INACTIVATION OF OOCYSTS OF CRYPTOSPORIDIUM-PARVUM BY ULTRAVIOLET-IRRADIATION

Inactivation of oocysts of Cryptosporidium parvum in clean water using a novel design of an ultraviolet disinfection system was assessed by a vital dye assay and by in vitro excystation. The disinfection unit s ystem is designed to expose the oocysts to ultraviolet radiation on tw o filters, providing a maximum total exposure to ultraviolet radiation of 8748 mW s cm(-2). Results revealed a reduction in oocyst viability of over two logs, indicating that this treatment has exciting potenti al as an additional treatment for water already treated by conventiona l methods. However, these data are only preliminary results using one isolate of oocysts and further trials must be conducted before this sy stem could be recommended for use.