The occurrence of Giardia and Cryptosporidium in raw waters of Taiwan

Bing Mu Hsu, Chihpin Huang, Chih-Li Hsu

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Giardia and Cryptosporidium have emerged as waterborne pathogens of concern. We collected raw samples from 13 water supply facilities twice and checked for Giardia cysts and Cryptosporidium oocysts. These water supply facilities include three large-scale plants near metropolitan areas, and ten simple facilities in small and secluded communities located in Taiwan. The immunofluorescence assay (IFA) was used for the simultaneous detection of cysts and oocysts under microscope. Correlations between the concentrations of these two parasites as well as their concentrations and raw water turbidity were calculated. In addition, risk assessments for cysts and oocysts in Taiwan water supplies were conducted. From these large-scale plants, cysts and oocysts were found in four and five of six raw water samples, respectively. Numbers of cyst and oocyst ranged from < 5 to 160 cysts/100 L and 10 to 40 oocysts/100 L. In the survey of simple facilities the frequency of occurrence of Giardia was 35% and for Cryptosporidium relatively higher, i.e., 60%. Their counts ranged from < 2.3 to 16.3 cysts/100 L and from < 2.3 to 19.3 oocysts/100 L, respectively. The results indicate that there is a likely risk of waterborne transmission of Giardia and Cryptosporidium infections if the raw water is not adequately treated.

Original languageEnglish
Pages (from-to)219-224
Number of pages6
JournalWater Supply
Issue number3-4
Publication statusPublished - 1999

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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    Hsu, B. M., Huang, C., & Hsu, C-L. (1999). The occurrence of Giardia and Cryptosporidium in raw waters of Taiwan. Water Supply, 17(3-4), 219-224.