The occurrence of Cryptosporidium sp., and eggs of soil-transmitted helminths in market vegetables in the north of Iran

Aim: This study aimed to investigate the presence of oocyst of Cryptosporidium sp., and egg of soil-transmitted helminths in market vegetables in the north of Iran.

Background: Fecal-oral transmission via consumption of contaminated food is the main route of transmission of intestinal parasites. Concerning the high risk of contamination of vegetable with intestinal parasites, raw consumption of crops can enhance the chance of transmission of intestinal parasites.

Methods: In this study, we collected 34 pre-washed vegetable samples including spinach, mint, parsley, oregano, chives, savory, radish, coriander, basil and tarragon from local markets in Tonekabon City, North of Iran. All vegetable samples were washed using sterile PBS. Parasitological examinations, including direct examination and staining with Lugol's iodine and modified Ziehl-Neelsen were performed on the pellet resulted from the washing process.

Results: The findings showed that 14/34 (41.17%) of collected samples were contaminated with at least one parasite. Eggs of Toxocara sp., Ascaris sp., Fasciola sp., Toxoascaris leonine, Trichuris sp. and Enterobius together with free-living larvae, amoeba cyst, cyst of Entamoeba coli and oocyst of Cryptosporidium sp., were observed among the positive samples. Furthermore, statistical analysis indicated that there was no significant correlation between parasitic contamination of vegetables and seasonal changes.

Conclusion: This study signifies that some parasites due to their resistant cell wall usually remain in an environment with the harsh condition and thus, consumption of raw vegetables increases the risk of transmission of them.