities (cow and pig farms) which seem to be contamination sources are located between sites E and F Although the prevalence ratio of these protozoans in livestock in the River X basin is
unknown, the ratio in Japanese livestock is generally high Sarashina et al (2002) have reported that the prevalence ratio of Cryptosporidium in 0 to 2 week-old Japanese
calves was 12% In addition, the average turbidity at site F was 6.4 while that at site E was 1.2 On the other hand, the protozoan concentration at sites F and G was not so different although the discharge point of treated sewage wastewater is located between sites F and G, which indicates that the sewage wastewater treatment plant is not normally a contamination source in the River X basin
Annual variation of concentrations of Cryptosporidium and Giardia was high The ratio
of the maximum concentration to the mean value at each sampling site ranged from 2 to
8 except for site C at which the frequency of the detection was extremely low, which indicates that the health risk caused by these protozoans via recreation or water supply
greatly fluctuates annually Meanwhile, the concentration of Cryptosporidium and
Giardia in a storm event was relatively high as shown in Fig 2 Reportedly, heavy
rainfalls contribute to protozoan runoff from contaminated soils (Curriero et al., 2001; Carmena et al., 2007)
Diurnal Profiles of Cryptosporidium Oocyst and Giardia Cyst
Fig 3 shows the concentrations of Cryptosporidium oocysts and Giardia cysts during the
diurnal survey day At sites H and I located in the area where many livestock production
facilities exist, the concentration of Cryptosporidium was higher than that of Giardia on the survey day The apparent fluctuation of the concentration of Cryptosporidium was
observed The maximum concentration was approximately 10-fold higher than the lowest value despite the stability of flow rate of River X The flow rate during the diurnal survey period was 27.2 ± 1.2 m3/min In Japan, most livestock wastewater treatment plants which discharge the treated wastewater into rivers are operated at sequencing batch mode, and the effluent discharge is normally performed in the morning and/or evening Therefore, the concentration might increased in the morning and evening Actually, in the morning, we confirmed that the effluent was discharged from the livestock production facility which is closely located in the sampling sites
0 1 2 3 4 5
Time
0 50 100 150 200 250 300
Cryptosporidium (Site J) Giardia (Site J)
Cryptosporidium Giardia
0
5
10
15
20
25
30
35
40
Time
Cryptosporidium (Site H) Cryptosporidium (Site I) Giardia (Site H) Giardia (Site I)
Cryptosporidium Cryptosporidium Giardia Giardia
Fig 3 - Diurnal profiles of the concentrations of Cryptosporidium and Giardia in river water (October
9 th , 2008) Sites H and I are located in the area where many livestock production facilities exist, while site J is located closely at the discharge point of treated sewage wastewater
Trang 6At site J which is located closely at the discharge point of treated sewage wastewater,
Giardia was detected in high concentration, while Cryptosporidium was rarely detected
Therefore, there would be patients of giardiasis in the watershed Although epidemiological information available on giardiasis in Japan is limited, reportedly,
Giardia was frequently detected in the influent at another Japanese sewage treatment
plant (Oda et al., 2005) The maximum concentration was approximately 10-fold higher than the lowest value Oda et al (2005) have reported that the concentration of Giardia
in the influent sewage wastewater markedly fluctuated although they did not analyze the prevalence in the effluent wastewater
Relationship among the Concentrations of Microbial Indicators, Cryptosporidium Oocyst and Giardia Cyst
Spearman rank correlation analyses were conducted using all the microbial analysis data during the annual surveys (Table 1) Significant correlations (p < 0.01) were found among protozoans and the microbial indicators with rs ranging from 0.354 to 0.616 except for total coliforms The correlation between these protozoans and anaerobic spore-forming bacteria was the strongest among the microbial indicators One of the reasons why the correlation was high is the resistibility of anaerobic spore-forming
bacteria to environmental stressors Like Cryptosporidium oocysts and Giardia cysts, it
is well known that anaerobic spore-forming bacteria are resistant to chlorination On the other hand, the correlation between these protozoans and total coliforms was not significant although total coliforms are currently adopted as environmental quality standard indicating microbiological (fecal) contamination in public water bodies in Japan As evidenced by the regression analysis data (Figs 4, 5), it is clear that the correlation of total coliforms with these protozoans is weak compared with other indicators
Types of
Total coliforms E coli
Anaerobic spore-forming bacteria
Heterotrophic bacteria
Anaerobic
spore-forming
Heterotrophic
* Significant correlation was obtained (p < 0.01)
Table 1 - Spearman rank order correlation coefficient (r s) matrix among microbial indicators, Cryptosporidium
oocysts and Giardia cysts during the annual surveys
Trang 7y = -5.519E-06x + 1.434E+01
R 2 = 2.681E-03
0
50
100
150
Total coliforms (CFU/100mL)
ysts/10L) y = -5.519×10 -6 + 0.1434
R 2 = 0.0511
0 50 100 150
E.coli (CFU/100mL)
y = 9.367E-06x + 6.740E+00
R 2 = 6.494E-02
0 50 100 150
Heterotrophic bacteria (CFU/mL)
y = 9.367×10 -6 + 6.740
R 2 = 0.0649
y = 0.0425x + 4.0472
R 2 = 0.2322
0
50
100
150
Anaerobic spore-forming bacteria (CFU/100mL)
Fig 5 - Correlation among Giardia cysts and microbial indicators
Fig 4 - Correlation among Cryptosporidium oocysts and microbial indicators
y = 4.581E-07x + 1.363E+01
R 2 = 7.148E-06
0
50
100
150
200
250
300
350
Total coliforms (CFU/100mL)
y =4.581×10 -7 + 0.1363
R 2 = 7.184×10 -6
y = 0.0124x - 2.5319
R 2 = 0.2253
0 50 100 150 200 250 300 350
E.coli (CFU/100mL)
y = 0.0487x + 2.6722
R 2 = 0.1179
0
50
100
150
200
250
300
350
Anaerobic spore-forming bacteria (CFU/100mL)
y = 2.580E-05x - 5.386E+00
R 2 = 1.907E-01
0 50 100 150 200 250 300 350
Heterotrophic bacteria (CFU/mL)
y = 2.580×10 -5 - 0.5386
R 2 = 0.1907
Trang 8CONCLUSIONS
This study identified some annual and diurnal differences in the concentrations of
Cryptosporidium and Giardia in river water which is used for drinking water sources in
Japan In addition, the relationship between microbial indicators (E coli, total coliforms,
anaerobic spore-forming bacteria and heterotrophic bacteria) and protozoans were revealed The ratio of the maximum concentration to the mean value at each sampling site during the annual survey period ranged from 2 - 8, which indicates that the health risk caused by these protozoans via recreation or water supply greatly fluctuate annually In the diurnal survey,
the maximum concentrations of Cryptosporidium and Giardia at some sampling sites were
approximately 10-fold higher than the lowest value The correlation between these infectious protozoans and anaerobic spore-forming bacteria was stronger than other microbial indicators, while the correlation between these protozoans and total coliforms was not significant although total coliforms are currently adopted as environmental quality standard indicating microbiological (fecal) contamination in public water bodies in Japan
ACKNOWLEDGMENT
Part of this study was financially supported by the Ministry of Environment, Japan (Environmental Research in Japan, 2008, 46: Evaluation and control of health risk from human-animal pollution sources in public water bodies)
REFERENCES
Carmena D., Aguinagalde X., Zigorraga C., Fernández-Crespo J C and Ocio J A (2007)
Presence of Giardia cysts and Cryptosporidium oocysts in drinking water supplies in
northern Spain, J Appl Microbiol., 102(3), 619-629
Carpenter C., Fayer R., Trout J and Beach M J (1999) Chlorine disinfection of
recreational water for Cryptosporidium parvum, Emerg Infect Dis., 5(4), 579-584
Castro-Hermida J A., García-Presedo I., Almeida A., González-Warleta M., Costa J M C
D and Mezo M (2008) Contribution of treated wastewater to the contamination of
recreational river areas with Cryptosporidium spp and Giardia duodenalis, Water Res.,
42(13), 3528-3538
Castro-Hermida J A., García-Presedo I., Almeida A., González-Warleta M., Costa J M C
D and Mezo M (2009) Detection of Cryptosporidium spp and Giardia duodenalis in
surface water: A health risk for humans and animals, Water Res., 43(17), 4133-4142
Cicirello H G., Kehl K S., Addiss D G., Chusid M J., Glass R I., Davis J P and Havens P
L (1997) Cryptosporidiosis in children during a massive waterborne outbreak in
Milwaukee, Wisconsin: clinical, laboratory and epidemiologic findings, Epidemiol
Infect., 119(1), 53-60
Corso P S., Kramer M H., Blair K A., Addiss D G., Davis J P and Haddix A C
(2003) Cost of illness in the 1993 waterborne Cryptosporidium outbreak,
Milwaukee, Wisconsin, Emerg Infect Dis., 9(4), 426-431
Craun G F., Calderon R L and Craun M F (2005) Outbreaks associated with
recreational water in the United States, Int J Environ Health Res 15(4), 243-262
Curriero F C., Patz J A., Rose J B and Subhash L (2001) The association between extreme precipitation and waterborne disease outbreaks in the United States,
1948–1994, Am J Public Health, 91(8), 1194-1199
Fayer R (2004) Cryptosporidium: a water-borne zoonotic parasite, Vet Parasitol 126(1-2),
Trang 937-56
MacKenzie W R., Schell W L., Blair K A., Addiss D G., Peterson D E., Hoxie N J., Kazmierczak J J and Davis J P (1995) Massive outbreak of waterborne
Cryptosporidium infection in Milwaukee, Wisconsin: recurrence of illness and risk
of secondary transmission, Clin Infect Dis., 21(1), 57-62
Masago Y., Oguma K., Katayama H and Ohgaki S (2006) Quantification and genotyping
of Cryptosporidium spp in river water by quenching probe PCR and denaturing
gradient gel electrophoresis, Water Sci Technol., 54(3), 119-126
MHLW (Ministry of Health, Labour and Welfare, Japan) (2007) Detection methods of
indicator bacteria, Cryptosporidium and Giardia in water supply system Water Supply
Division, Health Service Bureau, MHLV, Tokyo, Japan (in Japanese)
Mons C., Dumètre A., Gosselin S., Galliot C and Moulin L (2009) Monitoring of
Cryptosporidium and Giardia river contamination in Paris area, Water Res., 43(1),
211-217
Oda T., Kawabata M and Uga S (2005) Detection of Giardia cytes in sewage and estimations of giardiasis prevalence among inhabitants in Hyogo Prefecture, Japan, Trop
Med Health, 33(1), 1-5
Ono K., Tsuji H., Rai S K., Yamamoto A., Matsuda K., Endo T., Hotta H., Kawamura T.,
and Uga S (2001) Contamination of river water with Cryptosporidium parvum oocysts
in western Japan, Appl Environ Microbiol., 67(9), 3832-3836
Peeters J E., Mazas E A., Masschelein W J., Villacorta Martiez de Maturana I and Debacker E (1989) Effect of disinfection of drinking water with ozone or chlorine
dioxide on survival of Cryptosporidium parvum oocysts, Appl Environ Microbiol.,
55(6), 1519-1522
Rose J B., Gerba C P and Jakubowski W (1991) Survey of potable water supplies for
Cryptosporidium and Giardia, Environ Sci Technol., 25(8), 1393-1400
Sarashina T., Sakai H., Tsushima Y., Nagasawa H., Tanabe S and Uzuka Y (2002)
Surveillance of Cryptosporidium infection in healthy cattle, J Water Waste, 44(4),
291-294 (in Japanese)
Sunderlanda D., Graczyka T K., Tamanga, L and Breysse P N (2007) Impact of bathers
on levels of Cryptosporidium parvum oocysts and Giardia lamblia cysts in recreational
beach waters, Water Res., 41(15), 3483-3489
U.S EPA (2001) Method 1623: Giardia and Cryptosporidium in water by
filtration/IMS/FA United States Environmental Protection Agency Office of Water, Washington, DC EPA 821-R01-025