Discharges of\nWastewater Treatment Plants Needed Further\nMonitoring to Minimize Potential Risk of <i>Entamoeba</i> and <i>Blastocystis</i> for Public Health

The protozoan parasites <i>Entamoeba histolytica</i> and <i>Blastocystis hominis</i> are responsible for causing\nhuman amebiasis\nand hominis infections, respectively. These infections are highly\nprevalent and are often linked to waterborne diseases. Due to the\nabsence of regulations for monitoring these protozoa at the discharge\npoints of wastewater treatment plants (WWTPs), the effluents reaching\nsurface waters contribute to waterborne transmission. This underscores\nthe significance of the removal capacities of WWTPs in reducing the\nspread of these infectious parasites. Therefore, this study examined\nfive different types of WWTPs in Ankara, Turkey, over a year to assess\ntheir capacities to remove <i>E. histolytica</i> and <i>B. hominis</i>. The seasonal abundances of genes specific to\nthese protozoa in both the influents and effluents of each WWTP were\nmeasured using a quantitative polymerase chain reaction. The reduction\nin the number of protozoan rDNA copies between the influent and effluent\nsamples was evaluated as the removal capacity, expressed in log<sub>10</sub> reduction (LRV) values. The results elucidated that the\nremoval of <i>E. histolytica</i> and <i>B. hominis</i> was highly affected by the process used. Membrane bioreactor systems\ndisplayed the highest removal capacity with LRV > 3. Therefore,\ndischarges\nof WWTPs with other processes could need further monitoring to minimize\nthe potential risk for public health.