Soil Contamination With Oocysts of Cryptosporidium spp. in Isfahan, Central Iran

Cryptosporidium, a coccidian parasite, is the causative agent of watery diarrhea in humans and animals. The disease is mostly self-limiting in immunocompetent individuals, yet severe infection can occur in children and immunocompromised patients. The parasite is mostly transmitted to humans by water, yet it can also be transmitted by soil. The present study aimed to determine soil contamination rate of parks of Isfahan, Iran, with Cryptosporidium spp. oocysts. In this cross-sectional study, 140 soil samples from 28 public parks of 14 regions of Isfahan (central Iran) were collected during summer 2014. The soil samples were concentrated using the sucrose floatation technique, which was followed by preparation of microscopic slides. The slides were stained by the modified Ziehl-Neelsen staining method and were examined microscopically for presence of Cryptosporidium spp. oocysts using 100X oil immersion objective. Cryptosporidium spp. oocysts were observed in 31 out of 140 soil samples (22.14%). Also, all 14 regions (100%) and 17 out of 28 public parks (60.71%) were contaminated with Cryptosporidium spp. oocysts. Despite the climate temperature of Isfahan city, the soli of parks were highly contaminated with Cryptosporidium spp.