DESTRUCTION OF OOCYSTS OF CRYPTOSPORIDIUM-PARVUM BY SAND AND CHLORINE

Cryptosporidium parvum oocysts were shaken with sand at intervals ranging from 5 min to 2 h. Oocyst viability was assessed by the inclusion or exclusion of two fluorogenic vital dyes. After shaking with sand for 5 min, 90 min and 2 hours the number of non-viable oocysts increased significantly to 50%, 99.7% and 100% respectively. Increasing the duration of shaking caused non-viable oocysts to lose their contents and fragment. Following agitation with sand for 5 min and subsequent chlorination for 5 min, there was an increase in the number of non-viable oocysts to 68.02%.