the study of parasitic contamination of raw wastewater in kermanshah provinc

background: domestic wastewater is a most important source of infectious factors in the environment. the aim of this study was to determine the raw wastewater parasitic contamination of cites of kermanshah province. methods: this study was a descriptive cross–sectional one which was carried out in 5 months, sampling was accomplished once a five days from inlet raw wastewater to treatment plants of kermanshah, gilane-gharb, eslamabade-gharb, ghasre-shirin, sarpole-zahab and paveh (6 samples per month) and a total of 180 samples were tested. analysis to identify protozoan cysts and helminthes eggs according to a modified bailenger method by mac mster counting slide (with a hole size 0.3 ml) was conducted. results: the results showed that the average total number of parasite egg in raw wastewater cities of kermanshah, sarpole-zahab, paveh, ghasre-shirin, eslamabade-gharb and gilane-gharb 50.21, 53.41, 45.72, 35.85, 39.94  and 44.8 per liter respectively. for the amount of protozoan cysts was 30.1, 21.93, 25.42, 19.95, 18.1 and 15.61 per liter respectively. conclusion: the results showed that being infected with the ascaris worm in the community was higher than the other parasites and outbreaks of parasitic diseases in this province should be studied meticulously. upgrading wastewater treatment plants, non-irrigated of crops with raw wastewater and promoting the principles of correct disinfection of vegetables can help solutions to reduce parasitic infections in the community.