International Journal of Virology and Parasitology

Full Length Research Paper

Detection, Enumeration and Viability Evaluation of Giardia Cysts in Water Samples Using Flow Cytometry

Ahmad K. Dyab¹, Doaa A. Yones^*1, Douaa M. Sayed², Tasneem M. Hassan¹

¹Department of Parasitology, Faculty of Medicine, Assiut University, Assiut, Egypt.

²Department of Clinical Pathology, South Egypt Cancer Institute, Assiut University, Assiut, Egypt.

Accepted 10 June, 2017

Abstract

Giardia lamblia is a protozoan parasite known to be an important waterborne pathogen. The faeco-oral transmission of the parasite leads to the presence of its cysts in the environment. Giardia cysts are abundant in surface waters worldwide. Knowledge of the prevalence of Giardia cysts in water resources is important for controlling its transmission. The present study was designed for detection of G. lamblia cysts, its seasonal variability, count and viability assessment in water supplies of Assuit University Hospitals and Faculty of Medicine; using flow cytometry. Forty eight water grab samples (20 liter per sample) were collected from water supplies of the faculty and hospital's buildings from inlet, outlet and tanks during winter and summer 2014. All water samples were subjected to filtration, elution and concentration followed by flow cytometry. G. lamblia cysts were detected in 14 water samples with detection rate of 29.2%. The highest rate of positive samples was recorded in winter. The mean cysts number was 1066.3 cysts/L in summer and 837.1 cysts/L in winter. The percent of viable G. lamblia cysts reached 6.2% in summer and 5.75% in winter with insignificant difference. The results of the present study reflected the need for more efficient methods adapted by the water treatment facilities in this locality for controlling the quality of drinking water. The results demonstrated the benefit of flow cytometry as a rapid and simple method for evaluation of Giardia cysts in water samples.