High contamination of soil with Cryptosporidium oocysts in public places of Tabriz

Background & Aim: Cryptosporidium is zoonotic coccidian parasite that causes severe diarrhea in humans and animals worldwide. This study aimed to evaluate the soil contamination rate with Cryptosporidium oocysts of different public places in Tabriz, west of Iran. Methods: In this cross sectional study, 260 soil samples were collected by stratified sampling from 20 parks, 20 primary schools, 20 kindergartens, 10 street gardens, 60 backyards and 2 bus terminals. Soil samples were investigated by flotation technique using sucrose solution and stained by the modified Ziehl-Neelsen staining method. Data were analyzed with chi-square test, and P-values less than 0.05 were considered statistically significant. Results: Cryptosporidium oocysts were observed in 48 (18.5%) out of 260 collected soil samples. No statistically difference was observed among the 10 regions with the Cryptosporidium contamination in examined places in Tabriz city (p> 0.05). The highest contamination rate was observed in street gardens and backyards (23.3%) and the lowest rate was found in primary schools (12.5%). Conclusion: Based on the results of the present study, high contamination of soil with Cryptosporidium in Tabriz should be considered as a serious health problem, especially for children and immunocompromised patients. Taken together, soils from region 1 and 8 of Tabriz could be a potential source for Cryptosporidium infection.