Prevalence and molecular analysis of Cryptosporidium spp. collected from surface water.

Cryptosporidium is an obligate intracellular parasite reported from all over the world. This protozoan infects a wide range of animals as well as humans. Cryptosporidium parvum and Cryptosporidium hominis are the most prevalent infecting species with mild and self-limiting infection in healthy people. The protozoan oocyst is resistant to common water purifiers. Based on emerging evidence, Cryptosporidium is one of waterborne parasites considered a major public health problem in developing and developed countries. In this study, 42 samples were collected from 14 rivers in the catchment area of Lake Urmia in northwest of Iran. Moreover, amplification of SSU rRNA gene was performed, and polymerase chain reaction products were sequenced. The results of sequencing and comparing the sequences with those in the GenBank revealed that all the 17 positive samples were C. parvum, a zoonotic species and one of the most frequent human-infecting species. Considering these data, it is highly important to inhibit the spread of this protozoan by treating livestock and preventing human and animal effluents from entering the water.