Prevalence of Cystoisospora belli in Wastewater Treatment Plants in Sharkeya,Egypt

Discharge of untreated or insufficient treated wastewater may result in water borne Cystoisospora belli outbreaks. Influent and effluent wastewater samples from two different wastewater treatment plants (WWTPs) were collected monthly for the detection of Cystoisospora belli using centrifugal concentration and purification by zinc sulphate floatation, followed by molecular detection using real-time PCR. Results showed that the prevalence rates of Cystoisospora belli in influents and effluents of WWTPs were 14.5% and 6.2%, respectively. The removal rates of Cystoisospora belli oocysts in WWTP (A) utilizing activated sludge and WWTP (B) using trickling filter were 66.7% and 50%, respectively. There was no significant difference between removal of Cystoisospora belli in WWTP (A) and WWTP (B). The prevalence rates of Cystoisospora belli oocysts in raw and finally treated wastewater of WWTP (A) were 12.5% and 4.2%, respectively, while their prevalence rates in raw and treated wastewater of WWTP (B) were 16.7% and 8.3%, respectively. In conclusion, further studies are needed to clear the actual prevalence of Cystoisospora belli in the environment.