Inactivation of Giardia lamblia cysts by polychromatic UV
G-A Shin1, K G Linden, G Faubert
1Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105, USA. gwyam@u.washington.edu
Aims:
Giardia lamblia is one of the most important waterborne pathogens in the world. In this study, we determined the effectiveness of a promising alternative UV technology - a polychromatic emission from a medium-pressure (MP) UV lamp - against G. lamblia cysts in phosphate buffered saline (PBS) and a filtered drinking water.
Methods And Results:
A UV collimated beam apparatus was used to expose shallow suspensions of purified G. lamblia cysts in PBS or a filtered drinking water and the UV-irradiated G. lamblia cysts were assayed in Mongolian gerbils. The inactivation of G. lamblia cysts was very rapid and reached a detection limit of >3 log(10) within a UV dose of 1 mJ cm(-2).
Conclusion:
The results of this study indicate that MP UV irradiation is very effective against G. lamblia cysts in both PBS and a filtered drinking water.
Significance And Impact Of The Study:
It is likely that contamination of drinking water by G. lamblia cysts can be readily controlled by typical MP UV disinfection practises.
Related Concept Videos
Giardiasis
Physical Methods for Controlling Microbial Growth: Radiation and Filtration


