Browsing by Author "Hsu, CLL"

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Analysis for Giardia cysts and Cryptosporidium oocysts in water samples from small water systems in Taiwan
(2001-02-01)
Hsu, BM
;
Huang, CP
;
Hsu, CLL
;
環境工程研究所
;
Institute of Environmental Engineering
Giardia and Cryptosporidium have emerged as waterborne pathogens of concern. Twenty-six water samples were collected from small water systems in Taiwan and checked for the occurrence of both parasites. Water quality parameters and characteristics of the sampling sites were also recorded. The frequencies of occurrence for Giardia and Cryptosporidium were 46.2% for each; and their mean concentrations were 79.5 cysts/100 1 and 22.1 oocysts/100 1, respectively. The concentrations of oocysts and heterotrophic bacteria exhibited the highest correlation and followed the concentrations of the two protozoa. The water samples from sites with filtration devices had a lower oocyst concentration than those from sites without filtration devices, while no significant difference was found for cysts. The level of each parasite had no direct relationship with altitude. The cyst concentrations increased proportionally with the consumer population using the water systems. Risk assessment of the parasitic infections suggests that setting up disinfection devices in the small water systems would be needed.
Evaluation of two concentration methods for detecting Giardia and Cryptosporidium in water
(2001-02-01)
Hsu, BM
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Huang, CP
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Hsu, YF
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Jiang, GY
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Hsu, CLL
The cartridge filtration method and membrane filtration method based on the fluorescent antibody procedure were evaluated for their recovery efficiencies and detection limits of Giardia and Cryptosporidium. We assessed the performances of the two concentration methods for water samples collected from Taiwan water treatment plants. The membrane filtration method was characterized by higher recovery rate and detection limit comparing with the cartridge filtration method. The occurrences of both parasites, and the relationships of parasite concentrations with indicator microorganisms show inconsistency between the two methods. It was discovered that water turbidity reduced the recovery efficiencies, and raised the detection limits for both parasites regardless of the method used. (C) 2000 Elsevier Science Ltd. All rights reserved.
Examination of Giardia and Cryptosporidium in water samples and fecal specimens in Taiwan
(2000)
Hsu, BM
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Huang, C
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Hsu, YF
;
Hsu, CLL
;
環境工程研究所
Giardia and Cryptosporidium have emerged as waterborne pathogens of concern over the past few decades. Twenty-nine source water samples were collected from water treatment facilities and checked for the occurrence of Giardia and Cryptosporidium along with some water quality parameters. These facilities include ten large-scale treatment plants near major metropolitan areas, and eight simple facilities in small and secluded communities. The indirect immunofluorescence assay (IFA) was used for the detection of cysts and oocysts in water samples. In addition, fecal specimens were collected from watersheds providing source water for the treatment plants, and the presence of Giardia and Cryptosporidium was detected with the enzyme-linked immunosorbent assay (EIA). The mean concentrations of protozoa in large-scale plants were 66.8 cysts/100 litres and 89.2 oocysts/100 litres, while simple facilities contained 1.27 cysts/100 litres and 0.28 oocysts/100 litres, respectively. The concentrations of these two parasites exhibit the highest correlation with turbidity than any other water quality parameters. Among the 101 fecal specimens, eleven were positive for Giardia and 22 were positive for Cryptosporidium. It was also found that the occurrence of these two pathogens in the source water was directly linked to the surrounding farming activities, suggesting that farming activities should be kept at a certain distance from the watersheds.
Occurrence of Giardia and Cryptosporidium in the Kau-Ping River and its watershed in southern Taiwan
(1999-08-01)
Hsu, BM
;
Huang, CP
;
Hsu, CLL
;
Hsu, YF
;
Yeh, JH
Giardia and Cryptosporidium are important waterborne parasites. Thirteen water samples and 32 fecal specimens were collected from the Kau-Ping River and its watershed to test for Giardia cysts and Cryptosporidium oocysts. The detection methods are immunofluorescence assay and enzyme-linked immunosorbent assay for water samples and fecal specimens, respectively. Seven out of eight samples collected from raw water samples showed the presence of cysts, while six out of eight raw water samples contained oocysts. Cryptosporidium was present in 40% of the treated water, while Giardia occurred in all of them. Four out of 32 fecal specimens, collected from the hog farming region, tested positive for Giardia, and seven specimens tested positive for Cryptosporidium. Giardia was related only to Cryptosporidium but not to the others. (C) 1999 Elsevier Science Ltd. Ali rights reserved.
The prevalence of Giardia and Cryptosporidium in Taiwan water supplies
(1999-06-11)
Hsu, BM
;
Huang, CP
;
Jiang, GY
;
Hsu, CLL
;
環境工程研究所
Giardia and Cryptosporidium have emerged as waterborne pathogens of concern. Thirty-one water samples were collected from nine potable water treatment plants in Taiwan and investigated for the presence of Giardia cysts and Cryptosporidium oocysts. The immunofluorescence assay was used for the simultaneous detection of cysts and oocysts. The frequency of occurrence of cysts was 77.8% for Giardia and 72.2% for Cryptosporidium in 18 raw water samples. Ten out of 13 samples collected from treated water samples showed the presence of cysts, while in 5 out of 13 treated water samples oocysts were detected. The risk assessment for adverse human effects arising from the presence of cysts and oocysts indicates the possibility of waterborne transmission of Giardia and Cryptosporidium infection in Taiwan if water is not adequately treated.