Farizawati S, Lim Y A L, Ahmad R A, Fatimah C T N I, Siti-Nor Y
School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
Trop Biomed. 2005 Dec;22(2):89-98.
A study to determine the contribution of Giardia cysts and Cryptosporidium oocysts from cattle farms was carried out at the Langat Basin. This study investigated the contribution of cattle farms, located near Sungai Langat and Sungai Semenyih, towards river contamination with these cysts and oocysts. The findings showed that out of 24 samples of water taken from Sungai Semenyih, 4.2% was positive for Giardia cysts with a concentration of 1.3 cysts/L and 20.8% were positive with Cryptosporidium oocysts with a range of 0.7 - 2.7 oocysts/L. At Sungai Langat, from the 43 samples taken, 23.3% were positive for Giardia cysts with a range of 1.5 - 9 cysts/L whereas 11.6% were positive with Cryptosporidium oocysts with a range of 2.5 - 240 oocysts/L. Isolation of cysts and oocysts in bovine faecal materials revealed that 14.6% of faecal samples were positive for Giardia cysts which had a range of 75 - 1.3x104 cysts/g and 25% were positive for Cryptosporidium oocysts with a range of 50 - 3.9x105 oocysts/g. From the cattle wastewater, 98% were positive with oocysts and 6.7% with cysts. The concentrations were between 20 - 3.1x103 oocysts/mL for Cryptosporidium and 4 - 75 cysts/mL for Giardia. Given that the prevalence of Cryptosporidium and Giardia are high amongst the cattle and the positive findings of the (oo)cysts in the river samples, it could be deduced that there is a very high possibility of the cattle farms contaminating the river with Giardia cysts and Cryptosporidium oocysts. Viability study of Cryptosporidium oocysts in the surrounding soil and pond within the cattle farm showed that the viability of Cryptosporidium oocysts decreased with time. It was estimated that it will take 52 days for all the oocysts from both environment to be non-viable. With a viability rate of approximately 2 months in a cattle farm setup, river water contaminated with Cryptosporidium oocysts has a high chance of acting as an agent of transmission. As cattle farms are also inhabited by the owners and their families, this problem may pose a threat to humans (e.g. children) especially if they are dependent on the river water as their source of water for their daily activities.
在兰卡威盆地开展了一项研究，以确定养牛场中贾第虫囊肿和隐孢子虫卵囊的影响。该研究调查了位于双溪兰卡威和双溪士毛月附近的养牛场对这些囊肿和卵囊造成河流污染的影响。研究结果显示，在从双溪士毛月采集的24份水样中，4.2%的水样贾第虫囊肿呈阳性，浓度为1.3个囊肿/升，20.8%的水样隐孢子虫卵囊呈阳性，范围为0.7 - 2.7个卵囊/升。在双溪兰卡威，从采集的43份水样中，23.3%的水样贾第虫囊肿呈阳性，范围为1.5 - 9个囊肿/升，而11.6%的水样隐孢子虫卵囊呈阳性，范围为2.5 - 240个卵囊/升。牛粪便材料中囊肿和卵囊的分离显示，14.6%的粪便样本贾第虫囊肿呈阳性，范围为75 - 1.3×10⁴个囊肿/克，25%的粪便样本隐孢子虫卵囊呈阳性，范围为50 - 3.9×10⁵个卵囊/克。在牛场废水中，98%的水样卵囊呈阳性，6.7%的水样囊肿呈阳性。隐孢子虫的浓度在20 - 3.1×10³个卵囊/毫升之间，贾第虫的浓度在4 - 75个囊肿/毫升之间。鉴于牛群中隐孢子虫和贾第虫的感染率很高，且河流样本中（卵）囊的检测结果呈阳性，可以推断养牛场极有可能用贾第虫囊肿和隐孢子虫卵囊污染河流。对养牛场周围土壤和池塘中隐孢子虫卵囊的活力研究表明，隐孢子虫卵囊的活力随时间下降。据估计，两个环境中的所有卵囊都将在52天内失去活力。在养牛场环境中，隐孢子虫卵囊的活力约为2个月，受其污染的河水很有可能成为传播媒介。由于养牛场中还居住着场主及其家人，这个问题可能会对人类（如儿童）构成威胁，特别是如果他们依赖河水作为日常活动的水源。
