RESUMO
There is a direct relation between the prevalence of some parasitic diseases and the presence of those etiologic agents in water. The purpose of this research was to determine the contamination rate of wells drinking water to parasites in Mazandaran province in the north of Iran. 989 water samples were randomly taken based on the population of towns and number of health centers from 12 cities of Mazandaran province and transferred to the laboratory in sterile containers. Water samples were then filtered and analyzed according to the World Health Organization guidelines. Direct method and Gram staining procedure were used to identify the parasites. If cryptosporidium was seen, floatation [sheather's sugar] and modified Ziehl-Neelsen staining method were performed. Parasites count was undertaken using McMaster counting slide [0.3 mL]. 197 out of 989 water samples were contaminated with different parasites. From 197 contaminated samples, 20 different types of parasites were separated of which 53 [26.9%] were pathogenic, 100 [50.8%] non pathogenic, and 44 non-infective stages of parasites. Distance between wells and sources of contamination, type of water distribution systems, city and chlorination status had significantly statistical relationship with contamination prevalence [p<0.001]. According to the results and considering the direct correlation between safe water and human health, proper implementation of providing hygienic drinking water should be enforced